Pro's and Con's with upgraded rear-ends?

[Whuntmore]

I'm thinking about getting another rear end for my eagle.  This will probably be some kind of upgrade (ford 8.8, Chrysler 8.5, or something from a jeep (e.g. XJ rear end).  I might be doing alot of highway miles in the next few months, and I'm gonna have to upgrade the rear end, and I have a jeep 4 speed auto with O/D coming.


How many of you have done a swap like this?
what rear end was it?
and what issues/modifications did you have to do?  
did you have any ratio issues?
did you have brake cable/lines hookup issues?
was the rear end Drum or disc?
was it expensive or cheap to work on?
was it expensive or cheap to get?
Was your rear end a common or rare one?


This will be for regular street driving (winter/summer/highway) normal sized tires (between 205-235 at most) and very little off-road.  high end or drag racing rear-ends I won't be doing, but if you want to share, feel free.


Probably looking for a LSD, something reliable, not too expensive to purchase/fix/upgrade, and fairly easy to install.  I don't mind having to change over a shock mount.  I will also stick with the leaf springs in the back, and probably add a sway bar.

[mach1mustang351]

I got the chrysler 8.25.  I got it because it is the proper ratio I need for my car.  The 8.25 appears to have a little less aftermarket support for "cool" differential parts.  ie air lockers, E lockers, posi etc.  The items are available but it seems like they are a little less common and a little more $$$ to get.  For a stock upgrade it is an improvement over the amc 15 rear end. 

The biggest issue with a rear end swap is the dreaded front axle ratio mess.  It is well documented here but sometimes finding matching ratios for the front can be a mess depending on carrier.

I don't are about Disk brakes in the rear.  In my opinion there is no real advantage in a normal street car other than ease of future serviceability.

Just some thoughts. 

[eaglefreek]

How many of you have done a swap like this? I have
what rear end was it?Chrysler 8.25"
and what issues/modifications did you have to do?I removed both Jeep shock mounts and moved the Eagle shock mounts over to the 8.25" 
Any ratio issues?I had 2.73 gear and wanted 3.07 and it was way cheaper to buy a used rear  with the correct ratio. The common ratio in Dana 35, Chrysler 8.25 is 3.55. Explorers will most likely be 3.73 but 3.55 axles were available
brake cable/lines hookup issues? Not really
Drum or disc?Drum
expensive or cheap to work on?Dana 35, Dana 44 and Ford 8.8 have the most aftermarket support but parts for the 8.25 are readily available.
expensive or cheap to get?I think I paid $125 for my rear axle. If you have a junkyard where you can pull the parts yourself, you will probably get the best deal. I would be careful getting one from an offroader who upgraded. They may have abused the old axle before removing it
common or rare?Dana 44 are the most rare. Dana 35 and Explorer would be the most common. If you choose an 8.25" go with one from a 97+ Cherokee. They will have 29 spline axles vs the earlier 27 spline axles. The 97+ 8.25 are thought to be near as strong as a Dana 44. Explorer 8.8 will require the most fab work and are 1.5" narrower than the stock Eagle axle. The Jeep Cherokee axles are the same width as the Eagle axle.

I had a nice write up of my install, but it got lost in the great delete. Unfortunately, it was a few years ago and I can't remember all the details. Since you're switching to a OD transmission, 3.07's will be right on the edge of keeping the engine in it's sweet spot for best MPG. 3.55's would probably be best. I'm trying to get a AW4 installed in my Eagle with 3.07's, but I have been working out of town so much. I don't know when I will get to it. My biggest reason for the AW4 swap is to be able to install 3.55's and get better use out of 1-3 gears and put the engine in it's "sweet spot".

[Whuntmore]

is that where you got your 8.25 from?  A jeep cherokee?

What year(s) and what model/trim did you get it from?   

[eaglefreek]

Mine came from a 98 XJ supposedly. A guy was parting a wrecked one and I didn't see the Jeep since it was already scrapped. XJs would be the only ones you wpuld wantto get axles from. The Grands use coil springs.

[carnuck]

Max89059 did the 8.25 (from his XJ) which was a bolt in except the shocks (new mounts are easier than cutting and reversing the XJ ones which also requires new custom shocks) and Ebrake cables. The input yoke is slightly longer, so if you are lifted, the original driveshaft should work fine.
Pinion angle is great unless you plan a CV joint rear swap.

I'm doing the same with my wagon, but instead of 3.55 gears like SOTE has, I'll be running 3.08 with an 8.25 (got it from an XJ guy for less than $100 and I already bought a matching front for $100) I have to wait for my shoulder to heal (it's clunking even while typing this) and I find out in a bit if I need surgery or not.

[Whuntmore]

ok, it won't be lifted, so I need another yoke I take it...  custom?

[carnuck]

Nope. Just possibly a shorter rear driveshaft. The "nose" of the 8.25 axle is longer than the D35/M15 due to bigger bearings and stronger input gear.

[Whuntmore]

Nope. Just possibly a shorter rear driveshaft. The "nose" of the 8.25 axle is longer than the D35/M15 due to bigger bearings and stronger input gear.

So if I shorten the drive shaft, will the yoke just slip in then?  Well, that's not too bad then.   I'll need new 'U' bolts, and that rear end fits under the leaf springs - The same as the eagle.

That shouldn't be too bad in expense.  

What typical years you guys staying within?

How do you identify the rear ends?

[carnuck]

You "might" have to shorten the shaft (I haven't done mine yet, so I'm not sure how much)  The "cheap" way is cutting the inner end on the slip joint (I've done that before)