Does the trans case have external ribs on it, or is it a smooth case?
This will at least rule in, or out, the 56 series box.

Dodgeman, whatever happened to all that fast stuff at the end of your posts?

Update, after degreasing the whole tranny the only number i can find was 10421 0763. I have also noticed that the drive shaft seems to have been rewelded at some point, mabe shortend?

it sounds like a carrier bearing has collaped. stirp your box and if your lucky it may not of damaged the gears if this is the case new bearings will sort it out

Thnx for the offer and info so far guys, im goin to have a friend look at it and make sure that the box is the major problem. Thnx for all your help so far, im loosing sleep over this =(

Hi subwoffers,

I had the same thing happen to me. Sounds like 2nd gear is catching, going out of gear, catching. I broke two gearboxes this way.

The stock Datsun 1000/1200 4-speed is not strong enough to last behind an A15. For an A15-powered car, do what Datsun did: use the stronger A14 gearbox from a 75-78 B210 or 79-82 B310. You can use either a 4-speed or 5-speed. They are common at the wreckers down here in Seattle. If you need help getting one, let me know.

Quote:To repeat myself from my first post.

What gearbox is in it now?

The 1200 gearbox can be used to replace or repair an original 1000 one. Both are 56 series gearboxes.

The 56A gearbox from A12 powered B210 & B310 models can also be used as replacements. Some of the internals are different from the earlier 56 box, so these may not be suitable as a parts source for the earlier model.
Any of these will be ok behind an A15 as long as you don't abuse it.

Cars that came with A14 & A15 engines usually used a 60 series gearbox. If this is what you have now, then a replacement shouldn't be too hard to source.

If the fitting of a 60 series gearbox is an upgrade on the existing box, then you will need to fabricate a new rear gearbox crossmember as it is located further back than the original & you may need to adjust the tunnel shape.
Many of these in North America came as an overdrive five speed in either dogleg or regular shift pattern. The existing tailshaft would still be useable with either of these gearboxes.
These will take more punishment, but are not bulletproof.

The 63 series box can be found in some North American B210 models, & to fit one will take some tunnel work as they are the biggest, strongest & heaviest of the factory gearboxes for the A series engine, & for most people, completely un-necessary.

i had a prob like that with my celica box. the problem was it was out of oil. check the oil in it and top it up then take it for a rap around the block. see if that work. i hope this will help you.

The problem is there is no such thing as finding a replacment for cheap where im. Canada Bc, Richmond. Trannys are scarce. If a stuffed tranny is the case, what trannys can be swaped into this A15, the engine before was an A10

Could it be possible that you have stripped the mainshaft? If you can get another box for not too much i would replace it. that box sounds stuffed.