27 spline and 29 spline 8.25

[Omarmartinez33]

Hey guys I just wanted clarify on my rear axle swap. I’m getting 4.88 ratios but the ones I’m looking up is only for 27 spline. Is there a difference? Can I still put 4.88s on the 29 spline 

[Swampy]

Try looking again. even though they are the same axle it is different. the splines refers to the number of splines on the axle shaft, I believe (correct me if I am wrong) the split between 27 and 29 spline 8.25 axles is 1999, or 1997 not sure. I know my 8.25 axle was out of a 2000 xj so I have 29 spline axle shafts. The only difference is the axle shafts and they can be swapped between housings if you swap the correct parts as well (spider gears, locker, carrier etc)

 

But you will be able to use the gear set you found, if it is only a ring and pinion set there should be no interference as far as I am aware of. The issue of spline count would only come about when swapping carriers or installing a locker.

 

Hope this helps

 

 

[Omarmartinez33]

12 minutes ago, Swampy said:

Try looking again. even though they are the same axle it is different. the splines refers to the number of splines on the axle shaft, I believe (correct me if I am wrong) the split between 27 and 29 spline 8.25 axles is 1999, or 1997 not sure. I know my 8.25 axle was out of a 2000 xj so I have 29 spline axle shafts. The only difference is the axle shafts and they can be swapped between housings if you swap the correct parts as well (spider gears, locker, carrier etc)

 

But you will be able to use the gear set you found, if it is only a ring and pinion set there should be no interference as far as I am aware of. The issue of spline count would only come about when swapping carriers or installing a locker.

 

Hope this helps

 

 

Thank you they will be ring and pinion set 4.88. I just didn’t know if they are different between the splines 

[Swampy]

15 minutes ago, Omarmartinez33 said:

Thank you they will be ring and pinion set 4.88. I just didn’t know if they are different between the splines 

 

If its just the gear set it shouldn't be different. I don't know if the install kits are different between the two, hopefully someone else will chim in on this as well

[Pete M]

do you have a link to these gears?

[Omarmartinez33]

4 hours ago, Pete M said:

do you have a link to these gears?

https://www.summitracing.com/parts/spz-36268

[mnkyboy]

They are refering to the spline count on the pinion, all 8.25s are 27 so those gears fit either version of 8.25".

 

As far as shafts, basically the only difference between a 27 and 29 spline 8.25 is the carrier is bored larger on the 29 to accept larger side gears for the 29 spline shafts to fit in.

With just carrier swap and/or locker install you can convert a 27 to 29 spline shafts.

 

 

[mvusse]

On 5/10/2018 at 12:49 AM, Swampy said:

Try looking again. even though they are the same axle it is different. the splines refers to the number of splines on the axle shaft, I believe (correct me if I am wrong) the split between 27 and 29 spline 8.25 axles is 1999, or 1997 not sure.

 

The split is partway through the 96 model year. My early 96 XJ came with 27 spline shafts. The 96 parts XJ I bought was produced a couple months later and had 29 spline shafts as well as a different plug on the crank position sensor.