XJ 4.0 into TJ: Hardest engine swap ever

UPJOHN

UPJOHN

TJ Enthusiast
Joined
Dec 15, 2015
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Location
Bessemer, Michigan
My son has an 01 TJ that's been sitting in his garage since the 4.0 locked up last spring. I found an 01 Cherokee local on Craigslist with 100,000 miles for $400.00.
I figured it would be a simple swap. Boy was I wrong. The blocks are completely different where accessories. Alternator, water pump, power steering pump, oil filter-pressure sending unit, etc. Oh and fighting rust.
Worst engine swap I've ever done.
 
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Flivver250 said:
Do you have it back on the road?
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No. We pulled both engines last week. He ordered some small parts, and we finally got back to it today. The clutch alignment tool he ordered was wrong so he had to buy a clutch kit today just to get the right one.
We worked on it for eight hours and finally got the engine and transmission mated. We left it hanging on the engine hoist for tonight.
 
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UPJOHN said:
My son has an 01 TJ that's been sitting in his garage since the 4.0 locked up last spring. I found an 01 Cherokee local on Craigslist with 100,000 miles for $400.00.
I figured it would be a simple swap. Boy was I wrong. The blocks are completely different where accessories. Alternator, water pump, power steering pump, oil filter-pressure sending unit, etc. Oh and fighting rust.
Worst engine swap I've ever done.
Click to expand...

Should have asked first. I could have told you it would be trouble ;)
 
UPJOHN said:
I didn't realize there was such a difference in 4.0 blocks. When searching junkyards for engines they list the same engine for TJs, Cherokees and even Grand Cherokees.
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Oh yes, there are differences a plenty. In fact, even the engine from a 97 TJ is much different than an 06.

Obviously you can make it work, it’s just more time consuming.
 
What a pain. Keep the faith, at least you are working with your son....that’s awesome. Use the forum , these guys will help any way they can.
 
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UPJOHN said:
My son just called me and said the motor mounts from his TJ block won't even match with the Cherokee block. Both engines are 2001s.
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Uh oh... that’s something I hadn’t even thought about, but it makes a lot of sense now.

This just goes to show how many variations of the 4.0 there are. I’m not sure if there is a fix for this short of cutting and welding.
 
We're thinking of switching internals from the XJ block into the TJ block. That is if the cylinder walls aren't damaged.
A piston skirt dropped and lodged between one of the rod caps and the pan. We haven't pulled the pan yet, so don't know the extent of the damage.
 
Chris said:
Uh oh... that’s something I hadn’t even thought about, but it makes a lot of sense now.

This just goes to show how many variations of the 4.0 there are. I’m not sure if there is a fix for this short of cutting and welding.
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The motor mount problem does make a lot of sense based on the whole topic of the two engines being pretty much completely different which happens to make absolutely no sense to me. What the heck was Chrysler thinking?
 
JEEPCJTJ said:
The motor mount problem does make a lot of sense based on the whole topic of the two engines being pretty much completely different which happens to make absolutely no sense to me. What the heck was Chrysler thinking?
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They had to come up with ways to fit the 4.0 in different applications. The Wrangler has a frame, whereas the Cherokee is a unibody. That's going to result in different motor mounts no doubt.
 
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We got the motor mounts sorted out. The right mount from the XJ, the left from the TJ with one longer bolt and a spacer.
The only thing will be there is nowhere to mount the a/c compressor.
 
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Glad you figured it out! This should be a lesson to everyone of course. Always try and find a replacement engine from a TJ, and try to make sure it's from the same year as well. They changed a bunch of stuff over the years, which I can't even keep track of.

Would be nice if we could somehow compile a list of all the changes.
 
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I wish I would have found this earlier.
Still $400.00 for a good running 4.0 was a deal.
 
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Glad you got it all taken care of! I guess it goes to show it will fit, it just won’t make for the easiest of projects.
 
UPJOHN said:
No. We pulled both engines last week. He ordered some small parts, and we finally got back to it today. The clutch alignment tool he ordered was wrong so he had to buy a clutch kit today just to get the right one.
We worked on it for eight hours and finally got the engine and transmission mated. We left it hanging on the engine hoist for tonight.
Click to expand...
i know that this is old topic, but if someone reads this maybe it will help. they sell a universal clutch alignment tool for about 15$
 
Having a similar problem (possibly exactly the same) with a WJ stroker from a 99 Grand Cherokee I'm trying (AAAAAAHHHH!) to put into my 2000 Wrangler replacing my TJ that threw a rod. It was a great price, $400, but I'm freaking out because of all the issues.
I've got the engine in but my buddy noticed a space irregularity in the mounts. I will need to chain lift the engine again to adjust the motor mounts, which looks like your (thanks Upjohn!) suggestion might work out.
But then as components were going back in, I found a missing post for the alternator and no post for the ac condenser. As I struggle forward I'm wondering if pulling the engine back out and selling it to get the proper fitting motor in is the solution, or if I should fabricate some brackets. I have (till my cuz gets sick of me taking up his precious lift) the use of a full shop with metal fabrication and welding capacities. Any thoughts would be appreciated. One step forward, two steps back...
 
JamminJ33p said:
Having a similar problem (possibly exactly the same) with a WJ stroker from a 99 Grand Cherokee I'm trying (AAAAAAHHHH!) to put into my 2000 Wrangler replacing my TJ that threw a rod. It was a great price, $400, but I'm freaking out because of all the issues.
I've got the engine in but my buddy noticed a space irregularity in the mounts. I will need to chain lift the engine again to adjust the motor mounts, which looks like your (thanks Upjohn!) suggestion might work out.
But then as components were going back in, I found a missing post for the alternator and no post for the ac condenser. As I struggle forward I'm wondering if pulling the engine back out and selling it to get the proper fitting motor in is the solution, or if I should fabricate some brackets. I have (till my cuz gets sick of me taking up his precious lift) the use of a full shop with metal fabrication and welding capacities. Any thoughts would be appreciated. One step forward, two steps back...
Click to expand...
So I'm sorry, it's exactly the same problem. I was told the engine was from a Grand Cherokee. It wasn't so Grand.
 
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