Fizzpop

Hey guys I am currently in the process of doing an Automatic to Manual Swap on my 82 rx7. I am swapping in all of the manual parts from an 83 rx7 and I have run into an issue with the driveshaft. The manual driveshaft I have from the 83 is the right length but the flange at the differential end does not match with the bolt holes on the differential. What I planned on doing was taking the flange off the 82 auto driveshaft and swapping it over to the 83 driveshaft. The problem with this is the U joints seem to be unserviceable on the manual driveshaft. At least for those of us who don't have an anvil or a hydraulic press. Any thoughts?

Also would the U joints be the same for the 82 and 83 because if the holes are different for the two then I am not sure how to complete this job.

Thanks

j_tso

iTrader: (2)

There was a thread on here with someone servicing the 83+ u-joints.
Otherwise take both to a driveshaft shop and ask to swap the flange over.

mustanghammer

iTrader: (3)

The u-joints are not serviceable on the 82 driveshaft so swapping the rear flange yokes between the two shafts is not an option. What you can do is swap the flanges on the differentials so that you have something matches the 82 driveshaft you are wanting to use. Or find an 83-85 driveshaft to replace the 82 driveshaft.

There are two different flanges on the differentials. The earlier used through 82 has a smaller flange with a rectangular bolt pattern and the bolt holes are threaded. The 83 and later differential flange is larger with a square bolt pattern and the bolt holes are not threaded.

KansasCityREPU

iTrader: (9)

The staked u-joints can be removed and replaced with serviceable ones by a driveshaft shop. This is what I did on my 1985 GSL. They can swap the flange at the same time.

I'm not not sure about the 1983 u-joint part number. They could be the same as the 1984-1985. The driveshaft shop can help with that.

here is an old thread. Not all the links in this thread work now. https://www.rx7club.com/new-member-r...oints-1120560/

peejay

The local driveshaft shops do not replace the U joints, they just make a new driveshaft for $700 or so.

LongDuck

Just an FYI, but Mazdatrix could build you a new driveshaft with whatever flanges you want on it, along with user-replaceable U-Joints for what they charge for a standard driveshaft. I went this route and never looked back. So much easier to carry around U-joint spiders for spares instead of a spare driveshaft. Give them a call and see what they can do for you.

Years ago, I went to SevenStock20 and got a rythmic transmission knocking from the front as soon as I hit the california freeway systems. Thinking it was the driveshaft front joint going out, I stopped and talked to Mazdatrix who were very helpful. They suggested either driving to their shop to get a replacement driveshaft which was in stock, or drive it back home as it would probably be fine. I managed the trip back home taking it easy, and ordered the new shaft from them and put it in.

KansasCityREPU

iTrader: (9)

This looks promising for your location

https://www.drivelinesnw.com/service-center/

Import shafts

Many import vehicles have "un-repairable" universal joints. We have a solution for nearly all of these. We offer same day shipping on most complete BMW and Mercedes Benz drivelines and can repair most other import shafts in one day. Our process includes universal joint or yoke replacement and balancing to factory specifications.