B5 quattro rear diff bush

Ian2012

Registered User
I think my rear diff bush is past it's best what are my options oem or an upgrade option?? whats peoples advice here.


Thanks

ian
 

Tom_B

Registered User
Do you mean the centre driveshaft bearing?
 

Ian2012

Registered User
no the thunk noise is at the back, very reminiscent of old typ 85 and B4 q, funny thing is having driven qauttro for 20 yrs now the same faults are still there as each generation gets older.
 

Bradderz_1988

Dont replace it, Upgrade it !!
You need the apikol rear bushes and centre mount shoot hecktor a pm he will sort your needs you will be talking £300 notes though im going to be ordering the centre one soon thats £230 on its own first im sorting the turbo.
 

Bradderz_1988

Dont replace it, Upgrade it !!
I was thinking of just using poly sealant on the centre diff for now but had my eyes on the apikol but turbo is getting priority doug's just sent us out a new manifold then payday ill be getting the F21 upgrade.
 

Tom_B

Registered User
If you were planning to do the centre driveshaft bearing as well I have a brand new one from all German Parts which I got (and didn't fit) for my 2.5q a couple of weeks before I drowned it.
 

Ian2012

Registered User
Is the bush itself available from audi, and just replace it like you would on something like an S2 A arm bush????
 

Bradderz_1988

Dont replace it, Upgrade it !!
I suspect it is but will be some what near the price of an aftermarket jobbie, but my moto is why replace it when you can upgrade it ???

Heres the apikol one.
Apikol rear diff mount b4/b5 chassis
 

jcb

Registered User
i have the apikol (front) rear diff
if is a very nice and sturdy piece of kit

check the (rear) rear diff hanger. it has smaller bushes and mine were completely soft.
I tiger sealed them to good effect when I rebuilt the rear subframe
 

aragorn

"Stick a V8 in it!"
Staff member
Moderator
VCDS Map User
talking from experience here, DO NOT go too stiff on the rear end.

I fitted alloy subframe bushes, 80shore rubber rear diff carrier bushes and tigersealed up the front diff mount, and the result was the thunk turned into a horrible clank as you went on and off the throttle. Even engaging the clutch between 1st/2nd/3rd when driving like a granny sounded like you were trying to snap the diff out the bottom of the car.

What happens is all the driveline components begin to wear, CV's, Propshaft joints, diffs themselves etc all end up with a bit of slack in them. All of this wear means theres slack in the drivetrain, which at the moment is being absorbed by the nice big soggy diff mounts.

I ended up swapping the rear carrier mounts out for new standard ones and that made it much more bearable. Fixing a worn CV on the propshaft helped too. I also changed the gearbox which improved it a bit more as well.

I'd suggest new OEM rear bushes (they're only about 8quid each) and filling the front bush with polyurathane sealant is a decent compromise, stiffens it up but leaves enough slack so that it doesnt transmit horrible clanks into the floor.
 

HEKTOR

Registered User
talking from experience here, DO NOT go too stiff on the rear end.

I fitted alloy subframe bushes, 80shore rubber rear diff carrier bushes and tigersealed up the front diff mount, and the result was the thunk turned into a horrible clank as you went on and off the throttle. Even engaging the clutch between 1st/2nd/3rd when driving like a granny sounded like you were trying to snap the diff out the bottom of the car.

What happens is all the driveline components begin to wear, CV's, Propshaft joints, diffs themselves etc all end up with a bit of slack in them. All of this wear means theres slack in the drivetrain, which at the moment is being absorbed by the nice big soggy diff mounts.

I ended up swapping the rear carrier mounts out for new standard ones and that made it much more bearable. Fixing a worn CV on the propshaft helped too. I also changed the gearbox which improved it a bit more as well.

I'd suggest new OEM rear bushes (they're only about 8quid each) and filling the front bush with polyurathane sealant is a decent compromise, stiffens it up but leaves enough slack so that it doesnt transmit horrible clanks into the floor.

I have the total opposite experience of these parts. I fitted billet front & rear subframe mounts, apikol diff carrier bushes, apikol diff mount, track density engine/gearbox mounts etc and my car has never felt better. I dont get any of this knocking, clunking, clanking regardless of how easily or how hard i drive my car nor do any of the people/customers i know who have these parts fitted.
 

aragorn

"Stick a V8 in it!"
Staff member
Moderator
VCDS Map User
Well presumably your driveline is nice and tight then.

All i'm saying is if your already getting thunking, then its entirely possible that its NOT the rear diff mounts, and instead its caused by wear in the driveline components. If thats the case, stiffening everything up will only make the problem worse.

Others on SRS have found similar issues as you well know, so its not like i'm alone with this.

The stiff rear diff mounts and solid subframe also puts a lot more diff whine into the shell, although its most noticable at low speeds and mostly fades away once moving.
 

HEKTOR

Registered User
Well presumably your driveline is nice and tight then.

All i'm saying is if your already getting thunking, then its entirely possible that its NOT the rear diff mounts, and instead its caused by wear in the driveline components. If thats the case, stiffening everything up will only make the problem worse.

Others on SRS have found similar issues as you well know, so its not like i'm alone with this.

The stiff rear diff mounts and solid subframe also puts a lot more diff whine into the shell, although its most noticable at low speeds and mostly fades away once moving.

With 130k miles on it i cant see it being that "tight" when compared with similar cars of this age/mileage.

No one is saying you are alone on this. I was giving the other side (my opinion) based on my experience.

I have to disagree with this point. My experience is that i have no added noise or vibration from the rear at low speed. To be honest my car just feels fresh, crisp, new & has a better ride especially when compared to how it was before. I get a rumble from the rear when going from 60mph to 80mph then all is normal. For me this is the only negative and not much of one as it only occurs under load.

As i say this is my experience of these parts fitted to my car. Others may have experienced something similar to yourself or a slight vibration, rumble or like me a vast improvement in feel, connection front to rear, more stable at speed etc.
 

jcb

Registered User
well I am about as stiff as you can go in the rear (fnarr fnarr!)
solid alloy subframe, apilkol, tiger seal, powerflex rear everything else

I do get more transmission whine (tolerable)
The clunk I used to have is still there but less obvious (I am sure it was the rear diff and or the drive shaft CV's)
the slop on clutch engagement is much less than it was

the best part of it IMO is the rear end feels utterly connected to the road and any fast acceleration or launch type starts do not feel like I am taking up lots of rubber slack before anything happens

if there is slop in the drivetrain you need to invest some serious wedge if you want to remove all of it
 
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