I am having a strange issue with my 1992 f-250 with the 5.8 liter, auto tranny.

It starts up and runs fine-- for a little while. During its first about 15-20 minutes this thing will cruise no problem on the highway at 70-75mph. But once it's hot, it struggles to go 60mph. The truck just seems way underpowered, it revs high and isn't goin anywhere. Almost like driving into a serious head wind.

Any ideas? I can't think of anything that would cause it to be fine when cold then slow when hot. Maybe a tranny issue or transmission cooler issue (if it has one)? How can I tell what tranny I have? I did some research but it seems as if I don't have an overdrive button, so can't figure it out.

Please help, I gotta figure this thing out

 

Welcome to FTE!

There could be many things causing this. Has the CEL come on at anytime while driving? Have you repaired or replaced anything recently?

As far as the tranny is concerned, your VIN should be on the inside of the driver door and you can use this to determine which tranny you have. I believe you and I have the same tranny and I believe mine to be an AOD tranny. I have a '92, F-150, Auto, 4x4, 302

You can also use the "SEARCH" feature and using Quotes to help find topics regarding your issue.

Someone should chime in later with some ideas, and don't hesistate to POST here what you find out to be the culprit.

 

No CEL at anypoint, The only thing I've done lately is an engine oil change (did a higher viscosity high milage oil), and front brake pads. I though about a potentially dragging pad but it seems that would cause problems all the time reguardless of running temp.

I did multiple searches but can't find anything that resembles my issue.

 

http://www.**************/myfiles/transmission.jpg Here is a link to help you identify the trans. If no overdrive and stock then it should be a C6 but check it out to be sure.

 

Thanks, I've got the C6. Anyone know of an article that can walk me through the changing on my tranny fluid??? I think I'm gonna start there and see what happens.

Again I've used the search and cannot find anything in regards to a c6 fluid change or anyone having the problem I'm having. So any advice on things to check or replace will be helpful. I'm still in the dark on this

 

https://www.ford-trucks.com/forums/8...d-be-nice.html Have a read through this thread. Some good advice.

 

Does the tranny fluid in a 4x4 also lubricate the transfer case? If so do I need to add more fluid?

 

No the transmission and transfer case fluids are seperate although they both use the same type of fluid. Draining the trans fluid will not drain the transfer case, there is a bung on the transfer case for that.

 

since you just changed brake pads check the fluid level-of the master cylinder oif it is overfilled it will build pressure and apply the brakes when it gets hot under the hood, if that is ok possibly plugged converter-usually temp does not make a lot of difference though

 

Checked the brake fluid thing, not it. I still haven't figured this out. Anyone know what the fuel injection form of a choke is? because my father had conditions like this happen on his old carburated ford and it was a stuck choke.