I'm trying to locate one or more suspension noises on my Gen1 LWB (1990). Basically it makes a "thunk" under several different circumstances; I suspect it's all the same noise, but I'm not sure since I have yet to locate the source. The circumstances:

-Starting from a stop I hear the thunk as something seems to move backwards. I also feel it with my right foot on the gas pedal;

-Stopping at low speeds, a similar thunk that would seem to be the same thing going back forwards;

-When turning a corner at low speeds (e.g. in a parking log) specifically to the left;

-When going over a bump, seeming to come from, more or less, the right rear of the vehicle.

This seems to be more pronounced in cold weather (cold being < 60 degrees, which is what passes for winter around here). Like I said, if I had to locate it it would be on the right side, and seemingly more towards the back than the front. But I can also feel it with my feet on the floorboard, especially the right one that's at the gas pedal.

I've just replaced all four shocks (KYBs) and the bushings on the front sway bar. Suspension is all stock and most of it is still original.

I've tried getting underneath and grabbing and shaking various things, but nothing wants to move when I'm under there. Any ideas what are the most likely candidates for this kind of noise? Any suggestions as to how best to locate a noise that I can't readily reproduce by grabbing, shaking or jumping on the bumper?

thanks,
steve

I would look at worn upper control bushings.

go down the road straight and get on and off the gas. Does the truck veer slightly side to side? If so, check the trailing arm bushings.

I would also check trailing arm bushings. I had a very similar issue took, took it to several people including a mitsu dealership and they could not locate it. I changed out the bushings and noise gone. The bushings looked good but had gone soft. Everytime I stoped or hit the gas the trailing arm would hit the cup it sits in and make a thud! Hope this helps

Thanks, guys! I'm guessing that you all are right about the trailing arm bushings. I just took it on its first serious roadtrip since my engine rebuild, Austin - Angel Fire, NM, about 750 miles. The truck was great, but on the highway you definitely feel the rear sort of bouncing around and the whole truck wandering side-to-side on the road. I guess I'll have another project to keep me busy when I get home.

steve

Just a quick follow-up; has anyone done a trailing arm bushing job and can comment on the parts? oemmitsubishiparts.com has the official Mitsubishi ones for $25 (rear) and $7 (front). Other sites (like Auto Parts Warehouse) sell these TER bushings for $37 (rear) and $7 (front). Is there any reason to think that the TERs are worth the extra $12? Any other sources I should consider?

thanks,
steve

The OEM ones lasted how long? I'd just buy the OE units and be done with it!

I seem to remember an issue like this coming up not too long ago. In the end it was the jack moving around in the back. Just something to check.

Why pay more for bushings of an unknown quality?

I used OEM bushings when I replaced mine several years ago. I had to take the trailing arms to a machine shop to have the rear bushings replaced since I don't own a press.

I finished up doing the trailing arm bushings this weekend. Almost all of the thunks and rattles are gone and it doesn't wander all over the highway any more; you guys were spot on, thanks!

I bought the OEM bushings, pulled the arms last weekend (after a liberal application of penetrating oil a week or two earlier) and took them to the machine shop during the week to have the old pressed out and the new pressed in. Putting the arms back on proved to be interesting. I had to get creative; let's just say that two 12-foot racheting tie-down straps figured prominently in pulling the axle far enough forward to re-attach the front nuts on the arms.

Anyway, as always, thanks for the advice. Guess I might need to look at the front suspension now, but the rear seems to be nice and solid. I've been living with those thunks for several years, so I'll have to get used to not having them any more now ;-) I guess that re-doing things once every 20 years or so shouldn't be a surprise.

thanks,
steve