'88 300E floating around on accel, gear change...
 

Hi All,

First, great group, I'm grateful for the expertise of the members, and their willingness to share their experiences.

Now, I recently bought an '88 300E at a Salvation Army auto auction. I know from reading the posts that service records are paramount before making a purchase, oops. But I think I did well, aside from the Florida sun damage to the hood, the car is in great shape. The odo showed 60k, which I found to be inoperable after purchase, but I did find the PO who had donated the car. They said that the odo stopped working 3-4 years ago, but that the car was a fourth car, and they kept it for their kids when the came home from college. I'm guessing an extra 20k miles was missed. After doing a tune up, replacing the alternator, fixing the odo and replacing the 10amp OVP fuse, the car is running great. I travel from Sarasota to Jax Beach every weekend. I'm figuring the $3200 + $170 tune up + $200 alternator was a good deal.

Onto the problem: I'm finding that when I'm on the highway, the car seems unstable during gear changes and acceleration. The feeling is best described as the feeling you'd get in a baby buggy! When I accelerate to change lanes, the car seems to sway side to side until I settle into the lane. If I'm accelerating in my own lane, it seems like the right rear gets power before the left rear, and the nose of the car actually pushes left before coming back straight. When I'm going through the gears (automatic), I get the same feeling, just not as pronounced at reduced speeds.

I know I need new tires, and one of the tires is a different make, same size. I know I need an alignment too. The front steering seems to be in place, bushings are intact. I don't hear any clunking, nothing seems out of the ordinary as far as sounds are concerned. It's been a while since I had a rear-wheel drive daily driver, and I do seem to remember my '70 Cutlass had this symptom to a lesser degree, but my 300E feels downright scary if I'm changing lanes @ 75mph on the curving northbound lanes of I-75!

I see lots of folks replacing their shocks with Bilsteins, or upgrading their springs, is this why?

All your comments are appreciated, thanks

-Pete

Over time the links in the five-link rear suspension wear out. The earliest to fail and most common to cause your acceleration symptoms are the torque and thrust arms. They are the diagonal arms. The other links in the suspension are the camber (Top), tie rod (w/ eccentric cam & ball joint) and the spring link (lower control arm) - these last longer. When ordering torque and thrust links, you'll need two sleeves per side and new bolts kits. Good luck with your new car.

The thrust arm in particular can cause scary directional instability. It sounds like you have even more problems I particularly would check the subframe mounts also just in case those are shot.

Wanted to give a belated thanks for the input on this topic. I've been creating my parts/repair wish list/triage, and this has helped alot.
Thanks!

Pete

Brian

Have you done the torque or the thrust arms?

Are these DIYer projects? Can they be done without spring compression?

Haasman

You don't need a spring compressor for the rear links!
 

Theay are definetly a DIY project.
Pete,
You may also want to check the transmission mounts. They are cheap and easy DIY project as well.
Do you live at Jax Beach or Sarasota? I live in Orange Park...:cool:

Thanks JH.

What about rear suspension sub-frame bushings ... say on the 190E. Is this a DIYer or do I have to have special tools/ Hydraulic presses for the bushings?

Haasman

The only problem with the thrust arm for me was the new upgraded type has a sleeve that has to be pushed into the hole before the bolt goes in. That was a little hard.

Replacing these arms solved the problem I had where the car would feel like it skipped sideways when hitting a diagonal bump when cornering. Scary.

yal

How did you get them to go into the bolt holes? A press, force?!?!

I used a press. I guess I could have used a hammer but I like my fingers as they are, and the hammer didn't seem precise enough to do the job.

Do the sleeves have to be pressed into the new arms or into the subframe and carrier?

The old links had sleeves to, but they were changed along with the bolt kits. The new bolt kits require a 12 mm XZN (triple square) and are hard to get to in some sports. The nuts are 18 mm now too!! The old bolt kits were simple 17 & 19 mm standard and easy to turn. However, the old bolt kits and sleeves do not work with the new arms.

The sleeves only go into the carrier. For me the sleeves went in with my fingers, or maybe a tap with a small hammer, easy!! The old sleeves come out with the bolts or so they did for me. Akward work space is the more challenging part of the job.

The subframe bushings are much easier with the factory or Baum Tools but you'll have to spend $530-$670. The other way is to fabricate a setup with bolts, nuts, washers, and sockets or spaces. No sleeves or spaces. There are several posts in the archives about this and 124 & 201 chassis are basically the same.