4L80E troubleshoot

[muddycowboy]

ok so my wife took my 95 K2500 to work the other morning and had to come back home cause it would not shift past 2nd gear, mind u it was 0 degrees. i looked at it that evening and had no problems with it. i checked the fluid and test drove it with no problems. now a week later i noticed that it is running higher trans temps.

it is a Jasper brand trans. last summer i changed the fluid/ filter, installed a B&M deep trans pan, larger B&M trans cooler out front, and a trans temp gauge. it use to normally run between 120 to 140 depending on driving style, without heating up fast. now in the last week it is heating up quickly ( 5 miles rural, under 55) and is running around 160 degrees.

Any Ideas on what could have happened? thanks

 

[muddycowboy]

also like to add that the temp sensor is in the pressure test port.

 

[NVW]

The trans temp of 160 isn't bad. How are your coolant temps? The trans is cooled through the rad so if the coolant is higher so will the trans temp.

 

[muddycowboy]

stat temp, 195. but what gets me is they were never that high before not even in the summer.

 

[WarWagon]

Check for codes. Trans issues do not turn on the SES/MIL light.
Do you have all 4 gears including TCC lockup?
If the computer is unhappy you loose TCC and OD, 4th. This heats the trans up.

Last times I had trans heat issues was:
1) Bearing and sprag failed in OD and went through the OD gears. Trans ran very hot...
2) Lost a tire on a trailer and trans started heating up. Check tire pressure.

 

[muddycowboy]

just an update trans had a bad solenoid and ended up getting stuck in 2nd gear. took it to the shop and 300$ later its shifting perfectly

 

[the_coroner2002]

Don't want to jack your thread but im having the same issue, No 3rd or overdrive, Do you know which solenoid was causing the problem,? 98 yukon 5.7 4x4. I dont even know if I have the 4l60e or 4l80e.

 

[muddycowboy]

#2

 

[bk95td]

Don't want to jack your thread but im having the same issue, No 3rd or overdrive, Do you know which solenoid was causing the problem,? 98 yukon 5.7 4x4. I dont even know if I have the 4l60e or 4l80e.

You can replace ALL of the electrical components in a 4l60e or a 4l80e for around $135 See my thread in this section of the forum on installing the electrical kit. There is a link to the vendor that I bought the kit from.

 

[orrum]

Newbie here just thought I would mention Grounds, grounds, grounds its all about the grounds. Been thinkin about them wopdchucks chuckin wood lately.....