I am hoping I can pick Paul S's brain. I have a C4 with a TCI reverse manual valve body, fully rollerized, and all aluminum drums. I have had two professional trans builders look at it, but no one can fix the dreaded 2-3 flare. I have tried the H servo with cuts in it like TCI recommends, and a standard A servo, but nothing changes it. Front band has been adjusted from 1-3 turns out, and everywhere in between. Absolutely looks brand new inside, and no burnt clutches, so the trans is not slipping. Must be something with the apply timing and release of the servo. Could it be a leak in the servo, or something like that? Any help would be greatly appreciated, and if you need more info, please let me know. Thanks. Jeff
The dreaded 2-3 flare is caused by the 2nd gear servo releasing before the direct clutch can apply. You can adjust the band tighter (causing band wear and added friction that slows you down) or use less clearance in the forward pack. Just a note here - I don't believe you should ever use the "H" servo with the apply side deleted as was mentioned in your post. It can apply the band with enough force to break cases if the line pressure is also high. I designed a kit that can be installed to eliminate (and even tune) the 2-3 flare. The valve body has to be removed and it is modified - TCI will not like this but it does cure the 2-3 flare. The modifications will likely void any warranty so you decide if you want to do this or have TCI fix it. You can contact me through email to order the 2-3 Flare Eliminator kit at: paulstephens @ q . com (without the spaces) PS: I love TCI - nearly all their transmissions have this problem!
I have tried the band adjustment with no success. Line pressure is at 180 across the board. I have also tried an A servo, but that didn't change things either. My friend that is a builder wanted to come by tonight and air check everything. He thinks this might be a cause of a leak across the servo shaft from a worn out case. Any thoughts on that? Thanks. Jeff
I doubt that is the case with a C4. I have seen some with wear but the leakage is minimal with oil going through. If the "H" servo didn't cure the flare then no servo change will - it is the largest of all the servos and will disengage the slowest. A leak across the separator plate or a misaligned passage might cause the problem but it would more likely be a passage to the servo release that was too big or leakage at the direct clutch apply (stator support sealing rings, apply piston seal leak or cracked piston). The release of the servo has to be slowed down or the application of the direct clutches has to be sped up.
Paul, The H servo I have has the 3 cuts in the inner lip area, so would that allow the flare, and if I put in a stock H servo would it help eliminate the flare. I also picked up an R servo that I was going to try as a next step. What are your thoughts on that. Or can I just buy your kit for adjustment, and use some recommended letter of servo? Everything else in the trans is brand new, so I doubt it has anything cracked or worn, but I have learned to not overlook anything. Also 2 professional builders have both been through it, and can't see any issues. Your continuing help is greatly appreciated, and I know we will eventually figure it out. Then whatever solves it can possibly be a solution for others with the same problem.
The "R" servo will not cure your flare - it will be the same as the "H" servo. Changing to the stock "H" servo will perform the same on release - The large part of the piston is the release side and that is what you are using now for both the apply and release. If the maker, TCI, and your local experts can't come up with a cure then send me a request with a $20 Postal Money order and I will mail you a kit. It will come with pictures and complete instructions so you can install it yourself.
Paul, Is your kit something I can install while the trans is in the car, or do I have to drop it again? Since I just put it back in yesterday, I am not really ready to tackle it again. I have 4 race weekends in a row coming up, so I was hoping to have it fixed by then, and I wouldn't mind trying your kit if I can do it in the car. Otherwise, I will just have to close out the year with a 2-3 flare everytime. The thing that is weird to me, is that I have no burnt clutches or band from the flare. Also my onboard dataloger shows a spike in driveshaft speed when the flare happens. Could it be possible that I am just slipping tires on the 2-3 shift, and there isn't really a flare problem at all. I seriously doubt it though, because my car is a 300hp stock eliminator car on a 9" wide radial slick. Any thoughts on that one?
From message 123... You don't have to remove the transmission... only the valve body (which can be hard enough from under the car).
Hey Paul, I'm having issues with my C4. It will go into low and second but when it reaches the point to shift to third it will shift into neutral (or what seems like neutral) and just rev. Reverse is an issue as well. After its warmed up a bit it will go into reverse gear but doesn't want to when its cold. When its cold it puts a load on the motor when you put it into reverse but doesn't go anywhere. When I can get it to go into reverse after it warming up a few minutes it engages pretty hard and doesn't slip. It goes into park and neutral just fine. Trans fluid looks good and vacuum modulator has vacuum at the modulator. Any ideas? Thanks, Todd
Paul, I tried emailing you to get your shipping info, but haven't heard anything yet. Maybe I got the email wrong, but I want to order a kit. Would I be able to get it in time to install before next weekends race? Let me know. Thanks. Jeff
Todd, It sounds like you have a leaking or broken direct clutch apply piston seal. When in reverse the direct clutch applies without the forward drum but the pressure is higher. That would explain why reverse works after it warms up but high gear never works. Sorry to be the bearer of bad news but you are in for a rebuild.
You need to send me a Postal Money order for $20 and request an "anti-flare kit" for the C4. I don't ship before payment clears which is why I require Postal Money Orders - they are as good as cash. That way I can ship your order the same or next day that I get your order. You can email me here for the address and Phone number. I haven't receoved any e-mail orders in the last two weeks so it is likely that you have a wrong address.
