Transmission Issue..?

[TheNikeMan]

I will preface this by saying that I know very little about transmissions...(tried a little searching too)

 

My buddy has a 94 Silverado, 150k+ miles, 4x4...and mentioned to me that his overdrive will not stay engaged or won't engage at all. Gears 1-3 seem to be perfectly fine, but he has noticed a lot lately that when he runs 70mph his RPM's are nearing the 3000 mark, which leads him to believe that overdrive is not kicking it. He bought the truck used a couple years back and has never flushed the tranny or had service on it. It could be original for all he knows...

 

Just wondering where he could start looking though, any help would be greatly appreciated and will be passed on to the owner.

 

Thanks guys.

[Draenor]

How does the fluid look/ smell? I think the 1st thing to do is to change the fluid, filter and a good flush.

[TheNikeMan]

Thanks, he just went out and checked, and said there are small flakes showing up in the tranny fluid...hmmmm?

[TheNikeMan]

Bump for the flakes!

[AirForceAngler]

He's going to be having his transmission rebuilt pretty soon. Most likely it will eventually lose OD, 2nd and reverse. I think these are all affected when this certain planetary gear goes out that is pretty common on high mileage GM light-duty overdrives in that year range. Hope he has about $1500 saved up.

[peaceofmind22]

Definatly get that flush, and make sure you get a flush not a dump and fill. Example- midas has the flushing machines and it does a way better job than the dump and fill. The flush will get the old crappy fluid out of the torque converter too. Im a tech at a dealership and I even go to midas and pay for that flush instead of the dump and fill. As far as the flakes... it really depends how long he has been running that fluid. Metal tranfer is going to happen and there isn't much you can do about it but staying on top of fluid changes and it will help dramaticly. Fluid brakes down and offers less protection over time.