89 MJ

That’s probably true. Seems interesting that they’re all two tone though.

Are you thinking that’s the four wheeler of the year edition, or do you think that’s two tone paint? I could see it being either, but if it is the two tone paint, that means Chrysler must’ve changed the code in 87.

Bucket seats and a 4cyl. That’s not a combo you see often. Looks like a nice truck

I think most, if not all were 4.0, 5 speeds. You’d probably have a hard time finding one, so I’d bet that it would be easier to build one.

Merry Christmas!

It would make it fairly close to a 4.0 ratio, which probably wouldn’t be much good with the 2.5L. In my opinion, there’s a couple of issues with the 8.8. Firstly, they are too narrow for the rear of MJs unless you get one from an Explorer Sport Trac. The other issue is the ground clearance lost. My MJ has an 8.8 and 31s, and I hit the diff when o did some very minor trails.

That’s not good. Better than out on an adventure though.

That would most likely be built into the oil pump

Our trucks were twins when new, might as well keep it that way

I’d try dumping a can of sea foam in the oil and running it at varying rpms for a bit. Maybe 20 minutes or so. Maybe that’ll help, maybe it won’t, but it’s worth a shot.

Thank you! Glad you enjoyed it

You are correct. I get why you’re second guessing yourself, this is a super strange issue

Goodness, that's probably what Old Faithful wants to be when it grows up. At least its all rust proofed. So somehow, it seems that the lifters are getting way too much oil or possibly that the lifters are diverting all of their oil up through the pushrods. I'm betting the first option though. Does it sound like it has a lifter tick? Being that it did it with the old oil pump too, I think we can safely rule that out from being the cause. I found this on how the oiling system in the 4.0 works: This has me thinking that possibly the main oil gallery is either somehow larger than it is supposed to be or that the other oil galleries coming off of the main gallery are partially blocked. No clue how that is possible though. How did the main and rod bearings look when you changed them?

I like this idea a lot. And as a bonus, I'd think it should help keep the shop a little bit cleaner too.

I'd agree that the oil pressure seems on the lower end from a fresh rebuild. Might want to check it with a mechanical gauge. Is it a geyser out off all of the rockers or just a few of them?

I would say that is true

There’s definitely something there. I’m right there with you

I also don’t think that the 4.0 is much better than the 2.5L. Certainly isn’t worth the work to swap in a 4.0 from a 2.5L. The only reason that I think would justify a 4.0 swap is if the truck was going to spend a lot of time towing.

That’s what I thought. The vinyl floor trucks seem to rust worse than the carpet trucks, which makes sense.

What is your oil pressure when it’s running?

Could be. Looking closer, I wonder if the gauges are aftermarket ones for something like an 80s F150. And maybe the climate controls are aftermarket like Vintage Air?

Makes sense, this was just the first I’ve noticed it

And the build sheet says 3.55 gears. I thought all 2.5L AW4 rigs had 4.56 gears. The build sheet also says it’s an MPFI 2.5L

I wonder what’s up with those gauges in that MJ

The belt should have less than an inch of movement if it’s tensioned properly. I’d pull the belt off and figure out what isn’t spinning and replace it.