What Rear End Should I Go With?

[jthoward8]

Hey all! Nice to be back in the Jeep ownership category after a 10 year hiatus. SO, my new to me Jeep made it 5 hours of ownership before the rear end started humming. My mechanic looked into it, said it needs replaced. Here's my question, it's got a 4.10 running right now and I do a TON of highway driving. I plan to put 235/75/15 tires on her, never plan on crawling anyplace but parking lots, and I will do plenty of highway driving. What rear should I go with? And how do I do this moderately cheap? My mechanic is my bro, so he'll help for free. So I'd only be out parts costs.

A review:

1990 Comanche Base

2.5L 2wd 4sp manual

235/75/15 - Mall Crawler - Tons of Highway driving

[Dzimm]

If you can find a super cheap or free Dana 35 from an MJ I'd go that route.  

 

If you have to pay for an axle, get a C8.25 from an XJ and just move the perches to the right spot.  Most of these will be 3.55 gears.  You won't ever break it.  

[Jeep Driver]

I'll second the motion. 

 

Get an 8.25.

[MeanLemons]

8.25 with 3.55

 

 

those 4 cylinder with 4 speed manual transmission had 3.55 stock 

[HOrnbrod]

3 hours ago, jthoward8 said:

Here's my question, it's got a 4.10 running right now and I do a TON of highway driving. I plan to put 235/75/15 tires on her, never plan on crawling anyplace but parking lots, and I will do plenty of highway driving. What rear should I go with? And how do I do this moderately cheap?

 

What axle do you have? You either have a D44 or D35 rear axle in there now if it's a stock MJ axle. Check it out by the cover.

 

 

[Eagle]

Are you certain that it has 4.10 gears? If it's a 2.5L 4-speed, it should have 3.55 gears. The 4.10s were used with the 5-speed 2.5L MJs.

 

To be honest, since it's a 2WD and you don't have to worry about matching ratios between front and rear, it would be much less expensive to just buy a Chrysler 8.25 rear axle out of a 92 or newer 4.0L Cherokee with automatic. That will be the correct 3.55 ratio for your engine and transmission setup, it's a stronger axle that the Dana 35 that is probably what you have now, and you can buy a junkyard axle for a lot less than the cost of a set of gears, bearings, and setup. You will need to relocate the spring perches, but the existing ones can be cut off and welded into the correct location using your old axle as a setup template.

 

The best cheap axle swap is a 97 or newer XJ Chrysler 8.25, but for a 2.5L even the older 8.25 will be better than the Dana 35.

[MeanLemons]

Eagle is correct. 97+ 8.25 axle would be the best choice... since it’s 29 spline (stronger than the previous 27 spline version). 

 

And like he said. Even 27 spline 8.25 is still better than a d35.

[Pete M]

03-07 Liberty 8.25 would be my choice.  comes with disk brakes, 3.55 or 3.73 gears, and is a couple inches wider than an MJ axle to better fill up the rear wheel wells (MJs have a wider butt than XJs).  only real drawback is that there is more bracketry to cut off because the KJs were 3 link out back.  and I would go with the 3.73 geared for a bit more power.    car-part.com can help find ya one, but honestly Libertys are everywhere in the junkyards right now.

[mjeff87]

3 hours ago, MeanLemons said:

Eagle is correct. 97+ 8.25 axle would be the best choice... since it’s 29 spline (stronger than the previous 27 spline version). 

 

And like he said. Even 27 spline 8.25 is still better than a d35.

 

This.   Note the comment about the year and spline count.  Go for 97+ if you can.

1 hour ago, Pete M said:

03-07 Liberty 8.25 would be my choice.  comes with disk brakes, 3.55 or 3.73 gears, and is a couple inches wider than an MJ axle to better fill up the rear wheel wells (MJs have a wider butt than XJs).  only real drawback is that there is more bracketry to cut off because the KJs were 3 link out back.  and I would go with the 3.73 geared for a bit more power.    car-part.com can help find ya one, but honestly Libertys are everywhere in the junkyards right now.

 

Or this.  Again, note the comment about the year.  The 02 Liberty (first model year) got leftover drum brake axles.  Ask me how I know, LOL.

