wheel hub stripped thread differences

[samm]

Hi guys,

I suppose Im posting this just to share my experience that may be of some use.

Thread on E420 hub were stripped on my previous E420 and now I have stripped the ones on my current E420. LAst time it was rear, this time front. I have owned around 11 or 12 w124s and this has only happened on e420s. The metal seems different, maybe softer?

Wheel hubs for w124 e320 and e420 e500 are 2 different items and the wheel bearing will not fit. I got a e320 hub thinking its the same, but the bearing race was different size by maybe 1 or 2 mm.

For the E420 front wheel hub is 129 330 04 25

This part comes in sl500 and I think Sl300 and the E500 as far as I recall.

Anyway, an additional point: Tapping or rethreading the wheel hub results in a small amount of metal removal. I tested a standard thread versus the RE-threaded and there was slightly more wobble with the Re-threaded one. So, I may install a new hub (not used) or try to see if it is practical to use seom form of threadlocker (which I am not convinced is the best idea as I'm always fixing something behind the wheels). Keeping a torque wrench in the car all the time is going to be the norm for a while untill I am assured that there is no loosening of the bolts.

 

[gsxr]

I've never encountered stripped threads on any 124 hubs. If the threads are not too seriously damaged, you may be able to clean them up with a tap (carefully!) using cutting oil on the tap, etc. The tiny bit of metal removed should not cause any issues. Also, I use a small bit of anti-seize on all lug bolt threads, usually a 1-time application when I buy a car and R&R the wheels for the first time.

You are correct btw, the 034/036 (and also cabriolet, and LWB) all borrow the R129 front hubs, which are different/larger than the standard 124 hubs. Larger bearings, etc.

 

[samm]

So anti seize doesnt contribute to any looseness? Im assuming not seeing as you use it...
Is it like copper grease that you can put on the brake pads?

 

[samiam44]

Humm.. I thought they were the same bearings, but guess not.

I've never had a problem, but perhaps that car in the past had a tire store run on some rims with a 3/4 inch impact wrench designed for semi trucks. The 1 ton dually pickups, it's 350-375 ft-lbs. Yes you can absolutely use a helicoil and install it with red loctite. They stay pretty well. I'd be more incline to do that on the rear instead of the front. Bearing set + seal/grease is ~$35/40 in materials.

Not a fan of antisieze, but it's effective and a little messy. The big thing for lug loosening if I read the internet correctly is ppl painting the hubs and the paint settles or wheel digs into the paint and you loose pre-load. I clean my hubs, walnut blast or mask and glass bead the back sides. Prime and paint black. The wheel side, I use a datco with a roto-lock scotchbrite pad or sandpaper pad to remove corrosion- blend out any pits in the radius. Then a good coat of S70 grey graphite dry film lube. A remarkable product, but not cheap. Great of gun mechnisms too.
It's much easier and cleaner than anti-seize. Keeps your wheels from rusting on and make aligning lug bolts easy.

I've got a spare- I'm sure they are really plentiful. PM me if you absolutely need it. I'm sure Jeff or someone can send you one too.


Michael

 

[samm]

Hi Sam,

have you got used or new hubs for a e420?

I mean the main reason I'd want new is to make sure they have not been re-tapped. Like I said the bolts are slightly more wobbly when in the hole...

The graphite stuff, is it like a powdery item? Like the stuff you out in a lock?

 

[gsxr]

So anti seize doesnt contribute to any looseness? Im assuming not seeing as you use it...
Is it like copper grease that you can put on the brake pads?

It's a silver paste, similar to MB brake grease. I use Permatex 80078 (link). No issues with loosening, and although technically you should reduce tighenting torque a bit when using it, I stick with the 110Nm / 80 lb-ft and have never had an issue. Use it very sparingly and there should be near zero mess. I also use a very thin coat on the back side of brake rotor faces to prevent them from rusting to the hub surface.

Humm.. I thought they were the same bearings, but guess not.

R129 hubs use Timken Set 12 + 17. The standard 124 hubs use Timken Set 2 + 6, I think. Five bucks per set from Rock Auto, 2 required per vehicle (4 sets total).

