Cascade Crew

fiveoformula · Posted: Sun Jan 11, 2009 1:09 am Post subject: Slippage??

I think im having some issues with my trans... (700R4)
It has had a leak for a while, so I have been topping it off for quite some time now, so today when I got to work I stopped in the parking lot and added about 1/3 of a quart and parked it.

Later as I was headed off to my girlfriends house, doing about 45mph in O/D I down-shifted into 2nd to slow down for a red light, and surprise!! Im coasting as if in neutral! Shocked

Now it will slip out of gear if I downshift, or let off the throttle in high RPM's
This really sucks. Crying or Very sad

Anyone know whats going on?

rjmcgee · The Hammer Joined: 08 Jan 2004 Posts: 2328

2 out of the 3 700R4's I've had has done this. I forget now what causes this to start, but it wasn't really a big deal. It sucks driving though.

305 302eater · Posted: Sun Jan 11, 2009 10:53 am Post subject:

I had the same thing happen to my 700r4 in my rs way back when. It did it for about a year and a half then it went out. I also cant remember what caused it. I think I searched on tgo to find out.

fiveoformula · Posted: Sun Jan 11, 2009 6:30 pm Post subject:

Did either of you guys fix the problem or have a shop fix it?

chevymad · Posted: Sun Jan 11, 2009 6:50 pm Post subject:

I'm not positive, but I think thats a problem with the sprag. It works like a one way clutch and is supposed to give you compression braking, if i remember right. I also remember hearing its a weak link in the 700s. If thats the case the trans would have to come apart. I've only rebuilt one 700.. and basically just followed recommendations and the atsg manual.

fiveoformula · Posted: Sun Jan 11, 2009 6:54 pm Post subject:

chevymad · Posted: Sun Jan 11, 2009 7:07 pm Post subject:

If thats it yes. Trans would have to come out and apart. Maybe search will turn up more info. My manual is outside in my toolbox or i'd look it up.

fiveoformula · Posted: Sun Jan 11, 2009 7:13 pm Post subject:

If this ends up needing a complete rebuild, I will be looking into a T5 swap.
I had this tranny out, and gone thru about 20K miles ago, summer of 2006.

fiveoformula · Posted: Sun Jan 11, 2009 7:23 pm Post subject:

Also, would it be a good idea to dump the fluid and refill to see if that fixes it?

chevymad · Posted: Sun Jan 11, 2009 7:27 pm Post subject:

Post on tgo says overrun clutch hub or the sprag.

A complete overhaul probably won't be necessary. When the forward sprag breaks like this or the overrun clutches goes bad normally nothing else in the trans gets damaged. You should be able to do a clean patch by removing the pan, tcc solenoid, and tube to aux. valve body. Then pull the pump and release the band from the anchor with a pry bar. After that pull the band out and pull out the band drum and input drum. Inside of the input drum you need to remove the 3-4 clutches, then the forward clutches, and you can check the forward sprag that it only rotates one direction and that the o.r. clutches didn't get burnt. If it rotates free both directions all you need to do is replace it, install all the parts in reverse order with new pump gasket, pump o ring, pan gasket, and all should be good. This sprag also goes bad a lot in the newer Tahoes, and trucks when they think they're all that and try to do a burnout in the snow or when it rains-resist the urge.

fiveoformula · Posted: Sun Jan 11, 2009 7:32 pm Post subject:

Thanks for searching that, I wasn't coming up with anything...
Did that post say anything about what would cause this problem?

chevymad · Posted: Sun Jan 11, 2009 7:48 pm Post subject:

Apparently both parts are weak, and doing any downshifting is hard on them. When you downshift theres alot of spinning mass that the sprag has to suddenly stop.

fiveoformula · Posted: Sun Jan 11, 2009 8:23 pm Post subject:

According to this chart, it is looking like either of those 2 parts...

fiveoformula · Posted: Sun Jan 11, 2009 8:50 pm Post subject:

So far from what I have been reading, the trans will operate normal in O/D because the overrun clutch and the forward sprag aren't being applied...
But I will see these symtoms of slipping while (attempting) to engine-brake.

91camaro_rs · Posted: Sun Jan 11, 2009 10:11 pm Post subject:

O/D to 2nd? i didnt even know you can do that in a automatic lol i thought 45 is to fast for 2nd, i normally go from OD to D then maybe to 2nd. sounds like it would put a lot of stress on the the tranny puttin it in 2nd at 45. i thought 2nd was for like 15-25 mph

Quasi-Traction · Posted: Mon Jan 12, 2009 3:24 am Post subject:

so what's the vertict?

fiveoformula · Posted: Mon Jan 12, 2009 9:28 pm Post subject:

Quasi-Traction · Posted: Tue Jan 13, 2009 2:00 pm Post subject:

Twilightoptics · Posted: Tue Jan 13, 2009 6:01 pm Post subject:

Dewey316 · Posted: Tue Jan 13, 2009 7:39 pm Post subject: