My truck started hunting gears a week or so ago. On the highway it would unlock the TC in 4th, then shift to third, then back to fourth, etc etc. Even in town at 20 mph it would be shifting from gear to gear. I took it to one well recommended shop; they replaced the APPS (without getting my approval) and told me there were no guarantees; it didn't fix the problem... They agreed to take it off - they were sure they could use it (they put in two others this week and they fixed the problem for those trucks). By the way the dealer had 15 in stock...!!! Anyway after removing the new APPS they told me to take it to the dealer; no codes were being generated except an "unspecified code 32". I took it to a different shop (NOT the dealer...). They spent some time with it and noticed that the fluid level was too high (the first shop had flushed the tranny and replaced the fluid). They took out 1.5 quarts and guess what, the problem is gone!!! Hope this helps someone else out there.

 

Well, the "solution" of reducing the tranny fluid volume by 1.5 quarts worked for 1 day... The following day it was back just as bad (tranny hunting gears). So (as has been recommended by many on this forum) I sanded the metal under the ground wire attachments for the two batteries and the ECM, and wrapped aluminum foil around the black/tan wire that runs right over the alternator. I zip tied the end of the aluminum foil to hold it against the metal end of the ground wire (this was just a quick and dirty test since I didn't really think it would help). I zip tied the black/tan wire as far away from the alternator as I could without stressing out the wire harness. Result? Well, so far so good, but only one day under my belt, so I will reserve permanent judgement just yet...

 

After reading the first post I was going to reply that there was no way that a trans service was going to solve that issue, but I see you already found that out. The lockup hunt can be an interesting problem to make go away. To this day I still don't believe there is a single miracle fix for this, but rather numerous issues that can cause it. I'm hoping my 01 never developes this issue, but I know it can.

 

I replaced the bushes in my alternator. Fixed the problem, They were shot.


Dan

 

The brushes can cause a lot of elect. system problems. Even though they are putting out good voltages, it can be a "dirty" power with spikes embedded on the elect. wave which will wreak havoc on systems and drive you nuts.

 

how much for replacement bushings

 

cna you give me a little more info on this iam going trough the same thing and i have to clean the battery termals once a week to keep the tranny acting right thinks.

 

Mine just started that crap this week. Unlocks the TC and hunts around if you let off the throttle, but only sometimes. Gonna clean all the grounds, see if it helps.

 

I thing the brushes were less than 20 dollars. You can chang them on the truck.

Just because it fixed my problem, don't mean it will fix yours. It's been 6 months sence my problem.

Dan

 

I was having the same problems. It would come and go. About a month ago, I added the Edge Juice to the truck and the problems went away, for now.

 

There was a similar thread a few days ago. I know I had the same trouble. Need to wrap some tinfoil around the ground wire that is coming out of the wiring harness right above the the alt. Wrap it from where it come out to down near the battery ground on pass. side. That eliminates the "hunting".

Also, make sure ground wire is clean on battery and battery to body.

 

Mine will go through that too. Going from 3rd. to 4th. and back to 3rd. Seems to only do it when i'm towing though. Really bugs me.

 

Well, two tranny shops say the problem is not in the tranny, it is in the electronics. APPS replacement didn't fix it. Reducing fluid volume 1.5 quarts didn't fix it. Sanding to bare metal under the ground connections (both batteries and ECM) didn't fix it. Aluminum duct taping / aluminum foil wrapping the ground wire by the alternator, and attaching a drain wire that runs to the ground by the passenger battery, didn't fix it. Moving the wire as far from the alternator as I could didn't fix it. Replacing the transmission relay didn't fix it. I did notice that the previous owner got mud splashed into the fuse box (underhood fuse box); not sure if that could suddenly be causing problems. I haven't tried replacing the alternator brushes; this truck has 55K miles, is that enough for this to be the problem? The truck still jumps from 3rd to 4th, and from lockup to unlocked TC. It is very unpredictable (sometimes drives fine...). I haven't tried the DTT noise filter, or running an additional ground from the ECM, yet. One tranny shop said to have the dealer reflash the computer (bargain price of $90...), but I have heard in some posts that this can cause other problems (could be a faulty memory but I seem to remember reading this somewhere). Good luck to everyone else with this problem, I hope it is less elusive than my problem. The tranny shops say they don't get any trouble codes on their scanners, by the way.

 

If it's occuring pull over and dis connect the alternator and then drive it and see what happens.

 

Lumpy_63,

Sounds like we are in the same boat, up the same stream with a very short paddle

Batteries and Alternator Tested
APPS -- didn't replace
Grounds -- everyone cleaned
ECM -- new ground to battery
ground by alternator -- wrapped and grounded
ECM -- updated with latest flash program

Haven't had it hunt since doing all these but it still kicks out of Cruise
DTT Noise Filter -- going on tonight
Ground wire from Tranny case to frame -- If DTT doesn't fix it
Alternator rebuild -- last chance

Trade truck for one with a standard tranny --- Last resort.