Strange tranny issue

[Ratchetnator]

When i start the truck in the morning if I dont let it warm up for a while. It wont "bump" into reverse and I have to hit the gas to get it to go backward. So I normally back it in at night. Another day it did this when I went to take off going forward as well then once it was warm it was ok. Tonight, I pulled off from a stoplight at half throttle and when the tranny went to into 2nd it was like it didnt catch. I let off a little and it grabbed. The next stop light I did the same thing to see if it would do it again and it seemed fine. I checked the fluid and it was a little low but not bad. Should I start looking for a new tranny?

 

[littleboy]

When have you last changed the fluid and filter? It kinda sounds like the filter is almost plugged.

 

[Ratchetnator]

roughly 40k ago. I'll try that. The tranny has 195k miles. Almost wonder if the pump is going bad.

 

[THEFERMANATOR]

When have you last changed the fluid and filter? It kinda sounds like the filter is almost plugged.

What he said. Cold tranny problems are commonly caused by plugged filters. And in reverse the trans has to hit much higher pressures to hold, and with a plugged filter it can't reach them. Drop the pan and look for signs of clutch material, but a new filter and fluid won't set you back much and it's worth a shot to try. Also I would change the seal out in the trans that seals the filter.

 

[Ratchetnator]

Thanks alot. I should be able to do it monday. Im crossing my fingers

 

[bison]

Any codes??
Hooking up to a scantool will tell you the pressures.

 

[THEFERMANATOR]

Any codes??
Hooking up to a scantool will tell you the pressures.

Theres no pressure sensor inside the 4L80E trans. It will show you desired pressure, but you have to hook a guage up to it to know the actual pressure.

 

[WarWagon]

Fluid changes are needed every 25K or so on the 4L80E.
X2 on plugged filter.
You will find a lot of fine debris in the pan and that is more or less normal.
Chunks are a problem and indicate possible coolant in the fluid from a pinhole in the radiator oil intercooler.
You could only need a partial rebuild of the front pump and seals.

 

[Ratchetnator]

It was warm out today and the truck drove flawlessly start to finish. No codes whatsoever.Monday I will change the fluid/filter and test it. Just in case I was looking at tranny prices. I love these trucks

 

[Ratchetnator]

Changed the fluid and filter today. Truck seems to shift better. The fluid wasnt chunky or off smelling. It was still cherry red but I guess i'll see tmmrw am if my reverse issue has been solved

 

[Ratchetnator]

Just fired my truck up and went to put her in reverse. Went right in 10 seconds after starting and its 15 degrees out. Must have been a plugged filter. Thanks again guys