Trans fluid reservoir location?

[Moneyhan]

I have a 2004 GM Workhorse 8.1 with a Hydra-Matic 4L80-E transmission. For the life of me I can not figure out where the reservoir is to add tranny fluid. Does anyone know? Looked all over the web and in my manuals without luck.

Thanks in advance to anyone willing to help.

[RobRV]

I have never heard of them having any reservoir . Just fill the normal way when low using the Dipstick Tube!

[LarrytheBear]

Yep, what RobRV said. Get a long funnel and fill at dipstick pipe. Careful not to overfill.

[garyspang]

Make sure you only check the level at the normal operating temperature. The fluid has a high degree of thermal expansion. If over 50Kmi drop the pan and clean it, replace the filter and fluid. Fluid is very sensitive to thermal degradation and time in service.
I changed mine over to synthetic fluid, but that is another story.

[RTegarini]

Originally Posted by garyspang

Make sure you only check the level at the normal operating temperature. The fluid has a high degree of thermal expansion. If over 50Kmi drop the pan and clean it, replace the filter and fluid. Fluid is very sensitive to thermal degradation and time in service.
I changed mine over to synthetic fluid, but that is another story.

I don't have this specific transmission, but I know it's fairly common that not only does the fluid need to be hot, but the transmission in neutral when checked; would this be correct for this GM transmission? -RT

[garyspang]

Hi Ricardo
Yes, this applies to most transmissions under high service demands, such as our motor homes.
I even went one step further after Workhorse told me that synthetic transmission oil will make everything last longer. A hose was attached to the transmission oil intake, and the entire transmission was flushed while rotating and shifting, but standing still three times with one gallon synthetic oil at a time. Very costly for the wasted oil, but the only way to get the converter and servo actuators flushed reasonably well.
Now I still change it every 50k miles, but no longer am concerned with overheating the oil. I burned out a transmission on a previous motorhome. It was still under warranty, so the FLAIR manufacturer picked up the $3150 bill. Now with my second motor home, I am taking no chances. 131000 miles and never been stranded due to power train issues.

[spritz]

Mine is under the dog house and under the air cleaner, filler tube/dip stick is all I have.
I think I will change it this spring. Never thought about it until reading these Post's.
Checked it last season and it was still at the full line
Tim