engrboy5

So I have a chance to pick up some used 4.56s for the Chryco 8.25 in my 97 XJ for cheap. Doing some research though, I see there is a 27 spline and a 29 spline 8.25...the pinion shaft on the set I am looking to buy is 27 spline. So the question is, how can I tell if this will work in my rig? How can I tell if I have 27 or 29 spline pinion shaft?

Also, on the ring gear, the guy beveled the teeth in two places (??) to provide clearance for the crosspin... is that a problem?

Hoping some of you pros can help me out!

TIA
James

dan8yourv8

97-01 Cherokee came with the 29 spline 96 and older came with 27 spline but you never know if you still have the factory rear in your jeep so I would take the rear apart and count the splines just to make sure.

SeriousOffroad

Pinion spline count is not relevant.

OleBlue

Count the splines on the axle shaft, or in one of the side spider gears.

Buying used gears is always a gamble, the tooth shaving is a common way to get the pin past a fatter ring gear.

Based on the fact that you have a 97, i would say yours is 29 spline, not likely someone would have changed it out for a 27 spline, but its possible i suppose.

engrboy5

SeriousOffroad, can you elaborate on your comment that pinion spline count is not relevant?

Thanks.

engrboy5

OK, just to clarify, I'm talking spline count on the pinion gear shaft, not the axle spline count.

SeriousOffroad

They are all the same.

Big David

You get the 4.56 gear # by dividing the ring gear by the pinion or vise versa,I forget.

OleBlue

Come on now.

The spline count on the pinion shaft for all 8.25 is the same. The yoke slides on to the pinion shaft on the splined end. I think you are confused.

27 or 29 spline 8.25 refers to the spline counts of the axle shafts.

engrboy5

That clears up my confusion on the spline count...thanks all. But no one has really addressed whether or not there is a problem with the chamfered ring gear teeth. I'd like to see some opinion on that... Thanks!

SeriousOffroad

Grinding a tooth or two on the ring gear in order to remove/install the cross shaft is a vet common pratice and is even specified by some manufactures in their installation instructions.

The key is to take a little bit of material off at a time until the shaft just clears.

OleBlue

I addressed it in my first post! lol, Its ok as long as its not substantial