What engine and transmission do I actually have?

[Khor1287]

So when I got my 86 MJ i was told that it had an 88 v6 swapped into it. The problem is I don't really know and this being my first restoration I don't even know where to start looking. I've been pulling parts off and founds some stamps and lettering but its all Greek to me. 

 

So here is the back of the engine. It has some "F"s stamped in a couple places and some writing there in gold/silver. Do those mean anything to anyone? Cause they sure don't to me.

 

 

So I found these on the transmission and bell housing. Again, means nothing to me but these have got to be serial numbers or something that someone can decipher.

 

 

So all I know about the engine is that it has six cylinders and a carburetor. Before you ask, yes I'm replacing the rusted to heck freeze plugs. Popped those out and going to be flushing the block out as well. There is a ton of gunk in there. I just hope that the other plugs in harder to reach areas aren't in this bad a shape as well. Seems like that layer of gunk may have been keeping those two lower plugs from leaking too badly. 

 

The transmission is a 4 speed and was working fine once I was able to get it in gear. Well "fine" except I have not been able to get it into 1st. I'm hoping that is due to clutch release problems not something more serious. 2nd was hell to get into, 3rd and 4th much easier and reverse would just slip in without touching the clutch.

 

I really need to know what I have so I can be more efficient in ordering the correct parts. I also want to replace the fluid in my transmission while I have it out but don't want to put the wrong stuff in. Something looking like ATF came out of the speed-o port when I pulled it off but I probably wouldn't know ATF from MTF from gear oil from strawberry syrup so i need some help here. 

 

Any tips y'all can provide is much appreciated!

 

 

 

[HOrnbrod]

The bell housing number indicates a GM V6 housing as used on the 86 Jeeps w. the V6, and also Chev S10 2.8 V6's until ~1993 or so.

 

The 13-52-066-927 is the number for an S10 tail shaft. So it's probably had an S10 2.8 V6 swapped in. You need to find the engine block casting number to be sure. I don't know where the engine casting number is on the V6's.

[Green Mesa XJ]

The block cast number should be passenger side of the block top near the front sort of behind the exhaust manifold .

If it's not there it'll be drivers side front of the motor near the top of the timing cover, usually you have to remove the power steering pump bracket to find it.

 

But that looks like a one piece rear main seal which is GM 85 up, if it has a mechanical fuel pump on the drivers side of the block is is a 85 gm block that a few 86 MJ and XJ got, sort of a odd mid year casting.

 

However I suspect it is a newer than 85 block,meaning somebody dumped 1987-90 a s10 but you'll need to find the casting number to get the details.

 

 

 

 

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[Green Mesa XJ]

This is a bad photo of the usual spot gm puts the casting number,

Passengers side under the exhaust and above the engine mount.

 

The other spot at the top of the timing cover on the block behind the power steering

 

 

On the block I got a photo of the casting number is not there, but where the 2 is , is other spot where the casting could be.

 

 

 

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[Green Mesa XJ]

The bellhousing is the GM 2.5 & 2.8, I think it's for a GM T5 or whatever the 4 Speed equivalent is.

 

 

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[DirtyComanche]

The T4 is the 4spd version of the T5.  They're made by Borg Warner.  Out of curiosity I would try stuffing the shifter in the 5th gear position to see if it is actually a T4, it probably is, but I've heard of it happening before.

[Eagle]

Early in production of the XJ Jeep ran into supply problems with the AX5 and used the T5 as an alternate OEM part. I was under the impression that such problem were resolved before the MJ came out in 1986, but perhaps not.

[Green Mesa XJ]

It looks like a PO slammed in a later s10/Camaro 2.8 and transmission to me. The exhaust and oil pan also look wrong to me. But the casting number will tell the tale.

 

 

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[Green Mesa XJ]

saw your other thread with pictures of the MJ, definitely not a 86 set up, missing all the emissions crap (better off without it) and the alternator and ac compressor are later GM serpentine belts instead of V belts.

Looks like you've got the crappy jeep/chevy carburetor bolted on to what I guess was a later gm 2.8.

From what I can see looks like the crossmember and transmission mount would be correct for a factory ax5, which probably explains the ratcheting strap holding the transmission in.

 

Maybe be a mutt of a combination of engine and transmission slammed into it but it's a nice looking MJ.

 

 

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