tranny problem maybe? i hope its not serious

[EliteConcept]

ok so heres what i'm gathering so far.

Heres what i've noticed for a while now...
when the truck shifts at 45mph the rpms will jump about 200-300 or so...then it'll shift...being that i don't drive overly agressive or abuse my truck (because i know expos have weaker trannies) i just had been thinking it was just a really LOW shift and the engine had to bump up the rpms a bit more. because the times that i've PUNCHED it and it would seemingly shift flawlessly.

heres what i've noticed happening just in the past couple weeks
i leave my truck sit either at work/home/school for i'd say its always at least 5+ hours. When i go to leave it drives fine until i get to shift that usually happens around 45mph....just lately its not been shifting right. (I.E today i think it shifted into at 55??) Not sure if its related to the problem above.

The lady i bought it from had the tranny fluid and filter changed at about 45k ??(i believe, i know it wasn't TOO long ago) the truck and it just turned 69k last week.
the tranny fluid still appears to be a nice red color still..

any insight on what i should consider...i'm scared that its a big problem starting to arise....

 

[Dave W.]

Had about the same problem,after mine would get to normal operating temperature sometimes it would not shift from 1st to 2nd it would slip a little.
So I had tranny flushed and put in seafoam trans-tune and took it for a 60 mile drive on the highway. All cured.
Thats what my mechanic said to do by the way, he said the valves in tranny were probably getting a little stuck from gum and varnish.

 

[dogfriend]

I don't know if this helps or not, but at light throttle my truck shifts from 4th(direct) to 5th (OD) at 45 to 47 mph. You might want to lock out OD and see if that confirms that it is a problem with OD.

 

[EliteConcept]

without OD it should just stay in 4th right? so after it shifts at 35-37 thats the last gear?

i may try a flush and fill if nothing eles.

keep the help coming
thanks guys

 

[Dave W.]

Yeah that's the last gear before overdrive, try the seafoam also!

 

[EliteConcept]

so by having the dash light say "OD off" i would only have 4 gears?

the seafoam would just be an additive that i could pour into the tranny "filler tube" after a fluid change is done?

Having limited time what would be better
1. having a place like jiffy lube "suck" all the tranny fluid out.

2. having a shop drop the pan and change the filter and only like 4-5 quarts of the fluid. From what i hear thats about all that can be done with a pan drop, but i don't know.

thanks
ryan

 

[dogfriend]

Somewhat controversial. Some people warn against the power flush - I think it is a good idea but won't necessarily fix the problem if it is mechanical in origin.

If they do a powerflush, they probably won't change the filter (you must drop the pan) . If you drop the pan, you will need to replace approx 4 qts out of 10 qts total capacity.

I had the dealer do the powerflush once, the second time I dropped the pan myself, then did the home flush method to change the rest. See more here: Dead Link Removed

Dead Link Removed

 

[Dave W.]

The mechanic did a flush and dropped the pan and changed the filter. Yes the seafoam goes right into tranny from the filler tube.