Hi guys i have a 91 f150 with an E4od transmission when cold and just started up the transmission shifts smooth and fine through all gears but when warmed up it will a lot of times slip and go straight from 2nd to 4th gear

I realize this tranny is prob on its way out but is there any way of making it act a little better like a tranny cooler?
thanks

 

Time for a tranny service!

 

do you mean swap?

 

remove the fluid & change the filter..

Here's what I have done on every vehicle (auto trans) that I have owned for 30 years....

At 20k miles, I change the filter (due to possible residual/initial wear particulates that may be floating inside) and either drain the torque converter (if so equipped with a plug) or disconnect the trans cooler line at the radiator, fill the pan with fresh fluid, my wife starts the engine and when 2-3 quarts drain into a bucket, she shuts it off, I refill the pan and repeat until the fluid is clear and in case of the f150, 14 quarts of fresh fluid is in.

I change only the fluid after that (unless I determine substances/contamination in the oil). The intervals vary depending on the type of trans, type of fluid and conditions, but in general, every 30k miles. Heat is a killer on automatic trans fluid and when we lived in the desert area, I changed the trans fluid at the end of summer every year.

In regards to filters, oem is fine, but I typically use Wix.

In regards to trans oil, both in sticks and autos I have always used Valvoline.

I have also never had a trans failure in any vehicle I own and typically keep my vehicles for 10+ years, with over 100k on the odometer.

 

thanks beechkid i will def have to do that soon