Car rises in neutral and hunkers down in drive - PeachParts Mercedes-Benz Forum

Scott98 · #1 12-21-2004, 08:45 AM

I've always wondered if this is normal or if it's a sign that something is amiss? I read in a previous post that this might be a sign that the rear differential mount is bad. Has anyone else had experience with this? I've looked on Fastlane and I can't even find a rear differential mount.

Thanks,

Scott

boneheaddoctor · #2 12-21-2004, 09:08 AM

Its normal......its all in the geometry of the rear suspension if the car does it or not.

rgp123 · #3 12-21-2004, 09:38 AM

I am on my second '81 SD. My first did the squat and rise thing but my current one does neither. SD #1 had about 240k, SD #2 has 170k.

The "dr." is correct on the suspension geometry issue. Miles and care seem to be part of the equation.

RP

Hatterasguy · #4 12-21-2004, 09:51 AM

Mine does it to. My diff mount needs to be replaced, but it is still tight. I think some movement is normal.

Scott98 · #5 12-21-2004, 10:03 AM

Quote:

Originally Posted by Hatterasguy

Mine does it to. My diff mount needs to be replaced, but it is still tight. I think some movement is normal.

Where is the mount located?

Scott

Hatterasguy · #6 12-21-2004, 10:34 AM

Right above the pumpkin, it is square with two bolts in it.

tangofox007 · #7 12-21-2004, 10:51 AM

Quote:

Originally Posted by Scott98

I've looked on Fastlane and I can't even find a rear differential mount.

Look under "Transmission" parts.
http://catalog.eautopartscatalog.com/mercedesshop/sophio/wizard.jsp?partner=mercedesshop&clientid=mercedesshop&baseurl=http://catalog.peachparts.com/&cookieid=1EH0TL2AI1EO0NIFN5&year=1985&make=MB&model=300-DT-001&category=J&part=Differential+Mount

SD Blue · #8 12-21-2004, 10:53 AM

If your car squats and rises noticably, then you probably need to check a couple of things but more than likely your rear differential mount is in need of replacement. Is your car sitting a little low in the back?

This mount is a u-shaped mount on the rear of the differential. It is bolted to the chassis and has 2 bolts that hold the differential. Wear of this is not easily verified visually, but squat/rise is a dead give away. It easily replaced, be sure to have a jack under the diff. when you do it.($50)

Also, another thing you should check are the sub-frame mount bushings. These are located at the front of the trailing arm where they bolt to the chassis. (large at least 4-5" across)

I changed both of these out earlier this year and was very pleased with the handling improvement. Also the car now sits higher in the rear. I am not sure why but it seems the height of the rear has even improved a little with time.

(The old sub-frame bushings also make great jack pads. Remove the existing cradle on a floor jack and insert a bolt through the bushing.)

rgp123 · #9 12-21-2004, 11:18 AM

The sub-frame bushing replacement does a great deal for rear ride height and the jack tip is super.

Thanks

deeph8 · #10 12-21-2004, 11:34 AM

Will replacing this part reduce the noise coming from the differential?

SD Blue · #11 12-21-2004, 11:48 AM

Quote:

Originally Posted by deeph8

Will replacing this part reduce the noise coming from the differential?

What kind of noise are you talking about?

Scott98 · #12 12-21-2004, 01:20 PM

Quote:

Originally Posted by SD Blue

If your car squats and rises noticably, then you probably need to check a couple of things but more than likely your rear differential mount is in need of replacement. Is your car sitting a little low in the back?

This mount is a u-shaped mount on the rear of the differential. It is bolted to the chassis and has 2 bolts that hold the differential. Wear of this is not easily verified visually, but squat/rise is a dead give away. It easily replaced, be sure to have a jack under the diff. when you do it.($50)

Also, another thing you should check are the sub-frame mount bushings. These are located at the front of the trailing arm where they bolt to the chassis. (large at least 4-5" across)

I changed both of these out earlier this year and was very pleased with the handling improvement. Also the car now sits higher in the rear. I am not sure why but it seems the height of the rear has even improved a little with time.

(The old sub-frame bushings also make great jack pads. Remove the existing cradle on a floor jack and insert a bolt through the bushing.)

I'll take a look at them this weekend.

Thanks,

Scott

boneheaddoctor · #13 12-21-2004, 02:18 PM

Quote:

Originally Posted by SD Blue

If your car squats and rises noticably, then you probably need to check a couple of things but more than likely your rear differential mount is in need of replacement. Is your car sitting a little low in the back?

This mount is a u-shaped mount on the rear of the differential. It is bolted to the chassis and has 2 bolts that hold the differential. Wear of this is not easily verified visually, but squat/rise is a dead give away. It easily replaced, be sure to have a jack under the diff. when you do it.($50)

Also, another thing you should check are the sub-frame mount bushings. These are located at the front of the trailing arm where they bolt to the chassis. (large at least 4-5" across)

I changed both of these out earlier this year and was very pleased with the handling improvement. Also the car now sits higher in the rear. I am not sure why but it seems the height of the rear has even improved a little with time.

(The old sub-frame bushings also make great jack pads. Remove the existing cradle on a floor jack and insert a bolt through the bushing.)

My W116 has a new one....Still squats and rises......but the triple thunk in the 1-2 upshift is gone now.....

if a 126 or a 123 is different I don't know.

WannaWagon · #14 12-21-2004, 02:21 PM

My car does the squatting/rising thing, too. A couple questions:

Is the wagon rear suspension/subframe arrangement the same as the sedans (aside from the auto-height adjustment system, of course)?

How difficult is it to replace those subframe bushings? I know on many cars, it can be quite difficult, because the bolts/bushings are difficult to reach and often rusted solid.

SDBlue: Exactly what sort of "handling improvement" resulted from replacing these bushings?

#15 12-21-2004, 08:42 PM

My car squats a bit as well (remember shocks and springs). I can do the opposite in reverse as well.