Chimaera 4.0 GKN Diff (Help) + Rear Shocks

[chim326]

Does anybody know where to get and what type and size bearings are in the diff, The car is a 1996 model and whines like its in reverse gear constantly in all gears and gets loader the faster you go. Has anyone changed the bearings themself, Or can recomend somebody in or near Essex that can do the job. Also is it possible to change the bushes in the ends of the shock absorbers and where do you get them from.

Thanks.
Regards Steve.

[spend]

I would advise talking to Bernie at CTS (google Competition Transmission Services or gearboxman IIRC). He rebuilds the diffs for quite a few of us ~ guess he will supply parts ~ but is more than likely able to offer you information on the possible damage.

Bushes from your local indie/dealer I'd say.

Dave

[adrian@]

That sounds like a wheel bearing.....have you checked them. Just a thought as I have repaired many diffs with replacement wheel bearings.
Adrian@

[hugepiece]

same thing happened on my old 94 chim, in the end I bought a brand new diff from ReadManRacing and got Leven in basildon to fit it for me. It was expensive at 700quid but was literally BRAND new. I thought about the recon idea but everyone said it would be off the road for up to 6 weeks while they tried to source parts, apparantly one of the bearings is a non-standard size that needs to be specifically machined to fit. Also there is a place out near Hanningfield in essex that specialise in Triumph transmissions, they said they could also sort it in a few weeks.

[Parrot of Doom]

Have you considered that the diff might be a bit empty of oil?

Worth checking, costs nowt.

[chim326]

Thanks Fellows. Yep full with oil. And also checked wheel bearings which seem ok, Tried to purchase new bearings but they seem to be reluctant to sell and would prefer if you sent them the whole diff so they can do the rework.
Thanks for the threads.

[adrian@]

Consider sending the diff to GKN rather than anywhere else...the work there is PERFECTION nothing less....0121 344 3477 note the input shaft flange off this unit is off a Maseratti and they carry stock. Also how did the wheel bearing get tested, IF this is a running noise then you will need to be under the car, (whilst the car is supported) and running (a job for an expert). IMHO Adrian@

[that daddy]

the problem with most independent rear ends,is trying to simulate the loads that that are on the bearings when you drive,sometimes impossible to check,without an electronic stephoscope system that only some garages carry,bmw/ford RWD back ends can be like this when their in the air the bearing shows no signs of play or noise even when running in gear,because there are no loadings present,most annoying.

[adrian@]

I did say expert.....Adrian@...but a diff out and rebuild is not cheap.

Edited by adrian@ on Friday 2nd March 11:26

[spend]

If the bearing collapses & the diff starts behaving like a glorified cheesegrater ~ you wont need an expert to tell you there is something wrong From experience when the diff goes it sounded to me very similar to having a rear brake sticking with no pad material left.

Dave

[that daddy]

that daddy said:

the problem with most independent rear ends,is trying to simulate the loads that that are on the bearings when you drive,sometimes impossible to check,without an electronic stephoscope system that only some garages carry,bmw/ford RWD back ends can be like this when their in the air the bearing shows no signs of play or noise even when running in gear,because there are no loadings present,most annoying.

Sorry Spend, i should have said i was referring to the wheel bearing testing not the diff.

[spend]

No prob. just thought it was worthwhile putting the diff paranoia into perspective. In my experience it was not a subtle 'whats that' back end noise ~ its pretty much a "sh1t dare I move another yard" noise.... Apparently the nose bearing commonly collapses very quickly.

Dave

[that daddy]

spend said:

No prob. just thought it was worthwhile putting the diff paranoia into perspective. In my experience it was not a subtle 'whats that' back end noise ~ its pretty much a "sh1t dare I move another yard" noise.... Apparently the nose bearing commonly collapses very quickly.

Dave

Yeh,that seems to always be the bearing that takes the most stick Spend,spot on,always was on the old RWD ford live rear axle units.Pinion bearings 1st to let go,side carrier bearings seldom give nag.

[chim326]

After supporting the car on stands selected 4th gear and the got under the car and its definatly the diff that the whining is coming from. Anyway the diff is now on the bench with the back plate removed and the crown and pinnion look to be ok (oil is not burnt and there is no discolouration in the oil). But when you turn the flange or propshaft end of the diff it is very notchy and stiff and feels like it could possibly be from the nose cone bearing. Does anybody know where to start if I want to inspect or remove this bearing. I'm guessing here. Do you need to pull the driveshaft flanges from the diff housing first so that you can remove the crown wheel and planet gears. Or can you access it from the nose. Or should I just send it away to a Specialist, Is there anywhere that does exchange diffs. 90% sure it is the gkn type as it matches the pics in the bible. Does the BTR type diff bolt straight in and match the prop and drive shafts.
Thanks for the previous replys.
Steve

[spend]

GKN -> BTR is not straight forward, as well as changed chassis reportedly. A Griff owner in SYorks is having this done at the mo if you look at the griff forum (posted within last 2 weeks I'm pretty sure).

Inside of the diff is black magic ss far as I'm concerned but if my spare one ends up on my bench I wont be able to resist the temptation....

Dave

[chim326]

Spend I don't suppose you want to sell your spare diff do you. Ha Ha

[spend]

Its prob in a worse state than yours ~ thats how come I bought it for £1 but the CW & case is still OK which are the valuable bits I believe.

Dave

[That Daddy]

chim326 said:

After supporting the car on stands selected 4th gear and the got under the car and its definatly the diff that the whining is coming from. Anyway the diff is now on the bench with the back plate removed and the crown and pinnion look to be ok (oil is not burnt and there is no discolouration in the oil). But when you turn the flange or propshaft end of the diff it is very notchy and stiff and feels like it could possibly be from the nose cone bearing. Does anybody know where to start if I want to inspect or remove this bearing. I'm guessing here. Do you need to pull the driveshaft flanges from the diff housing first so that you can remove the crown wheel and planet gears. Or can you access it from the nose. Or should I just send it away to a Specialist, Is there anywhere that does exchange diffs. 90% sure it is the gkn type as it matches the pics in the bible. Does the BTR type diff bolt straight in and match the prop and drive shafts.
Thanks for the previous replys.
Steve

Theres no black art to diffs Tvr or otherwise,but you do need to know what your doing concerning the mesh of the crownwheel & pinion unit,at least has to be checked on the build up,if you dont feel confident enough to take on this kind of task,just get a specialist rebuild.

[chim326]

Thanks Spend, I used Competition Transmission Services or gearboxman , And he did the business. Excellant service and fast too. Its a totally differant car and a pleasure to drive.
Thanks fellows for the tips and threads.
Steve.

[GarryM]

What would you expect to pay for a diff rebuild then? Looking at this thread I suspect it's a lot less than I've just paid!