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trans shift issue

beamer1341

NAXJA Forum User
Location
Northfield VT
looking at buyin a 90 xj the guy says it has a shifting issue; skips second gear, he says the solenoid gets extremely hot. I dont fool around with trans that much just cause they seem like a headache does anyone know if it could be something as simple as swaping the solenoid out?
thanks
 
Hard to say. Maybe somebody with more experience with the insides of the AW4 will chime in. If it was a simple fix, usually the owner resolves it before selling.

If you are buying a vehicle with an unknown condition on a major component, the price should really reflect that...........ie: factor in the cost of replacing the transmission into the bid. Always assume the worst and use it to your advantage in negotiating.
 
How would he know the solenoid gets hot? It's inside the transmission. If it's just a bad solenoid it would probably be skipping both 2nd and 3rd. They are easy enough to test with a meter by measuring their resistance at the trans computer under the dash. Figure $140 to replace all three solenoids (or junkyard), and dropping the pan on the trans.
 
That definitely sounds like a bad solenoid to me. If you test drive it, you could reach up under the passenger side of the dash and unplug the trans computer. It should shift manually with the shifter. That would confirm an electrical and not mechanical problem.
 
That definitely sounds like a bad solenoid to me. If you test drive it, you could reach up under the passenger side of the dash and unplug the trans computer. It should shift manually with the shifter. That would confirm an electrical and not mechanical problem.

i was reading the aw4 manual and it said pullin the tcm fuse or discon. it it would shift in 1st only and jump to 3rd. like the issue it has now. but i was looking at qudratecs site for a new aw4 it said it was only on 2wd 91+ any help?
 
If the TCU is unplugged or the fuse pulled, you should get the following

Shifter in (1-2) => 1st gear (may upshift into 2nd near redline)
Shifter in (3) => 3rd gear
Shifter in (D) => 4th gear
Torque converter will not lockup at all.
 
If the TCU is unplugged or the fuse pulled, you should get the following

Shifter in (1-2) => 1st gear (may upshift into 2nd near redline)
Shifter in (3) => 3rd gear
Shifter in (D) => 4th gear
Torque converter will not lockup at all.



These are the exact problems I'm having with mine! Where is the fuse to the TCU? THanks
 
How would he know the solenoid gets hot? It's inside the transmission. If it's just a bad solenoid it would probably be skipping both 2nd and 3rd. They are easy enough to test with a meter by measuring their resistance at the trans computer under the dash. Figure $140 to replace all three solenoids (or junkyard), and dropping the pan on the trans.
this is my bet, or the TCU is losing power / not working.

Don't look at buying a new transmission off quadratec first of all... quadratec is expensive, and you don't need a new one (AW4s last forever) and you probably don't even need a transmission. Sounds more like electrical issues to me. Just make sure you verify that using the method lawsoncl posted about (unplug the tranny computer or fuse and drive it manually) before buying.
 
Sorry about thread jacking, but mine is a '96 the only fuse I found was small spade 10 amp and it's good! I unplugged my TCU and drives the same! There are a red and yellow wire going to the TCU 1 is hot all the time the other is key on hot, not sure about the rest! Starting to think TCU, dealer says $150 is that about right or is there a better source! Thanks, Troy
 
junkyard is a better source. You won't pay a dime over 50 bucks, I can get them for 10 bucks each around here.
 
Oh, and forgot to mention - one thing that can cause the TCU to lose power (at least on a 96, and probably 91-96 as well as possibly 87-90) is if the grounds connected to the inner fender on the driver side right by the ECU and airbox come disconnected. This is your prime candidate if the HVAC blower also stops at the same time or works intermittently.
 
91 TCU is 5300 8383, 92-93 is 5600 6947, and 94-96 is 5602 6769. Not sure of what the actual differences are - I know 91 and 92 both have power/comfort switch support, and 96s certainly do not trigger a CEL when you disconnect the solenoids and sensors from them (I tested this on my 96, unplugged the solenoid+OSS cable from the engine harness and took it for a drive. No CEL and it shifted great.)
 
Might but I'm not all that sure if his info is correct for it fitting 87-90.

I really need to test this all out at some point... I've got enough random parts hanging around it wouldn't even take that much, just have a million other things on the list.
 
Sorry about thread jacking, but mine is a '96 the only fuse I found was small spade 10 amp and it's good! I unplugged my TCU and drives the same! There are a red and yellow wire going to the TCU 1 is hot all the time the other is key on hot, not sure about the rest! Starting to think TCU, dealer says $150 is that about right or is there a better source! Thanks, Troy

If it drives the same with the TCU unplugged, then the problem is not the TCU!
 
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