Originally Posted by mpatrick19

First time posting here. I have read all 36 pages of this thread and I have not seen a post about my problem. First off I have a 2000 with a 3.9L 2wd, I am assuming the 42re trans. The problem that i'm having is that the transmission is down shifting while i'm coasting. For example, driving on highway about 60-65 i let off the gas and when i hit 55mph it shifts down, then when i need to accelerate it shift harshly back into o/d. It gets more noticeable the longer I am driving, maybe heat related? I have adjusted the tv cable with no results other than the timing of the shifts. I was going to do fluid and filter tomorrow, other than obvious things is there something i should look for with the pan off? TPS sensor is also good. One more thing, this started happening right after my battery got disconnected.

Originally Posted by army_greywolf

MonteC I did a bad thing.

I was traveling to NY state from Louisiana a few months ago, the trip was excellent and went well, my loaded return trip not so much. I believe my governor pressure solenoid burned out during the trip. This threw a few codes, namely P1675 (don't quote that, its the one that indicates a 12V+ short to solenoid or a ground fault either or)

Anyways, it caused my loaded truck to drop out of lock up in 3rd gear. I knew it was bad, I pulled off and tried a combination of tricks to fool the computer into believing there was no solenoid fault so I could get lock up to work and at least make it home. I knew this would lead to trans failure but had little choice in the matter the truck did not have what it took to haul the load. I drove approx 450 miles at steady 55 like this. The fluid is discolored, (dark RED not brown) and I'm positive had some clutch material floating in it. I have up til now replaced the fluid with a simple pan drop, filter change and band adjustment every 15K or so since I got the truck, until now the transmission shifted flawlessly.

When I plug the relay back in without bypassing anything or rerouting the wiring to fool the computer and make it shift normally I have two conditions. One is delayed shift and two is the OD slips ever so slightly, it seems to slip alot less when given more engine load...does that make sense? After the truck warms up the code returns (sometimes immediately after startup sometimes not) I know the solenoid is bad, I tested the field coil, it is shorted to ground somewhere but tapping it causes it to work...so anyways, requires replacement. I'm not expecting miracles but is there a chance replacing the solenoid could return the truck to normal driving status? Do you think something else is going on as well? Will replacing the gov sol and transducer possibly break these components if my trans goes south in the short term (could I reuse these since they are comparatively expensive). I am leaning on a rebuild but need two months out of the truck to pay for rebuilding the trans.

Originally Posted by mpatrick19

Well here is an update. I changed the fluid and filter yesterday. I let it drain for about 3 or 4 hours while I was replacing most of my front end. The fluid didn't look too bad, there was only a little bit of metal sludge on the magnet. I t looks like the tranny was never serviced before this, its got about 137k on it. I also checked all the electrical connections and they seemed fine, checked the drain back valve it was clean and i was able to blow air through it. After everything was finsihed I drove it home from my brothers shop, about 15 miles mostly highway and I didn't have overdrive, switch did not make a difference. Rechecked fluid when I got home it was fine, I did use ATF-4+ btw. Have checked all fuses, O/D switch, nothing seems to change. Not sure what to do next.

Originally Posted by tango-52

Regarding my previous update post (two posts prior), it wasn't the wavy ring (overdrive clutch wave spring, aka snap ring OD brake rear wave), or the one that nests with it (overdrive clutch reaction ring aka snap ring OD brake rear flat). Both were still there. I did find two more ring pieces though. It turns out that the "direct clutch pack snap ring" (aka snap ring OD direct clutch wave) had grenaded and there was nothing left in the groove. There was a little wear on the direct clutch pressure plate ring, probably from rubbing agains broken snap ring parts. Everything else looks pretty good. Just have to pick up those two parts (snap ring and clutch plate) tomorrow and I should be good to go. Time will tell if it fixes the "no reverse" problem. That will teach me to go by a part description over the phone. Next time I will point at the picture. LOL.

Originally Posted by army_greywolf

I replaced the governor pressure solenoid, tranducer, installed a new seal for the gear selector shaft, and found the small fork like device that is supposed to sit between the front band adjustment screw end and the band. It is whole, the screw as not, I dug around and found the missing piece of the screw having all parts accounted for I was able to reassemble the pieces with some grade 8 hardware and a bench grinder to recreate the adjustment screw. I also pulled apart and drained the cooler lines, forced some air pressure through the lines (not too much) and put it all back together. Just got back from driving it to the gas station, I have all gears, it shifts properly, 2nd gear is rather abrupt (I think my adjustment might be a little too tight) but it's all there behaving right and no codes. I am concerned though, to bring it up to the correct fluid level, it took ten quarts and change. I ended up having to drysweep up alot of fluid I spilt all over while blowing lines out but that seemed like an awful lot. Also the magnet had quite a bit of material attached to it, but nothing bigger than dust size. The band was ok btw.

I still plan to rebuild it. Got any recommendations for a truck with 7"lift and 37s? I am running 4.56 gears. If I could get some help there putting together a build sheet that would help immensely.

Originally Posted by army_greywolf

I'll dig for it, thanks. Yanno I missed the chunk of metal the first time I went in to check the solenoid, but then I was determined to repair an electrical problem. I dumped the fluid out haphazardly, let that be a lesson to everyone, LOOK IN THE PAN. I took it for another drive with concerns about the condition of my front band, after a couple wide open throttle pulls it "seems" ok. I'll post a youtube video for thoughts on this from the gallery.

I will get a core trans and rebuild that from scratch in my leisure time rather than have the truck down to do it. This is my second ever auto trans rebuild, I hope it will last another 120K or better. Any particular severe duty components I should be looking for? I do side work for logging companies which can mean my truck travels for miles through mud/sandy terrain over and around stumps carrying varying loads and sometimes dragging a trailer along up to 8000 lbs. I saw reference to clutches in relation to color, what about bands? Are there better than stock front pumps? Is the GM Solenoid conversion worth the price and does it last as long as replacing the stock with another OEM?