We're trying to swap transmissions in my son's '88 RX7. All the bolts are out and the bottom part of the tranny has a good 1/2" gap from the engine, but the top is stuck tight yet. It seems to be at the place where there's just a NUT - in the center top of the transmission. Does the bolt also have to come out? I've searched the forums and found opinions for yes and no. Some even say when putting the transmission back in that the bolt needs to be installed first. I'm confused and am not sure what to do. Just keep wiggling the tranny and pulling away from the engine?

Here's a picture of the bolt, but it's not a very good one. Not much room there.
Looking at the end of the bolt, it's split, like there's room for a screwdriver to adjust it. I can't figure out why that's there.




Thanks.

 

if there is a gap at the bottom, but none at the top, its probably not coming out because its too misaligned. i bet if you tilted the engine forward, or supported the back of the oil pan, the trans would fall right out

 

Thanks. You were right on. It came out very easy once we lifted the front of the engine a bit.

Looking at the replacement tranny, it's a little different in appearance than the one that was in the car. When he bought the car, he knew the tranny was grinding in some of the gears, and this spare tranny came with the car. After getting the original out and comparing them, will they be compatible?

I looked for any numbers on them to compare and only find a sticker on each one.
The original tranny: H010694
The replacement tranny: C00972

The reverse or whatever switches are mounted in a different place (though the wiring looks the same). There is an extra spring/clip type thing in the shifter mount area of the replacement tranny that is not there in the original.

It looks like the spare has been taken apart before - RTV on the seams.

Any suggestions? Just rebuild the original, not knowing the condition of the spare? Is there any way to thoroughly test the transmission while it's out of the car?

 

It looks like we broke the spring in the shifter mount area - and it's missing in the original transmission. I guess that'll have to be fixed if we end up using that one again.

I think we'll go ahead and put the replacement in and see what we end up with.

Looking online, I think they're compatible.

 

We can't get the transmission up to the engine, so I thought we could put the driveshaft in to turn the splines to see if they'll match up...The driveshaft won't fit on the replacement transmission.

The transmissions are different - at least the output shaft diameter. The old one is about 24.1mm and the replacement transmission is about 27.2mm.

Now what? Different driveshaft? Fix the old transmission? Get a rebuilt?

I'm wondering if the transmission is from a Turbo car. Then, would an aftermarket turbo differential from Mazdatrix work - and bolt up to the non-turbo differential?

 

the trans on the left is a turbo, and the right is a non turbo. they take different flywheel/clutch/starter/driveshafts, but otherwise bolt right in

 

Your best bet will be to sell the turbo transmission and purchase a non turbo one.
Replacing clutch parts is suggested while you have the transmission out, if needed.

 

yeah. we couldn't get the replacement transmission in. The input shaft diameter is different too. 23.7mm for the original, 26mm for the replacement.

I guess, a different N/A transmission would be the cheapest way to go.

Or, is the turbo tranny a desirable one to switch to and then get new clutch/differential/whatever is needed? Money is a concern, however.

 

the turbo trans is desireable trans, its stronger, MUCH stronger than the N/A

if your not worried about power, sell the turbo trans, you can buy almost 3 n/a trans for the price of 1 turbo trans, i've seen them sell for $300 used, and n/a go for under $100 usually on THIS community. junkyards don't care, a trans is a trans to them

 

I might pick that turbo tranny up from you. I already have an S5... but... can never horde enough. Local, btw. And no, I will not pay $300 for it in unknown condition.

 

OK archaphil - PM me and we'll see if we can figure out something.

 

Shifter Spring part # is M501-17-465
Did change it with all the bushings while I was at it

Both together cost you ca 30$

 

Replacing the N/A trannie with another N/A trannie is by far easier. The entire turbo drive train is different from flywheel to rear end.

 

We did put a different tranny in. Bought one off of a local guy. It went in in 10 minutes. Easy swap once you get the correct tranny that actually fits.