Chimaera transmission noise

[PhysDoc]

I'm having a weird problem with my 1996 chim. After a run, when coasting up to lights or creeping forward, or just pulling away I get a nasty 'thump thump thump' noise. I can feel it through the car. It only starts doing it after a run of 15 or so miles.

It feels like something binding, like the brakes, however they aren't smoking or smelling, so don't think it's that. There's no other noise. Could this be a propshaft joint? Don't understand why that should get worse when hot though.

Any suggestions or anyone had this? Thanks

Edit: it does it in a straight line, so don't think it's the limited slip diff binding.

Edited by PhysDoc on Friday 20th May 19:56

[steve j]

PhysDoc said:

I'm having a weird problem with my 1996 chim. After a run, when coasting up to lights or creeping forward, or just pulling away I get a nasty 'thump thump thump' noise. I can feel it through the car. It only starts doing it after a run of 15 or so miles.

It feels like something binding, like the brakes, however they aren't smoking or smelling, so don't think it's that. There's no other noise. Could this be a propshaft joint? Don't understand why that should get worse when hot though.

Any suggestions or anyone had this? Thanks

Edit: it does it in a straight line, so don't think it's the limited slip diff binding.

Edited by PhysDoc on Friday 20th May 19:56

Hi PhysDoc, I`m chasing a knock on the rear of my Chim 400. Yesterday I removed the exhaust, checked and greased the propshaft universal joints, I also checked the differential bolts. I greased the C/V joint a few months ago and now it all feels tight when turning the wheels. I`m going to drain and refill the diff with new oil and also having two new tyres. I would suggest checking your drivetrain for starters, then the diff retaining bolts, I`m sure others will reply soon with other thoughts, hope this helps.

[PhysDoc]

Hi,

Thanks for your reply.

Changing the diff oil this afternoon did nothing, so propshaft and CV joints next. Are the CV joints a standard item or from another vehicle, or am I committed to paying TVR tax? Racetech have them at £80 beer vouchers each exc. VAT.

[hillclimbmanic]

PhysDoc said:

Hi,

Thanks for your reply.

Changing the diff oil this afternoon did nothing, so propshaft and CV joints next. Are the CV joints a standard item or from another vehicle, or am I committed to paying TVR tax? Racetech have them at £80 beer vouchers each exc. VAT.

I paid £164 delivered, for all 4...they are cosworth items...EBay
108mm 28 splines...

[PhysDoc]

hillclimbmanic said:

I paid £164 delivered, for all 4...they are cosworth items...EBay
108mm 28 splines...

Ahhh, smashing, that's a great help. 164 sheets for all four is a much better price!

Thanks

[N7GTX]

I got mine from this company recommended by a Cerb owner. I opted for a stronger unit after speaking to the company.
If you are not blasting around/trackdays/hillclimbs then the standard items above on eBay from the Ford will probably be fine. Must be 108mm dia and 28 spline.

http://www.prolinx.biz/pages/Products/ViewCategory...

[PhysDoc]

CV joints arrived, and I intend to do them this weekend, although the more I think about it, the more I convince myself it's the diff that's expired. Anyway, I'll do the cheapest things first.

Quick question: I don't have any bearing pullers, are the joint an interference fit on the splines? Will I be able to beat them on and off with knackered socket and a hammer?

[N7GTX]

After removing the circlip they may be tight, very tight or slack. I did mine without any special tools and knocked the tight ones off with a nice 3lb hammer.
When fitting the new ones, ensure square and use a soft faced hammer, block of wood or a large impact type socket so as to prevent damage to the new parts.

[PhysDoc]

Got the CV joints done -- filthy job, but it seems to have cured the heavy banging/binding problem.

I'm not happy with the left-hand wheel bearing though. Are they standard size taper rollers (if so, what size), or are they best bought from racetech or similar?