Stripped bolt heads on distributor rotors: How to remove?? HELP

[Roma_500E]

Hi guys,

I tried to replace my old rotors and could not do it It is 3 mm hex but it spins inside of a bolt (either bolt was crap or it was too tight) anyway now tree bolts are completely gone , they are round inside instead of angular 3mm hex.

So ... any ideas how to remove them ? Cuz I do not know where those bolts go so do not want to destroy the whole engine while drilling them out .

On the attached picture is only one bolt getting bad , I had no chance to take them after all three became crap. I ve attached pic so that you know what I am talking about.

Dave ? Gerry ? Steve ? any ideas ?

 

[JordiC]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

I had one bolt pre-stripped thanks to a prior doofus. I just inserted a slightly larger size torx bit and tapped it in slightly, it came out rather easily once turned. Simple bolt extractors work better if the bolt is especially stubborn. There are far worse places to have a stripped bolt on these cars, the ones on the rotors are reasonably accessible. Make sure you have a quality set of hex tools, especially in 3mm and 5mm and don't over torque those bolts. IIRC gsxr recommends a drop of threadlock on each just to be sure the rotor doesn't fly off and mince itself up.

 

[Roma_500E]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

I had one bolt pre-stripped thanks to a prior doofus. I just inserted a slightly larger size torx bit and tapped it in slightly, it came out rather easily once turned. Simple bolt extractors work better if the bolt is especially stubborn. There are far worse places to have a stripped bolt on these cars, the ones on the rotors are reasonably accessible. IIRC gsxr recommends a drop of threadlock on each just to be sure the rotor doesn't fly off and mince itself up.

Thanx, I will try to use 4 mm if I can insert it . we will see.... otherwise it seems to me that I have to drill it out.

Make sure you have a quality set of hex tools, especially in 3mm and 5mm and don't over torque those bolts.

Thats true , I thought about that too. All my tools are craftsman which is not bad . May be somebody overtightened those bolts ....

 

[emerydc8]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

This happened to me too. I think I used a Craftsman easy out and it came right out as I reversed the drill rotation. Jordi is right -- This is not a bad place to have a stripped bolt. The good part is that the new rotors have new bolts attached to them.

I keep thinking I should buy some of these but never get around to it. http://www.500eboard.com/forums/showthread.php?3628-Multi-spline-Extractor-(aka-quot-Easy-Out-quot-)

 

[Roma_500E]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

guys ! I always find useful advice on this forum I actually did not know about those easy out tools

 

[emerydc8]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

If you decide to go with the drill-type easy out, you may need to use a 90 degree angle bit driver (pic). I think I had to use one to get the drill bit in the right position. They are only about $20.

 

[Roma_500E]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

If you decide to go with the drill-type easy out, you may need to use a 90 degree angle bit driver (pic). I think I had to use one to get the drill bit in the right position. They are only about $20.

I guess there is no so many space to fit a drill ? I have to look at tools at Sears and see what will work ...

 

[emerydc8]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

I would do what Jordi suggested and try the slightly larger sized Torx (not Allen) bit. Tap it in with a small hammer, then use a ratchet to try to break it loose and unscrew it. You don't have much to lose by trying. A 90 degree angle bit driver is handy to have in your toolbox though. I just ordered the multi-spline extractors.

 

[Jimbo]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

I used a Dremel tool to slice a notch in them so a flathead screwdriver could be used to extract. Good thing they give ya' new ones !

 

[vexed]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

I have stripped a few of those. A right angle drill and an screw extractor worked although I completely bored out the bolt before I got the extractor to bite. A pain more than anything. The dremel is a good idea also.

 

[Roma_500E]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

Well it looks like I am not the only one who stripped those bolts. It seems that they (Bosch) know that bolts are crap and get stripped right away so they provide a new ones.

 

[DerFuror]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

Don't Mickey Mouse a critical repair. Get the multi-spline extractors. Problem is solved & goes away for good...instead of potentially increasing exponentially.

 

[samiam44]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

I broke the rotor apart carefully. Lost tension and now the come out by hand.

 

[500AMM]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

Hi,

I have been through this myself and the entire happening was not so nice and lead me to investigate the problem further to solve it forever. Summer 2012 I posted the dramatic part of it here; http://www.500eboard.com/forums/showthread.php?2833-Short-clip-of-possible-EZL-failure That thread drifted over to other running issues, so I like to repost the story and pics here since this thread is specific for the problem.

