4 Speed box parts

CG McD

Member
Hello all, our mechanic has our 1973, P6B 3500S G/box in pieces and asks me to look for the following parts.
(He's an ace Triumph car and general mechanic)
Input Shaft
Spigot bush
one Syncho ring

The gearbox has some years ago with previous owner been refurbished, so bearings and gears are all good.
He did send me some stamped numbers from the box 48112989 B & another that is abit hard to read

Any help? We are in New Zealand, If need be we could get bush made etc, but would need accurate measurements I guess.
 
They're really hard to find, even in the UK, which is why people try to convert them

In NZ, they tended to fit 5-speed Supra boxes, at least back in the 90s when I lived there
 
Spigot bush, as in goes in the crank? If real thing (549911) is unobtainable, start with an SD1/LT77 bush and bore it out to 5/8". Its listed by lrdirect and all4x4.com.au as that number. the synchro (571936) is the same number as in the 4 cylinder boxes....? One listed here Gearbox parts & spares | Shop4Autoparts
at GBP34, but others appear at over $500! Primary pinion might be made of unobtainium, different number from 4cyl box. I just converted my 74 s to an LT77 , so I have a 4speed sitting around gathering dust. Needs layshaft bearings, based on noise in 1st and 2nd, poor selection.
If the bearings and gears are ok, whats gone wrong with the input pinion? They are commonly ruined by being run dry, or with failed layshaft bearings. I have a spare LT77 (25A, whatever thats from?) that needs attention, but having trouble finding somebody in Melbourne to look at it - most people will only look at 4x4 LT77s.
 
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Thanks, we are getting closer, I have the spares, now, , turns out the bronze spigot was replaced with a steel ring (of lesser width as well), so that was the cause of the woes. Have correct spigot, new input shaft and other parts to fit, and mechanic is onto it this week.
 
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