I have a 89 Cherokee with an I6, 4 speed auto, SelecTrack and a Dana 35, 3.55 axle. The axle is completely toast and I've been looking for a replacement. I found a 2000 Chrysler 8.25 in reasonable shape (I think - I haven’t actually seen it yet). I read that it's a direct bolt on replacement and would be an improvement over the 35 but I'm confused about the drive shaft. Some folks say the original drive shaft can be reused and others say a shorter one is required as the 'nose' on the 8.25 is longer

The truck is original height, i.e. not lifted. I don't think the 8,25 drive shaft is available and even if it is, it's unlikely from the same transmission/xfer case combo as my 89 (4 speed auto/SelecTrack). Has anyone with a stock height XJ done this swap using the original 35 drive shaft?

The truck is stuck out of town; if it was local, I think I could resolve any drive shaft length problems but I need to get the truck home and a slightly ‘too long’ shaft might work to get me home as it’s only temporary – or is that just aksing for trouble? Thanks for any advice.

 

You will need the shorter shaft at stock height. It will work with your t-case just fine. If you run the longer one you take a chance of damaging your t-case and or rear axle .

 

It depends on what out of town means. If your 89 Cherokee broke down and left you a few miles out of town you could put the new axle in your rig and leave the rear shaft off and put it in 4WD high and drive it slowly for a couple of miles until you got it home then work out the rear drive shaft length. If you mean many miles get a u-haul car hauler and bring it home that way.

 

Hey Rock:

Thanks for your note. I've wondered before aobut pulling the drive shaft and driving temporairly on the front axle - good to know that it's an option, even if only for a short distance. In this case, the truck is about 300 kilometres away so it wouldn't be an option even if the rear wheels did move. In additon, there are some extreamly large hills on route, all paved mind you, but going down those on the front alxe only would be tempting fate I think.

Good suggestion on the U hall tow option though. I'll check that out.

 

Other than losing fluid out of the tailshaft I'm still trying to figure out why everyone says it not OK to run on the front axle alone for an extended period of time.
What if I left it in 4W full time (with both shafts in)? would the transfer case break or something? Aren't the front shafts and axles turning all the time anyway. Aren't the axle gear ratio's the same? In fact the chain in the transfer case is turning too!
If a one time trip of 300 miles running on the front axle alone would "break" my jeep I'd think I'd be looking for a different brand of vehicle.

 

Ok, I was talking about putting the 8.25 in before you drove it home powering only the front axle until you addressed the rear driveshaft length. If you can get a car trailer depending on what is wrong with the 35 you maybe able to load it on the trailer anyway. I've done it on a guys 76 GMC one ton, on my trailer by doing the rear shaft removal and low range 4WD.

I'm not saying that running it would break anything, I'm saying that I'm not going to tell a guy to go ahead and run a rig in 4WD on the front axle only if I don't have any idea what is wrong with the axle he is saying needs replaced. That is all I'm saying.

 

Hey Guys:

Just to clear things up. I got the notion that I could swap in a temp axle but even that could involve a rear brake job and new E cables (and ??), all of which are easy enough to do (for me) but costly to do remotely. I'll probably end up going that way anyway as that will likely be the only viable option (along with a shortened drive shaft - I was really hoping to avoid that part). I still have a line on a dana 35 which will fully bolt right on, but if I can come out of this with an even slightly better rear end, it's a small consolation.

In my current situation, I can't run on the front axle alone because the rear wheels won't move - the internal diff gearing is completely seized. The only thing that unhooking the drive shaft will do is leave a truck without a rear driveshaft and rear wheels that wont move. Perhaps the carrier could be pulled out to free the axles?

It seems to me that most 4x4's were not designed to be powered from the front wheels alone - I'm not sure the transfer case is up to the load and the front end drive comments are weaker (arn't they?). It makes sense that it would work for a short distance without any problems but over a longer distance, seems like it could be an invitation to other problems. If driving on the front axle alone was a typically acceptable mode, why wouldn't MFR's include that option in their transmission/xfer case options. I could see cases why you'd want to do that, (better traction in winter - of course you can just run in 4wd but wouldn't front wheel drive only would presumably offer better fuel economy). My guess is that the cost increase required to beef up the front end and drive components to sustain front wheel only drive mode would make this option prohibitive. Maybe a front wheel drive 4x4 is available? - I seem to recall that there may be some old small 2wd/awd cars and truks that work this way? You guys obviously know a lot more about this than I do.

 

If you want a 8.25 in it why not put it on a trailer? That way you can get it home and do what you want.

 

The 8.25 will swap straight over - but you won't be able to preserve ABS if you have it (better off disabling it anyhow, y'ask me.)

You'll definitely need the shorter driveshaft - the pinion is longer on the 8.25. I think you'll also need the handbrake cables, but I can't swear to that at the moment. Everything else should be cake.

 

I'm doing the same thing, but the problem that i'm running up against is their is 2 lines going into the Crysler axle and the Dana 35 axle has 3 lines going into the axle. what i'm saying is 1 is the Emergency Cable (2) is a Hydraulic Brake line (3) is a Vacuum line in the Dana Axle. The Crysler 8.25 Axle has (1) Emergeny Cable and (2) Hydraulic Line. that is it. Please Help!!!!!!

 

whoa old thread brought back to life, the c8.25 used the bolt that holds the brake lines to the axles as the breather too. So its an easy fix. I actually unbolted the brake likes from the wheel cylinders and reconnected those to the 8.25 (couldnt remove the rubber line from the body hard line). I used the same ebrake cables, just had to adjust it. it has alot of adjustment

 

What you think is a "vacuum line" is really just a vent line - it's there to allow the pressure to equalise as the axle heats up and cools down (normal with use.) This line doesn't really connect to anything - there's a plastic filter bung in the upper end, it terminates somewhere above the floorboard level, and it doesn't really do anything else.

Yes, you should have it.
Yes, the 8.25" probably has it as well (just attached to the stud for the brake junction block, most likely.)
Yes, if you don't have it, it should be added (it can save blowing out a seal or a gasket if the internal air pressure gets too high from generated heat.)

Most transmissions and transfer cases have similar vent lines - the crankcase isn't a strictly sealed system, and the temperature-related changes in pressure are relieved through the PCV/CCV system.

 

I've done the swap. 99 8.25 to replace the 35 in an 88.

Just be sure to get the u-bolts and plates from the donor Jeep. Easy.