10 replies to this topic

[tb205gti]

I'm building a new engine for my Innocenti, but the gearbox on the engine is shot. I have a very solid gearbox from an A 998 that Iød like to use - but will it fit the A+ 1275 engine?

Don't worry about the gearing, I'll swap the diff for one that suits the engine better.

[Spider]

If the 998 gearbox is a Rod Shift type, then no worries, but you will need a 1275 Primary Gear to suit the drop gears from the 998 Box.

 

If it's a remote type shifter, there are a few that fit the 1275 engines, but not all.

[tb205gti]

Yes it is a rod change. The primary gear, the one in the gearbox? So I'll take that from my 1275 gearbox and for it to the 998?

[xrocketengineer]

The primary gear on the crankshaft must fit the 1275 (the 998 will not fit) and also mesh with the idler. There are A+ primary gears and pre A+ for the 1275 and 998. 

Edited by xrocketengineer, 05 April 2018 - 10:09 PM.

[Spider]

The primary gear on the crankshaft must fit the 1275 (the 998 will not fit) and also mesh with the idler. There are A+ primary gears and pre A+ for the 1275 and 998. 

 

Just to (hopefully!!) help a bit here, all pre-A+ Primary Gears have 24 teeth and the A+ types will have either 29, 30 or 31 teeth.

[nicklouse]

dont forget the transfer case needs to match the gearbox.

[whistler]

Yes.

Edited by whistler, 06 April 2018 - 10:45 AM.

[tb205gti]

dont forget the transfer case needs to match the gearbox.

 

Hmm - how can I make sure it does? Is this down to specific castings, or are there differences between the A 998 and the A+ 1275?

[tb205gti]

The primary gear on the crankshaft must fit the 1275 (the 998 will not fit) and also mesh with the idler. There are A+ primary gears and pre A+ for the 1275 and 998. 

 

So I'll just reuse the primary gear and the drop gears from the 1275?

[nicklouse]

dont forget the transfer case needs to match the gearbox.

 
Hmm - how can I make sure it does? Is this down to specific castings, or are there differences between the A 998 and the A+ 1275?

earlier gearboxes have a smaller shaft on the idler gear. so just make sure that you use the right one. also make sure the drop gear set will fit the box.

[MrBounce]

Also the 1275 Transfer Housings have a breather hole, whereas the 998 does not. Easy to amend, but still a pain if you need to do it...