TR4/4A TR4 / late TR3A Starter Pinion

[Geo Hahn]

How many teeth are on the pinion on a post-50K TR3A or TR4 starter?

I'm thinking it's 9 or 10.

Casually looking at my 'spare' I see it has 10 and I get the sinking feeling that it is really for a MGTD or such. At least it has the castellated nut on the end that makes a pinion swap fairly simple. Thanks!

 

[TR3driver]

10 is correct. The pre-50K starter had 9.

Your spare might still be for a MGTD, but at least it has the right number of teeth.

 

[Geo Hahn]

Good grief -- no wonder they advise against using the pre-50K starter on a post-50K flywheel. I thought it was just the direction of the bevels.

Nevertheless, that is what I have been doing for the past 30 years (some PO swapped in a late engine but kept the original gearbox so no room for the late starter). Yes, I could get a hi-torque that would be correct and fit but I just enjoy the mystery of it all.

 

[TR3driver]

Wow, I'm surprised it works for you. A local friend had the same situation without knowing it; and I wound up helping him figure out why the starter was turning but the engine wasn't. It worked the first 30 or 40 times, but eventually started slipping.

That was with a gear drive starter though, so maybe the extra torque was part of the problem.

I assume you realize that the early flywheel will fit a late engine, no problem. Let me know if you are interested, I've got several of them weighing down the ceiling joists in the garage.

 

[Geo Hahn]

Thanks for the flywheel offer, I'll keep it in mind. I've been waiting for the clutch or gearbox to have to come out for something else to do something about this mismatch. I don't mind waiting.