It all started with a cap & rotor breakdown at summer 2012. At a study of the broken parts I found the head on one of the three rotor bolts broken off and subsequently causing the ultimate breakdown. I immediately thought I had overtightened the bolts. But at a closer study of that bolt I found excessive corrosion in the bottom of the key grip, and the fracture surface on the bolt stem did also have clear signs of corrosion. Again, I could have overtightened and initiated the cracking myself and the corrosion developed to fracture, but the aggressive corrosion all over the bolt head was a mystery.

Both my cars are stored over the long winters we have up here, and any longer storage of the .036 means moisture problems inside the caps. So at springtime I opened both caps to clean them, and to my great shock was another bolt head inside the other cap broken off and was barely hanging onto the bolt, I could just pick it off with my fingers! When I tried to open the other two bolts one slipped over due to a badly corroded grip, but I managed the last one. I don't have any bolt extractor so it became a Dreml job and damage of the rotor. On one of the images you see the bolt where the head simply has rusted loose. On the image with the damaged bolts alongside you see that the bottom of the key grip has broken out on both.

This fracture is a combination of yield stress and corrosion. The reason for the excessive corrosion is probably the atmospheric conditions inside the caps. The caps do only have drain ports in the bottom, but nothing at top, which means it is no ventilation. So when the engine heats up the moisture vaporizes but the high humidity remains entrapped in the cap, and combined with the high voltage it will create Ozon (O3), which is quite corrosive even to steel materials. The bolts do also have an insufficient corrosion protection and have no chance to withstand such conditions, especially if the car runs in humid and cold climates.

To solve the problem I replaced with 5 mm stainless steel bolts. I used A4-70 quality, but A4-80 with a tad higher strength doesn't hurt, however the rotor bolts are not exposed to high loads anyway. Here is the bolt specs:

• OE bolts is DIN 7984, M5 x 14mm, 8.8 strength, 3mm allen key grip, reduced shank w/fixed locking washer
• The bolt I used is regular hexagon socket screw DIN 912, M5 x 20mm, A4-70 strength, 4mm allen key grip

The rotor bolts has a reduced shank with fixed washers, so when they are installed on the rotor they remain in place but play freely. It is important to maintain this feature, but I didn't find any similar SS bolts around with a reduced shank, so I used regular bolts and cut to correct length and partly filed down the threads to allow the necessary free play. I also used stainless split washers instead of the regular washers. These bolts do also have a 4mm allen key grip which is a great benefit for better control when torqueing by hand.

NB!! If you get problems with slipping key grips on the OE bolts, be VERY careful with hammering any extractor tool or torx key into the bolt head to get them loose. The rotor bracket is made of aluminium so it's a high risk to introduce cracks in it, also into the brittle rotor material.

-arnt-

 

[Taxi Driver]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

Hi arnt, what I experienced was, on the last of the two distributor fingers the 3mm hex socket broke and stayed inside the bolt.
My solution to get that one out was, MIG weld one 10mm headed bolt onto it and at the second try it came out.
The fixing bolts on the new distributors were, luckily, 4mm hex headed. On the distributor bracket/hub I use thread lock, don't
want them to come loose.

Yeah the moisture problem, Think I will remove the caps and store them in the safe, this coming Winter, Roger

 

[500AMM]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

Hi arnt, what I experienced was, on the last of the two distributor fingers the 3mm hex socket broke and stayed inside the bolt.
My solution to get that one out was, MIG weld one 10mm headed bolt onto it and at the second try it came out.
The fixing bolts on the new distributors were, luckily, 4mm hex headed. On the distributor bracket/hub I use thread lock, don't want them to come loose.

Yeah the moisture problem, Think I will remove the caps and store them in the safe, this coming Winter, Roger

Roger, I have also broken a couple of 3 mm allen keys to open those rotor bolts, even with a reasonable torque they seem to be hard to open after a longer time in use. It was smart to weld on a hex head to solve the situation! I never use any thread lock ala Locktite on the rotor bolts either.

---------- ---------- -----------

FYI - I've enclosed some pics showing essential details on the parts for the distributor set-up.