 

 

[HOrnbrod]

1 hour ago, Pete M said:

03-07 Liberty 8.25 would be my choice.  comes with disk brakes, 3.55 or 3.73 gears, and is a couple inches wider than an MJ axle to better fill up the rear wheel wells (MJs have a wider butt than XJs).  only real drawback is that there is more bracketry to cut off because the KJs were 3 link out back.  and I would go with the 3.73 geared for a bit more power.    car-part.com can help find ya one, but honestly Libertys are everywhere in the junkyards right now.

 

This. If you going to swap axles, ditch the drum brakes at the same time. Disk brakes are soo much better. 

[Eagle]

3 hours ago, Pete M said:

03-07 Liberty 8.25 would be my choice.  comes with disk brakes, 3.55 or 3.73 gears, and is a couple inches wider than an MJ axle to better fill up the rear wheel wells (MJs have a wider butt than XJs).  only real drawback is that there is more bracketry to cut off because the KJs were 3 link out back.  and I would go with the 3.73 geared for a bit more power.    car-part.com can help find ya one, but honestly Libertys are everywhere in the junkyards right now.

 

The other drawback to the Liberty axle is that it doesn't have leaf spring perches that you can just cut off and relocate -- with the Liberty axle you have to buy a set of perches on top of the cost of the axle. Not a huge expense if the Mopar Performance Catalog still has their perches, but aftermarket percehes are pricey. If you try to grind the old ones off the original axle, then you lose having that axle as a template to set up the new one.

 

Yay! Mopar Performance does still offer their excellent leak spring perches, for a whopping $9.60 per PAIR! And they are sized to fit the tubes on the 8.25 axle, I think

 

http://www.moparonlineperformance.com/product-p/p4120074.htm

[MeanLemons]

I used the perches from tractor supply company for like 3 bucks each on my 8.25 

[jthoward8]

PO said it was for sure a 4.10. Although he also said "no leaks" and this thing literally effing HATES ANY TYPE OF FLUID to stay in it's respective place. Looks like the vote is to go with the 8.25. I LOVE this group. Everyone is so damn helpful and willing to toss out advice! I will start hitting up salvage yards and see what I can locate that is functioning for now. Right now she's put back together, for the dif at least. Tomorrow we are going to tackle the fuel leaks, the gearbox leaks, the oil leaks, the powersteering leaks, and replace most of the steering components. Then we can weld in a new cab! Thanks so much everyone for the advice!

[Eagle]

2 hours ago, MeanLemons said:

I used the perches from tractor supply company for like 3 bucks each on my 8.25 

 

3 bucks? What I found on their web site ate 15 bucks a pair, which is half again the price of the Mopar Performance units and not as nicely made.

 

https://www.tractorsupply.com/tsc/product/carry-on-trailer-weld-on-spring-seats-3-500-lb-capacity?cm_vc=-10005

 

Did I misss something, or have prices skyrocketed since you bought yours?

[MeanLemons]

3 hours ago, Eagle said:

 

3 bucks? What I found on their web site ate 15 bucks a pair, which is half again the price of the Mopar Performance units and not as nicely made.

 

https://www.tractorsupply.com/tsc/product/carry-on-trailer-weld-on-spring-seats-3-500-lb-capacity?cm_vc=-10005

 

Did I misss something, or have prices skyrocketed since you bought yours?

Wow the prices increased.   Now i thought about it a bit.  I realized I bought something else for $3 and had it mixed up with this. But now I remember. It was definitely $9 for the pair.  I guess the prices increased to $15 because of the steel tariff?. I know a lot of steel products increased a lot lately. 

 

Sure it doesnt look as nice as the genuine mopar ones, but it does the job as well. And still doing it’s job well. 

[mjeff87]

JT.....where ya from?  Your profile doesn't list your location.

 

Plenty of folks here from all over the place.....if you're close enough to someone, you just might score some wrenching help

 

Jeff

[Eagle]

2 hours ago, MeanLemons said:

 

Sure it doesnt look as nice as the genuine mopar ones, but it does the job as well. And still doing it’s job well. 

 

Doing the job is what counts. And if you're in a hurry, if I read the Tractor Supply web site correctly, most stores will have them in stock. The Mopar parts have to be ordered, even if you go to a dealer.

[jthoward8]

13 hours ago, mjeff87 said:

JT.....where ya from?  Your profile doesn't list your location.

 

Plenty of folks here from all over the place.....if you're close enough to someone, you just might score some wrenching help

 

Jeff

 Hey Jeff!

 

I am from Pittsburg, Kansas. Thought I listed that, I will fix it right away!