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spline question

G

gijosiahh

NAXJA Forum User
Location
Richmond VA
i had a hard time trying to search for this, so bare with me. my question is: is switching to a different spline shaft as easy as simply switching shafts?? i have a 29 spline 8.25 and a guy is selling a 27 spline 8.25 locally that has 4.10 gears, which would be nice. SO, can i simply pull the shafts out of the 27 spline axle and put my 29 spline shafts in, or is there more involved?

thanks for any help.
 
You can swap the gears onto your present carrier as the 29 spline shaft is actually stronger than the 27 spline shaft.
 
so is this what i need to do?: i want to use the 27 spline axle housing. can i just take the ring gear off the carrier from the 27 spline axle, put it in my 29 spline carrier, install it in the axle and put my 29 spline shafts into it? will the ring gear still fit right with the pinion? i don't know how to set gears, so would i be good to go or does the backlash have to be adjusted and all that stuff?

thanks
 
You need to swap your axles and carrier into the 27 spline housing, and install new axle seals. The pinion gear in the 27 spline housing can be left alone. After you put the ring gear onto your 29-spline carrier, you will have to readjust the the gear backlash and carrier bearings preload.(this is done with threaded adjusters on the 8.25, not with shims) The adjusters are kind of finicky to get back in under the bearing caps, and there are adjustment rods for the adjusters that make the job a lot easier.
 
The 29-spline shafts should be slightly larger than the 27-sp, so you'll need to swap seals.

The spline count refers to the engagement with the side gears in the carrier - and I'm inclined to think that you can simply swap out the side gears (but I've not seen the two side-by-side to measure.) If this is the case, you don't even have to disturb your R&P to change side gears - so it would be ideal.
 
5-90 said:
The 29-spline shafts should be slightly larger than the 27-sp, so you'll need to swap seals.

The spline count refers to the engagement with the side gears in the carrier - and I'm inclined to think that you can simply swap out the side gears (but I've not seen the two side-by-side to measure.) If this is the case, you don't even have to disturb your R&P to change side gears - so it would be ideal.
Click to expand...

Yeah that would be a lot easier than swapping carriers and reinstalling the ring gear. Can anyone verify if this would work?
 
ok i've got another question. i might also get a HP D30 with 4.10s out of a 94 XJ. my current axle is an 2001 LP 30, so its got the larger ujoints. will these shafts fit directly into the 94 HP d30 or is there more stuff involved?
 
It would be a hell of a lot simpler to just buy a set of gears and a master kit for your 8.25. Why go to all that extra work? Besides, then you can choose the exact ration you want and be confident in the setup.
 
The side gears will not interchange. 29s are bigger. There was a thread here in the last couple weeks that posted pictures of them side by side.

The D-30 shafts will interchange, but if the '94 has a disconnect housing, You will need a new axle seal.

Try looking at the FAQ posts. There is a lot of info on the axles there.
(edited -problem with my browser )
 
tbburg said:
The side gears will not interchange. 29s are bigger. There was a thread here in the last couple weeks that posted pictures of them side by side.

The D-30 shafts will interchange, but if the '94 has a disconnect housing, You will need a new axle seal.

Try looking at the FAQ posts. There is a lot of info on the axles there.
(edited -problem with my browser )
Click to expand...

Thank you. Got a link to that thread in your subs, or are you going to make me look for it myself?:wierd: :D
 
I'll re-post those 27vs29 spline pics for everyone. Also the seals are the same for both shafts, the outer diameter of the shafts is the same at the bearing/seal seats but the 27 spline tapers more than the 29 towards the spline end of the shaft. Like stated earlier, if you swap carriers you will have to reset the backlash and you will need some basic knowledge on gear set-ups and a dial indicater with a magnetic base. You will also need the adjuster cup tools to get the backlash right and to get the preload on the carrier bearings correct.

Here are the pics;

27vs292af5.jpg


This is why you need to change the carrier, the 29 spline side gears have a larger O.D. where they go into the carrier.
27vs291ow7.jpg


27vs293lh3.jpg
 
Makes some sense that the bearing surface for the seal would be the same (are the wheel bearings therefore also the same?)

Looks like the 29-sp side gear is, what, 1/8" larger than the 27-sp? I don't suppose you happened to measure, did you (more for my own curiousity than anything else...)

And I see that both versions are C-clip axles, meaning that C-clip eliminator kits would be in order.
 
Yes, the wheel bearings and seals are the same. I didn't measure them but 1/8" would be close. They are both "C" clipped, I would just recommend disc brakes as a cheap solution for keeping the axle in when/if it snapps. There are a few different junk yard disc brake upgrades for the 8.25.

I carry 2 extra shafts while wheeling "just in case".
 
kj139 said:
It would be a hell of a lot simpler to just buy a set of gears and a master kit for your 8.25. Why go to all that extra work? Besides, then you can choose the exact ration you want and be confident in the setup.
Click to expand...

well a guy is selling a 8.25 and hp30 with 4.10s out of a 94 for 200 bucks. sooo i'm thinking it might be a good deal. the 30 needs new joints and seals, but i can just use my shafts from my lp 30. i don't know what i'll do about the 8.25" yet. i might just get it and run the 27 spline. i only have 32s on the jeep, so i'm not real worried about breaking a shaft.
 
5-90 said:
And I see that both versions are C-clip axles, meaning that C-clip eliminator kits would be in order.
Click to expand...

They make those for the 8.25???
 
JNickel101 said:
They make those for the 8.25???
Click to expand...

If they do I'm un-aware of them. Disc brakes will get them same thing done for you. You can at least get the Jeep to a spot on the trail that a repair can be done without the wheel/axle slidding out.
 
JNickel101 said:
They make those for the 8.25???
Click to expand...

Dunno. Worth checking, and if you do find one I'm sure there are quite a few people here who would like to know about it.

Either that, or if you come up with one that works, on the same theory as then one for the Ford 8.8" (I'm sure that one exists.)

(If you need help finding bearings & seals, I have all of the Timken books and can look them up by dimension for you, if you need me to.)
 
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