One image shows the drain ports in bottom of the distr.cap. If it has been drain ports in top of the cap too it would help out to dry up moist and evacuate entrapped humidity. My guess is that the missing drain ports is to avoid the risk for water intrusion from top, in case the engine is cleaned/flushed, unwanted fluid spill etc.. I have a couple of old caps laying around handy for some testing. I've also found a cutting tool for the Dreml to cut some tiny slots in top.

I ordered a new bolt w/washer for the rotor bracket, but the new washer didn't fit, it was too wide?! So be aware and take care of the old washer in case you are doing a parts replacement. It has also been some changes to the rotor bracket from fixed nuts on the old style to threaded bushings on the new style, both works fine.

It has also been an upgrade on the distributor housing cover. On my '92 it is the early style shown on top of the image, the second style is on my '94, and the lower cover is what I received from Autohaus AZ - which they sell as an OE part...however it does the function.

The rotor bolts are also updated. I don't know if it is for better corrosion resistance or simply a cost reduction for MB. At left you see the old style, and at right is the newer style, both have the tiny 3 mm allen key grip.

 

[jhodg5ck]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

get a set of junky TORX bits from your local Harbor/Chinese freight...find the size that has a goodly bit of intearance in said 3mm hole.

Sometimes I find leveling the end of the TORX bit on the grinder makes for more bit into small situations such as this...Be that as it may, knock said TORX bit into the stripped out hole, you don't need much of a hammer in this instance..@ least compared to removing stripped cylinder head bolts w/ the same method..

I find the hitting loosens things up...be sure to hold the bit Very square/make sure it is bottomed before making a go of it.

I've had Countless stripped fasteners here @ the shop and my 10$ torx kit has saved me an ungodly amount of time and frustration! Best part is when one of them brakes you can still swap it out for a new one..;-)

Good luck!

jono

 

[500AMM]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

I guess in most cases are the rotors taken out due to replacement. The Torx trick is nice, and the point is to get that thing out some way without destroying the rotor bracket and insulator cover. A Dreml, grinding machine or a pair of pliers easily do that job, but it is messy.

The message with my solution was to replace the rotor bolts with something else as a prevententive caution.

 

[jhodg5ck]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

I always install the new bits w/ a touch of anti seize and am Careful not to over torque which is easy to do.

I've never had any trouble w/ the rotors I've installed later on down the road.

Jono

 

[jano]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

Be wary that if you torque while your engine is warm, you will end up overtorquing.

 

[clarkz71]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

I always install the new bits w/ a touch of anti seize and am Careful not to over torque which is easy to do.

I've never had any trouble w/ the rotors I've installed later on down the road.

Jono

Exactly what I did at the dealer when I worked on the rare M119 cars that come in.

See a lot more of them now that I'm part time at a MB independent.

 

[Cobra]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

Hi

There is an astoundingly difference in quality depending of brand of rotors and caps, i have recently learned...

I changed my rotors and caps in june this year, the last time was in 2006 at 130 000 km, now at 190 000 km they was not that bad, but
the odd minor misfire at idle and a look at my notes told me there was time to change them.

I bought a set of Berus from Ebay UK and put them on, very simple work, no problems with screws on the old Bremi rotors at all.

I noticed after a while an increase in fuelconsumption and some not so minor misfires at idle at the redlights, it suddenly wanted
13,5 liter of fuel per 100 kilometers, at this years vacation to Germany it engulfed 14,6 liter per 100 km!

Even on a rapid journey i have never exeeded 13,5 liters per 100 km.

And in Germany the misfires was apparent.

This weekend i removed the caps and rotors, and found this...



It may be hard to see in the picture but after under 5000 km the caps and rotors show quite some oxidation, there are marks after the rotor in the oxidlayer on the caps pegs to the ignition wires, so much oxidation after under 5000 km!

The rotors are also miscoloured and have a burnt look.



This a Beru cap.



This is the Bremi caps and rotors after 60 000 km.

Of course one of the screws in one of the Beru rotors failed, the tiny 3 mm allen key slipped and i tried with a size 20 Torx but that
slipped in the hole and a size 25 was to big, the hole in the screw is very shallow so you can´t drive the Torx so far in that you want.

Fortunatily Roger ( Taxidriver ) came by for dinner and some wine, so the morning after we got down to the garage and and cut a slot in the screw and inserted a flat screwdriver and could brake it loose.



