Track bar

What is the difference in the trackbar's between a 90 and a 91 XJ?

I need a new one and I happen to have access to a track bar off of a 91. My jeep is a 90. Looking up the part number online I see it only fits 91 and up.. I held it up to the old one (still on the jeep) and I cant see anything. Someone please educate me. :wierd:

FYI
The part number for my new bar is 18205.04 OMIX-ADA

If you have the trac bar off the 91, do you also have the bottom bolt? I'm just guessing, but my guess is the bottom bolt and bushing sleeve for the early trac bar is a different size.
I do remember the bottom bolt as being a hybrid in the Renix, S.A.E. threads, but the bolt shank or bolt shoulder was metric. Like I said, just a wild arsed guess.
I do know the part number for the bolt is different between the Renix and later years.

5-90 would probably be the one to ask about this, hardware is is specialty. He may be over on Jeepforum.

No, I do not have the bolt for the new track bar but I do have a new bushing kit for the old one. Maybe I can do something there. What I don't get is that all the adjustable track bars are for all years but the OE bars are year limited.

Probably because they are adjustable? Sometimes they say "universal" but you still need to specify vehicle year. Therefore it could be different parts. It's quite easy to take it apart, then you could really compare them. Also, why bother put a used track bar? Was it just changed on the donor truck?

It is not used, it is new in the box. I bought it for my 94 before it was wrecked.

Well if we leave it to catalogs, it won't fit! But you got both man it can't be hard to spot the difference! Compare them again, and compare the ends especially. Maybe you were holding it wrong when looking at it?

EDIT: the adjustable one can take many shapes therefore will fit in more possible places, even with modifications on the vehicle

Iirc, the big difference will be on the taper end. Slightly different shank size.

I just did this exact swap today. Took the track bar out of a 90 I'm parting out and threw it in my 91.. Fit perfect with no issue at all.