TR4/4A TR3 and TR4a flywheels interchangeable?

[tdskip]

I thought there are some slight differences but can they be swapped? Would it require a different starter if you did put a TR3 flywheel into a TR4a application?

Thanks!

 

[TR4nut]

The TR3 flywheel is set up for the fingered clutch, which I think is larger and heavier than the diaphram clutch on the 4A - so you may need to redrill for the pressure plate depending on which you use. Also, if it is an early TR3 with a press in ring gear I think that is for the early bomb starter and that would be more of a problem as it is incompatible with the 4A starter. Later TR3A and TR4s have the bolt on ring gear which would be compatible.

 

[tdskip]

Thanks Randy!

 

[TR3driver]

The gear-drive starters make an easy way to mix-n-match flywheels, as they will work with any exhaust and any gearbox. A local friend of mine even took his starter back to the vendor and got it converted to the other flywheel type.

Should be no problem using the TR3/4 'finger' clutch in a 4A, but be sure to change the throw-out bearing to match. The TR3/4 clutch takes a flat face bearing instead of the rounded face used with the 4A clutch. ISTR the bearing carrier is different as well, but I could be mistaken on that point.

 

[PeterK]

also ... The input shaft cover on the gearbox for the finger type clutch setup from a 3 is a different length (longer ISTR) than the 4A diaphram clutch cover. Also the bolt circle for clutch mounting is different between the 3 and 4A(same as the TR6).

 

[TR3driver]

The input shaft cover on the gearbox for the finger type clutch setup from a 3 is a different length (longer ISTR) than the 4A diaphram clutch cover.

That is correct, although curiously enough the factory did not change the part number.

However, the shorter cover works OK with the early clutch; and you can just hacksaw off the end to make the early cover work with the later clutch.