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1991 XJ 4.0 HO What to do....

1991xjbeater

NAXJA Forum User
Location
Union, Ohio
I need some suggestions as to what I should do with this vehicle.

I have a 1991, 4 door, 4.0 HO XJ that has a rebuilt engine with 20k miles on it. The jeep has about 180k miles on it. The main seal is leaking and the transmission is now not shifting properly. It doe snot like to down shift. I has a bad nuetral start switch and needs new suspension and exhaust. It is in good body condition and everything else works great. It has power everything.

Should I spend a little money and get a rebuilt or used transmission or have it diagnosed to find out the true problem or should I sell it cheap or maybe look for a small block chevy and transmission to swap in it and then get new suspension for it?

What do you guys think?
I am leaning towards selling it cheap for someone to turn into an offroader only.

Thanks, Chris
 
take the tranny switch apart, clean and regrease, check fluid levels in the tranny as well. If that does not help have it looked at. Probably 80 to have someone diagnose the problem. with the Aw4, it is generally all the way gone, or fixable for cheep.
 
Thanks for the info and repsonse. I have the info on cleaning the switch, but have been to lazy to do it. I have a bypass switch on it right now and it works well.

Chris
 
I have not tested it. I was told that it could be the Crank shaft position sensor. It was idling high and then shutting off when I gave it gas. That has gone somewhat away and now I have the high idle, does not want to downshift problem. I drive this as my beater and have a lifted 03 Rubicon as my DD. I do not want to dump a small fortune into right now. i would be ok with $300.00 to make it run right.
 
I was told the bad new today. I need a new transmission. I got a cost of $1200.00 for a new unit. I am not going to do it. I need options if anyone has them. I guess it might be time to part the thing out.

Thanks, Chris
 
If the body is good, it's ALWAYS worth fixing. Do you trust the tranny guy? Sorry, but they are notorious. And I apologize to any honest transmission mechanics out there. I know there are a few.
 
x2 on not trusting the trans guy unless you know better.
they know we're all afraid of catching aids from tranny fluids, and will listen to them as 'guru's'...
BEFORE you do anything else, double check your grounds and tps. both will cause bad shifting.

selling an xj is allways a bad idea, your not gonna get anything for it, unless you put a boatload of money into it... theres practically no market for non running xj's, craigslist has PLENTY.
 
My 93 xj lost every gear except 1st and reverse I ended up getting a new tranny and putting it in myself in all I have spent 200
100 for tranny
10 for flush
6 for seal
10 for new bolts
30 for new filter and I'm only 17 so its definitely worth it
 
I was told the bad new today. I need a new transmission. I got a cost of $1200.00 for a new unit. I am not going to do it. I need options if anyone has them. I guess it might be time to part the thing out.Thanks, Chris

I can't help but think you're getting screwed (let me guess AAMCO?). What are the symptoms? You mentioned it not wanting to downshift?

More than likely the problem is simple and does not require replacing the transmission. The AW4 transmission is electronically controlled and the transmission computer tells it when to shift based on throttle input and speed. Most of the time erratic shifting is due to a bad throttle position sensor (TPS) sensor. They do wear out and can be tested fairly easily with a meter. They cost about $30 and literally take 5 minutes to replace. A bad TPS sensor would also explain the erratic idle, btw.

If the tranny really is bad (probably not), a rebuilt can be had for around $600. A used one can be had for as cheap as $50 from local junkyards.
 
I do trust the guys that told me the bad news. Not AAAMMMCCCOOO ever. They are a local shop and I trust the people that told me to use them. I am going to ask how they tested it when I pick it up today.

I had people tell me to try the TPS and see what happens. I will check it first, replace if needed and change the fluids and see what happens.
I have checked every ground I could find. Loosened, clean area and tightend.
I will also look into a used tranny. Can't be that hard to replace.

I know about not being worth much and I would love to keep it and fix it up to be my DD again. My lifted 03 Rubicon gas milage is hurting. It is in good shape with one rust spot in the right rear fender well. The paint is wearing off, but everything else works.

Thanks to everyone that replied and gave great answers. I will keep this updated as to what I try and what fixes it.

Thanks, Chris
 
I was about to replace my tranny too, went to a shop had a guy hook up a computer and drive it. said new tps needed. 50 bucks later it drove like a new ride. couldnt believe it. that was 8 years ago and many miles back.
 
OK

I picked up the Jeep and was told that they hooked up the computer and got no codes. He checked the TPS and it is working. He drained the fluid and let it sit overnight and found lots of metal in it. He said that was not a good sign. It meant that gears were more than likely wearing to the point of no return. The cost was for a replacement unit that had been tested and had a 90 day warranty. He said they could rebuild mine at a higher cost.
I am going to search for a junkyard unit.

He also mentioned that 5 people were interested in buying it.

Thanks for all of your help.

Chris
 
Metal in an automatic transmission is almost always particles from the clutch plates (which are cheap). Gears in an automatic are in constant mesh and wouldn't have any wear.

Common transmission house scam is to pull the tranny pan, throw chips in it and show it to the customer. This is called "Panning for Gold".

Your symptomns: Does not like to downshift" does not sound like transmission failure. When you pull out the dipstick and smell it (sorry, the transmission dipstick), does it smell burnt? Is it nice and red or is it btownish? Does it seem to slip when you put it into gear?
 
They added new fuild after draining the old out to check it. I will run it tomorrow and see was it smells like. It does not downshift unless I gun it and let off. It might be ok for a couple seconds and then goes back to high rpm. I really don't think it is slipping, just high rpm and not liking to downshift. Does not slip when put in gear.

Thanks for the info.
 
They added new fuild after draining the old out to check it. I will run it tomorrow and see was it smells like. It does not downshift unless I gun it and let off. It might be ok for a couple seconds and then goes back to high rpm. I really don't think it is slipping, just high rpm and not liking to downshift. Does not slip when put in gear.

Thanks for the info.

That matches the normal symptoms for a bad TPS. The sensor itself isn't much different than an old style analog volume knob. They wear out, get bad spots and get "noisy". Before you drop $1200 on a tranny try replacing the TPS sensor. To truly test the sensor you need to use an analog meter and make sure the output changes smoothly as you move it through its range. No codes or checking with a digital meter won't always show an obvious fault.
 
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