When you compare the to rotors you can notice some differences, the Beru rotor have a small peg who pickup the spark from the
center peg in the cap, the Bremi rotor have a plate with a hole in it to take the spark from the caps peg, this make the Bremi rotor
to have a much bigger surface to receive the spark from the cap.



On the Beru caps you can see four distinctive spots on the center peg with heavy oxidation where the sparks have jumped from cap to rotor.

The material in the Bremi caps and rotors looks superior to the material in the Beru caps, the brass looks much moore of a higher quality.

I have now bought caps and rotors from Aiaautoparts in USA for 180$ including shipping, this is a good price and they are Bremi parts wich is the only make i will use from now.

I´ll have read this about Beru parts on the Swedish Mercedesforum but i thought it to be the usual myth, of witch there are so many
in the hobby, but not this time...

I read a comment where sombody wrote that Berus will only last about 10 000 km on a E500, but i disregarded that, not so any moore..

There are no other changes of any other parts as airfilter, fuelfilters, plugs or anything, on a testride yesterday with the Bremiparts installed and a 220 km journey at quite a pace, no old woman to church driving, i got 11,7 liters per 100 kilometers... thats a clear and
distinctive result.

I am sort of flabbergasted of this, i have used Beru parts for a long time, even proffessional in the capacity of workshopmanager of the
Swedish postaloffice and i have never had a reson to belive that Beru was second to none, but this is puzzeling me.

Does someone have clue?

Best Regards
Totte

 

[clarkz71]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

Good post, makes me glad I used Bremi caps & rotors on my 400E.

The Beru wires are GTG though.

 

[gsxr]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

Beru and Bremi caps/rotors are not common from USA vendors. We mostly see Bosch over here. That's what's on almost all my cars...

UPDATE: I had a defective Bosch cap, new out of the box... took me hours and hours to diagnose. I now use Beru caps and rotors. Beru rotors are reboxed OE Doduco complete with MB Star logo. Beru is OEM for some M119 ignition parts. Bremi is not OEM for any M119 ignition parts.

 

[gerryvz]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

I scored some Bremi caps from a 1995 E420 a couple months ago at a local wrecking yard. They seemed in great condition and are in my parts warehouse as spares.

 

[clarkz71]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

Beru and Bremi caps/rotors are not common from USA vendors. We mostly see Bosch over here. That's what's on almost all my cars...

Actually this seller on e-bay has had Bremi caps and rotors for a few years now, I got mine from him.

Also Karlyn STI sells Bremi ignitions parts.

http://www.karlynsti.com/Folders/Product_Information.htm

http://www.ebay.com/itm/331010407584?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

 

[gsxr]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

The more common WorldPac vendors (including AHAZ, ElAutoParts, PelicanParts, Importec, Amazon, and others) usually only carry Bosch. Pelican also shows Bremi rotors and Beru caps. RockAuto has Bosch, "Duduco" (sic) and Beck/Arnley which is just a reboxer, plus some off-brand stuff.

 

[clarkz71]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

True, that's why I posted those 2 links above. Both are Bremi caps & rotors.

Quality is equal to MB original parts, I compared them (the Bremi's) to the dealer
parts when I was still working there in 2011. The dealer OE parts are Bosch but
not the same as aftermarket Bosch sold at World Pac and other distibutors.

 

[500AMM]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

Hi

There is an astoundingly difference in quality depending of brand of rotors and caps, I have recently learned...

I changed my rotors and caps in June this year, the last time was in 2006 at 130 000 km, now at 190 000 km they was not that bad, but the odd minor misfire at idle and a look at my notes told me there was time to change them.
........
........
........
I am sort of flabbergasted of this, I have used Beru parts for a long time, even proffessional in the capacity of workshop manager of the Swedish postaloffice and I have never had a reason to belive that Beru was second to none, but this is puzzeling me.

Does someone have clue?

Best Regards
Totte

Hei Totte.

Many thanks for useful information!

My SuperMerc shall have a complete replacement during the coming hibernation, so I better try the Bremi then. I guess the key size on the rotor bolts still are 3 mm? If so I already have the solution with the stainless steel bolt replacement ready to go on too. (post #14)

Many thanks!

