Just picked up my travel trailer today for the first time in six months, while towing it home i noticed a very firm if not hard 2-3 shift under heavy acceleration up a hill. I dont remember it shifting this hard last year, although i will admit i had my foot in it too check out the new straght piped exhaust, which i never do. Now i got the truck used last august so i only towed with it maybe three times before parking the trailer for the season. The trailer wieghs close to 8000lbs. Is this normal? Anything to check? Tranny was flushed 4500 miles ago. Of course i'm leaveing for indy wednesday. Figures!!

 

What other mods are on the truck? If you've got a chip, it's possible that firm shifts are programmed in. If the truck has internal tranny mods, that could also explain firm shifts. Firm is better than sloppy!

 

See thats the problem, i bought it used off of a ford dealer lot. I know for a fact it was used to haul a large slide in camper, the trucks from alaska by way of n. carolina, so its seen some highways, although it only had 42k on it when i bought it. Nothing is obivously aftermarket on it and its truly a cream puff inside and out, no farm truck.(no offense to farmers) Although i cant see in the tranny, the fluid was clean when i bought it. I guess i'm just being paranoid, at least i hope!!

 

Are you taking it out of O/D while you are towing? Reason I ask is when You lock out the O/D it causes higher Rpm's before shifting in order to prevent slipping in the tranny. It is a safety feature built in.

Fire Rooster

 

no, i only took it out to see if it was the 2-3 or 3-4 shift after it shifted so hard.

 

when you had the fluid changed did they change the filter too? This can also cause hard shifting in your case the extra weight could bring this differnt type shifting to light or exacerbate an existing problem.

Fire Rooster

 

No filter, i did a flush with a fluid exchange machine, i ran it twice, so it actually had 30 qts run through it. (the fluid is free to me)