rotary_neubie

Is there a difference between the lsd drive shaft, and a open diff drive shaft? are the interchangeable?

rotary_neubie

Well for all of those who were curious, there is a difference in bolt pattern.

rhinor61

There are difference between years
79-80, 81-82 and 83-85 but not between models.

Also there is difference in length within the year if its manual or automatic transmission.

Example the is a different rear flange used on 83 gs/gsl compared to a '81 gs/gsl so to use a '81 driveline with replaceable u-joints you need to change the rear differental flange to the '81-82 year.

Make sure to get the correct bolts for the year you are using.


John

RotaryRyan

one time i got an 83 driveshaft and it didnt fit my 84

rhinor61

Well, I double check the parts microfiche before postiing, so I don't know what to tell you about that.

I ran a '81 driveline on my '83 PRO7 car and it was only a swap of the pinon flange swap when I put in the driveline.



John

RotaryRyan

the bolt pattern was a little different so i got the whole driveshaft rebuilt.

theres a place down here that can replace the "unreplaceable" u joints with a press.

Jason Guthrie

I have an 85 SE. Went to the junkyard on several occassions looking for a driveshaft replacement and I found a few variations in the shaft. I pulled one and took it home and it did not match up to my car. There was a shielding on the end of mine that was missing from a number of the ones in the junkyard. As well, the first one I brought home had a different bolt pattern. I pulled both drive shafts from 84-85 GSLs, 5 speeds.

rotary_neubie

I ended up changing the piece that to drive shaft bolts up to. Now I have an open diff shaft, and the piece it bolts to, on my lsd rearend..... I hope they are both the same strength is all.

peejay

There are THREE different driveshafts.

'79-82 (has C-clip, replaceable U-hoints), '83-85 (has staked-in, non-replaceable U-joints), and cars with 4-speed automatic ('84-85? also has staked-in, non-replaceable U-joints, but is SHORTER)

Mazda changed the flange bolt pattern when they went to non-replaceable U-joints.

Use either the driveshaft that will work with your rear, or change the pinion flange to match your driveshaft (non-trivial unless you know what you are doing, since it's easy to muck up the pinion bearings when you tighten it down)

Saxrasta

The yoke plate for GSL-SE models is slightly different than the other models. (I suppose the main difference is whether you have the 12A engine or the 13B) The holes just don't line up. I own an '85 GSL-SE. I purchased a used drive shaft for an 85 rx-7 and it didn't fit. It will fit any non-SE models from 1985 and probably 1984. If anyone needs a drive shaft for an 84 or 85 rx7 with a 12A engine, contact me at Saxrasta@excite.com. New shafts cost anyhere from $225-$465! There's no reason to pay that much.

PT Ray

I will stand behind this. For the ones that are having problems finding a shaft that fits using the above criteria, you seem to have something in common among yourselves. You are replacing a bad shaft with a used shaft of unknown certainty. First you have to make sure the replacement is correct. Or better yet, make sure your car is setup with the correct shaft/flange. I am sure that as common of a problem driveshafts are, many 83-85 rx7's have had the flanged swapped inorder to use what was labeled as a serviceable shaft or just because thats what was available for a fix. That leaves the next owner thinking he has the correct shaft combination, or that because it is an 84 salvage car, it has the correct shaft. This is at least how I see it.