I was told that the axles on my 91 z28 were 28 spline axles,well the rear end went and I took it all apart and the axles are 26 spline.are they suspose to be 26 or 28 spline?

 

Rear end has probably been swapped out at some point.

I have never seen an original 91-92 car wit 26 spline axles, all I have seen including my own two are 28 spline.

No bigge, if rebuilding however, if not going to a physically stronger rear, spend the extra $200 and get new 28 spline axles and rebuild it as a 28 spline unit.

Extra strength never hurt a 7.5 :-)

later
Jeremy

 

when they told you your rear had 28 spline axles when in fact it had 26 was "when gm built it and it left the assembly line it had 28 spline axles". there's no way of knowing what might of been done to it in the past 15 years.

 

Is there anywhere you would recomend to find a 28 spline rear axle for a 91 Z28,all i can find are 26 spline. Please let me know if you know of any good places near houston or somewhere were i could have it delivered. Thanks alot.

 

Look here.

You're going to have a tough time finding "an axle". Reason being, when the junkyard takes "an axle" out of a rear end and sells it to you, it renders the ENTIRE REST OF THE REAR junk. Worthless garbage as far as they're concerned. No other customer is going to walk in looking for "a whole rear end for a 91 Z28 except for one axle".

So, you don't go to the junkyard and buy "an axle" for a hard-to-find application like that; you buy A WHOLE REAR END, and the junkyard is just kind enough to dispose of the leftover pieces you don't want for you.

Meaning, you have to pay for THE WHOLE REAR END, to get "an axle" out of it. Assuming of course that you can find one in the first place.

You can have those others up there on your doorstep on Thursday morning; probably for less money (maybe ALOT less) than you'll have to spend to get "an axle" from a junkyard; and they'll be NEW, and better than stock in every way.

 

Aftermarket 28 spline axles for third gens are only around $125 each. They're far superior to a factory 28 spline axle which will be hard to find since they were only produced from 90-92. I have yet to see a 90-92 third gen in any of the local pick N pull type yards. There's just not a lot of them out there and the ones that are out there are being held onto.

If you pulled a 26 spline axle out, you'll need more than 28 spline axles to upgrade your diff. You're also going to need a 28 spline carrier (posi).

On the front of the passenger side tube close to the center section, there will be an axle code stamped in the tube. It's very hard to read. A good wire brush and some cleaner should make it readable. This code can tell you what year your diff came from. With 26 spline axles, it's not from a 91 however the housing could be and the axles and carrier were swapped out to 26 spline by a previous owner.