Need help with transmission

1993 jeep grand cherokee LT 4wd, 4.0ltr 6cyl engine

Just the other day while backing the jeep out of the garage something really strange happened to my transmission.

Seems like all the shift points moved.

Park is now reverse. But locked of course and the engine dies.

Reverse is now neutral and neutral is now drive.

Can someone tell me what happened here?

I didn't try to drive the car because I thought I would damage the trany further.

Anyone have anything I can try?

guess no one here has ever seen this problem

When you say it seems like it's locked, that's bad to me. How many miles and what engine?

Hi Fred
Seems all the shifter positions have shifted.

When the shifter is in the park position it normally locks the transmission right?

Park should be a neutral like position normally.

But now when I put the transmission into park it locks the transmission like it should in park but for some reason its in reverse and it can't move so it kills the engine.

I've checked the cable both bottom and top and it has not slipped and moves the transmission lever(arm?) its full throw.

It's got to be something internal that has broken or slipped to cause this slip in detent positions.

I guess I'm going to have to go to the local dealer and put myself in the mercy of those clowns :banghead:

Again, how many miles on? If it's over 200k then it might be time for a rebuild. Did the problem start suddenly or gradually?

I've read a lot about the NSS (neutral safety switch) in the Cherokee section. Apparently when it gets dirty it can send incorrect signals and cause issues like what you're experiencing. Check the Cherokee section, there are several threads where people cleaned their NSS to get back on the road.

If that's not it then I'd agree it might be time for service.

yes it is over 200k

would the nss switch cause park to be reverse

reverse to be neutral

and neutral to be drive?

yes the problem happened suddenly. When I backed out of the garage it was acting normally. By the time I tried put in park at the front door it killed the engine.
I couldn't figure out what happened.
I tried to start it in park, it turned over but seemed like the starter was under great load.
Then I put it into neutral and tried to start. It started and just took off. It had started in drive because it thought it was in neutral. Then I shifted around and found that reverse now acted like neutral.
Could a screwed up NSS switch cause this?
Does this transmission shift electronically?
Does anyone know exactly which transmission is in this car?

yes it is over 200k

would the nss switch cause park to be reverse

reverse to be neutral

and neutral to be drive?

With this and your following post, it sounds like there might be multiple problems. The NSS won't cause the gears to be different, that's usually a linkage issue. But the NSS malfunctioning will allow you to start in something other than Park or Neutral.

I just re verified everything.

You cannot start the engine anywhere but park and neutral. Like it should.

But since park is now reverse it doesn't want to turn over there.

The engine will turn over in neutral but since this is now drive or some forward gear
the car wants to move forward when you crank and will take off if it starts.

I looked under the shifter console and everything looks connected and in place.

Is there any adjustment in the cable that goes from the shifter and the transmission?
Could something have slipped here and be causing this?

Like I said before the lever where the cable attached to the transmission seems to be going it's full throw. But since I don't know how far it went before this happened I am not sure.

Is there anything I can try here before I have it towed to the dealer????

I have to say that I'm out of ideas. I've never encountered something like this, unless the transmission needed a rebuild.

Someone told me the linkage has slipped and to adjust it. The linkage is a cable and I don't see that it has slipped.
In a couple days I will have it towed to the stealership. :banghead:

I decided to drive the jeep a little today. We are on a farm so I have plenty of fields to drive around on.

I started it in neutral. It won't start in park because I think in some gear there. The parking pawl is engaged though and it can't move.

At first neutral seemed like neutral, but then after a few seconds it started to go forward in neutral.

Ok so I put it into drive. It shifted through first and second.

Then I got up the nerve to try it on the gravel road.
The transmission shifted through all the forward gears normally.
I tried down shifting using 2 and 1. All seemed normal.

But there still is no reverse in the "R" position. It almost seems like another forward gear, but not. Sometimes it will bog the engine in reverse and then lets up????

So maybe all this will give someone some more clues.

thanks

check the shifter linkage at the transmission itself. Either have someone inside the vehicle holding the brake and remove the linkage off the ballstud on the transmission and shift it yourself. You could also jack up the wheels off the ground and do the same thing, just make sure you put it in N before going in or out of R or D. It sounds like your linkage is off/out of adjustment.

The more I hear, the more I'm thinking rebuild. If the problems were always the same it could be the linkage; but since things change....

Yes I'm thinking rebuild or replace myself.

What's confusing me is that why are all the forward gears working so well?

Probably if I knew more about the inner workings of the auto trans I would be more clear.

Give me an old manual trans any day.

I prefer manual myself, they don't break after 150k like automatics.

Very basically: The auto trans has gears that are always meshed. There are cogs on each gear that disengage them from the shaft they're on; the cogs are operated by fluid pressure; on older transmissions they used metallic bands that were tightened around certain parts of the shaft, to stop that shaft and allow another to rotate. Depending on which shaft is rotating, you have different gear ratios.

What might be happening in yours based on what you've said is that there's some inconsistency in operation, due either to fluid blockage, a weak spring, or worn parts.





Of course I could be 100% wrong and it's just a sensor :confused: but you'd need to have it hooked up to the diagnostics at a trans shop to find that out. So before I'd pay for a rebuild, I'd maybe try some fresh fluid and have it checked.

In addition to what fred was saying, if you go to a tranny shop, have them do a fluid pressure test. That is a key diagnostic test that can help you figure out if you have a slipping clutch or band or any other problem you may have.

1993 jeep grand cherokee LT 4wd, 4.0ltr 6cyl engine

Just the other day while backing the jeep out of the garage something really strange happened to my transmission.

Seems like all the shift points moved.

Park is now reverse. But locked of course and the engine dies.

Reverse is now neutral and neutral is now drive.

Can someone tell me what happened here?

I didn't try to drive the car because I thought I would damage the trany further.

Anyone have anything I can try?
you should take a look at the shifter cable sometime it needs to be adjusted.goodluck

Thanks guys for all the help.

The jeep is at the transmission place for diagnostics and probable rebuild.

I'll keep posting updates of the cause and cure.

thanks

hi jeepjerk,sorry i Did not reply sooner,it seems to me that you a problem with the shifter cable.This is what i want you to do.have a helper with you.someone will be under the car.
with the ignition on position(do not start)foot on the brake have the person in the car move the shifter back and forth while the one under looking at the cable end checking for any damage.if you can jack all four wheels off the ground and disconnect the end of the cable
start car and move the transmission manually now see if you have reverse .if you have reverse the problem is with the cable,if not the problem is with the transmission.
Good luck, Thanks for the email.

The repair guy said the forward clutch assembly was seized up. So just had him rebuild it. It's working fine now.

新人来报道！呵呵！

Wow, I've never heard of anything like that happening in normal operations -- glad you're back on the road. Now that I'm thinking about it, that would play havok with the fluid pressures causing the odd shifting issues you had.