REAR AXLE SWAP. I HAVE A QUESTION.

[Guest]

I bought a 93XJ rear axle (with locking diferential) to replace the one in my MJ88. They are same ratio and have some small diferences in supports and drums. Beside this, is anything that i should know/look out for before doing this?

Thanks.

Fernando

[87manche]

you will have to weld perches on that axle.

[Guest]

Thank you 87 manche. I know need some modification to bolt it.

Is there anything else from the mechanical point of view?

Mine is not locking and new is locking.

[87manche]

what axles?

if the pinion depth is different you may need a shortened or lengthened driveshaft, off course that depends if you're lifting at the same time.

More details please.

If it's the same axles then you'll just need to measure the perches out and center the axle, weld perches and bolt it up.

[Guest]

Sorry for my english. I speak spanish.

 

I bought the assembly . This means: the housing with the axles, diferential, pinion-gear , drums, brake parts, everything assembled. It has also lubricant and it is ready to run.

 

Hope to be clear. sorry again.

[JOMJ87]

I think he was asking you if it was a dana 35 or a different axle than what is already on your jeep. and also if its high pinion or low pinion and all of the other technical aspects of it.

 

Cole

[Guest]

I have now a DANA 35 in my 1988MJ and the one I bought is DANA 35 too from an XJ93 with the locking diferential inside.

 

I cannot answer about the high and low pinion. I do not know what this is. The yoke is the same and in the same position if this info helps.

 

I have both tags with the jeep codes also as info. The one in the MJ is 5300 4769 and the one to be installed is 5206 8072.

[jage]

Make sure you axle ratios are the same. (o.k. you already said this) You probably already know this but if the front is 4.1 the rear must be 4.1 or 4.11 also. 3.54 or 3.07 or anything else and you cannot drive in 4wd until you get one regeared.

 

There probably isn't a brake proportion valve on the XJ axle. This is a lever that increases the rear brake power when the bed is loaded.

 

Those are the only things other than what's already been said. I am putting an XJ axle on my MJ as well. Let me know how it goes.

[87manche]

I just did this swap a few months ago. It's as simple as measuring and welding on the perches.

I was lucky enough to have a spare Mj axle to take measurements from.

The easiest way to do it is to pull the original, and set it on jackstands. Pull the differential cover and make sure that the face is plumb. This gives you a reference point for making the same measurements on the new axle.

Get a magnetic angle finder and measure the angle of the perches.

You'll also need the location of the perches on the tubes.

Setup the new axle with the face plumb and setup your new perches in the same place as the old and at the same angle with your angle finder.

Weld perches on.

Percheas can be made out of some 2x4 box, I simply ordered the mopar performance ones from the Jeep dealer, but I don't know if that's an option fo you.

[Eagle]

Fernando,

 

The difference is that the 1988 axle does not use a 'c' clip to retain the axle shaft in the assembly. The outer bearing is an enclosed assembly and it is retained in place by the outer retainer plate.

 

The 1993 Dana 35 axle uses the same ring and pinion gears, but it does not use the retainer at the outer bearing. This axle uses a c clip inside the carrier to lock the inner ends of the axle shafts into the carrier. In general, the newer Dana 35 axles are considered inferior to the older axles because if the shaft breaks, the new design allows the wheel to fall off the vehicle. With the older design, the retainer plate at least holds the wheel in position.

----------------------------------------------------------

Fernando,

 

La diferencia es que el 1988 eje no usa un 'C' clip para retener el túnel de eje en la asamblea. El cojinete exterior es una asamblea encerrada y es retenido en el lugar por el plato exterior.

 

El 1993 Dana 35 eje usa los mismos engranajes del anillo y piñón, pero no usa la iguala en el cojinete exterior. Este eje usa un 'C' clip dentro del portador para cerrar los fines interiores de los túneles de eje en el portador. En general, los ejes Dana 35 más nuevo se consideran inferiores a los ejes más viejos porque si las interrupciones de túnel, el diseño nuevo permite que la rueda para caigase el vehículo. Con el diseño más viejo, el plato de iguala por lo menos asideros la rueda en la posición.

[Regger]

Also,

 

If I'm not mistaken, but the brakes on the MJ are larger in diameter than those on the XJ... But its not a simple swap.. The axle flange bolts patterns are slightly different.

 

I did this exact swap on the G/F's SAS S-15 jimmy that was using my old MJ axles. She blew up the MJ axle, and I got an XJ axle for cheap, but without brakes.. So I had to make a new bolt pattern on the old MJ backing plate to fit.

 

Worked good right up until I swapped it a few weeks ago for a ford 8.8

 

Also, 87manche is correct in his step by step of setting up new perches, but I prefer to set up the pinion angle while the axle is in the jeep. This way, you get it perfect, and if you are lifting it, or are doing a lift at the same time, the pinion will be exact for the lift.

 

I also prefer to set my perche spacing based the on the frame and not the spring position. The reason for this, was I found out the hard way, that I had a slightly bent shackle(previous onwer smucked a barrier, but told me it was lightly and it just dented the rear fender...HA...) that pushed my rear end over and caused it to dog track. When I put in a new axle, I set the perches equal distance on the axle.. Didnt solve my tracking problem.. The next time I swapped axles, I dropped plumb bombs donw from the side of the frame and measured from those to the axle flanges and centered the axle to the body and frame. At that time I still didnt know what was causing my dog tracking, but even though the perches were not equal distance to the axle, the axle was centered to the truck and made it drive straight

 

I now know that the shackle was bent, and even though it been replaced, I still set up axles centered to the frame and not axle.

 

HTH

Ryan

[Guest]

Gentlemen . All your inputs are very clear and helpful.

 

THANK YOU very much.!!!!

 

Eagle: Your wonderful spanish surprises me. Keep it up!!!!! It is very friendly to receive your comments in spanish.

 

Regards. Fernando

[87manche]

regger:

I didn't have any problems moving my MJ brakes over to the XJ axle, but they were both non-c clip. I wonder if that's the difference.

I took my backing plates and drums over with all new hardware on the inside.

[Eagle]

Gentlemen . All your inputs are very clear and helpful.

 

THANK YOU very much.!!!!

 

Eagle: Your wonderful spanish surprises me. Keep it up!!!!! It is very friendly to receive your comments in spanish.

 

Regards. Fernando

Thank you, but I admit to cheating. My wife is Chilena and I am learning to speak Spanish, but my Spanish is very poor and I used a translation program for that post.

 

Ciao

[Regger]

regger:

I didn't have any problems moving my MJ brakes over to the XJ axle, but they were both non-c clip. I wonder if that's the difference.

I took my backing plates and drums over with all new hardware on the inside.

 

Yes, that would probably be why they were the same if they were both c-clip styles...

 

Thanks,

Ryan