Rear toe out of spec. Where to begin???

[Unkle Mike]

First I’d like to say, I purchased a MY95 E420 from Cars n Bids about a month ago (link).

My maiden voyage was a 6 hour road trip from the SF Bay to SoCal and what a dream it was to drive!!! Made the trip with no problems and because California had all that rain, the scenery was truly amazing.

Car hasn’t given me any problems thus far. I’ve made a couple updates to the car since my purchase:

New hood liner
Lowered on H&R/Bilsteins
Smoked tail lights (Depo)
LED headlights and reverse lights

Anyway, so my problem is after I lowered it I took it too get an alignment and the tech told me that that toe on my driver side rear is severely out of spec (toe in) and there was no adjustment he could make to compensate for it.

Told me I probably have bent suspension components and I should start rebuilding my whole right rear. What???

Nothing looks bent so where do I start? LCA, tie rod? Any info would really help.

Thanks in advance.

 

[gsxr]

Congrats on the new ride! Looks like you got a really good deal on that purchase. And now a bunch of questions:

1) Where was the alignment performed - MB dealer, or elsewhere?

2) Can you post a photo or scan of the sheet with the final alignment numbers?

3) How low is the car now, as measured from fender lip to wheel center, as shown in the photos below? Measure at all 4 corners, on a level surface, and note the amount of gas in the tank as well. Pretty likely it will be in the ballpark of 13.5-14.0 inches, depending on what H&R springs were installed.

4) If the passenger side is fine and driver side is way, way out of spec... there's a chance something is bent on the driver side. It may be the knuckle, as if the car slid into a curb or otherwise had a sideways impact at the wheel/tire, that is typically what gives first and bends. It's unlikely the LCA is bent or damaged, and if the LCA is shorter than normal, this results in excess toe out, not toe in. (I'm also not sure why the tech said to rebuild the OPPOSITE side... either fix the bent side, or rebuild BOTH. Was that a typo?)

5) Despite the low miles (119k) it's almost guaranteed the 4 subframe mounts are collapsed... and the 5 links at least should be inspected for wear at the bushings. If there's no record of replacement and the mounts look like the old/worn ones you'll see in various forum threads here discussing this, it wouldn't hurt to replace them. However it won't help your alignment / toe issue.

BTW, welcome aboard!

 

[Unkle Mike]

So glad to be on board with you all! GSXR coming in like a super sleuth and found the auction link!

But to answer all your questions:

1) Alignment was done at a random tire shop who I trusted with my other cars but I’m finding out real quick that MBZ are NOT like other cars.

Planning on taking it to an independent MBZ mechanic for a 2nd opinion, unless you think it wise to just go to dealership. That’s going to be another $155.

2) Didn’t even get a printout of the alignment specs. Rookie mistake

3) Car’s ride height is as follows:

DRIVERS SIDE
Front 13”
Rear 12 5/8” (problem corner)

PASSENGER SIDE
Front 13”
Rear 13 1/8”

So there’s toe in and -camber on that “problem corner” along with being 1/2” lower.

4) I was thinking that exact same thing. Some type of sideways impact. There are a couple other spots on the car where gaps between body panels don’t line up exactly (ie lower half of drivers door) but mostly straight.

And yes that was a typo, mechanic told me to rebuild the drivers rear where the problem is.

5) I definitely see wear and tear with the bushings and links. Haven’t seen the subframe mounts yet but I will plan on getting that all sorted out, front and back. Was planning on doing some polyurethane upgrades where I can from like Powerflex or something.

That’s all I got for now. Mechanic did mention the knuckle as a possible culprit of the problem. Seems like it would be an expensive part. Any sources for that?

Thanks all!

 

[gsxr]

Whooo, your car isn't lowered, it's slammed! Wow. Be careful, you are likely going to be kissing parking curbs up front and bending the lower radiator support. I don't like going under ~14.0" for this reason. Also, you are very close to sitting on the suspension stops all around.

Typical deviation in ride height left to right is about 1/8", or max 1/4". Your front is level but the driver rear is 1/2" lower than passenger rear, which is odd. You can try to compensate with different thickness spring pads, but I'd also inspect for other issues like subframe bushings (which affect rear ride height) or accident damage.

Don't do poly bushings of any kind - period - unless it's a track car being raced. Trust me. OE suspension components only.

If the knuckle is bent and needs replacement, a good used one is fine. They are easily available and cheap due to low demand. You can probably get one from a late 124 or a 210 at Pick+Pull. I think some other chassis are donors as well. Eyeball the portion where the rear tie rod connects to the knuckle, compare left to right. They should look absolutely identical (although mirror image). If one side looks even the slightest bit of an angle different... something is awry.

BTW, with the super low ride height, you will also have negative camber... ask the MB specialist or dealer to use E420 Sportline specs when aligning. And at <13" rear height, you may have rear tire wear issues. It won't be as bad with stock 15" tires but if you go wider, you'll likely need camber correction as well.

 

[Unkle Mike]

Yeaaa, low and slow is the way to go! Haha but personally I think the car is getting along perfectly fine at that ride height. Even took my mom out in it for an hour long trip to the beach and she had no qualms with that ride quality.
I also almost always reverse into parking spots so I shouldn’t be kissing many curbs

I will take your advice and not do any poly bushings

I guess now I will have to hunt down a knuckle and got to YouTube University to see how to replace it. I’ll wait to see what the MB mech says 1st and tell him to use the sport line specs.

I expected some negative camber but it’s noticeably more negative on the problem side.

Regarding ride height though, could it be possible that I screwed up the height specs when I left the spring super compressed overnight? It got late and I was frustrated lol

 

[gsxr]

Keep in mind that in the rear, camber is a direct function of ride height. The lower it is, the more negative camber you have, and it's not adjustable with stock components. So, with the driver side ~1/2" lower there will be more negative camber. The tough part is figuring out if it's "normal" for the ride height, or if something is bent/damaged.

Leaving the spring compressed overnight won't affect anything, btw. However I'd make sure the passenger side is fully seated. And, you should try to level the car out with a full tank of fuel, i.e. if the front is 13.0" try to get the rear also close to 13.0" with a full tank. The rear will lift slightly (1/4 to 1/2") with an empty tank, vs full tank.

Replacing the knuckle is pretty straightforward: bolt off, bolt on. This assumes the axle shaft comes out easily and isn't rusted/seized in place. If you do this, make sure to replace the lower support joint, both sides are likely toast unless a PO changed them recently. Cheap at ~$20/ea for Lemforder made in Germany joints, search the forum for details. Probably need to do the opposite side also. On the new/donor knuckle/carrier, make sure the hub is dead smooth & silent. If not, replace the wheel bearing too.

 

[Unkle Mike]

Looks like I got some work to do! A million thanks sir! Will update once I get the alignment results later this week.

And in case anyone was here for the car…