Strange behaviour from the rear end

[Guest RichJ]

I know the title is a little vague, but I dont know how else to describe it.

 

Basically, since I booted it coming off a roundabout there appears to be some abnormal vibration coming from the rear end of the car. Originally, I suspected I might have a problem with the rear tyres as they are a little old, but upon further inspection I cannot see any problem with them.

 

Its pretty hard to describe but it would appear that whatever the problem is it is making the ride feel like I am traversing a rutted road, even when the road is perfectly smooth, sort of similar to having a flat, a constant judder from the rear end.

 

Any ideas as to what might be the cause of this?

[SUPRASUZUKI]

You'll get better help than this as more people wake up, I'm sure.

 

My advice, just to keep you busy?

Get it jacked up now, support it with stands. Get underneath and have a look for anything obviously broken / loose.

 

I'm guessing that the problem will not be too difficult to spot.

 

Hope it's not too expensive to fix mate.

[Nic]

Has it just started happening or gradually got worse? Have you hit anything (curb, pot hole etc.) with the rear wheel. Does the vibration get worse under braking?

 

It could be as simple as an unbalanced tyre or as complicated as worn rear suspension joints, wheel bearing, knackered damper, etc.. Impossible really to diagnose on here, you really need to get the car in the air and get everything thoughtly checked out by someone who knows the Supra.

 

Although first thing you could try is getting wheel balanced.

[Guest RichJ]

Just suddenly happened, didnt catch anything with the rear wheel and the tarmac where it first happened was pretty smooth. I will have another look underneath later, I couldnt see anything last night but it was fairly dark at the time.

[Ian C]

I had an end-of-life Pirelli deform it's sidewall once, and that gave a slight bombombombombombom sort of effect, more pronounced when I turned right as the tyre was on the left. Jack the back up and spin the tyre while watching it edge on - see if the tyre oscillates in and out.

 

-Ian

[vvteye]

Reminds me of the two occasions I had something similar. 1st time the problem got worse then my wheel fell of at 30mph!!! two sheared studs etc... 2nd time took it for balancing and noticed that a weight had come off which had caused the sudden change. Once replaced went like a dream.. Couldn't believe how bad an unbalanced wheel would feel on a car TBH.

 

Hope it's nothing more expensive than that!

[Guest RichJ]

Bit of an update, I had a good look under the car and I cant see anything obviously wrong. So I took it out for a little spin to see if I could locate the problem any better, not with that much luck though ...

 

The judder seems to start as soon as I go past 60mph, doesnt matter if I am cornering or running straight and the car doesnt appear to pull to either side when going straight on a flat bit of road. Below 60mph everything appears fine.

 

I am not completely convinced it is coming from the rear end now either as I can feel a slight judder through the steering wheel. The main reason I initially thought the problem was at the rear was due to the boot rattling (time to sort out some new boot rubbers I think )

 

I will jack it up tomorrow and spin the wheels to see if that shows up anything, not sure I can jack the front up myself though as its pretty low Ill give the wheel studs a check over at the same time.

[leelbuk]

Does sound like you've lost a weight on one of the wheels. As you accellerate past 60 does the vibration start to dissappear at all.

 

If you cant see anything wrong underneath get the rear wheels balanced. Only costs about £3 per wheel here in Bristol.

[Guest RichJ]

Does sound like you've lost a weight on one of the wheels. As you accellerate past 60 does the vibration start to dissappear at all.

 

Yes, it seems to be at its worst just past 60 and gets less noticable as the speed rises, Ill take it down and get the wheel balance and tracking checked out later in the week.

[leelbuk]

Yeah thats what happens, as the car approaches a certain speed the the wheels will be at an RPM where it starts to resonate and causes the vibration. As you accelerate further past 60MPH the wheel resonates less.

 

Fingers crossed thats what this is as at least it's a nice cheap problem to fix which is rare when it comes to cars!

[Guest RichJ]

Finally got to the bottom of the problem, managed to find enough free time from work this afternoon to take the car down to have the wheel balance checked ... there was nothing wrong with the balance of the front wheels, but whilst balancing the rear wheels they noticed a slight buldge in one of them that was causing the problem. Kind of obvious once I had seen it.

 

According to the guy who checked the tyre what happened was the rubber had perished enough to allow water to seep in and distort it. New set of rear tyres and the problem is completely solved, probably should have replaced them earlier, although the tread on the old ones was still good they did look like they had been on the car some time, I guess the previous owner didnt do too much mileage.

[leelbuk]

Glad you got it sorted so now you can enjoy her! It gets me down whenever somethings wrong with mine. At least 2 tyres where not too expensive and now you know they are doing their job - glue-ing you to the road!