4WD HI Driveabilty - need some diagnosis help
 

With winter right around the corner, I'd like to finish up my last bit of maintenance, that being the t-case and diffs.

I decided to test out the 4WD to make sure Hi and LO engage. Both engaged fine. When i wanted to go back to 2WD from 4HI, the selector shifted fine, signal light for 4WD shut off, but the Jeep was still in 4WD. It took a little bit of driving before it popped back into 2WD.

Second, while in 4WD, during acceleration, the Jeep pulls to the right. In 2WD, no pulling issues.

Lastly, its been a while since I drove an XJ, or any Jeep with the NP 231, so I may be a little bit removed from the sounds that come from this T-case or when the front diff is engaged in 4WD. How loud or how much noise do they make? I think I am overdue for fluid changes on both given the previous owner's lack of proper maintenance. Would fluid flushes resolve some of these issues?

Thanks!

I will have to leave the diagnosis of pulling to the right to the more experienced guys but I can tell you that it should take a little bit of driving before the 4wd goes back to 2wd.

Also, with new synthetic diff fluid, the hum from the front in 4wd is very soft. So soft that passengers in the jeep dont notice it. I dont usually hear anything from the t-case specifically, I think it is just tire noise from the fronts tires being engaged.

Chuck

I have to fight to get mine back into 2wd, if I back up it will go back to 2wd soetimes. Rumor has it theres a spring in the tranfer case that causes this.

pulling to the right is common.


grease your steering joints (TRE's), and inspect your front axle u joints. replace as necessary.


but I got to tell you... you have a part time 4wd system. that means 4wd on dry pavement is NOT acceptable. it WILL CAUSE steering issues, and bind the t-case. usual result is a blown/sheared in half t-case. so keep it to crappy road conditions, please.

do you have a vacuum selector on the front axle if so it could be sticking my xj comes out of 4x4 with in the first 10 feet of driving

I had a previous XJ for like 7 years, 2 dr 5 spd manual, also a 96. Never used the PT 4WD unless we had snow or real bad weather conditions. My old never pulled like this, making me think something else is up. I could be wrong, possibly forgot the quirks of the XJ. I don't recall the way my old one sounded in 4WD, so I'm going to have to inspect that further.

And as for disengaging of the 4WD......I'm thinking something is either not greased, cleaned, etc......my old XJ disengaged within a distance of 20 feet after putting the lever back into 2WD.

Pics of vac selector? Location? Does the 96 XJ have this part?

only the renix XJ's with the 231 had the vac disco, its the same premise as lockout hubs but is a vacuum motor, collar and 2 piece axle shaft on the passenger side.

The linkage may need to be adjusted

Ive always had trouble going back to 2wd as well, I usually tap the throttle a few times or shift to natural and it would unlock