 

[bing]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

so what's the difference in price Bremi V Bosch caps & rotors ?? And does Bremi make seals that sits under the rotor as well ?

 

[500AMM]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

so what's the difference in price Bremi V Bosch caps & rotors ?? And does Bremi make seals that sits under the rotor as well ?

bing,

Do you mean that insulation cover behind the rotor bracket?

 

[8899]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

so what's the difference in price Bremi V Bosch caps & rotors ?? And does Bremi make seals that sits under the rotor as well ?

Wow, I wish I had known about the Bremi option prior to my ordering caps and rotors from AutohauzAZ just last week. Their prices are as follows:

Distributor cap - $81.70 EACH
Distributor rotor - $34.45 EACH
Dust Shield/Insulator - $95.00 EACH

 

[500AMM]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

Wow, I wish I had known about the Bremi option prior to my ordering caps and rotors from AutohauzAZ just last week. Their prices are as follows:

Distributor cap - $81.70 EACH
Distributor rotor - $34.45 EACH
Dust Shield/Insulator - $95.00 EACH

Greg,

The price on the insulator cover is really insane, I bought that from AHAZ a year ago myself. It seems to be Bosch based on the logo and the PN. Enclosed the three verisons I have seen. The upper is on my '92, the second one (black) is on my '94, and the lower is what I got from AHAZ - which do the job very well.

 

[samiam44]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

First I've heard of poor quality on after market Bosch parts.

 

[Cobra]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

Hej Arnt!

I noticed in youre post of the rotordisaster that the brand of the rotors seems to be Beru, is that right?

There is a distinct difference in feel of how well the 3 mm Allen key fits in the fasteningscrews of the Bremis and the Berus, and also
in the apparence of the metal in the screws.

Youre fastening screws of the rotors looked like they had been exposed to a severe salty humified atmosphere, do you live by the sea?

I put the Berus on i june and removed them last weekend, the weather in Sweden this summer has been fantastic with nearly no rain and very few days with
any humidity to talk about, and they showed no trace of to have been exposed to humidity to the bare material of the caps other and the metal parts.

The Bremis does not show any signs of to have been exposed to humidity at all, not even on the metalparts, other than normal of the milage, and that after 60 000 kilometers.

The car is always stored i a warm garage.

This make me wonder even moore on the obvius difference in quality of the materials in the two brands.

It would bee very interesting to know what brand of rotors you out there who have had problems with slipping Allen keys on and bad burning or oxidation on the rotors and caps.

I bet that Beru is quite common...

No, i do not work for Bremi, but i get pist off when someone sells substandard parts to superiorstandard parts prices...

The Berus was more expensive than the Bremis.

Best Regards
Totte

 

[bing]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

bing,

Do you mean that insulation cover behind the rotor bracket?

Yes !

Greg,

The price on the insulator cover is really insane, I bought that from AHAZ a year ago myself. It seems to be Bosch based on the logo and the PN. Enclosed the three verisons I have seen. The upper is on my '92, the second one (black) is on my '94, and the lower is what I got from AHAZ - which do the job very well.

the black one appears MB OE back in the day. I remember when I replaced mine they were black too. Got a pair OE from dealer in bosch/rust color for 90 bloody quid! Crazy price for a piece of plastic

First I've heard of poor quality on after market Bosch parts.

Don't think Bosch are an issue here. It's Bremi V Beru quality comparison and as posted by Cobra his experience with Beru caps/rotors was disappointing

 

[500AMM]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

Hej Arnt!

I noticed in youre post of the rotordisaster that the brand of the rotors seems to be Beru, is that right?

Nope - all is OE Bosch with the MB-star embossed.

Youre fastening screws of the rotors looked like they had been exposed to a severe salty humified atmosphere, do you live by the sea?

Nope - I live in the inland with a typical dry climate for the region.

The Berus was more expensive than the Bremis.

I browsed Ebay.de yesterday and the Bremi parts appears to 50% of the Bosch price, I don't know the Beru prices.

The car is always stored i a warm garage.

Totte - that is the big, big, big advantage when storing an M119 powered car and avoid moist problems. My garage is a regular cold garage with good ventilation, but the cars are subject to all climate variations, additionally I don't drive them so often. This gives ideal conditions for moist problems. I gave a description about the moist and corrosion problem in post #14. When the moisture has built up inside the distributor caps, it is entrapped, that's the culprit for the oxidation. Next does the Ozon, high voltage and heat causing the severe corrosion attack.

