inspecting a diff...

[mpbarrett]

spent the last few days doing lots of long overdue work on my Herald. I am planning to take it on the 10CR in September with my wife... so no pressure!

I have picked up a 3.63 diff for free. At the moment it has 2.89 diff and GT6 ratios in the OD gearbox. A  3.63 will make it a bit more relaxed on the motorways....
My plan was to trade in the 3.63 diff for a reconditioned one (£££) but I would quiet like to see if I can check the condition without putting it in the car. The previous owner said it was a noisy but it does not have too much backlash.
So I am after advice about what to look for inside the diff? Or should I just give up and pay the dosh and get it reconditioned?
BTW on a past 10CR run my GT6 (2.5L) broke its new reconditioned diff at the top of a French mountain pass so am slightly concerned about diffs and 10CR but at least the Herald does not have the torque of a 2.5L 6...

Mike

Past 6.63 broken diff...
 

and a nice steam train with grand children, Nene Valley railway.

[Nick Jones]

Big backlash tends to come from knackered thrust washers on the planet gears or worn cross pin. These just clonk and clank.

The whine is the gears not meshing properly either because they’ve been incorrectly set in the past, bearings are past their best or the gears themselves are worn.

If the gears are really shot it’s obvious enough, but even gears that look ok can make a noise.

You'll struggle to find an expert who’ll guarantee noise-free with used gears, but at least you’d be reasonably sure it was basically fit and less likely to fail catastrophically.

You could try contacting Paul Hughes at 2 Spec Transmissions (he’s a Triumph person) or if you can track Marcus (Bewdley) down, he can likely help you.

[Hamish]

I use Pete Cox for my 3a axle lsd and 4.1 upgrade. And gearbox / OD work. 
 

I'm sure he does most Triumph running gear  he is in the midlands but does courier stuff.

https://petecoxsportscars.co.uk