Rear suspension rebuild questions

[GnatGoSplat]

for now, at least get a reading to see estimate your toe... I would guess from your description that the left rear tire is toe in way too far, which means it point in.

 

ALTERNATIVELY.... maybe it is closer to straighter then before, and the front was adjusted for an out of adjustment rear.... as a minimum, go get a free alignment check and post results.

 

Wouldn't left rear tire need to be toed out too much to pull to the right (need to turn wheel to the left to keep straight)?

I have a cheap alignment checker tool, it's basically just a really long bar to measure the distance behind the tire vs in front of it. You put it behind the tire and set to 0, then put it in front of the tire and it will give a toe-in or toe-out reading. Before, it was reading > 4-degrees (assuming units is in degrees). Now it is reading <1, so now it appears to be more parallel. Would a change of around 3-degrees be enough to make this much difference?

 

Your alternate explanation is plausible. I've been having major problems with rear tire wear ever since the tow company replaced both front links with junkyard parts several years ago (they'd severely bent/creased the original ones). Last winter, I put tires with 80% tread on the rear, and now they are nearly bald after maybe 10-11 months. The original link was noticeably bowed and the bushing holes deformed to where bushings wouldn't stay tight in them. That suggests a pretty decent impact with something, however, my wife doesn't recall ever hitting anything with the rear wheel. I wonder if they put in the bad link to begin with and just adjusted the front end to where it tracked straight, after all, I can't imagine a car would track perfectly straight with alignment bad enough to consume tires so fast.

 

Sears would not be my first choice.

 

You know that the car tracked straight, prior to you dropping the rear suspension.

 

You know which way the car tracks now.

 

Loosen the rear subframe, pivot it back where it was, tighten the bolts. See what happens.

 

Problem is, I don't know where the subframe was since I didn't make any marks. I assumed it'd go in straight due to the guide pins. I'm not really sure if it's in straight or not. The hole for the left-side guide pin is elongated side-to-side so it shouldn't have much front/rear movement, but the hole for the right guide pin was perfectly round which should prevent side/side and front/rear movement, but I didn't really notice if the holes were significantly oversized in relation to the guide pins. Could be my whole issue has to do with the tow company adjusting the car to track straight with bent parts, or maybe the guide pin holes do allow enough play to cause problems, I have no idea.

 

Unfortunately, Sears was the only place I could find that can do an alignment on the weekend. It has to be on the weekend due to our work schedule.

[White93z34]

When I did my lateral links, I had to get the car aligned, it pulled to the left pretty crazy after I got done.

 

Edit: I don't see any way in which a rear subframe could alter alignment, there are no elongated holes, the body side holes are immovable, along with guide pins that force it into place.

 

The only points of adjustment in the stock rear are: rear lateral link slotted adjusters, and slotted strut holes/cam bolts if equipped.

 

if you did not touch the rear links is it possible that the front one you replaced was bent and the car had previously been aligned that way, and now that it is straight it has thrown the alignment back out?

Edited November 12, 2012 by White93z34

[GnatGoSplat]

Yep, the front one I replaced was bent and car was tracking straight before. I'm assuming the tow company put in a bent link as my wife doesn't recall ever hitting a curb. I didn't know the tow company bothered to align it, but maybe they did. That would make sense, because I wouldn't think a car should track straight with a bent link.

[19Cutlass94]

Seems like these stock links are pretty easy to bend..

[94 olds vert]

Easy to bend? That's an understatement. Especially when they get rusty they bend extremely easy.

[white96supreme]

my wife doesn't recall ever hitting a curb.

My wife says that all of the time, especially when I ask how the wheels on the car are all scratched up. She claims that she didn't do it.

[jman093]

Yep, the front one I replaced was bent and car was tracking straight before. I'm assuming the tow company put in a bent link as my wife doesn't recall ever hitting a curb. I didn't know the tow company bothered to align it, but maybe they did. That would make sense, because I wouldn't think a car should track straight with a bent link.

 

Trust me, there's no conspiracy by the tow company to cover up some odd suspension damage. It's unlikely they could damage it and no tow company would bother to cover it up if it did happen, they'll just deny it.

 

As Nate said, stock ones are notoriously easy to bend. It doesn't take a curb check or accident to bend it. A medium pothole or hard corner is enough to do the trick. Looking at the cars that come into where I work, I would definitely bet more 1st gen w-bodies have one or more bent links/trailing arms than don't. The tubular 2nd/3rd lateral links are much stronger and as Ken said, they allow for actual toe adjustment. 2nd/3rd gen trailing arms are the same as 1st gen except for the V8 cars.