Then a good coat of S70 grey graphite dry film lube. A remarkable product, but not cheap. Great of gun mechnisms too. It's much easier and cleaner than anti-seize.

I can't find this via Google. What is the brand name? Have a link? Are either of these equivalent?

https://www.amazon.com/Graphite-Dry-Film-Lubrcnt-Aerosol/dp/B00869WCH6

https://www.amazon.com/CRC-Graphite-Lube-Aerosol-Black/dp/B007I9XUD0/

 

[samm]

Thanks for that info on the paste, may start doing that too..

 

[samiam44]

Thanks dave- I knew the R129 were Timken set 17 and 12... but didn't know the others. I ussually get them next day from Amazon for about ~$20 for both.


Mines used, and I'm sure it's fine. You can go new.. that's fine too. No, it's a dry film lube which is made to stay put. Not the LPS stuff- I don't like messy.


Trivia: Timken was the originator of the tapered roller bearing. For self adjustment- like our cars, do you know what clearance they recommend? -0.004 to 0.010 inches. I think peak brg life is around 1-2 thousands.



Michael

 

[gsxr]

Trivia: Timken was the originator of the tapered roller bearing. For self adjustment- like our cars, do you know what clearance they recommend? -0.004 to 0.010 inches. I think peak brg life is around 1-2 thousands.

Those clearances are huuuuge! 0.004 to 0.010 inches translates into 0.100 to 0.250 mm!! Mercedes spec for clearance is 0.010-0.020mm (0.0004 to 0.0008 inch).

At 0.08mm (<0.004 inch) the front wheels feel very loose / sloppy when you push/pull by hand at top & bottom.

 

[samiam44]

They are going negative 4 though to positive 10. Ideal is just less than zero.
I think my being on the positive side of thing is measure able and practical for long bearing life.
Dry film I'm using tiolube 70

 

[samiam44]

http://www.timken.com/pdf/10424_Engineering and Lubrication Manual.pdf

 

[samm]

the cordless impact is what dameged the threads on my hub.

I was thinking back to a few weeks ago and I now realised it. I was balancing the wheel on the hub as there was a speacer. so i tried to get the bolt into the thread gently with the impact, must have put in slightly bent. Thing is I do this all the time, must just have been because of the spacers on the front causing the wheel to not sit properly

anyway at least I get new front wheel bearing out of it...

 

[nocfn]

I noticed on my 036 some oddities in the front lug threads. I obtained a spare set from Captruff and trued them out as GSXR suggested, and changed the bearings out with new. When the time comes I have a perfect set sealed in plastic ready for install.

 

[samm]

nocfn did you tap your hub or fix the threads on the bolts?

 

[nocfn]

For my case, i used a different lug bolt and ran it all the way thru. So it may have been just jimmied threads. As a precaution I bought a tumbled set from Captruff after the fact, and there was no issue - as there wasn’t a feeling that I wasn’t grabbing. So I may have corrected the perceived problem with new lugs, or by using a different lug and running it all the way in. I did not
Tap it.

 

[samm]

Any suggestions for front wheel bearing brands?

I have seen FAG and SWAG as well as LUK.

 

[gsxr]

Timken, as mentioned previously... made in USA. Oh, and use the OE MB neon-green grease; 45g in the bearings+hub, 15g max in the dust cap.

 

[samm]

oh I ordered 2 150 g tubes! Never mind.

I dont know where to get those timkens. I noticed the orginals were KOYOTO or KOYO or similar, sounds Japanese.

My options are FAG or SWAG or LUK. Likely getting FAG, German top quality.

 

[gerryvz]

Get Timken. They are at any Napa store.

 

[samiam44]

Timken via amazon. Oe is ntn .

 

[samm]

the ones that came off my car are KOYO.

Also the ones on the 420 in the scrap yard were koyo as well. Interesting..

 

[samm]

I went with the F.AG. bearings, made in Spain. They have a very good reputation so Im looking forward to no issues!

 

[samm]

hey so new FAG bearing and Mercedes green grease on the front. Installed new Brembo brake discs and Yellow Stuff brake pads as well. Lets see how the braking goes!!