My rotor disaster probably started of myself overtightening the bolts. That can over time form micro cracks in the bottom of the key grip in the bolts. Then the moisture and the corrosion started, and the cracks developed to fracture.

-a-

 

[sheward]

Re: Bad bolts on engine rotors , how to take them out ?? HELP

I thought I would add yet another testimony to the degree and effect that deteriorating distributor caps have on M119 motors. I recently replaced 20,000 mile 10 yr old caps and eliminated that small occasional stumble at idle others have referenced. I even had an isolated incident where the car would not start/backfired seemingly out of the blue. I could clearly see where the voltage was arcing inside the right cap.

drew

 

[AlexV]

Rotor Bolt (Stripped)

Hello,

My new insulator shield arrived yesterday. I installed it to find the car is once again not firing up on that side. This has happened quite a few times now, I feel as though it must be due to me not tightening the rotor bracket bolt or the rotor bolts enough and I fear breaking that rotor bracket bolt the most! The car was running fine for a few days with new cap/rotors and a chipped up insulator on one side.

I stripped one of the rotor bolts trying to remove it today. The bolts on these rotors are not of the best quality! Can someone please tell me a good method to get it out? I read that needle nose pliers work, but there is no way I can get a grip on the bolt. The bolt is completely round inside, I tried a larger allen key and torx with no success, so I could use some help.

I included a picture of the new rotor and there is wear around part of it, this must have something to do with the problem I am experiencing and the other side looks fine. The new cap still looks to be in good shape.

Thanks.

 

[samiam44]

Re: Rotor Bolt (Stripped)

Torx should take it out.


What brand of cap is that? All mine are a reddish and bosch.


Michael

 

[gsxr]

Re: Rotor Bolt (Stripped)

I stripped one of the rotor bolts trying to remove it today. The bolts on these rotors are not of the best quality! Can someone please tell me a good method to get it out? I read that needle nose pliers work, but there is no way I can get a grip on the bolt. The bolt is completely round inside, I tried a larger allen key and torx with no success, so I could use some help.

The rotor screws with 3mm hex socket head are notoriously problematic. Make sure you are NOT using a ball-end Allen wrench! And make sure the driver is fully seated. They require an unusual amount of care when installing / removing. I hate touching the damn things. A couple people went to the extreme of sourcing aftermarket bolts with 4mm socket heads (not easy to find). I've seriously considered that myself...

What brand of cap is that? All mine are a reddish and bosch.

Black caps are probably Beru. I have a couple sets of those, older ones made in Germany (I'm not sure about the newest Beru). I like them, been running them in the red race car this year with zero issues so far (using Bosch rotors, as I was unable to source Beru rotors anywhere in USA). I have detailed photos of Bosch & Beru caps+rotors uploaded to my website here.

 

[Stevester 500E]

Re: Rotor Bolt (Stripped)

You would think mb techs,having encountered this issue, would have suggested a different fastener design. And that MB would have made a better design. How about a simple Philips screw.

 

[AlexV]

Re: Rotor Bolt (Stripped)

The Beru caps were recommended to me, they're manufactured in Germany. I'm glad to hear that someone else is aware of the rotor bolts and it's just not me. I used my bald-end allen for easier access on the one bolt and that was the end of it within one revolution.

I plan to compound some epoxy in the open end of the screw tomorrow and an expendable torx bit to see if that offers up any results.

 

[modzona]

Re: Rotor Bolt (Stripped)

You can use a dremel tool or something similar and make it flathead screw.

 

[Jimbo]

Re: Rotor Bolt (Stripped)

You can use a dremel tool or something similar and make it flathead screw.

^^^^^^ What Martin said !

 

[samiam44]

Re: Rotor Bolt (Stripped)

I take out stripped allens on quite a few occasions. Find a torx that fits and it will dig in and come right out.

I've had them for a long time- but the 1/4 drive stahlwille allen sockets are awesome for these tasks. A bit pricy these days- but you'll use them lots.


Michael

 

[500AMM]

Re: Rotor Bolt (Stripped)

The Beru caps were recommended to me, they're manufactured in Germany. I'm glad to hear that someone else is aware of the rotor bolts and it's just not me. I used my bald-end allen for easier access on the one bolt and that was the end of it within one revolution.

