maxmueller333

Hello all, I am new to Jeeps and bought myself a 98 ZJ 5.2 with 265k miles. It’s looking pretty nice and the history was pretty good, so I bought it for a grand.
Im sure it has issues but I have two that seem very obvious, but I don’t know what it means. At least there is no check engine light.

When reversing on a hill/sitting on a hill, the moment I put it from R into Drive the RPM go close to 0 and instantly catches itself, that’s when the Jeep is hot.
This morning when it was cold, it stalled and shut off. Restart everything fine.

On flat/not very steep surfaces I don’t have any problems. Also engaging Reverse no problem, only when I put it from R into D on a hill.

Also it idles pretty low at <400 rpm, and the needle slightly goes up and down.

The second problem is a whining from the auto trans I think, I only hear it in first and second, after that I don’t hear it anymore but that might be due to driving noise. The whine increases with RPM, it’s the loudest at ~2100 and not really noticeable under ~1500. Only notice (hear?) it at low speeds.
Sounds pretty much like when a car goes reverse (when the geartooth are straight to each other I think).
The fluid doesn’t look too fresh, but as i found out I have to drop the trans pan to change it so now I have to wait for parts.
But does anyone know what the whine indicates (maybe it’s normal) or how severe the condition of the Autotrans is?
It shifts fine everytime so that’s good.

Today I got the „service 4wd switch“ warning for a minute, but I’ve read that’s no concern. But who knows if that’s related.

If you made it this far, thank you very much for your time!
i sure would appreciate some knowledge, I am young and still need to learn.

dave1123

Disassemble and clean the throttle body. This will improve your idle and probably eliminate the stalling as well. Treat that transmission well. At the mileage that's on it, it's getting pretty tired and needs loving care. You can get a neoprene trans pan gasket from the dealer that can be reused a number of times as long as you don't use sealer on it. The one on my WJ has been thru 4 fluid changes and still doesn't leak. Use nothing but ATF+4 fluid and change the filter. Check the fluid level hot, at idle, and in NEUTRAL, not PARK. It makes a difference of about a quart. Check the pan for filings stuck to the magnet or grey powder mixed with the film on the bottom of the pan. The grey powder is clutch material that's worn off the plates and the steel filings are from the driven clutch plates. Any large pieces are a cause for concern. The whine may be from the pressure pump, but some will last a long time before having problems.

Pull the rear differential cover and inspect the condition of the gears and their wear pattern. Try to move the pinion up and down looking for movement of any kind, also backlash, as in radial motion before it moves the ring gear. You should do the same with the front axle if it's constant 4wd. Then you'll have a good handle on what to worry about.