Input shaft woes

Author
Discussion

B19GRR

Original Poster:

1,980 posts

261 months

Wednesday 28th September 2005
quotequote all
Hi all,

As part of my bid for world domination, I need to change the gearbox in my 240Z. I was told by a well respected individual that I'd be able to use the BW T5 box from an early (84-86) Z31 300ZX Turbo and get a suitable bellhousing from the US 280ZX Turbo. Great, so I've got all those bits but now I'm left with a problem. The Z31 lay gear has 23 teeth where as the 280ZX only has 22. The Z31 shaft is also 6cm too long to even think about using:
[pic]http://www.equiview.co.uk/240z/input_shafts.jpg[/pic]
So I'm a bit stumped. I don't think a machine shop could work the Z31 shaft to length because it narrows down after the spline section. The only possible thing I can think would be to cut and shut the longer shaft, but that frankly sounds like a bad plan to me.

Any ideas oh knowledgeable ones?! Who's bright idea was it to make the shaft in one piece? I've invested a fair bot of time and effort in to getting to this stage and I really don't want to be screwed right at the last hurdle!

Cheers,
Rob

annodomini2

6,899 posts

256 months

Wednesday 28th September 2005
quotequote all
Just a thought, but can you not get the 23 tooth lay gear transfered onto the shorter input shaft (assuming they're not one piece, and equivalent size etc), local gearbox refurb place may be able to do it?

nel

4,793 posts

246 months

Wednesday 28th September 2005
quotequote all
I redckon that you're on the wrong forum matey - can you not contact the "respected individual" who gave the advice on compatability? Failing that specialist forums would almost be more use to you....

B19GRR

Original Poster:

1,980 posts

261 months

Wednesday 28th September 2005
quotequote all
annodomini2 said:
Just a thought, but can you not get the 23 tooth lay gear transfered onto the shorter input shaft (assuming they're not one piece, and equivalent size etc), local gearbox refurb place may be able to do it?


Yup, shaft and gear are all one piece. Had the box down at the local tranny guy today, whose first words were (to the effect of) "If the gears are different, you're screwed." Mutterings about changing the enture layshaft etc. did not appeal to me, has to be said.

nel said:
I redckon that you're on the wrong forum matey - can you not contact the "respected individual" who gave the advice on compatability? Failing that specialist forums would almost be more use to you....


Will do when I get a chance. Any ideas for more specialist forums than the mighty PH?

Cheers,
Rob

MR2Mike

20,143 posts

260 months

Wednesday 28th September 2005
quotequote all
nel said:
I redckon that you're on the wrong forum matey - can you not contact the "respected individual" who gave the advice on compatability? Failing that specialist forums would almost be more use to you....


This is the engines and drivetrain forurm isn't it? Looks correct to me...

There is a possible solution, but I don't know the cost or suitability for this aplication...

I have seen gears on once piece shafts like this fixed by grinding the old gear off, and pressing a custom made one in its place...which in this case would be made from the long input shaft gear. Possibly the parts could be splined together for strength.

nel

4,793 posts

246 months

Wednesday 28th September 2005
quotequote all
B19GRR said:

Any ideas for more specialist forums than the mighty PH?



first link I got from google was this one - www.classiczcars.com/modules.php?name=Jig

No doubt there are loads more out there if you hunt down the links. You'll find someone who's already done this before....

Best of luck

B19GRR

Original Poster:

1,980 posts

261 months

Wednesday 28th September 2005
quotequote all
MR2Mike said:
I have seen gears on once piece shafts like this fixed by grinding the old gear off, and pressing a custom made one in its place...which in this case would be made from the long input shaft gear. Possibly the parts could be splined together for strength.


I've been staring at them and have wondered if that would be a possibility, either splined or keyed, or welded. Would be good to find someplace that's done that wort of work though.

nel said:
first link I got from google was this one - www.classiczcars.com/modules.php?name=Jig

No doubt there are loads more out there if you hunt down the links. You'll find someone who's already done this before....


Ah, I thought you meant transmission specialist forums (rare to non-existant) rather than Z. I do believe I'm actually the first person to attempt the swap with the Z31 box though, all the Yankees would just used the box straight from the 280ZX Turbo which is a bolt on and drive swap. I shall go have a word with the tech gurus on hybridz.org, those ClassicZcar boys would faint at the idea of a non-original gearbox

Cheers,
Rob

nel

4,793 posts

246 months

Wednesday 28th September 2005
quotequote all
One feasible solution would be to machine a new splined section onto the Z31 input shaft. This would require that the existing splined section is ground flat then the shaft diameter could be built up where necessary using a few consecutive layers of weld applied by an automated welding jig used for shaft repair (normally submerged arc I seem to recall).

