transmission slipping????

[jcdubbu]

ok here is the scenierio.....i bought a 1993 chevy 2500 with a 6.5 diesel in it and a 4 speed auto with overdrive. the day i got it, i drove it about 20 miles getting up to about 65 mph. i had to comes to a stop for traffic and as i started to increase speed again it shifted into 2nd fine and would not seem to shift into third gear. top speed was about 45mph and was almost red lined. i pulled onto the shoulder and came to a complete stop and checked tranny fluid; seemed to have no burnning smell and was a tad over the full mark. got in truck and shut it off and waited for a minute, started up and proceeded to drive at highway speeds for about 40 miles with no problem. came into town and truck ran fine for about an hour in stop an go traffic shifting beautifuly. got out of town and drove at highway speeds (pulling a few steep grades) for about 20 miles and then all of a sudden it reved up and seemed like the tranny was slipping. tried to shift into 3rd gear but nothing would catch. came to a coplete stop once again and once i started going it was shifting good again. about 20 miles later it slipped out of gear and once again i pulled over, only this time for the rest of my journey it would not shift out of second gear and top spped was about 45mph. got home let truck sit for about and hour got in it and ran good till about 30 miles down the road and it started repeating the same problem. PLEASE.....does anyone have advice?????

[FearlessFoe]

hmm.. Was overdrive on? You might want to check your torque converter and look through that.. The way it works is from fluid being forced to the sides when it spins faster, which creates friction between plates. Sometimes if theres not enough fluid, it won't grip. But that doesn't seem like that'd be it because you are still moving in first and second.. Do you know how old your transmission fluid is? It might need to be changed..

[fuzzypuppy]

Oh man, I'll bet it has the 4L80e too, mine does, best thing to do is to have a diagnostic run on it by a good trans shop, your description could point to a couple of things, sticking valves, pump bad, clogged filter, the best advice I could give you though is to not run it too much with this problem, what would have been a minor fix to start could end up destroying your trans, my 4L80e went without notice and ran $2500.00 though I had it repaired H/D, this did not include r&r of the unit.
My next mile would be to the trans shop if it were mine.

[jcdubbu]

well i know that the truck sat for about 4 mos. and the individual i bought it from was a AMS oil synthetic dealer. he said he change fluids but u never know....when i checked the fluid i would say it was about a 1/4 inch over the hot mark (in the cross hatched area on the stick when cold). fluid does look pretty clean. could over filling it effect operation?

[Bob B]

Originally Posted by jcdubbu

well i know that the truck sat for about 4 mos. and the individual i bought it from was a AMS oil synthetic dealer. he said he change fluids but u never know....when i checked the fluid i would say it was about a 1/4 inch over the hot mark (in the cross hatched area on the stick when cold). fluid does look pretty clean. could over filling it effect operation?

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Hi, Just speculating,
If it's too full when cold and the oil hasen't expanded yet, It could be a lot more overfull after warmed up.
This might lead to foaming and then causing erratic operation.
Bob B

[jcdubbu]

thanks for all the input ppl. decided to take it to a tranny shop and have it put on a scanner. he told me i needed to replace my tps sensor, the input and output sensors on the side of the transmission, and a fluid and filter change. did so and all problems are fixed.....what a relief!!