nasty01cummims

So i noticed about a month ago that around 45 mph my trans( still stock with 74k on the clock? will shift in and out of od intermitently. However if i get on it hard from a stop it does not do it. And my strans temp usually runs about 160*. But last night i was coming home and i was having the usual shifting problem but if im in od and get on it hard it will shift in and out of od 2 or 3 times and my trans temp is running about 140 now?. Sorry about the long post but im stumped guys. I really need yalls help. So thankyou in advance

ado2b1

You sure its in and out of OD? At 45 that would most likely be the TQ converter locking and unlocking. First pop the hood and see if there are any wires touching the alternator. Had that happen to me once. Pulled the wire off the case and tied it out of the way.

If there is none of that. Try cleaning all of the chassis grounds including the negatives on the battery terminals. These past couple of weeks mine had been doing the off/on lockup again. Cleaned the terminals to a shine, put plenty of dialectric grease on. Cleaned the chassis/body ground at the firewall on passenger side (goes to one of the computers), also on both fenders at the front. I know there are a couple more but didn't look for them, and didn't have a computer to jump on here to find the rest.

ado2b1

...the original post I got the info from...

Originally Posted by jrs_dodge_diesel
There are 6 key spots to clean. Each negative battery terminal (1,2). There is a wire that runs from each negative battery terminal to the body of the truck with an eye terminal (3,4). Not only did I clean the connector, I took some sandpaper and took the sheet metal to bare metal to give a better electrical connection. The most critical wire to clean is the one on the PCM (Powertrain Control Module) which sits on the firewall, on the passenger side (5,6). The PCM is what controls the lockup clutch. There is a ground wire on it that runs to the firewall. On my truck, I did not like the amount of corrosion I saw on my PCM ground wire, so I replaced it. Made a new one with soldered eye terminals to minimize corrosion. I also sanded the firewall and PCM where the ends connect.

nasty01cummims

yea not that u say that i think it is the tq locking and unlocking. but what would make my trans run 20* cooler? could it be ambient temp?

Chaser10

If cleaning up the grounds doesn't fix it, below is link to another angle of attack that worked for my 01. Good luck.

https://www.dieseltruckresource.com/...g-t251528.html