Rally car gearbox query

[swervygerdy 0]

Hi folks

 

Just wondering can someone help with a few gearbox related questions. I'm trying to determine what ratios I have and if I can improve anything. 

 

I've followed the forum advice and removed the diff cover. The final drive is 14x67. I then removed the 5th gear cover and counted 32 teeth.

 

Is that enough info to identify what the internals are from? 

[allanallen 528 2 Cars]

Well it’s a 4.785 FD which I think means it’s a Quaife crownwheel/pinion rather than a parts box Peugeot one.

Not sure on what 5th is, I’d personally get spinning and counting to see what’s in there, possibly a Quaife gear kit?! 

 

The FD suggests it’s been built with rallying in mind. 

 

This is quite a helpful tool to help you determine what’s in there

http://zoldalma.webzona.hu/gear.html

 

The Quaife gear ratios aren’t listed on there but you can get them off their site and input them yourself manually. 

 

Edited April 2, 2018 by allanallen

[petert 588]

Just a side issue. I threw my Quaife 4.785 in the bin recently. I bought it in 2007 from AB and all it's every done is race miles. So bugger all really. The case hardening on the pinion had worn through. AB stopped selling them because of that issue. Luckily he had a few spare Bacci cwp's that he brought to Aus with him. So just be careful if it's of that age.

[Biggles 65]

2 hours ago, allanallen said:

Not sure on what 5th is, I’d personally get spinning and counting to see what’s in there, possibly a Quaife gear kit?! 

 

Quaife 5th is 22/23 so it's not a Quaife gearset.  32 on 5th (from the info I have) suggests a std GTI 5th but my info is not complete so it could be something else.  That said, a 4.8 FD (or thereabouts) on a std GTI 'box is a popular rallying combination so I'd say that's a fair bet.  Sticking it in 1st and counting the revolutions should tell you whether it's a 1.6 or 1.9 (3.251 vs 2.923).

[swervygerdy 0]

This is all excellent info.

 

The car was indeed apparently  built by AB motorsport before I purchased it in early 09.

 

If I rember correctly, the ad mentioned a hybrid box consisting of 1st and 2nd from a 1.9 and 3rd 4th and 5th from a gti6 but this is the first time I've investigated.

 

Forgive my ignorance,but to determine the ratios....... put it first, spin the road wheels by hand and count the turns of the final drive?

 

There  was some metal swarf in the diff oil when I drained it but otherwise the box seems fine

 

 

[petert 588]

The GTi 1-2 and the GTI6 3-4,5 is certainly one of his specialties. It will also more than likely have a roller bearing on 1st gear. If so, you have a very nice gearbox. Is the casing finned?

[Biggles 65]

GTI-6 5th is 39/41 though (according to Servicebox) so that doesn't tie up with the 32 mentioned in the first post.

[swervygerdy 0]

Just to confirm, thus is the 5th gear cog?

[petert 588]

yes, are you sure it's not 33?

Edited April 3, 2018 by petert

[welshpug 1,657]

that and the one that turns it is also 5th.

[swervygerdy 0]

Further investigation tonight. Definitely 32 teeth on the 5th gear cog.

 

Also put the box in 1st gear, turned the engine by hand 6.75 turns for 1 full revolution of the pinion wheel. 

 

So 6.75 / 4.785 = 1.41 1st gear

 

Am I doing this right?

Edited April 8, 2018 by swervygerdy

[Biggles 65]

Were both wheels in the air ?  What sort of diff is fitted ?  I seem to have a vague recollection that if both wheels are in the air and a free or ATB diff is fitted then because the two wheels rotate in opposite directions, you have to double the figure you get - ie 1st is actually 2.82 - which within the limits of experimental error would likely make the 'box 1.9 GTI ratios with the 4.8 FD.  Or is all this a figment of my disordered brain ?

[swervygerdy 0]

Yes, both wheels in the air. Tranx plate diff fitted

 

Does this only affect 1st gear as the rest of the ratios do seem a bit more sensible?

 

2= 1.89

3= 1.71

4= 1.09

5= 0.88

 

Fd = 4.785

 

 

[Biggles 65]

Not that I'm aware.  Seems a bit odd as the figures for 2, 3, 4 & 5 are the numbers I've got for a GTI (again within the limits of experimental error - 37/20, 34/25, 31/29 & 32/37 - the options for first are 39/12 or 38/13, 1.6 or 1.9 respectively).

I'd hazard a guess at you having a 1.9 gearset.

[allanallen 528 2 Cars]

3rd gear looks very wrong! A gti has a 1.36 3rd 

[swervygerdy 0]

Tried 1st again. Actually 15.75 engines revs to 1 pinion gear. (Blame the navigator!)

 

15.75 / 4.785 = 3.291

 

Bit more like it

 

[petert 588]

Most likely a 3.25:1 1st gear then, from a 1.6L.

[swervygerdy 0]

Yeah, 1and 2 from a 1.6gti and 3,4 and 5 from a 1.9.

 

[swervygerdy 0]

Not wishing to start another thread, I've purchased a gearbox from eBay. It has a 4.9 cwp and I'm told a LSD. Could someone identify the make of differential? I can see no "makers mark" as such.

[swervygerdy 0]

[brumster 135 1 Cars]

Visually it looks identical to the Tran-X that I had in my car once upon a time. In particular, the profile of the diff, the 4 slots in the circumference. I would try giving Quaife (now own Tran-X) a call and ask them about the part number, they might be able to help. If they're not helpful, you could try 3J Driveline (who are ex-TranX) and they'd probably know.

 

But it looks like one. Having said that, I've never seen a Gripper up close and I think a lot of the diff manufacturers are just copying other's designs, so it might not be 100% conclusive

[allanallen 528 2 Cars]

I’d say Tran-x also

[Thijs_Rallye 87 4 Cars]

2 hours ago, brumster said:

Visually it looks identical to the Tran-X that I had in my car once upon a time. In particular, the profile of the diff, the 4 slots in the circumference. I would try giving Quaife (now own Tran-X) a call and ask them about the part number, they might be able to help. If they're not helpful, you could try 3J Driveline (who are ex-TranX) and they'd probably know.

 

But it looks like one. Having said that, I've never seen a Gripper up close and I think a lot of the diff manufacturers are just copying other's designs, so it might not be 100% conclusive 

3J = the actual TranX guys. They left and started 3J as soon as it was sold to Quaife.

 

This is a Gripper LSD.

[swervygerdy 0]

Ok, I'll make some call tomorrow. 

 

At least it's "as advertised" so far with the cwp ratio and a LSD of some sort.

 

Final question, am I right in saying this shifter mechanism is part of the "satchshift" kit?

[welshpug 1,657]

yep that arm is part of the satchshift kit.

 

do you have the matching pinion?