This would then give you enough meat so that the splined section and the end of the shaft could then be remachined in the appropriate location. Obviously this would not be a cheap solution but it is technically feasible if you can find the right engineering shop.

All the best.

stevieturbo

17,453 posts

252 months

Wednesday 28th September 2005
quotequote all
Have you tried contacting any of the BW gearbox people in the US ?

www.fortesparts.com/tremec.html
www.ddperformance.com/
www.g-forcetransmissions.com/tran_gt-5.asp

G-force offer uprated gearsets....perhaps they have lots of old parts lying about ?

www.5speedtransmissions.com/tr-3550.html

These guys do a lot of conversions. Perhaps a conversion suitable for a big V8, might offer something. Even if it means getting a new clutch plate to suit the box they reccomend ?
www.jagsthatrun.com/

kevinday

12,008 posts

285 months

Thursday 29th September 2005
quotequote all
Rob,

When I used to run a 265bhp 240Z gearboxes were an issue, I broke several! There were a variety of different gearboxes in use, some were stronger than others.

For advice I suggest you talk to Mike Feeney (if he is still around). Mike used to drag race Zs of varying descriptions and ran the Z club spare parts department. I have not seen or spoken to Mike in about 10 years but he used to live in Essex. Try the Z club for contact details.

B19GRR

Original Poster:

1,980 posts

261 months

Thursday 29th September 2005
quotequote all
Hi Kevin,

Mike is still very much around and active in the Z Club, he's a very 'respected individual'

Cheers,
Rob
Z Club member 151 (no I'm not that old, they just recycle the numbers!)

kevinday

12,008 posts

285 months

Friday 30th September 2005
quotequote all
Good to hear Mike is still around, I had Zs from 1983 to 1997, started with a 260Z 2 steater with uprated brakes and Spike Anderson uprated engine (about 205 bhp, then had a 240 Samuri (as on my profile) and finished with a 280Z 2 seater.

Good luck with your gearbox problems

350matt

3,752 posts

284 months

Friday 30th September 2005
quotequote all
how about changing the clutch centre plate to one with the required spline?

You can even get clutch plates custom made - just ask your local clutch re-lining place


Matt

nel

4,793 posts

246 months

Friday 30th September 2005
quotequote all
350matt said:
how about changing the clutch centre plate to one with the required spline?

You can even get clutch plates custom made - just ask your local clutch re-lining place


Matt


I also thought of that but didn't 'say' it because I suspect (but am not sure!) that the lay gear is the bit in the gearbox at the other end of the shaft rather than the splined section.

B19GRR

Original Poster:

1,980 posts

261 months

Friday 30th September 2005
quotequote all
Well I'm running out of options with this box at the moment. I'm going to see a guy this weekend (hopefully) who's got a T5 from a Chimaera so that I can check the input shaft on that. If it looks like a World Class T5 input can fit in to a Non World Class box then I think I can get a Ford shaft with a 23T lay gear and either have that modified to the Nissan 1" diameter 24 spline clutch or get a custom clutch plate.

If the WC shaft won't fit, then it's back to the drawing board

Cheers,
Rob

B19GRR

Original Poster:

1,980 posts

261 months

Saturday 1st October 2005
quotequote all
Back to the drawing board I go then. The synchro/baulk ring was a different size on the Chimeara T5 shaft so that ideas a no go.

Ho hum

Cheers,
Rob

falcemob

8,248 posts

241 months

Saturday 1st October 2005
quotequote all
Change the clutch........

B19GRR

Original Poster:

1,980 posts

261 months

Saturday 1st October 2005
quotequote all
falcemob said:
Change the clutch........


Erm, that's not going to magically make a shaft that's 6cm too long the right length is it?

Cheers,
Rob

stevieturbo

17,453 posts

252 months

Sunday 2nd October 2005
quotequote all
What about www.gearboxman.co.uk

Cant any of the gearbox people help ?

B19GRR

Original Poster:

1,980 posts

261 months

Sunday 2nd October 2005
quotequote all
stevieturbo said:
What about www.gearboxman.co.uk

Cant any of the gearbox people help ?


I'm waiting for replies from gearboxman and various American places, bit of a twiddle thumbs experience.

I'd be happy with any shaft of the right length that will fit, as Matt said I could then get a custom clutch plate to fit.

Cheers,
Rob