Wanted Potential Diff Needed

[ktnez99]

Hi fellow Zeds!

My car may need a Diff and I'm wondering if any of you have a re-conditioned one, by any chance?

It's a BMW Z3 2.8L 1999 RHD Pre-Facelift model.

 

[mrscalex]

Hi fellow Zeds!

My car may need a Diff and I'm wondering if any of you have a re-conditioned one, by any chance?

It's a BMW Z3 2.8L 1999 RHD Pre-Facelift model.

If that’s an LSD I would be prepared to dig deep even for a secondhand one. I’d consider getting yours repaired as well as a replacement.

 

[ktnez99]

If that’s an LSD I would be prepared to dig deep even for a secondhand one. I’d consider getting yours repaired as well as a replacement.

Get mine reconditioned? And put it back on?

 

[mrscalex]

A secondand LSD diff is going to cost you £500+ and you won’t know the condition for sure.

I would hope a repair might be less.

 

[t-tony]

What makes you think you need one?

Tony.

 

[gookah]

if you are scrapping an old one can I have the cover plate, they are not made anymore. A few quid your way

 

[ktnez99]

What makes you think you need one?

Tony.

Because both the bodywork specialist and @Mnbrennan said it sounds like my car's diff has gone. @Rha suggested changing the oil first to see if that improves the sound. Have recently had two new drive shafts on the rear fitted so I'm wondering if these have had any impact.

 

[ktnez99]

if you are scrapping an old one can I have the cover plate, they are not made anymore. A few quid your way

If I need a Diff - and I really hope I don't - I'll get mine reconditioned.

 

[t-tony]

Because both the bodywork specialist and @Mnbrennan said it sounds like my car's diff has gone. @Rha suggested changing the oil first to see if that improves the sound. Have recently had two new drive shafts on the rear fitted so I'm wondering if these have had any impact.

I would certainly try Roy's suggestion first, got to be worth a shout. Is it really noisy? Is there any "backlash"?

Tony.

 

[mrscalex]

Not wishing to doubt the view of those who have seen it.

But was it okay before the driveshafts were fitted? If it was you’ve got to start there.

Were the wheel bearings changed when the driveshafts were replaced? If not they should have been and attempting to reuse them would likely give issues.

Diffs, just like gearboxes and engines rarely go wrong on these cars.

 

[Mnbrennan]

Not wishing to doubt the view of those who have seen it.

But was it okay before the driveshafts were fitted? If it was you’ve got to start there.

Were the wheel bearings changed when the driveshafts were replaced? If not they should have been and attempting to reuse them would likely give issues.

Diffs, just like gearboxes and engines rarely go wrong on these cars.

Hi mate

I've listened to it. It's not your usual diff whine. It's more like a growl and it's loud. As the bearings are hung from the body through a number of bushes I've discounted it

 

[mrscalex]

Hi mate

I've listened to it. It's not your usual diff whine. It's more like a growl and it's loud. As the bearings are hung from the body through a number of bushes I've discounted it

You’re best placed if you’ve heard it. But I’d like to know if it started when the driveshafts were done.

Not sure I get the bushes/body thing?

@ktnez99 were the driveshafts BMW or a pattern part?

 

[ktnez99]

I would certainly try Roy's suggestion first, got to be worth a shout. Is it really noisy? Is there any "backlash"?

Tony.

It is noisy and I didn't realize how noisy until Martin took me a circuit in his on Saturday meet at C&M.

 

[ktnez99]

You’re best placed if you’ve heard it. But I’d like to know if it started when the driveshafts were done.

Not sure I get the bushes/body thing?

@ktnez99 were the driveshafts BMW or a pattern part?

One drivershaft was off my car and re-conditioned because the wait was going into three weeks and the other was, I think, an aftermarket part. The bodywork specialist said it sounded like the diff and without saying anything, took it to a mechanic and asked him to drive the car - he said the diff was shot. However, they are also wondering whether the driveshafts are responsible.

 

[ktnez99]

You’re best placed if you’ve heard it. But I’d like to know if it started when the driveshafts were done.

Not sure I get the bushes/body thing?

@ktnez99 were the driveshafts BMW or a pattern part?

Not wishing to doubt the view of those who have seen it.

But was it okay before the driveshafts were fitted? If it was you’ve got to start there.

Were the wheel bearings changed when the driveshafts were replaced? If not they should have been and attempting to reuse them would likely give issues.

Diffs, just like gearboxes and engines rarely go wrong on these cars.

The mechanic before the one who did the driveshafts who I'd used for a few years had said the driver's side rear bearing needed replacing but kept messing me around with booking the work in so I changed and the "new" mechanic said it wasn't the bearing but the driveshafts. It was making noise before the driveshafts, to be honest, and I'd asked him about that but he said it's a noisy car, being low to the ground. The noise is louder now, after the driveshafts.

 

[mrscalex]

Comments like it’s a noisy car because it’s low to the ground don’t help your mechanic’s credibility.

You don’t normally get any noises like those you are explaining.

Regardless of the diff which I just don’t know and I will respect @Mnbrennan s view, the bearings could have got damaged if they were reused and it’s logical to change them with the driveshafts out anyway.

Can’t be sure on driveshafts either but recon/aftermarket quality is a potential issue too.

 

[ktnez99]

Comments like it’s a noisy car because it’s low to the ground don’t help your mechanic’s credibility.

You don’t normally get any noises like those you are explaining.

Regardless of the diff which I just don’t know and I will respect @Mnbrennan s view, the bearings could have got damaged if they were reused and it’s logical to change them with the driveshafts out anyway.

Can’t be sure on driveshafts either but recon/aftermarket quality is a potential issue too.

Totally agree on the credibility of the mechanic. The bearings weren't changed so, again, that's cause for concern. It goes without saying that I won't be going back there!
Other than this, I'm wondering what to do.

 

[mrscalex]

Well go back there is exactly what I’m thinking you should do if he hasn’t done it right. Hence all my questions to try and establish any error or poor judgement on his part.

This could be a very expensive job to put right for you otherwise.

I’m very suspicious he knows he didn’t do it right and/or damaged the diff if he’s making excuses about inherent noises.

If you do want to go back to him I’d get a view from a reputable garage, not necessarily a BMW specialist although that may help. All our advice on here may not carry as much weight as a professional report.

 

[t-tony]

I'm seriously leaning towards one or both rear wheels bearings knackered. Although it is possible the diff could be the culprit I have never known one get excessively noisy on a BMW. One way to test is remove drive shaft and fit in it's place a large nut and bolt to compress the wheel bearings and then spin the wheel by hand.

Tony.

 

[ktnez99]

I'm seriously leaning towards one or both rear wheels bearings knackered. Although it is possible the diff could be the culprit I have never known one get excessively noisy on a BMW. One way to test is remove drive shaft and fit in it's place a large nut and bolt to compress the wheel bearings and then spin the wheel by hand.

Tony.

That's an idea, Tony. Cheers.