Quick question on this ollllddd thread. On drilling the 2-3 hole, if you go to large, do you get the flare? Say Im not running a corvette servo....stock is .082, Transgo replacement plate is .082, Transgo HD2 kit suggests .093 or .101 for high stall converter, and above you suggest .116? I think I drilled mine out to .116, but now I have the flare. UGH. Bought a replacement plate, and dont want to hose it up....so what would you suggest? What do the different sizes actually do? If this is the orifice where 3rd gear fluid flows to apply the 3-4 clutch and at the same time disengage the band via the servo....then I dont know why enlarging it too much would impact the band release/3-4 apply in a different relative manner. How would it release the band before the 3-4 applies, causing the flare? Would just going with the corvette style servo "fix" this? What if I go to a corvette servo in the future WITHOUT changing the size of this orifice?

I dont have a shift kit in the trans, so its basically stock. Im just looking for crisper shifts and better holding power/less slip.

Thanks

 

You correctly understand that the 3rd apply has to first fill the 3rd accumulator which is the part of the servo that also disengages the band.
The flare is caused by the band disengaging before the 3-4 clutch engages. While this could be caused by the band disengaging too soon, it can also be caused by the 3-4 clutch engaging slowly due to wear and/or leaks in the 3rd feed circuit.

No guarantee, but most of the separator plate drilling advice here assumes the Corvette servo.

Perhaps PBA or one of the other pros will have drilling advice to reduce your flare and still keep the stock servo.

 

Thank you.... And I *did* pick up a corvette 093 servo assembly from a 4th gen Formula a weekend or two ago....I dont want to just stab parts at it and guess....and hope for a good outcome (I know its easy to change, once you get a clean shot at it. Id have to drop my exhaust and lower the 4x4 trans/xfer case....not easy). The trans was 100% fine until I swapped out the valve body (the TCC valve must have been worn, as I was getting a shudder upon application that it cured), and replaced the sepreator plate as part of it. Only problem was I *thought* I had put a Transgo HD2 kit in it years ago, and drilled the new plate accordingly. Dumbazz me realized I didnt install a kit....so all other parts were stock. One of the side effects of age, apparently.

I have picked up a new plate, and plan on swapping it in this weekend. I like the 1-2 shift, the TCC apply, the 3-4, the 3-2, etc....its just that damn flare on the 2-3 that just started. As a side note, the inside of this trans was immaculate. The bottom of the pan was fairly clean, and nothing on the magnet. The screens on the TCC solenoid and the top of the separator plate had noting in them either. It was a beautiful thing to behold. LOL

*IF* there are suggestions on this, Id appreciate it....as I dont (can't?) leave well enough alone and just drop it in un-modified.

THANKS!!!!

 

With a 553 (Standard V8) 2nd piston, Drilling the 3rd Clutch hole to big will cause a 2-3 flare, The 553 is easier to knock off than a 093 (Vette) 2nd piston. It's simple hydraulics....A smaller area is easier to overcome than a larger area.

You have 2 options.....
Install a 093 piston & hope it cleans up the 2-3 shift....It will help for sure!

Install a new plate & drill the 3rd clutch hole to match the OEM plate.

 

With the Transgo 46-PLT-96 you have to at least drill it according to the stock V8 instructions.
The stock 2-3 shift (i.e. 3rd feed) hole is only .078.
What did you drill the current troublesome one?
Still hoping one of the pros has some advice on this; at least acknowledge whether a too-big 3rd feed hole might cause a flare.

 

Wellllll....I went with option B, picked up a new plate and redrilled it according to my stock size plate. I believe my 3rd is now a .082 (was drilled to .12), and my and 2nd is .073 (was .082), and voila....flare is gone. I really should have installed the 093 vette 2nd gear servo piston, but I wasnt in the mood to drop my trans and remove the exhaust to access it.

HOWEVER, while the flare issue is gone......my damn converter lock up is hosed up again. It basically locks up well in 4th gear as it should.....after a few second...shudders...and releases. Repeats over and over again......FML. Really thought the rebuilt valve body would have cured this (has the Sonnax TCC valve in it), but nope. But I was wondering....since my "aggressively" drilled separator plate seemed to cure the converter shudder problem (but created the flare), was there some orifice I drilled to for the Transgo HD2 kit instructions that impacts converter lock up? Obviously not the 2nd or 3rd gear holes....

UGH

 

Bad TCC solenoid? Are we assuming the TC is good, not sure how many miles yours has.

Have you checked line pressure?