Remington H.

iTrader: (2)

Hi, I have swapped a 6.0/4l80e(2001 chevy 2500 hd) into a 91 fullsize blazer and had a few questions that all the transmission guys could maybe help me out with. 1. what is the configuration for the cooler lines? 2. whenever I drive the truck for about 30 minutes or more, the tranny gets really hot. And whenever I stop at a light after driving and start back up it will shift into 3rd but fall right back into 2nd almost consecutively after shifting. and it will sit and do that even when I have my foot on the gas and even when I manually shift it. But if I stop and let it sit for about 10 minutes or so it will shift normally again for another 15 minutes of driving til it heats up again and the same thing happens. Any ideas what could be causing other than heat????? 3. Also when I got my transmission it didnt come with 2 sensor hookups that are on the harness(neutral safety and gear selector????? on or next to arm that connects to shifter) and I didnt think much of it. But from the start, my transmission wouldnt shift into 4th when driving. I even tried to manually shift and nothing would happen, it would just wind up 3rd. Any ideas????, because I am fairly new to the 4l80e and really need some help.

Thanks guys,
Remington

James B.

iTrader: (1)

I posted this in another thread you were asking about this in too:


Is the fitting you are using in the back the quick-disconnect factory one? The reason I ask is because it protrudes into the case and the center support and provides cooling and lubrication oil to both rear planetaries. If that fitting were removed and replaced with just a NPT fitting you would be having cooling problems.

Remington H.

iTrader: (2)

yeah I am still using the factory quick disconnects but my cooler inlet and outlets are very close together at the front both being quite close to the dipstick tube????? I will try to get some pictures.

Remington

James B.

iTrader: (1)

Okay, you have a pre-97 4L80-E. Those have both connections up front. You can see on the picture where the inlet used to be because there is still a boss for it in the casting. On your trans the inlet is the forward bottom one and the outlet is the top one.

Remington H.

iTrader: (2)

ttt anyone else????? What about the eratic as well as lack of shifting I mentioned?????