[GnatGoSplat]

My wife says that all of the time, especially when I ask how the wheels on the car are all scratched up. She claims that she didn't do it.

 

Hahah, true, although I usually believe my wife because she is very careful and has never curbed any of our 18" wheels.

 

Trust me, there's no conspiracy by the tow company to cover up some odd suspension damage. It's unlikely they could damage it and no tow company would bother to cover it up if it did happen, they'll just deny it.

 

Actually, the tow company did bend one quite severely and admitted it when we pointed it out. Turns out both front ones were bent/creased and they replaced both with junkyard parts even though they were only responsible for bending one. I don't know if they attempted to align it or not, but it tracked straight when they were done with it and it was tracking straight even with the bent one I just replaced.

[Crazy K]

<-- knows his stuff.

 

you'll need to get a four wheel alignment check to make sure everything is straight.

[alec_b]

You said with your cheapo toe checker that the toe changed almost 3 degrees? Good lord will that ever change your steering/tracking. Hell a 1/2 degree of toe change can affect tracking. You really need to get the thing on a rack and see where your alignment numbers are.

[GnatGoSplat]

Yeah, I'm not actually sure the units of my cheapo toe checker, but I assumed degrees since I don't know what else it could be. Maybe it's divided in 1/10-degrees so 1 = 0.1 and 4 = 0.4? Not really sure.

 

Definitely do need to get numbers on it. Wife didn't want to go out this past weekend, so I changed the LIMG instead (needed it, badly) and we'll have to get it aligned next weekend.

[GnatGoSplat]

Got it aligned as best as Sears could do it. To get it completely in spec, he said he'd need to elongate the front strut tower holes and replace one of the knuckle bolts with an eccentric adjustable bolt since camber is off on the left side. I elected not to bother having that work done. Here are the before and after specs:

 

Interestingly, aside from the left camber, toe was completely fine in the rear. So that means the toe was WAY off on the old parts. Also interestingly, total toe on the front was fine, so the wheels were parallel. I think Ken and my suspicion were correct that the place the tow company hired to replace the rear links must have put the bowed link in from the beginning and adjusted the front tierods equal amounts to get the car to track straight.

 

Looking at the measurements, it looks like the front camber could easily be brought completely into spec simply by shifting the subframe a little bit to the right (pass side) to achieve +0.3 camber on both sides. Should be super simple and way easier and more correct than pulling the strut assembly and elongating holes, but I guess alignment guys are strictly "by the book". Not that I care much about 0-camber anyway, but next time I have to drop the subframe, I'll probably just nudge it a little bit towards the pass side. Rear just needs KYB struts that come with elongated holes, although if there is any play in the rear subframe at all, it could theoretically be nudged a little to the left to split the difference on the rear camber and be brought into spec that way too.

 

Well, it's close enough that it shouldn't wear down the tires nearly as fast as when the rear toe was off with the bad parts. In fact, had I known all it really needed was tie rods adjusted an equal amount on each side to get it to track straight, I would have just done that myself.

[White93z34]

I'm always annoyed that these shops that charge $80-$90 for an alignment can't be bothered to shift the subframe to bring it into alignment.

[GnatGoSplat]

Yep. Not to mention it's way easier than the fudge-fix of elongating strut tower holes and still leaves the car factory perfect. If I'd have been able to speak to the tech directly, I'd probably have tried to convince him, but the wife brought it in and I talked to the service manager on the phone. When I mentioned adjusting the subframe, he said, "no, no, that won't work." However, I know it most definitely would have worked. I didn't push it since it's not off enough to be a big deal.

[94 olds vert]

Yeah shifting the cradle will work, I have done it. It's a much more permanent fix than slotting the strut tower holes. Shifting the cradle is pretty easy.

[GnatGoSplat]

Now the car is vibrating. Bad. Steering wheel shimmies back & forth. Feels like a wheel is gonna fall off. 20-something degrees and I gotta jack up the car and crawl around on a dirty garage floor trying to figure out WTF is wrong with this car. Again.

[Schurkey]

Now the car is vibrating. Bad. Steering wheel shimmies back & forth. Feels like a wheel is gonna fall off. 20-something degrees and I gotta jack up the car and crawl around on a dirty garage floor trying to figure out WTF is wrong with this car. Again.

