Off Roading Forums banner
1 - 8 of 8 Posts

Discussion Starter · #1 ·
O.K. this is not for me but my girl friend. She wants a 4x4 to keep up with
my toyota so she found a wrangler. It took forever but she found one that is
an auto. It is a 90 with 4.0 auto. What are some problems we should look for?
The original owner still has it, and is a late 40ish women, so being 4wheeled.. doubt it. Well my g/f will want to wheel it, most likely run 33's like me. We dolight mud trails in the woods here in missouri. Will the auto handle this without any major modifications? Will the axles hold out for light wheeling? Should I make her get a 5-speed, or will the auto cut it? Please clue me in on anything you wish to for warn us with.


Discussion Starter · #3 ·
There should be no problems with the auto. transmission. I've driven Jeep autos for over 20 years and have two now, one a YJ and one a CJ and they're used hard. Never had problems with the autos.

'94 YJ and '85 CJ7 with stuff done to it/wwwthreads_images/icons/crazy.gif

Discussion Starter · #4 ·
I too have a 1990 YJ but if I were to do it all over again I would buy a 91 or newer. The 90's came with either a 2.5 FI or 4.2 egine with a carter carb. The 91 and newer had an option for the 4.0 High ouput fuel injected engine. The carter carb. has been very problematic for many people. (just look and see how many people have upgraded to fuel injection). The engine is probably the 4.2 engine...unless the original owner installed a new engine. The 4.0 engine has around 180 horses compared to the 115 horses in the 4.2 engine. I wouldn't give up my jeep for anything but I'm in the process of swapping out the 4.2 and looking for a 4.0 engine. Don't waste your time with the carter carb. Keep on looking, there are plenty of deals out there.

Happy Jeepin'


Discussion Starter · #5 ·
I have to agree, the 4.2 is a pain in the ass. Wait until you you find a 91+ 4.0. You will be much happier with it. People in my club are swaping out thier 4.2's because they are tired of screwing around with carbs on the trail. I'm sure there are people who love carbs but for ease of operation you can't beat fuel injection. Check out they hav a classified section that usually has decent built-up jeeps for sale.



· Registered
1,736 Posts
I have seen a 90 with the 4.0 in it also, so that may be possible. Perhaps it was right at the changeover time??? Not sure, but I saw one on a used car lot once.

I've got the auto in my 88 YJ with the 258, and it is a good tranny, 199,000 on it now, no issues. Just keep the fluid clean, and replace the filter at good intervals.

For 33s you may want at least 3.73s. I have 4.10s. I don't know that you will want to run them on the 3.07 stock gears, if that's what it's got. You may want to consider a tranny cooler for the tranny.

Bottom line, the tranny should hold up to wheeling. Supposedly it was put behind the 304 for a while? Some say it lives behind the big v-8s too.

Good luck

88YJ, 4"susp, 33"BFGMT, 9k#winch, rear homemade swingout, reb.258, 999, 4.10, weber32/36, GMHEI.

Discussion Starter · #8 ·
Hopefully you won't see any problems. I do hafta agree that finding a '91 or newer would be ideal. I shopped around quite a bit for mine and once I drove the 4.0 injected mill, I was hooked. Good Luck!

'91 Wrangler in the building stage
1 - 8 of 8 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.