1989 ba10/5 rear main seal

[Buffalo Man]

So you absolutely have to remove the engine to change the rear main seal on the ba10/5 equipped comanches, huh? 

 

This is a serious problem... I bought this Comanche for $8500 (ouch) and while it is not rusty, and very clean 4x4, it has taken so much money in like 2 months... 

 

I don't really have any other options, too much student loans to finance anything, (and honestly wouldn't want to anyway... )

 

If I'm ripping the ba10/5 out, I may as well put in an ax-15 but that's at least $700 if I rebuild it myself and install it (have never done this before)... All searches for reasonable used ones are over $1000...

 

I am feeling very disheartened that I had to sell my property to afford a decent truck, and now it's leaking majorly from the RMS and I am here .. maybe this is more of a support request?

 

How do I get through this? Do I just put the ba10/5 with 220000 back in?

[89 MJ]

I do not believe that you have to remove the engine to change the RMS on a 4.0, regardless of engine.

 

Where are you finding that the rebuild for the AX-15 will be $700? Or is that figuring the initial purchase of one that needs a rebuild? I'm seeing rebuild kits for $350. That is assuming that you have the AX-15 crossmember already and that you're clutch and flywheel are in good shape. I would also only do an external slave AX-15 swap, as the internal slave cylinders don't seem to be made well anymore.

 

How do you use the truck? If you do a lot of towing and hauling or like to drive the truck like a sports car, it would be worthwhile to swap to the AX-15. If you just casually cruise around in the truck and don't really use it for truck stuff often, the BA10/5 will do just fine. In fact, my BA10/5 was a much smoother shifting transmission than my rebuilt AX-15 is. 

 

How much oil is the truck really leaking? Unless the oil leak is very frustrating to you (I am one of those people that hates leaks) or the clutch is getting oil on it or its causing other problems, you can buy a lot of oil for $700. If the engine also has 220k miles on it, there is a chance that the crank is worn and a new RMS won't completely fix the leak anyways. 

[JZLAJeep]

The transmission type is irrelevant to the rear main seal replacement. The transmission gets pulled (usually) regardless of the type. We were lucky enough to find an AX-15 from a Cherokee in a junk yard. Keep an eye out there.

[Eagle_SX4]

Neither the transmission nor engine needs to be removed to replace the engine rear main seal. The only thing that has to be removed is the oil pan. Which you can remove if you unbolt the shocks and let the front suspension drop out of the way.

[87MJTIM]

You don't have to pull the trans to change the RMS.

 

The RMS is a two piece seal.

 

You have to drop the oil pan and remove the rear main bearing cap. The lower half of the RMS is in the cap.  Use a small brass punch to remove the upper half of the RMS.

[Buffalo Man]

1 hour ago, 89 MJ said:

I do not believe that you have to remove the engine to change the RMS on a 4.0, regardless of engine.

 

Where are you finding that the rebuild for the AX-15 will be $700? Or is that figuring the initial purchase of one that needs a rebuild? I'm seeing rebuild kits for $350. That is assuming that you have the AX-15 crossmember already and that you're clutch and flywheel are in good shape. I would also only do an external slave AX-15 swap, as the internal slave cylinders don't seem to be made well anymore.

 

How do you use the truck? If you do a lot of towing and hauling or like to drive the truck like a sports car, it would be worthwhile to swap to the AX-15. If you just casually cruise around in the truck and don't really use it for truck stuff often, the BA10/5 will do just fine. In fact, my BA10/5 was a much smoother shifting transmission than my rebuilt AX-15 is. 

 

How much oil is the truck really leaking? Unless the oil leak is very frustrating to you (I am one of those people that hates leaks) or the clutch is getting oil on it or its causing other problems, you can buy a lot of oil for $700. If the engine also has 220k miles on it, there is a chance that the crank is worn and a new RMS won't completely fix the leak anyways. 

The truck was purchased to do farm work, pull small stumps, haul dirt, gravel, a trailer with roughly 2500lbs, get out of the mud, and do truck things. Though it is in nice shape, it's not really about that for me. Also, my crippling student debt means that I am married to any vehicle i may have until someone dies. 

 

There's an ax15 transmission near me for $200. Kit is about $350, but it needs all sorts of other things other than rebuilt in order to get in there. $700 is kind of speculative. The kit from dead jeep is $2500ish, which is fine... I may just buy the kit because I don't really want to mess with finding all the parts and then finding out what condition they're in and such. Its just really inconvenient and most of my savings :/

 

Unfortunately the RMS leaks so much oil that it got on the clutch ,which now slips. The Chilton shop manual Rear main seal writeup says "remove transmission" as step 1 for ba10/5 and says "disconnect negative battery terminal" for the ax-15... 

 

 I got the oil pan off enough to look up there and found a brand new oil pan gasket... Bad news... and there is no transmission inspection plate in there that I could see. It doesn't look like I can access the RMS from that side.

 

I put the project down and went home, so I'll send pictures next time I get out there to verify ... 

 

 

[87MJTIM]

Manual transmissions don't have inspection plates.  The dust shield is a solid, single piece of metal.

 

You have to remove the rear bearing cap to access the RMS.