renegade intake? for cross fires

The early C4 Transmissions are unique.
I have never seen that plug before.
But I have worked with my 1987 Corvette 700R4 & later model years.

The 3-4 relay upshift valve in mine used a roll spiral pin to retain I recall.

The 3-4 relay valve bore in yours Gibbles is Counter bored for a press in soft cup plug.
I think you found the culprit.
I think it would be wise to install a Pipe thread plug.
1/8"-27 TPI- threads per inch.
Can not tap any deeper than the factory counter bore hole.
Red or Green Loctite it, the screw in pipe plug.

May need a different size pipe thread tap.
Measure the OD of that soft cup plug with dial calipers or a Micrometer. Post the measured OD size.
 
Any metal debris or friction material in the trans pan bottom Gibbles ?
 
Only a very small amount of metal and clutch material , i assume flowed from what i could not get out of the converter, or what was in the valve body from when i lost the 3-4 pack.

Also this time around there is a night and day difference in the way it shifts, very distinctive solid.
 
Also that cup plug had some little wings at the top, one was still attached when i found the plug, but it was very brittle.

The metal the plug is made from is pretty hard.

I could not find the other 3 pieces, either they were never there or they are in my filter.
 
Everything must come apart and checked.
No exceptions .
Torque converter rebuild also.
 
that's one thing I'm not sure on, the converter...
I did what I could to flush the thing out when it was off, I also managed to get out several quarts when drained.

Rebuild sounds like shell out another $250-$300 for a new one?
 
Not a bad idea, I also have a bunch of different high powered magnets on the bottom of my pan, right under where this valve sits I have the most powerful one.
That's where I found the cup plug.
 
yeah! those magnets can prevent a great deal of problems by preventing small metal debris from getting sucked into transmission oil pumps
 
I would call Buckeye Torque converters in Ohio.
Talk to them.
Rebuild should be $150 or so.

You have no way to see inside and check.
How many times do you want to rebuild and Fail again ? !
 
Driving my Corvette today.
Ran around Chicago Expressways.
Hit 140 mph again passing Full Bore.
I blew all away .
Left in the Dust.
My Buckeye Torque converter I credit for success .
 
Pulled the valve body, the plug was still in there...

I tapped the hole anyways, perfect fit for the plug that came off of my drain plug, since i have a thermo sensor there now...

Doing more reading i found this...
http://sethirdgen.org/tranny.htm

At the bottom describes my issue... Forward sprag...

So i pull the transmission today, confirmes that per my gm manual the sprag is correct.

So i proceed to replace the cheap sprag with the borgwarner unit.
Following the assembly instructions in my manual the forward sprag free wheels the opposite direction...

So thinking the check instructions are backwards like the reverse sprag i do digging and find out it was indeed backwards!
I made a little note in my manual...
Very anoying...

Tomorrow I'll check everything else again, verify fluid paths in the input drum and get it back together.
 
good info on the link, I took note of this part.

Low/reverse piston: This is the large piston at the rear of the transmission's internal components. Never reuse casting number 8681725, as it is known to have durability problems. Replace it with one that has casting number 8685550 (GM part number 8685549), which is a much stronger piece.
Click to expand...

I looked up the suggested part number and the casting is done much differently, however I did look over mine and it looks ok... I'm also not sure if this is a drop in part for an older 700r4...

Thoughts?


I also installed the new rear case support with the wide rear sprag, the ebay ad said it was from a 4x4 4l60e, it was a perfect fit!

Last time I also installed a "case saver" instead of the anti clunk spring in the low reverse clutch pack/rear case support.
I noticed I had a nice clunk last run, while taking the transmission apart I worked to find the source of that clunk, seemed to be coming in the direction of that "case saver"
I reinstalled the anti clunk spring, and I cannot reproduce the clunk any longer...


I also got my input shaft end play down to .008, pretty much the minimum...

and for my forward sprag, these are the instructions that had me put it in backwards, the first time around I used the video 99% and used the manual as a general reference for clearances.

From my 1984 GM manual
upload_2016-6-16_6-43-35.png
The video had me put it together so it turns in the other direction.
Might be the reason why my downshift was so violent... :)

also my overrun clutch was a bit burnt, not surprising since it was working pretty hard...

my 2-4 band was also a bit burnt, I assume it might be related to the backwards sprag...
the good news is the drum looks good, but I'll verify it's still flat before re-using.

I got the servo pin setup to be right at that minimum clearance as suggested by the super hold 4th servo instructions.

Maybe it might be a good idea for me to put it right at the middle of the suggested clearances this time around?

I bought a new band and overrun clutch pack, the forward clutch pack took some stress but it still looks good.
 
I also noticed that the wording in the forward sprag instructions above tell me to put it together the correct way, the smaller gear is for the overrun clutch pack, larger is for the forward pack....
Just that image is very confusing...
 
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