71A Gearbox Parts

[Mgdatsun]

The attached photo shows the worn gear I would like to replace in a FS5C71A gearbox I am rebuilding. The previous owner mentioned that it would pop out of 5th gear, so maybe a synchroniser for 5th is needed also. Thanks for your correspondence dat2Kman if you have these parts available.  

[C.A.R.]

I wouldn't bother replacing that reverse idler gear unless it has some massive chips running along the length of the teeth.
Finding a replacement in better condition will be a challenge. If you want to tidy it up, I'd just run over the burred edges with a diamond file.

Popping out of 5th is the result of the steel bulk ring being worn & not having enough preload to 'lock'  the coupling sleeve onto the gear, which makes it pop out of 5th.
The Porsche style bulk rings are NLA, so you'll have to find a good second hand replacement.

Edited June 19, 2016 by Lurch ™

[dat2kman]

Keep reminding me, i'll get back into the shed for more clearing up sometime this week.

I know I have two wood crates f dismantled 71A boxes.

[Mgdatsun]

PM sent to dat2kman

[Howdy]

Like Lurch said re reverse idler gear, most look like that. A common reason for the early boxes to jump out of 5th is the big nut on the main shaft comes loose, might be worth checking.

[Mgdatsun]

Thanks for the advice on 5th gear, I will check out main shaft nut. My reverse idler has a complete tooth missing, was working fine but seeing I had gearbox apart thought I would try and find a better one.

 

Regards

Stuart 

[Howdy]

Owch, must have tried a RonnieRollback in reverse.

[dat2kman]

Surprisingly the one on the left still holds reverse gear, as the baulk ring was in good condition, and selector fork had been spray welded and reshaped/filed to original factory thickness.

 

The picture is upside down?

Edited July 23, 2016 by dat2kman

[Mgdatsun]

PM sent dat2kman

[Mgdatsun]

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