Well, I have been keeping my eye out for an OM617.95X diesel engine and finally bought a 1983 Mercedes 300SD here in town. The motor ran like a top with little if any blowby out the oil fill hole. The auto trans. was shot which didn't bother me 'cause I wasn't going to use it anyway. $800.00 for the Benz later and out came the motor. I told the owner all I was really after was the engine and a few loose ends and he said he was interested in the rear window and tail lights so I told him he could keep the car if we could pull the engine out where it sat. He was elated to do that deal. Spent 4 1/2 hours one day with my brother, tools, lift and a trailer and got it out. What a greasy job!
Went through the diesel with a fine tooth comb and had the valve cover, turbo housing, intake manifold and exhaust manifold powdercoat the various colors, they are beautiful to say the least. I bought the transmission adaptor plate, motor mount saddles and oil pan kit from Mercedes4X4 in Tennessee. It is very nice hardware but not without some issues... Once the motor was finished I planned on waiting until school got out to do the swap (my wife is a school teacher) Well, that didn't pan out because the clutch slave cylinder decided to give up the ghost in mid May. I pulled out the transmission only to discover the AX5 had other, more serious issues
I completely rebuilt the AX5 with all new bearings, seals and cluster shaft. I also did the 5th gear retainer mod and all is well. As a side note there is a flaw in the 5 gear needle bearing assembly which puts into proper place the 4 absent needle rollers which I rectified before re-assembly.
Well, do I re-install the trans to the 2.5 gas engine or do the diesel swap? Diesel it was. What I thought would take me 2 weeks took almost 5 weeks to complete. I am by nature OCD and have to be owning a precision plastic injection mold making shop. Our adage is this: "There is never time to do it right but there is always time to do it over" So, I try to do things right the first time.
The engine swap went well enough as I gutted out most all of the under hood wiring removing all of the EPA and engine fuel injection wiring, sensors and the such. I then pre-wired all of the needed connections so when the motor went in it was simply plug and play. While the stock motor was out, I painted the engine compartment the matching orange and frame with the new mounts the factory black. It came out purdy. Now comes the problem(s), the engine adapter plate has a design flaw in it in that the Jeep starter motor does not seat squarely to its mount. The clearance hole provided needed to be moved .125 closer to the starter mount otherwise the starter ***** up a little because of what is actually 2 very small but problematic lips in the starter casting. These lips not only cause the starter to ****, they cause the 3/8" allen bolts to bind up as well. Also, I had to machine away a fair size portion of the 3 piece laminated engine adapter in order to just get the starter in place to begin with. Another problem I had was with the oil pan modification. As built per the specifications with the inside front walls required to be flush with each other the timing pin in the harmonic balancer then hits the forward lip on the new portion of the aluminum pan. This had to be ground away as well.