I've got a '85 base model and I bought a '85 LSD third member. It fit in fine and the drive shaft hooked up okey, but I can't get the axles to go in. Are they different size splines/axles? my axles slide right into my old rear end.

 

According to Mazdatrix 84-85 12a should be the same...only different axles are on the 13b (gsl-se)

 

So, if I've got a GSL-SE third member, the axles splines are different than the ones on my base model axle?

 

No, they are the same. The only difference with the GSL-SE axles is that they are longer outside the wheel bearing (and of course different bolt pattern). From the wheel bearing inwards they are identical.

Count the number of splines in the side gears of the diff, versus the splines on the axle. They should be the same. (26 spline for large axle, 24 spline for small axle, according to the solomiata website. Never actually bothered to check, myself)

It is entirely possible that the third member you got was from an '81-83. Small-axle rears weigh a lot less, so they're a good swap into later cars.

 

If I had a 81-83 axle, wouldn't the flange on the drive shaft be different? It bolts right up to my '85 drive shaft and looks like the pics of the 84-85 rear ends I've seen.

 

The driveshaft flange can be changed. Also, the '83 uses the early axles and the later flange.

Just yank the pumpkin out and physically verify that the axles fit. The hard part about pulling the centersection is getting the axles out, the easy part is dropping the driveshaft and unbolting the pumpkin from the housing, so you've practically already got it out.

When in doubt, find it out!

 

sory to bring up a months old thread and ask a question that has been tip toed around alot on here.


But according to bizzaro's post to mazdatrix the '79-'83 axles are the same, same part number, so therfore are interchangable, right? or am i wrong, ive been searching for about an hour now, and cant find squat. (ive asked this question befor and cant get a strait answer)