98 V70: Rear End Vibration

Post by **sleddriver** » 08 May 2016, 17:45

Here's another issue that needs solving. I recently had four new tires installed by DT locally. Vibration begins around 62mph and it quite noticeable. Went back to have the rear tires rebalanced. Still occuring. I have Columba style wheels. Could one be bent? Is it possible to straighten/fix/repair? Any long term issues with high mileage S/V-70's rear ends? Don't hear any roaring like a bad wheel bearing.

Could the rear end be out of alignment? (Is that possible?) Not sure what's going on but it sure would be nice to get this figured out.

I suppose I could jack up the rear, set a dial indicator on the the wheel facing outward and measure the runout. I'd need to remove the tire though to check runout parallel to the forward car axis.

What do you think?

Post by **jreed** » 09 May 2016, 05:09

It might be helpful to try swapping the rear wheels to the front and see if the vibration moves to the front. If so, that may help isolate the problem to the wheel rather than the suspension.

Post by **sleddriver** » 09 May 2016, 21:03

This evening my other parts order arrived with the rear brake pads. While in there, I checked for looseness, bearing noise while spinning the tire, etc. RR side appeared fine, but LR I detected a noticeable 'dry bearing sound' while quickly rotating the tire/wheel/rotor unit by hand. This is also the side where a Michelin wore so much on the inside, that a belt was exposed, then separated, then made a very LOUD WAP, WAP, WAP, forcing me to immediately pull over and change to the spare. Never have had a tire wear like that so unevenly on this car.

I checked the new LR tire thoroughly for signs of scuffing, uneven wear, blocking, etc. and found nothing.

Between the last tire that was at that position, my noticing a 'dry bearing' sound, and the "rear-end-vibration" at 62mph, it all adds up to me as something that's Tango Uniform when rotating. The LAST thing I was is for 'the wheels to come off....'

First step is for another trip to DT to have all tires balanced, noting any thrown weights, and have the tires rotated F to R to see if the problem moves.

While pondering this situation, it occurred to me that I may have done harm by carrying too much weight in the rear. About 5yrs ago, I re-roofed my house...myself. Each shingle bundle weighed about 85#'s. I did carry at least one significant load of maybe 10-12 shingles. If I recall correctly, the V70 has a useful payload of about 950 #'s. So I may have exceeded it. I did carefully distribute the weight between the two rear wheels, trying to stack the heaviest part directly over the axles.

In the future, I stayed below 950#'s. Then far larger loads were hauled when my neighbor allowed me to use his old F150 tank. From that point on, no more shingle hauls in the sled.

Perhaps my over-weight caused the rear end to sag, harming the springs & bearings.

I'll need to give a careful listen to the RR bearing again.

Post by **scot850** » 10 May 2016, 15:10

It is possible to damage tires and rims from the round. I have 2 x 17" Volvo alloy rims on my winter tires that are no longer round. These came with the car. I have a replacement set waiting to go for powder coating to replace those before next winter. Tires can get damaged by pot-holes and knock them out of the round, but in your case it would seem un-likely to be the tires, but again I have had bad tires from new. Having them swapped from front to back will help identify which tire/rim combo may be at issue. Have one side done at a time as this will identify which side the issue is and then which rim.

I am more concerned that you had a tire where out on one side. This is either a camber or toe out issue. Have you had the alignment checked recently or before having the new tires fitted?

You may not have damaged your cars suspension it may just be worn out in some part(s). Check the suspension end link bushes for the rear control arms as they can wear badly and I have seen them bent.

Does your parking brake work? It could be a stuck piston as the rear calipers don't work so hard so they have an issue of sticking on (were the brake pads evenly worn on both sides of the rotors?).

Parking brake shoes de-laminate and can cause a horrible vibration, the cables also seize and can cause the brake shoes to drag. If you haven't stripped and lubed all the moving parts of the parking brake recently, then it is time to do so.

Neil.

Post by **erikv11** » 10 May 2016, 16:04

Not much to add to comments so far, except to +1 to Neil's comment regarding

sleddriver wrote:... Could the rear end be out of alignment? (Is that possible?) Not sure what's going on but it sure would be nice to get this figured out. ...

Yes, the rear toe is adjustable, and if a delta link is bad then other aspects of alignment could be out too. I would get it checked, be sure the alignment shop/tech knows how to do and check a 4 wheel alignment, many I have been to do not.

Post by **sleddriver** » 10 May 2016, 17:19

Yep...problem is finding a good alignment shop. Yet another search....

I'll install the new Meyle HD OTR's first, then go for an alignment and discuss the inner tire wear, vibration, etc.

My indy gave me a thought: Swap rear tires to front, jack up front, spin using engine and check for roundness. Wouldn't I need to block up the suspension though? Don't need to spin them too fast, but fast enough (with good light) to see if doing so causes the suspension to wobble.

I could have possibly bent the LR axle as well, due to excessive weight. This would lead to inner tire wear on that side. RR tire didn't exhibit this wear pattern and I've never cross-rotated tires before. Always front to back.

BTW, anyone have an opinion on Optimal vs. Centric vs. FEQ, vs. MTC for rear bearing/hub suppliers?

Post by **erikv11** » 11 May 2016, 01:19

Probably want to make sure it is an FAG or Timken bearing. But I have never had to replace one, wait to hear from someone who has ...

Post by **scot850** » 11 May 2016, 11:59

I replaced the whole rear hub with the bearing in it on a 93 850. Not very difficult, but finding a 4 stud hub was fun! Disappointment was it was no better with the new parts fitted. Never did find the cause of the rubbing sound from the rear of that car.

Neil.

Post by **sleddriver** » 20 Aug 2016, 19:12

UPDATE:

This was the answer. Front toe was 3X over-toed, thrust angle was pointed left of the driver. After all was properly aligned & the steering wheel recentered, the ride is greatly improved. Still need to listen to one front & two rear wheel bearings.

erikv11 wrote:
sleddriver wrote:... Could the rear end be out of alignment? (Is that possible?) Not sure what's going on but it sure would be nice to get this figured out. ...
Yes, the rear toe is adjustable, and if a delta link is bad then other aspects of alignment could be out too. I would get it checked, be sure the alignment shop/tech knows how to do and check a 4 wheel alignment, many I have been to do not.