Drive shaft U-Joints 1994 RX-7
 

All,

Please forgive me if this subject has already been covered, I am new to this Forum and this is my first posting. I have a 1994 RX-7, I just replaced the transmission (manual) and found that the u-joint at the rear yoke of the drive shaft that mates with the rear differencial, has a "detent" or click at the neutral point. What I mean is when you leave the yoke centered (both up and down and left and right) the yoke holds in a neutral position. If you move the yoke up or down and/or left and right, it feels like it indexes (clicks) at the exact center points. Is this normal.....I would guess not? However the car drives smoothly.

Second, I understand that the u-joints are not replaceable? Is this in-fact true, do I need to purchase a whole new driveshaft? If so are there any dealers that sell these for a 5-speed? Does anyone rebuild them? Does anyone have rebuilding kits? How about used?

Any help on this subject would be appreciated,

Thank you,

Jim

That's fairly common, and it's not a problem. I've actually never heard of FD U-joints failing to the point where they need to be replaced - Mazda did a good job on the driveshaft, and if you have no vibration at speed, you'll be just fine.

If there is a problem, I'd get a used driveshaft - they're gonna be a dime a dozen, and far cheaper than trying to replace the non-serviceable U-joints.

Dale

that explains a lot....went to a local auto parts store to see if they were replaceable."oh yea, we have to order them but i can get 'em"......when they showed up they definately were not for the rx7!!!....when i had the shaft out they felt like they could use a new set.....but i guess there not replaceabl and there not loose so f>&K it!

thanks for verifying that though Dale Clark......my search is now over..

Drew

Not sure about used driveshafts being a dime a dozen though! :)

16-year thread bump. What are people's opinions about driveshaft u-joints now that they are getting to be 30 years old? I noticed evidence that both the front and rear universal joints from my car have flung some grease onto the nearby parts of the powerplant frame and chassis. I haven't noticed vibrations or clunking, but I have the driveshaft out of the car (while replacing rear differential mounts) and do feel the same 'indexing' or 'notchy' behavior described by the original poster. The car has about 99000 miles on it now.

Some searching suggests the OEM u-joints are staked but they can be replaced with serviceable ones by a competent shop. Also Banzai Racing sells an aluminum replacement driveshaft.

You could get an aluminum one with serviceable joints I guess
Aluminum Driveshaft 93+ RX-7

I still have yet to personally see a bad FD driveshaft. They just aren't under much load at all due to the PPF.

Also I've NEVER heard of them flinging grease or anything.

I'd just run it until it starts making noise or something. It's really not worth going to great lengths for something that's most likely not a problem.

Dale

+1 its one of the few (three) parts i've never seen fail on an FD

Slightly off topic, but curious as to what the other two of three FD parts you've never seen fail might be?

probably the blower motor, and the steering column?

some of the funnier things, the baffles in the gas tank sometimes break off. ive seen the hood catch break, and the thing that the hood latch bolts to (FD01-53-150B) break off
ive seen the dash break, not the normal plastic bits, but like the whole big dash was just broken somehow. (FD01-60-350D-02)

i mean there are plenty of things that are really robust, most of the suspension and brakes. window regulators last almost forever. trans is pretty strong too, it really only breaks when you put too much power into it, etc