Rear suspension noise + jumps/skips over bumps

[pablo94sc]

About two weeks ago I noticed, when going over rough pavement at low speeds, my rear right suspension sounds like a tennis ball bouncing in a small cardboard box. I haven't been able to replicate the noise yet while parked and haven't been able to get underneath it since all my "free" time is being spent studying. Why I took 19hrs this semester...??? :aigo:

Anyway, a couple nights ago the car also developed a skip when turning over rough pavement. Feels like the entire rear jumps about 1-2" to the right.

Finally, and this may just be my imagination, but it feels like the rear end is drifting or hanging out to the right when I'm in motion - like when you're driving an old truck or van with a solid rear axle that's aligned, but out of alignment with the body. If you don't know the feeling, I'm sure you've seen what I'm talking about. The car tracks straight, but it feels like the car itself is crooked.

I'm not sure where to start. :1zhelp: To be honest, I've been so busy with school that the car side of my brain is completely useless. Any help or ideas are appreciated. Spring break is next week and I'm going to have to fix it then, on the cheap since I'm officially a poor college student again :icon_bigg, or else hope it holds out until May.

PS: Car is an '89, non-TEMS, and if I need struts would you prefer the KYB GR-2's or the Monroes for an OEM type replacement? http://www.partsgeek.com/catalog/1989/toyota/supra/suspension/strut_assembly.html Or do you guys prefer the Gabriel units that Autozone carries?

Any other parts I may need to consider when replacing the struts, like shock mounts, spring perches, or the like?

THANKS!

 

[IJ.]

There is a spherical ball bush in the rear upright, if the bolts are tightened without the cars weight on the suspension it will destroy itself.

Jack the car up under the rear upright so the cars weight is on the suspension then grab a rear wheel and see if it will wiggle/move at all.

 

[IBoughtASupra]

Ian, I have read your posts before about this piece and weight not being on it when its tighten causing it to fail.

Is it in this picture in the TSRM? Its the only picture the TSRM has of the rear suspension where it shows struts, arms and hubs.

http://www.cygnusx1.net/Supra/Library/EPC/291420/catalog.aspx?F=4804&P=1

 

[IJ.]

48725 from memory.

The same applies to ALL the stock bonded bushes as they tear the inside steel free if tighted unweighted.

 

[IBoughtASupra]

Cool.

Just learned something here!

Thanks.

OP, Check on the parts when you have the time and post up results.

 

[Poodles]

Could be more than one thing. Usually that sound is caused by a worn top mount (or loose nut). The rest wouldn't be caused by that though.

On the question of shocks, stay away from Gabriel or Monroes, they're junk. KYB, Tokico, and Bilstein were OEM suppliers for our cars.

 

[OfnaRcR4]

Does it sound like a rubber bouncy ball being quickly shaken around in a plastic box? I know that's weird but that's the sound mine made when the top mounting nut (center shock nut) wasn't tightened all the way. Annoying as hell! Anyone got an idea on how to tighten this? My shock shaft spins when i try to tighten it. Doesn't make sense because there's supposed to be a slot in the top mount that prevents this.. hmm.

 

[roadboy]

they have a tool which you can lock the shaft in place while you tighten the nut, you can prob rent it somewhere like a auto store.

 

[destrux]

Grab the swaybar near the ends and see if shaking it up and down shows any play in the end links. Could also have play in the two rubber pivot bushings where it bolts to the subframe.

There's a ton of things that can make noise back there, but that's a common one.

The shocks can too, if they are old. They don't need to be leaking to be worn out either. I've replaced shocks that clunked terribly that looked just fine. I suspect it's internal damage from constantly bouncing over really bad roads.

The rear shock nuts barely have any torque on them, it's really important to use new locknuts when you change them so they don't back off during use. The top mounts do have flats to hold the shaft from spinning, but they strip easily if you overtighten the nuts at all. You can use vice grips with a piece of copper pipe as a cushion to hold the shaft if this happens.

