Modrod

Access flange on the gas tank is on the front side of the tank, not the top. You can get to it from underneath the Jeep by the axle. Jack stand it and let the axle drop out of the way. Just remember the rubber grommet that is on the end of the return tube. It seems to always get stuck to the bracket thing at the bottom of the tank and needs to be put back onto the return line before reassembly and will slide back into the hole in the bracket on the bottom of the tank.

Modrod

A lift doesn't necessarily mean it was beat on. I see a lot of Jeeps that are more show than go. What you want to look for is the over all condition of the Jeep and look for damage from underneath on the uni-body frame rails and floor pans. If these are not dented or scraped up then they didn't off road it very hard. Also, look into the oil fill cap for sludge and chocolate milk. If it is wet or chocolatey on the cap it has water in the engine and the head gasket is bad or the head is cracked. Then take the radiator cap off "year dependent and when the engine is cool" and look for oil in the coolant for the same reason. Look for damage on the suspension arms, lower shock mounts, diff covers ect. And any jerry rig crap on it. Like blocks on the rear leaf springs made of scrap metal, stretched out or bent to crap brake lines, duct tape and bigger the blob better the job welding on it. If nothing major then it is probably fine. They are tough, not indestructable, but tough.

Modrod

You need to get on your back and crawl under there and shake the crap out of it or let it idle with it securely chalked and E-Brake on. I have seen this problem before and "USUALLY" it is the heat shield welds on the Cat. You can get one huge hose clamp, or a couple of medium size ones that you put together and clamp it snug up against the body of the cat. Or, you can wiggle it until it breaks off. I try to keep it on there so it doesn't catch weeds on fire when you drive over them and cause you to be on the news for the 600,000 acre forest fire.
If it is really really dented like you say, yes it could be all the platinum coated, ceramic honey comb material rattling around and you will have to buy a new one. The thumping could be that your exhaust is a pretzel now from whatever did the dent to the cat and it is hitting the bottom of your Jeep. If the cat is jacked up, get one from Summit Racing with the correct size housing and inlet, outlet size and have Mineke weld it on for you. $70 for the cat through Summit. If you get the factory exact copy of it you will pay twice that or more to have it installed and purchase price. But if you install it yourself it would be the same price as the other way.

Or, the thumping could be your sway bar bushings. They tend to go back to the earth over time, dust to dust kind of thing. It can also be your track bar bushing and or bolt is loose on the track bar.

The more stuff you do yourself, the more you can spend on fun stuff and not all on just the maintenance stuff. Otherwise, my Jeep would have $10k in it and be worth $4k. lol

Modrod

UPDATE:
There are some problems with the Durango/Dodge filler neck fix for the closed to open cooling system conversion. The stock upper radiator hose on our XJ's is very small compared to most car/trucks/suv's. The Dodge filler neck is about 1 3/4 of an inch and the hose on our radiators are only 1 1/4. So it is tricky getting the hose to fit or adapt to.
So, I think the best way to put a filler neck and eliminate the closed system is to get the SUMMIT RACING filler neck which is about the same price $28 + shipping. It is 1 1/4 out diameter and our radiator hoses are 1 1/4 inner diameter. Perfect match.

The part is:
Moroso 63745

DieselD

I want to swap a 231 into my 91 that has a 242. I have a read some info and it seems 91+ have a 21 spline shaft I would like to get it off a 96+ so I have the seal flange. Would it work? I'm having trouble finding out if the linkage would bolt up or if I'd need to switch it or Fab something.

Modrod

The only other thing is maybe a T-case 1 inch drop kit or slide yoke eliminator for the T-case. Wait until you get the lift installed and see if the drive shaft vibrates. If it does, you will have to do one or the other kits. Drop kit $30, SYE $180 and a bit more technical to install. But the SYE is the best way to go. But the Drop kit works and is cheap.

Modrod

91+ have the 23 spline shaft. 90 and earlier have the 21 spline shaft. Plus, you can swap any linkage from one case to the other. These NP/NV T-cases are like LEGOS blocks. The parts are about 90% interchangeable.

DieselD

Thank you for clearing that up. So I will look for a 96+ 231 at the jy.

Zack92MJ

NOOO KEEP THE 242! I wish I had a 242!

DieselD

You can buy it when I pull it! Lol its only got 314k on it...

I was just reading some more. And what about my axle? Not sure if it would b a vaccum disco or not and how that (if it would) affect the 242->231 swap... its a 91.

Jeepyjeepy

I just got an mj and since the windshield wiper stuff is the same ill ask this here. Aside from my left wiper falling off at the press on place (fix that with a screw lol) i only have one speed....slow!...... what is the best/key things to look at when diagnosing this?

zakattack13

I am new to jeeps .. Jus bought my first xj about 2 months ago .. Among many problems that im workin on there is one that i jus cant figure out .. For some reason on the driver side the blinkers stop blinkin when the brake is aplied this only happens in the drivers side .. Both front and rear blinkers stay on steady when i apply the break?? Any one got any ideas ??

dukie564

you have a poor ground at the driver's rear taillight. It should be behind the kick panel behind the spare tire. Refresh the ground (nice and shiny) and check the wire condition.

straight s!x

hey guys i have a 98 cherokee 4 door and my passanger window (power) works some times then stops. i took off the panel and messed with the wires but theres a ton of wires and wondering if ne one had the same problem and can tell me how fix it..idk if its the motor or a wire some times it works some times it wont

zimbobwye

I'm sure someone else could give you more/better direction. But, I believe your problem lies in your driver's door panel.
Does it operate intermittently from just the passenger's side, or the driver's side, as well?