Any GM guys who know a 700 R4 really good

[Princess Valiant]

82 Chevy blazer (full size)

305/700 R4

no reverse. When i put it in reverse it just makes a whirrrrrrrrr noise and does not go.

I have all foward gears.

I pulled the pan and I don't see clutch sludge or anything really off.

I don't really know what i am looking at??

Anything unusual?

 

[RustyRatRod]

They had problems with the reverse valves in some that caused shudder in reverse and reverse failure like you're experiencing because the reverse valve can get stuck. An upgraded version is in all the kits now as far as I know. The bad news is, as far as I can remember, the reverse valve is not accessible unless you pull the front pump, because that's where it is. I've been in a couple but I cannot remember if the back of the pump protrudes enough into the case to access the valve after you remove the valve body. Since the top half of the valve body IS the transmission case, I don't think there's any room to access it. That's all I can recall. I can tell you this. I've seen a couple of times where guys were able to "unstick" that reverse valve by gently applying some gas pedal and shifting from D to R. I mean gently too like on high idle. Increases pressure just enough to sometimes unstick the valve IF that's what it is.

 

[Princess Valiant]

My mistake, I pulled the pan but didn't drain it out completely and kinda missed this because with a layer of red fluid it looked ok.
I think the previous knew this and added a bunch of new fluid because the fluid was red red, but over filled.


This is part why I hate automatics.

I'm going to say the rear planetary gears are stripped.

 

[RustyRatRod]

I'm unsure that's anywhere near enough metal for stripped planets. But let us know what you find.

 

[Princess Valiant]

I'm unsure that's anywhere near enough metal for stripped planets. But let us know what you find.

There was probably way more metal but the pan bolts weren't on very tight. So my theory is the previous pulled the pan, said "oh ****" buttoned it up, over filled it with new fluid.

Then sold it without disclosing anything only to be discovered when it wouldn't back off the trailer.

It's OK, we're not even going back, thing was cheap enough, had he disclosed that info the vehicle would still be here. (It's not mine, a friend) (probable LS swap) ***rolls eyes*** you know these GM types.

Now we know what the score is and to time move forward.

 

[RustyRatRod]

There was probably way more metal but the pan bolts weren't on very tight. So my theory is the previous pulled the pan, said "oh ****" buttoned it up, over filled it with new fluid.

Then sold it without disclosing anything only to be discovered when it wouldn't back off the trailer.

It's OK, we're not even going back, thing was cheap enough, had he disclosed that info the vehicle would still be here. (It's not mine, a friend) (probable LS swap) ***rolls eyes*** you know these GM types.

Now we know what the score is and to time move forward.

There you go. As my dear departed friend Billy Peyton always said, "make chicken salad outta chicken ****".