 

[IJ.]

Does it sound like a rubber bouncy ball being quickly shaken around in a plastic box? I know that's weird but that's the sound mine made when the top mounting nut (center shock nut) wasn't tightened all the way. Annoying as hell! Anyone got an idea on how to tighten this? My shock shaft spins when i try to tighten it. Doesn't make sense because there's supposed to be a slot in the top mount that prevents this.. hmm.

The D hole is a bit oversize for the shock shaft and rounds out easily, I used a pair of locking pliars right at the top of the shaft to hold while tightening.

 

[pablo94sc]

Sounds exactly like a rubber ball in a box. I got a moment to look up under the wheel well and low and behold, oil stains all over the PR shock. Bounce test told me the same thing, so I'll be ordering some KYBs soon. Anyone found a cheaper price than $40ea?

Do you recommend replacing the top shock mount as well, or is it too soon to tell?

Any thoughts on using a rubber shaft boot to protect the shock? The car doesn't have any installed presently.

I'll be checking the bushings as well when I get the car in the air.

Also, are these shocks or struts? If they are shocks I'll feel safe swapping the springs to the replacements at home. If they are struts, I'm definitely having a shop swap the springs over.

Torque specs that I know so far:
20lb/ft for the top shock nut
10lb/ft for the three top bolts
101lb/ft for the bottom shock to axle carrier bolt
133lb/ft for the sub-frame-to-body bolts

Thanks again!

Edit: Jack the car from 48725, 48725B, or 48725C? Want to make sure I use the right point.

 

[ifyouaint1sturlast]

Wow, thread bookmarked. This is a lot of great info guys, thanks.

 

[hidenplanvew]

alot of shocks/struts hace an allan head or it will be square at the top so you can use a wrench or allan head to hold the shaft in place... I wouldnt jack on any part of the suspension I would go on the pinch weld unless your going to tq the nuts for the bushings, also dont take the springs off the struts/shocks without using a spring compressor to remove pressure from the tophat... That nut can come off at about 20 ft per sec, thats enuff to take an eye out or hurt someone ..

 

[destrux]

It's not just struts that have springs under preload, shocks with springs on them do too. Not all of them, but most of them. You'll need that spring compressor.

 

[pablo94sc]

I may just have a shop swap the springs over for me. While I can easily rent a spring compressor from AZ, I also know how cheap their tools can be. Better safe than sorry.

Still wondering if anyone has any thoughts on proactively replacing the top shock mounts and getting the shock dust boots/bellows. We'll likely be selling the car in the next two years, or 200k miles, which ever comes first.

 

[supraguy@aol]

I had put rubber shock covers over the shock's piston on my rear koni's.
I guess they helped protect them; and they certainly didn't hurt anything.

 

[OfnaRcR4]

Thanks IJ, now I just have to figure out how to hold it while tightening it because it doesn't have any allen top.

 

[hidenplanvew]

I have used the HF spring compressor and it isnt 1/2 bad (just make sure to put something on the threads) it just takes a little work to do and alittle time. If you know a shop and have a good relationship with them most will swap over springs for free or very cheap. I usally just hit the nut on the top of the shock or strut with an impact to break it free and re install. If you have to put a vice grip or something on the shaft do it at the highest part you can and protect the shaft with ducktape or something. If you dont and scratch the shaft part that goes into the cylinder of the shock you might as well just trash the strut/shock.

 

[pablo94sc]

Thanks for the tips on removing and reinstalling the top nut. I'll probably skip the rubber shock covers. No sense spending more money that I have to.

 

[pablo94sc]

Just an FYI for those looking for stock-type replacement struts on the cheap, Monroe has a $60 rebate when you buy 4 of their OESpectrum struts (71214 and 71215) until April 30th. I almost went this route, but you have to reuse the lower spring perch. This was a deal breaker for me, but it might work for you.