I plan to compound some epoxy in the open end of the screw tomorrow and an expendable torx bit to see if that offers up any results.

AlexV,

The joyful "rotor bolt syndrome" lives on as ever.

And here is the solution, post #14 and partially post #16;
http://www.500eboard.com/forums/showthread.php?t=4559

Whatever you end up doing - DO NOT HAMMER ON THE ROTOR BOLT HEADS!! That may induce cracks in the alu.rotor bracket.


-a-


---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----

Just for testing I made additional vent holes on one of the caps on the Limited, the principle is shown on the enclosed image. It works great and shows no sign of entrapped moist due to improved ventilation. I used a cutting disc on the Dreml to make the slots. Something to think about for those living in climates with low and varying dew point during the year.

 

[Christian_K]

Re: Rotor Bolt (Stripped)

I killed a aluminium bracket this year myself, by hammering a Torx into them trying to get em loose. It was just slight force buts enough to make a 150€ damage. It Killed the Rotor and the holder bracket lol... What a luck i have 2 other M119 engines sitting in my garage, so i borrowed one from them. The Rotor by Bosch i bought new.

I hate these bolts as much as GSXR. After i added ported heads and stuff and with new braket and rotor, i had this ticking noise from a bad AE FOL 147 lifter, so i had to disassemble everything again. I was really in a fight with myself, particulary beacause of these crap rotor bolts. And indeed i managed to round 2 from 6 total. So i enden taking all bolts out of the rotor, put them into my bench vise and hammered a Torx into all 6 of them. So now they are T20 IIRC instead of 3mm allen.

But thanks for the tip and measurements Arnt.
Dave, i really would love to hear more about the recent Beru caps.

 

[500AMM]

Re: Rotor Bolt (Stripped)

I killed a aluminium bracket this year myself, by hammering a Torx into them trying to get em loose. It was just slight force buts enough to make a 150€ damage. It Killed the Rotor and the holder bracket lol... What a luck i have 2 other M119 engines sitting in my garage, so i borrowed one from them. The Rotor by Bosch i bought new.

I hate these bolts as much as GSXR. After i added ported heads and stuff and with new braket and rotor, i had this ticking noise from a bad AE FOL 147 lifter, so i had to disassemble everything again. I was really in a fight with myself, particulary beacause of these crap rotor bolts. And indeed i managed to round 2 from 6 total. So i enden taking all bolts out of the rotor, put them into my bench vise and hammered a Torx into all 6 of them. So now they are T20 IIRC instead of 3mm allen.

But thanks for the tip and measurements Arnt.
Dave, i really would love to hear more about the recent Beru caps.

Christian, I better start a mass production of this solution now – I'm gonna be stone rich!!

 

[AlexV]

Re: Rotor Bolt (Stripped)

I wanted to post back with an update. I'm happy to report that I was able to remove the stripped screw. I tried quite a few methods to get the stingy thing out, I steered away from using a hammer in the process and did not want to make the problem worse or destroy the rotor bracket... The one method that worked for me was drilling out a descent size hole and then inserting a screw extractor followed by a little tap from a tool, I felt one of them grip after a few attempts with various sizes and finally got it out. I'm lost for words about the design of those screws.

Now it was time to install the new rotor and troubleshoot why the cap/rotor were not firing. I installed the new insulator shield, rotor, and cap to find the car was still not getting any juice from that side. At this point I thought it could be possible that I might have crossed two cables when I installed the new rotors on that side. I took the time to check the wires were in the correct position and they were. I felt a little lost as to what could be going on, I decided to remove all the parts for the 8 or 9th time and dealing with the screw dilemma. This time I tried to not apply as much force when securing the rotor bracket to the cam, I was very careful when tightening the rotor to the bracket in fear of stripping more bolts and made sure the cap was properly seated before tightening everything up. I got in the car expecting the same results and she fired up on both sides, the car has been running smoothly for the past two days.

Does anyone happen to know the specific torque requirements for the cam bolt? I read it was around 16-20 lbs for another MB, I could not find the data for our car though. I'm not sure what else might have been causing this issue considering these were all new parts being used. :? I'm still scratching my head over this one, but glad the car is running well!

Thanks for all the helpful suggestions!!