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News of the Aussie makes for a 27 to 29 spline Conv.


NAXJA Forum User
Draper, UT
I have never worked on Diff's before, but I know a little. When going from the 27 spline to the 29 spline carrier do you need to do any thing to the pre-load? Is it a simple bolt on? The Aussie is a "lunch box" auto-locker right that in teh installation of teh lcoker I would not have to take teh carrier apart either....

I am looking at adding another 1 or 2" of lift over the next little bit so I can put 33"s on I would like to get the Aussie for my 8.25 but I have the 95 8.25 with the 27 spline. SO with the Aussie I would go for Chro-Molly shafts in the 29 spline also (that makes it comparable to the D44 right?).

I dont have the tools or the experiance to start taking apart the carrier, so is it a direct swap from my 27 spline to the 29 spline?
To convert from 27 to 29 splines you need a 29 spline carrier, and side /spider gears, you cant just swap out the side gears and axle shafts. The bore of the side gear and carrier is larger to accept the larger axle shaft. It isnt just a simple parts swap - you need to be able to reset your pinion/gears to do it.
Second what Art said... there's a difference in diameter of about .1 inches in the side spider gears with the 29 spline carrier having the larger bore.
But there will no longer be any spider gears--just the Aussie gears that engage with the splined shaft ends that replace the side spiders. This being so, the real question is not whether the innards of the carrier are the same or different, but rather if the empty carrier itself is able to accept the larger 29 spline shafts, correct?

So, Art, are you saying that the case itself is not able to accept the 29 spline axle shafts? I have a keen interest in this topic myself as I have a pair of stock 4.10 axles from a 96 that I assume have 27 spline shafts. I was considering getting a Powertrax No-Slip for my 8.25 but didn't really want to get one in 27 spline configuration as it seemed a waste of capability vs. the 29 given the price. So I was wondering this exact thing earlier today. . .

I went to a local 4wd shop today and talked with the owner to try to answer my question. He showed me some spider gears from both a 27 spline and a 29 spline Chrysler 8.25 carrier. First, the 29 spline shaft is clearly a larger diameter, but more importantly, the diameter of the cylindrical area of the side gears that seats into the side of the carrier is clearly larger for the 29 spline gear, indicating that a locker designed for the 29 spline case will not fit in the 27 spline case and a locker designed for the 27 spline case would be too small for the 29 spline case. Nevertheless, the diameter of the axle shaft bearing surface at the outer end of the shaft is shared between the two differing spline count shafts, and thus the outer bearing would be compatible with the 29 spline shafts. In order to do the swap, a carrier swap is essential, then. So I am in agreement with Art, who said almost all of this with fewer words which I understood less well until I actually saw the parts side by side.