Anybody ever done this swap? 82 RX7 12a to 91 13b and tranny, wondering what you did with the driveshaft. I have the yoke for the 13b tranny is it possible to shorten the stock driveshaft and have the 13b yoke put on without any complications if I were to take it to a driveshaft shop?
Thanks in advance

 

send 82transam a pm regarding this. he has done this personally

 

Mine was actually made new (although i got it used from someone on here), but if the FC and FB driveshaft are the same diameter (I'm not sure that they are as I've never actually seen a T2 driveshaft in person) then I don't see why you couldn't have the T2 yoke welded on there. The whole thing is only a hair shorter than a stock FB shaft.
Any competent driveshaft shop should be able to help you out

 

Ohh yours was made new? I could have an issue then because the diameter of the driveshafts are different. Guess I'll have to wait for the funds and get a new one made

 

Ah yeah if the diameter is different then that won't work. I forget how much I paid exactly (again, bought it used) but expect to pay somewhere in the $300-350 range, more if you want aluminum (mine is just steel)

 

Not true. A good driveline shop can combine different diameter drivelines.

Put the yoke in the trans until it stops, pull it out 3/4"-1". Bolt the stock driveline to the diff. Load the suspension. Measure from u-joint center on the companion flange, to the u-joint center on the trans yoke. Take the yoke, companion flange, and measurement to the driveline shop. They will make you a driveline with new u-joints, balanced for about $180. Best money spent and no headaches about putting u-joints in with the nylon retention.

 

^Really? That's good to know. I'd be interested to see how they make it all work with different diameters. I agree, that is money well spent.

 

I put a 327 Corevette early Fuel Injection motor with a TKO transmission in an Arnault Bristol and the customer had a Dodge pickup rear end. I forget the name of the shop but they were big in Portland, Or literally just put one tube inside the other and ran a bead. They were able to balance it all out. Never had any vibrations. I thought it was hokey too, but they said it's common practice when gender bender u-joints are unavailable or the two ends are too different to weld the tube to.

 

Thanks for all the replies guys. Took it down to the driveshaft place yesterday. Said we'll have to ship it out of town for balancing since his machine apparently can't balance these driveshafts. He said its a tougher job than usual but now that I've read in here I'm thinking he's just tying to get more money out of me cuz lets face it, 20 year old walking in, all this guy sees is $$$$$$$. If he tries rippin me off I'll be taking it to another place

 

Nothing special about RX-7 driveshafts or the custom unit you need made. Any shop should be able to make and balance it. Mine was made from off-the-shelf Ford parts the driveline sourced from their inventory.A couple hundred bucks and I had a strong,greasable, rebuildable unit thats held up fine for over 10 years.

 

you can also call up mazdatrix and theyll make ya one as well i just called them yesterday about doin it since im in the same boat as you lol

 

I had this done recently due to converting my 82 RX7 12a auto to a manual using a TII tranny. I had the yoke for the TII tranny, took that with my factory auto driveshaft and careful measurements and they worked their magic (inc balancing) all for just $137 Aussie dollars. Done in 3 hours.

Easy!!

 

If the driveshaft shop can't do the complete job (welding and balancing), find another shop.

 

Got er done at a local driveshaft shop. $500CAD later she fit like a dream. Hopefully it'll hold up when the car starts