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Gearboxes

PostPosted: Sun May 10, 2020 5:25 pm
by sclemow
Hi
I am just rebuilding my gearbox and have found a small chip in 3rd gear. I was wondering if anyone has a part set of close ratio helical gears and would be prepared to sell 3rd gear?
Also, another couple of questions.
Mine has an aluminium tail housing - were they cast originally?
How do I tell between early and late baulk rings?
And finally I have an original aluminium bellhousing for a rocket box, but would ideally like one for my 2000e box with hydraulic slave cylinder. Does anyone have one?

Re: Gearboxes

PostPosted: Sun May 10, 2020 5:53 pm
by Craven
Let us know the number of teeth on that gear.

Re: Gearboxes

PostPosted: Sun May 10, 2020 6:25 pm
by sclemow
Hi
Thanks for the reply. It's 24 teeth.
Cheers
Simon

Re: Gearboxes

PostPosted: Mon May 11, 2020 4:16 pm
by elangtv2000
Standard tail housings were cast iron.

Early synchro rings have 3 cutouts around the perimeter, while later rings have recesses cut into the perimeter. Lots of photos of each type available online.

Just how big is the chip? Photo?

Re: Gearboxes

PostPosted: Mon May 11, 2020 7:57 pm
by promotor
sclemow wrote:Hi
Thanks for the reply. It's 24 teeth.
Cheers
Simon


If your tooth count is correct that 3rd gear is for a close ratio gearbox ie 2.5:1 1st gear rather than a 23 tooth 3rd gear for a semi-close ratio 'box (2.97:1 1st). The close ratio gear sets are quite hard to find - that may or may not work in your favour if someone else has been trying to find other gears for a 2.5 'box and has failed to complete the set.

I can't help you with a 24 tooth unfortunately. Best of luck in your search.

Re: Gearboxes

PostPosted: Wed May 13, 2020 9:52 pm
by sclemow
4634426B-2F0A-42F3-BC4D-3E77C7F66B87.jpeg and


It’s not easy to get a photo, but here it is.

Re: Gearboxes

PostPosted: Wed May 13, 2020 9:57 pm
by sclemow
promotor wrote:
sclemow wrote:Hi
Thanks for the reply. It's 24 teeth.
Cheers
Simon


If your tooth count is correct that 3rd gear is for a close ratio gearbox ie 2.5:1 1st gear rather than a 23 tooth 3rd gear for a semi-close ratio 'box (2.97:1 1st). The close ratio gear sets are quite hard to find - that may or may not work in your favour if someone else has been trying to find other gears for a 2.5 'box and has failed to complete the set.

I can't help you with a 24 tooth unfortunately. Best of luck in your search.


Hi
Thanks, it is a close ratio set, I worked through the ratios and confirmed it.
Thanks
Simon

Re: Gearboxes

PostPosted: Wed May 13, 2020 10:49 pm
by Craven
You could try Redline [email protected]
They did have some C/R gears at one time, I bought a couple of 2nd gears from them way back. 27 teeth not to be confused with 27 teeth of the 2000E gear. Tricky those C/R boxes.

Re: Gearboxes

PostPosted: Wed May 13, 2020 10:50 pm
by vstibbard
TTR seem to selling individual ratio's for CR boxes, not sure if they are helical or straight cut, still maybe worth a call.
V

Re: Gearboxes

PostPosted: Thu May 14, 2020 7:40 am
by promotor
sclemow wrote:
promotor wrote:
sclemow wrote:Hi
Thanks for the reply. It's 24 teeth.
Cheers
Simon


If your tooth count is correct that 3rd gear is for a close ratio gearbox ie 2.5:1 1st gear rather than a 23 tooth 3rd gear for a semi-close ratio 'box (2.97:1 1st). The close ratio gear sets are quite hard to find - that may or may not work in your favour if someone else has been trying to find other gears for a 2.5 'box and has failed to complete the set.

I can't help you with a 24 tooth unfortunately. Best of luck in your search.


Hi
Thanks, it is a close ratio set, I worked through the ratios and confirmed it.
Thanks
Simon


Is that the chip in the photo at the end of the tooth and nearest to the dogs on 3rd? If so, it doesn't look too bad, and is not on the drive side of the tooth.
Ideally it would be good to change it if the gearbox was noisy, but if not then maybe it'll be OK to go back if you struggle to find a replacement. You might be able to dress it back with a stone and then a very light polish of the edges.
Was the gearbox noisy?

Re: Gearboxes

PostPosted: Thu May 14, 2020 7:48 am
by nmauduit
I'd be interested in other opinions, but considering the small size of the missing bit (half thickness triangle at the end?) I would be tempted to smooth the broken ridge with a stone and reuse it if the alternative are too scarce or worn... is there signs of heavy wear on the mactching gear?

what would gearbox expert think ?

---- just realized Promotor replied to my questioning (while I was typing I guess)...

Re: Gearboxes

PostPosted: Thu May 14, 2020 12:31 pm
by sclemow
promotor wrote:
sclemow wrote:
Is that the chip in the photo at the end of the tooth and nearest to the dogs on 3rd? If so, it doesn't look too bad, and is not on the drive side of the tooth.
Ideally it would be good to change it if the gearbox was noisy, but if not then maybe it'll be OK to go back if you struggle to find a replacement. You might be able to dress it back with a stone and then a very light polish of the edges.
Was the gearbox noisy?


Unfortunately I don't know if it was noisy. The car was not driveable when I bought it. Generally I wouldn't put a gearbox back together with chipped teeth, but it sounds like I might have to reevaluate that in this case given the difficulty in finding them.

Re: Gearboxes

PostPosted: Thu May 14, 2020 1:16 pm
by elangtv2000
I'm not a gearbox expert, but I've rebuilt 6 of these, and I would agree with Promotor's suggestions to stone/polish if you can't find a gear. I'm the sort who also doesn't like to use a chipped gear, but if the damage is slight and can be mitigated, and a replacement is not available or way too expensive, I'd give this a try.

Re: Gearboxes

PostPosted: Thu May 14, 2020 3:03 pm
by h20hamelan
I have used eutectic before

https://www.castolin.com/en-CA

Edit, I should be more specific. They sell a kit, some places rent them. It’s like powder coating.

Re: Gearboxes

PostPosted: Thu May 14, 2020 4:50 pm
by nmauduit
h20hamelan wrote:I have used eutectic before

https://www.castolin.com/en-CA

Edit, I should be more specific. They sell a kit, some places rent them. It’s like powder coating.


on a worn bearing maybe, but I would not try it on the tooth of a car gearbox...