Reverse shifting

[Tatman48]

hey all, 2008 yukon xl denali I noticed for fast few weeks after driving for a period of time and coming to a stop. when I shift into reverse to back into a parking space. it takes about 4 seconds for reverse to engage. never use to do that but lately it has. from a cold start it shifts normal, I put into reverse and it is instant but seems after it warms up it is not the same. thinking of adding a bigger trans cooler but thought I would ask, my 08 has the 6l80 trans

 

[BG1988]

hey all, 2008 yukon xl denali I noticed for fast few weeks after driving for a period of time and coming to a stop. when I shift into reverse to back into a parking space. it takes about 4 seconds for reverse to engage. never use to do that but lately it has. from a cold start it shifts normal, I put into reverse and it is instant but seems after it warms up it is not the same. thinking of adding a bigger trans cooler but thought I would ask, my 08 has the 6l80 trans

solenoid is sticking..

REPLACE FLUID Don't flush (may damage it) ADD cooler for long life...

start in NEUTRAL Gear ? does it still do it..?

Are you the only one using the suv?? (for diagnostic purposes)

 

[Tatman48]

I will try starting in neutral tomorrow am

 

[BG1988]

I will try starting in neutral tomorrow am

are you the only one that uses the suv?

 

[Tatman48]

Yes only driver

 

[BG1988]

Yes only driver

did you ever switch gears fast and gun it?

 

[Tatman48]

No, I am a pretty concervative driver. In the am when I start it up and put into reverse there is no delay whatsoever. But when. I get to work and go to back into a parking spot I have to shift into reverse and count to like 3 or 4 and then hit the gas. If I hot the gas too fast, when it actually kicks into gear it jerks.

 

[Tatman48]

Going to add a cooler in the next month, i have to change oil pump anyway so might as well do it all at once. getting the low oil pressure at start up, good pressure when driving but if I sit at a light for to long the oil light comes on and it tells me to shut off engine. I realize it is probably just the o-ring on pickup tube, but the truck has 167k so Might as well do pump as well..thanks for info on trans. I will have to look into the solenoid mentioned above.

 

[thompsoj22]

if you youtube 6L80 delayed reverse it is as they refer a common problem with high mileage trans. their find was the teflon check balls in the valve body shrink and get stuck in there port yours would be specific to reverse if thats what it is. cost or the check ball less than a dollar but getting to it is another story. it is heat that shrinks them so maybe a trans cooler will get you down the road before the repair?