I pulled the 7mgte engine out of my Datsun 240z and now I am staring at my transmission. The bell housing bolts were not as easy to get to as I had hoped. Might be possible if you dropped the tranny down a bit, but otherwise super difficult, I had to use just a socket as a wrench wouldn’t grab and the ratchet would hit the firewall, and turn it by hand after I got it loose to get the bolts out.
My fear would be that I manage to get the engine together, put it in and have the transmission go bad soon after. Some say they have never had this happen, others say it will happen eventually. The benefit is that my car weighs about 1/2 as much as the supra so there should be less strain on the transmission. I kept my tires skinny so that they will also act as a relief. My concern is that when I got this transmission it had been behind built supra motors according to the previous owner, being drenched in oil I can only imagine what kind of life it has been through.
The transmission is an R154 from a toyota supra. They are known to be stout until they are not. There is a weakness in the oil delivery to a thrust washer causing that to give which then causes an excess clearance causing the actually gear to wear out. When this happens the car will start popping out of first and then gears will start wearing out. New gears if available are about $500 a piece.
My transmission currently does not have the issue of popping out of first gear. It shifts ok, although getting into reverse is a bit difficult sometimes.
Driftmotion does rebuilds including the upgraded weak parts (chromoly thrust washer, billet bearing retention plate), new forks, new bearings, new seals for $1200 total ($700 for parts, $500 for labor). Shipping to and from is probably going to run $200-250.
What would you do? Don’t fix it if it ain’t broke? Fix it because it will be a pain in the ass later? I am super on the fence here.