666cody666

So i found out my vibration in my car was from the driveshaft. I took it in to my school shop so i could do the U-joints on it. well the teacher gets them and when we are about to put them in we find out the caps are too big. he calls the parts place up and they say those were for an 83-under and the 85's are irreplacable. so my question is with all these rotary places on the forum do one of them make a u-joint for these cars or does anyone have a used one for sale for the right price?

Thanks

SCCAIT7

Do you have the old u-joints? There is a drive shaft place about 15 minutes from my house... If you ship me the old ones ill get you the ones to rebuild it. The parts places never have stuff right.... One last option... Check for a 1979... even though your car is an 85....

Kentetsu

Somebody on here found the correct part number needed and posted it. But I searched for it a while back and was unable to find the thread. Maybe you will have better luck if you try...

mustanghammer

iTrader: (3)

The early shafts - to 83 I believe - are rebuildable. They also have a smaller flange at the axle. The post 83 shafts are not rebuildable and have a larger flange at the axle.

Because of these differences you cannot swap an early shaft into you 85 model car without also changing the companion flange on the axle or without drilling a second pattern in the large flange for both large and small flanges. Some people will do the later because it gives them greater flexibility when searching for spares.

Mazdatrix.com sells rebuilt shafts for both style flanges for about $200. You could also inquire with professional drive shaft shops in your area to see if they have a solution. Beware however, not all driveshaft companies can handle RX7 work correctly. Go to someone with experience.

On the street I would go with a quality rebuild from Mazdatrix. For racing I would recommend a new shaft from Mazda - Mazdatrix sent me in that direction when I inquired about one for my racecar. So, that is what I did and it works great at all RPMS in all gears. Purchased through their motorsports support program it was $378 plus shipping.

Kentetsu

What I meant to say, was that somebody on this forum succesfully replaced the ujoints in a later model drive shaft. I believe he may have had to cut the old joints to get them out, but he found the correct model of ujoint to put back in. I wish I could find that thread, because it would be useful to a lot of us. Haven't seen it in years though...

kymber39845

I had to deal with this exact same issue not too long ago and through my research I found that my car is an 83 1/2. I spliced her with an 82 and that's how I found out they changed the driveshafts halfway through the year. I lucked up and another member had an aftermarket shaft from Mazdatrix that he gave me. It works great and the u-joints are replaceable. The u-joints the parts store sold me would have fit this one, but the originals were non replaceable.