Hello, My friends 95 S10 is having transmission trouble. Truck details:

4.3 Vortec
700R4 Automatic Transmission
4X4
262,000 Miles

He said the truck will go fine in first and second gear but when it starts into third it revs real high. Sometimes it will catch third a bit but just kicks back out. The problem has gotten progressively worse over the last 2 or 3 days to the point where it won't go past second gear without revving real high and you have to manually put it back in second. It runs perfectly in first and second. He is going to bring it over tomorrow night so we can change the transmission fluid and filter. Does anyone have any opinions here? Is this a common problem? Does it sound like the transmission is done?

I haven't seen the truck so I cant describe the fluid level or if it's clean etc. It does have a lot of miles on it and has never been opened. He said he put some Lucas oil in it but no luck.

Any help is much appreciated.:runaround:

First check fluid level and condition.
Any transmission /engine codes?
Does reverse still hold and work good?
Pull pan and check filter and see what is in bottom of pan.
let us know what you find.