My W-bodies, and other vehicles I've owned have done that multiple times.

 

Each time has been the result of a defective tire. Broken belt, tire is no longer round. The surprising part is that I won't own a Goddam Firestone tire ever since I bought a '76 Nova with Firestone 721s, and the belt popped at highway speed on the way home from work.

 

I've got a broken belt on the right front of my '93 Lumina; which would be replaced by now if the transmission hadn't shit the bed forcing the early retirement of that vehicle. It's a Goodyear tire. Unlike Firestone, Goodyear isn't particularly known for defective belts. I just got lucky, I guess. Goodyear hung me out to dry, refused to warranty the defective tire.

 

If it does the shimmy/shake only while braking, you've got warped front rotors. Also common as dirt on the early W body. I bought a brake lathe, not entirely to service my W bodies--but it helps.

Edited February 20, 2013 by Schurkey

[GnatGoSplat]

Hmmm, wife says it's worst when braking and coasting, so probably not the rotors. It's WAY worse vibration than warped rotors. It actually makes the car feel like it's shaking back and forth side-to-side. Could be a messed up tire, it definitely feels like something is loose and wobbly.

[rich17]

check the lugs for tightness then wheel bearing.

[GnatGoSplat]

Very strange. I expected to find a problem, but I checked everything I could think of. Checked upper strut mounts, checked struts for play, jacked up the rear end, shook the crap out of the wheels, got under it and shook things, grabbed trailing arms, lateral arms, pushed and pulled on them, then jacked up the front and gave everything there a shake, checked sway bar mounts, checked lugnuts, spun the tires looking for weak spots or bulges. No problems found! A total mystery.

 

Later, I wondered if a missing wheel weight could do this. I looked at the edge of the wheels and right rear one looks like a spot where there may have been a sizable wheel weight. The rear tires were actually good ones I pulled off the 88 which had been sitting for several years. Tire shop told me they were out of round. They managed to get them balanced and we couldn't even tell there was anything at all wrong with the tires. So I'm thinking those must be sizable weights and if one goes missing, it might make a huge difference.

[White93z34]

Sounds like you may be on the right track.

[GnatGoSplat]

Source of the vibration became pretty obvious. One of the front tires has a bulgy section where all the tread is worn off and part of it even wore down to the belts causing them to start to separate. I guess it really was as out of round as it felt. Good thing I noticed it. My wife said she hit a curb with that tire a week or so before she started noticing vibration. I guess that must have been the cause, because the rest of the tire's tread is still well above the wear bars except for the bulgy area and I can't think of any other explanation. Had to switch over to the 077's today, a bit earlier than I'd hoped since I see potential for snow on Friday and Sunday, but maybe it'll fizzle out as most forecasts for snow around here do.

[Schurkey]

Source of the vibration became pretty obvious. One of the front tires has a bulgy section where all the tread is worn off and part of it even wore down to the belts causing them to start to separate. I guess it really was as out of round as it felt. Good thing I noticed it. My wife said she hit a curb with that tire a week or so before she started noticing vibration. I guess that must have been the cause, because the rest of the tire's tread is still well above the wear bars except for the bulgy area and I can't think of any other explanation. Had to switch over to the 077's today, a bit earlier than I'd hoped since I see potential for snow on Friday and Sunday, but maybe it'll fizzle out as most forecasts for snow around here do.

 

My W-bodies, and other vehicles I've owned have done that multiple times.

 

Each time has been the result of a defective tire. Broken belt, tire is no longer round. The surprising part is that I won't own a Goddam Firestone tire ever since I bought a '76 Nova with Firestone 721s, and the belt popped at highway speed on the way home from work.

 

I've got a broken belt on the right front of my '93 Lumina; which would be replaced by now if the transmission hadn't shit the bed forcing the early retirement of that vehicle. It's a Goodyear tire. Unlike Firestone, Goodyear isn't particularly known for defective belts. I just got lucky, I guess. Goodyear hung me out to dry, refused to warranty the defective tire.

 

Tell your wife to stop feeling guilty. The tire wear proves that that tire was defective long before she "hit the curb" with it a week before noticing the vibration. That tire's been bad for months; it just took awhile to get bad enough to notice the vibration.

 

Broken belts in tires suck. And it almost seems like it's becoming more common.

[GnatGoSplat]

Yep, you were right about it being a broken belt. She has actually been driving on it for months!

With the 077s on it, she said it drives like a brand new car. I'll bet!