I had this hapen on my S10 a few years ago after I lowered it. The pinion angle was changed on the drive shaft so ti would studder whenever starting off from a stop and would go away after I got moving. Can this happen on an rx7 one piece driveshaft?

 

its most defenatly your u joint i have the same problem and just ordered a new drive shaft cause mazda made them non servicable after 83 on rx-7's you can always lift up the car high enough to get under it and try turning the drive shaft and right after the housing it should give.

also its very unsafe to drive the car if it is the u joint because it can break and bounce around and destroy the tail of the tranny housing and then catch the ground and serve as a pole vault.

 

i've heard this as well, but i like to tempt fate, so i drove mine for 2 months on a bad u-joint... although i deffinitly would NOT reccomend it, it sucked my gas mileage, robbed my power, and made my *** sore from the vibrations

 

Here are some simple checks.



1. Pop the hood, start the engine, rev it. Does the engine seem to rotate to the pass side excessively? If it does, check motor and tranny mounts.



2. While driving at a steady speed, blip the thottle. Do you hear a clunk from the rear? Check the rear diff mount.



3. Jack car up, with jack stands, check the u-joints. If there appears to be any play in them, remove and check further. Bad u-joints can either bind up or be excessively loose. While the car is up, grab a rear tire and rotate forwards and reverse, any clunking can point to u-joints or the irs, (gears, half shafts)



4. If the shudder is only at standing starts and hard high rpm shifts, I stand by my first post. Eliminate all the others first before you have to pull the tranny.