Gear wear: replacement or not?

Technical advice Q&A

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Philippe-J.
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#1 Gear wear: replacement or not?

Post by Philippe-J. » Thu Aug 21, 2025 11:37 am

I need your opinion & advise about the condition of my reverse gear, on main shaft, of my gearbox.
As can be seen on the photo for 2 of 3 of them, some teeth are slightly nibbled:

Image
Would you guys advise to change or can I live with it? (before I close and reinstall the gearbox+engine in :bigrin: )

Thanks
Philippe-J

1967 S1(.25) OTS ... coming together
https://renov-ots-1967.over-blog.com/

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mgcjag
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#2 Re: Gear wear: replacement or not?

Post by mgcjag » Thu Aug 21, 2025 12:08 pm

I'm no gearbox expert....but if something is worn a replacement would be better....but are they available?...Steve
Steve
69 S2 2+2 (sold) ..Realm C type replica, 1960 xk150fhc

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lowact
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#3 Re: Gear wear: replacement or not?

Post by lowact » Thu Aug 21, 2025 12:16 pm

Are a couple of the teeth chipped with sharpish edges? If so I'd lightly grind these a bit smoother and happily live with the result for another 50 years ...
Regards,
ColinL
'72 OTS manual V12

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Philippe-J.
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#4 Re: Gear wear: replacement or not?

Post by Philippe-J. » Thu Aug 21, 2025 12:34 pm

Steve: a quick look at the usual's catalogues shows that the answer looks like negative. Ebay propose some used parts, but what about their condition?
Colin: all edges are sharp. I was considering loading those decays with my MIG, then grind them to shape. How about that? Maybe overkill? :doh:
Philippe-J

1967 S1(.25) OTS ... coming together
https://renov-ots-1967.over-blog.com/

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40GT
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#5 Re: Gear wear: replacement or not?

Post by 40GT » Thu Aug 21, 2025 1:03 pm

Don't go near them with a welder, you'll destroy the heat treatment. I would just live with them, unless you do a lot of miles in reverse.
Sean

S1 2+2 1966 BW RHD
XK120 1954 comp LHD

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Philippe-J.
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#6 Re: Gear wear: replacement or not?

Post by Philippe-J. » Thu Aug 21, 2025 1:19 pm

Thank you for the advice Sean (not to drive too long in reverse, that is :smile: )
Philippe-J

1967 S1(.25) OTS ... coming together
https://renov-ots-1967.over-blog.com/

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Gfhug
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#7 Re: Gear wear: replacement or not?

Post by Gfhug » Thu Aug 21, 2025 2:25 pm

Always carry a passenger to push you back? :bigrin:
S2 FHC Light Blue
S2 OTS LHD - RHD full restoration

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Series1 Stu
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#8 Re: Gear wear: replacement or not?

Post by Series1 Stu » Thu Aug 21, 2025 5:02 pm

As per Colin's advice.

Get a carborundum stone and gently remove any sharp edges and radius off any crevices that could potentially lead to cracks forming but be careful not to remove too much material. It might also be worth doing a dye penetration test to look for any cracks that might not be visible to the naked eye. If there are any cracks then try to find a replacement.

You have the gear on the bench, you might as well do everything you can to prevent a failure in the future.

Regards
Stuart

If you can't make it work, make it complicated!

'62 FHC - Nearing completion
'69 Daimler 420 Sovereign
'93 Jaguar X300 XJR basket case
'93 Audi 80 quatrro Sport

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abowie
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#9 Re: Gear wear: replacement or not?

Post by abowie » Fri Aug 22, 2025 12:19 am

I imagine all reverse gears look like that.
Andrew.
881824, 1E21538. 889457. 1961 4.3l Mk2. 1975 XJS. 1962 MGB. 1979 MGB.
http://www.projectetype.com/index.php/the-blog.html
Adelaide, Australia

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mtnjag
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#10 Re: Gear wear: replacement or not?

Post by mtnjag » Sat Aug 23, 2025 3:42 pm

Was it a problem when you were using the trans in the car?
Layne
Car #876005, 62 OTS

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