Wybuck

Hi all, first time posting, I have a 98 XJ w/6" lift 5 speed manual w/231 TC and 307 gearing. I also run 33's on the jeep.


Question; I would like to upgrade my gearing on the cheap and I'm thinking 355 gears out of a 00 XJ in the JK. Was thinking of buying both front and rear axles and doing a hack and tap at the same time to help with the vibs I'm getting right now. what do you all think about this and how much is involved in changing the front axle? I know the rear isn't that had to do.


One other question; can I use the axles out of a Grand to do this, there is one sitting right next to the 00 XJ with same gearing although I'm sure it has ABS.


Thanks all in advance

toasterknight

You can't use Grand Cherokee axles. I would avoid an 00 as well. The best axles are the last half of 99 but anything from 97-99 is wonderful as long as it has a 8.25 rear.

Wybuck

Thanks for the reply toasterknight,


That's good info to know the years I would be looking for to replace the axles with. Is there a marking on the axle some where to let me know its a 8.25 or do I measure them? All axles I've seen at the JK were 3.55 gearing.

toasterknight

The 8.25 will have a flat bottom. Most of those years should have the 8.25 unless they have abs.

Wybuck

I have one additional question dealing with the Hack and Tap of the TC output shaft and what front drive shat to use in the rear.


I called Iron rock about their Hack and tap kit and they told me to stay with a 1998 front drive shaft for the rear.


They told me that the front differential on a 2000 is a low pinion and won't work for the rear of a 98. is this true and why? don't understand what high pinion and low pinion is.


Also are there other years of the XJ with the same front drive shaft as the 98?






Driveshafts

Front Driveshaft - From 84 thru 86 the front driveshaft was a true CV style ("beer can on a popsicle stick"), 87 + The front is a "double cardan" two-piece driveshaft with a CV joint at the transfer case end.

Rear - The 228 and 229 transfer cases used a fixed output yoke, with a 2-piece incorporating the . Otherwise, The rear is a one-piece shaft with standard u-joints at both ends. The http://www.cherokeetalk.com/forum/# is located on the output shaft of the transfer case. On 84-95 models, the yoke slides in and out of the transfer case and is lubricated by the ATF fluid internally. On 96-01 due to a design change, the slip yoke is external (does not slide in and out of the transfer case). This slip yoke is covered with a rubber boot.

Axles

Front Axles
Dana 30 high pinion - reverse cut - 27 spline, 1.16" diameter shafts, 7.13" ring gear - used 84-99 (some axles through 91 are vacuum disconnect, 92+ are non-disconnect, 89-95 with ABS have 5-297x u-joints, all 95+ have 5-297x u-joints, all others have 5-260x u-joints except 84 thru 86 they were CV type rather than open u-joints)

Dana 30 low pinion - standard cut - 27 spline, 1.16" diameter shafts, 7.13" ring gear, 5-297x u-joints - used 00-01

toasterknight

The low pinion is a longer driveshaft. You want the double cardan as its a stronger joint.

Low pinion means the pinion shaft comes out below the center line of the axle and high pinion mean it comes out above the centerline.

caronaxtr

Like stated above, try to get a HPD30 out of a 96-99 XJ, and go with a Chrysler 8.25 for your rear. the swap for the front is a direct swap. Depending on what rear axle you have now, if you have the D35 rear axle all you'll need for the 8.25 are new u bolts as the 8.25 has a larger axle tube. I'd recommend doing a disk swap before you swap the rear axle as it's the perfect time to do that. you can either use junk yard Grand Cherokee parts or you can buy a Tera Flex rear disk conversion. I did the Tera Flex conversion before I swapped in my 8.25.


Easy Mod and huge upgrade going with the HP30 & 8.25 (if you're running a D35)

Wybuck

toasterknight,


I took a look at the diff covers you posted and it looks to me like I'm already running a 8.25 rear axle (I think). the Dana 35 and the 8.25 are really similar in shape and size. My cover has been dinged up some but it doesn't have as deep a bevel to it as the 35 does. I guess I could measure the shackles and see if they are 3".


My 98 is also a 5 speed with 3.07 gearing in it. That's why I want to go with a 3.55 rear and front. I know everyone says to go deeper with the gearing but 3.55 would be a big step forward for me. I have 33" tires on now but am thinking about going to 31's so 3.55's would work well.


Thanks for all your help, its a great thing really

Wybuck

Just checked again after rereading your post about the flat bottom on the rear diff. Yes mine has a flat bottom.

Wybuck

Toasternight, what is a HPD30 out of a 96-99 XJ? lost me there!

toasterknight

It is the front axle out of those years.

toasterknight

High pinion Dana 30

JandDGreens

I have already swapped my axles. Got mine out of a 94 XJ. I know it would have been better if it was from a later 96-99 (2 reasons stronger front axle shaft knuckle/u-joints and the splines on the rear axle are better than the 94), but since we already had a donor vehicle my cost to do it was minimal. It was well worth it too since my rear axle was a 35 and 3.07 gears really wasn't cutting it. It was nice that I also had the front and rear drive shafts from the 94 to insure the right fit. Also saved the axle shafts from my Dana 30 for trail spares.
They started using low pinion Dana 30 in 2000, Why???

toasterknight

They were phasing out the xj and had low pinions from the tj and just put those in.

andrewmp6

Any xj with a 4.0 auto should have 3.55 gears in it,Look for 92-99 for the front axle,The rear axle any chrysler 8.25 will do but the late 96-01 is 29 spline axles it in vs the 27 spline axle in the earlier years,The chrysler 8.25 is none abs so you will lose your abs swaping it in it.The only abs rear axle is the dana 35 which is the weakest of the stock rear ends.The zj and tj fronts will bolt in but both are low pinion,The wj and jk won't work unless you cut off all the mounting tabs and spring plates and weld on new ones.