I've got a 1986 CUCV 4x4, 1.25 ton, with 6.2 diesel and the automatic transmission.

I noticed I had a bad rear main seal leak, so I figured I would take care of it, and I pulled the pan, pulled the rear main seal, and I discovered that my rear main bearing looked like someone had taken an angle grinder to it.

Before I can use my truck again, I will need to get the crank turned, and put in new rod bearings, new mains, and a new oil pump.

I know it will not be easy, but I need to do the crank change with the engine still in the vehicle. Is this procedure described anywhere ? I have the US Govt Service manual for my truck, but I did not see an in vehicle crank r&r described.

I have done a crank r&r before in a 2wd International diesel truck, but not a 4x4 CUCV.

I'd like to see the procedure outlined somewhere.

If it were possible to pull the engine, I would. It's not possible in this situation, so I have to deal with what I have.

Further info:
The truck has 38,000 original miles on it.

I am fairly sure the damage to the bearings came from allowing someone to use the truck, and I think he lost the oil and kept running it.

I have flushed the engine and the oil pan and no debris is visible, it just appears it was run oil starved.

 

I have done an in-vehicle crank r&r one time before, but it was a 3.0 V6 Mitsubishi engine.

I removed all of the connecting rod caps (keeping them in order, of course) and pushed the pistons up in their bores. Be careful not to rotate the crank around into a removed con rod. Then i loosened all of the main cap bolts and completely removed all but two of the main caps (opposite ends, for support). Then had help holding the crank in place while removing the remaining main caps.

After parts arrive and crank is back from machine shop, install new block side rear main seal half and bearings (pre lubed, of course). Install all cap side seal half and all bearings (again, pre lubed). With a buddy's help, raise crank into position (again, pre lubed) and install one cap on each end of crank running the bolts in hand tight. Then install the remaining caps, making sure to hold the crank up against the block while seating the bolts. Torque as necessary. Reassemble everything.

This is how I would do it, if I had to.

Be careful, take your time, and good luck. Keep us posted.

 

Thank you for the helpful reply and information.

I got started this afternoon. The end caps are all that are holding her in. I got scared once or twice, but it went ok.

The biggest problem is getting things around the 4wd and the cross member(k-frame).

I don't have any help, so I am spending tonight in my shop and am making a cushioned cradle for the crank to sit in on a high lift transmission jack.

I will lower the crank onto the cradle, and lower the jack and take it out. $120 to get it turned .10/.10

PS: Did I mention I am doing this on dirt ? Yes, I do have it cribbed properly, but working on dirt stinks.

 

The front axle and cross member is the main reason that I suggested a buddy's help. Good to hear about the cushioned cradle, good idea.Improvise, Adapt, Overcome.

Thats also a good price for the turning. I had mine turned and I paid $200.

Yes, working on dirt stinks. But you say it's in your garage? It could be worse, it could outside in the cold, it could be raining or windy.

 

Don't forget the timing chain is still an attatchement point.

 

Good eye, Racer. I thought that I was forgetting to mention something.

Yes, the crank would be hanging by the timing chain if not removed. That would suck.

 

Man sometimes it sucks having to work on the ground like that let alone having to do a crankshaft like that (in the truck) I have a 84 CUCV myself and could not imagine not pulling the engine to do a crank but you may want to consider dropping the front axle as this would give you a lot more room to do the deed And having a good rubber mat is a plus for lying on the ground in any weather IMO