Hi everyone,

Yes, I have searched and found bits and pieces of answers across this forum and other Jeep forums. I'm looking for a comprehensive list of the expansion plugs (freeze plugs as some people still call them), namely their location on the 4.0L engine and the sizes of each.

From what I've gathered, there are:

(5) 2" plugs along the side of the block
(1) 2" plug on the back of the block inside the bellhousing
(1) 2" plug on the back of the cylinder head
(1) 2.141" (2 9/64") on the back of the block where the cam sits
(2) 1" plugs somewhere else on the head
(3) 3/8" threaded plugs, which I believe one goes on the side of the block, one on the back of the block, and one in the head

Please correct me if I'm wrong! I'm trying to find a full kit that has all of these. Dorman #557-017 only has (5) 2" plugs and (2) 3/8" threaded plugs... not sure what good that will do.

Also does the 2.141" one need to be changed behind the cam, I've heard they usually don't because they are just holding back oil and not coolant.

 

Uh oh, problems with the 96 block?

 

Thankfully no, that has about 5k miles on it now with zero problems. I picked up another 2000 XJ (I might have a problem) that I'm swapping a 99 4.0 into. I want to do a partial rebuild on the new engine and the expansion plugs look iffy.

 

Good to hear!

Well I picked up a 98 ZJ block that was in much better condition (known history) than the other one I already had. No need to rebuild and plan to do the same as you. Do a little "refresh". So, following

 

How about this set?

https://www.summitracing.com/parts/s...-8084/reviews/

 

That looks like it should cover everything. Technically there's 3 threaded plugs in the block, but you shouldn't really have to replace them. Even if you wanted to you can just take the stock ones out, clean the up and reseal them with RTV.

$16.99 isn't bad at all either, what's weird is the difference in Summit's pic vs. Rockauto's pic of the same part #....

Summit's version of Sealed Power 381-8084 @ $16.99:



RockAuto's version of Sealed Power 381-8084 @ $35.99:



Summit's is missing 1 threaded plug, while RockAuto's is missing one 2" plug which you DO need (the little 1" ones that it includes aren't needed for a 4.0). So either way go with the Summit kit.

 

I discovered it on Amazon, also which a different pic from both lol. Wtf?

Ill go with this and update if (if not) included is everything necessary.

Any tips on how to properly install? Really want to get this right as this is exactly why Im having to replace the engine :O

 

No idea, maybe they are all using stock photos of a different kit.

Proper removal would be to tap on one side with a punch until the other side pops out, then grab it with pliers and yank it out. Proper install is to use a punch or socket that fits inside the diameter of the plug and tap it in. For instance on a 2" plug I'd use a 1-7/8" socket and a hammer/mallet to tap in.

Some people recommend a very thin coat of RTV on the outside edge before installing, it wouldn't hurt. Also you tap it in until the bevel on the block is flush with the lip of the freeze plug. If you look closely there's a decent bevel on each of the freeze plug bores. Just get it as close to you can as flush. And that's it!

 

I just bought a set of these @ Oreileys (special order) and the part number on the bag is 381-8084. Made by Sealed Power/Federal Mogul.
It stung a little but I also ordered their installing tool kit for $65.00... I know it's not necessary but I want to make sure I get the plugs seated correctly so I don't have to do this exercise again.