part throttle 2-3 shift feels wierd

[toomanymodz]

Hey all..

New tranny and I've noticed a few things. First is the 2-3 shift. Under light acceleration the car will nose down and I can feel myself moving forward in the seat. The 1-2 shift feels firm like it should, like a little bump in your back when it hits. But the 2-3 is just the opposite, it sort of slides into drive. Under harder acceleration it's fine. I adjusted the TV cable like this: pushed the button and moved the cable back towards the firewall. Then I mashed the accelerator pedal to the floor (mat out of the way) and it clicked into place.

Second item is the 3rd gear indicator. It isn't working with the new tranny. Is there something that I could look for and correct?

Third item is a slight rumbling sound in reverse. No noises in the other gears, only reverse makes a strange noise. Thoughts?

 

[mikestertwo]

Hey all..

New tranny and I've noticed a few things. First is the 2-3 shift. Under light acceleration the car will nose down and I can feel myself moving forward in the seat. The 1-2 shift feels firm like it should, like a little bump in your back when it hits. But the 2-3 is just the opposite, it sort of slides into drive. Under harder acceleration it's fine. I adjusted the TV cable like this: pushed the button and moved the cable back towards the firewall. Then I mashed the accelerator pedal to the floor (mat out of the way) and it clicked into place.

Second item is the 3rd gear indicator. It isn't working with the new tranny. Is there something that I could look for and correct?

Third item is a slight rumbling sound in reverse. No noises in the other gears, only reverse makes a strange noise. Thoughts?

Is this a BRF trans? If the direct clutch is dual fed (3rd gear) the nose over feel on the 2-3 shift may be caused by binding. Basically it is in 2nd and 3rd at the same time for a moment during the shift. That is common with that mod. There is a fix for it. The 3rd gear indicator may not be working 1) the 3rd gear pressure switch may be bad 2) There is no 3rd gear pressure switch on the valvebody 3)wrong/bad wiring harness inside the transmission

 

[toomanymodz]

That makes sense. Not sure if its a BRF. I hope so. Is the fix you're referring to something that can be done by simply pulling the valve body? I'd rather not have to drop the trans. As for the 3rd gear indicator, I guess I can live without it. I think Erics chip uses the VSS rather than the 3rd gear indicator when determining the ignition timing.

 

[mikestertwo]

That makes sense. Not sure if its a BRF. I hope so. Is the fix you're referring to something that can be done by simply pulling the valve body? I'd rather not have to drop the trans. As for the 3rd gear indicator, I guess I can live without it. I think Erics chip uses the VSS rather than the 3rd gear indicator when determining the ignition timing.

The correct way to get rid of the binding problem is changing the return springs on the direct clutch pack. That involves pulling the trans. You may want to talk to Chris at CK performance. I know he has a modified spacer plate that may alleviate some of the problem.

 

[toomanymodz]

Wonderful. Pulling the trans isn't an option right now. I can't miss the annual Buick show coming Feb 12th. I guess I could swap my old Jimmy's trans back in it if need be. Thanks for the info.

 

[Steve V]

CK has a nice plate that may help,I'd try that before swapping the unit.

I'd also be interested in hearing about the mods the return springs?

 

[mikestertwo]

PM sent

 

[JimP]

After having done a dual feed on my recent build I had a similar issue, that I would only feel under very light throttle. I enlarged the band release hole in separator plate to .120" for when the dual feed was done. This cured my problem right up, and was easily done with trans in the car. This is where I would look but hopefully you can talk to one of the experts or they will chime in. When I had rebuilt my trans I had one of Chris' older kits, apparently his new plate is much better suited for dual feed applications.

 

[toomanymodz]

I wonder if there is anybody in the Tampa FL area that can perform that modification. I'd hate to remove and ship the trans due to time/cost.

 

[TurboBuRick]

Subscribed

 

[toomanymodz]

I just got off the phone with the guys at CKPerformance. They were very helpful and said they have occasionally seen this issue from time to time. He first recommended adjusting the TV cable another notch or two towards the firewall. Then I explained that mine was already as far back as it can go, and in fact it's already starting to limit my throttle travel. They said the quick fix is to pull the pan and filter, then remove the bolt that holds the TV cable assembly. Then basically shim it with a 1/8 or 3/16 shim. This will allow me to relax the TV cable a click or two and still get the pressure that is needed. He's gonna talk me through it over the phone once I pull the pan. These guys are awesome. I can take pics of this mod if folks would like me to. Perhaps others have run into this same issue and have performed this same fix?

 

[onebadsix]

Subscribed , I have been having the same problem , any info would be helpfull

 

[toomanymodz]

Ok, I did the modification today. It allowed me to move the cable forward a click or two so that I have ample cable travel again. I knew that the throttle movement was being somewhat limited by the TV cable because my TPS volts could barely get to 4.00 After doing this the volts can now easily reach 4.35. The mod also raised the shift points when under light acceleration. In my case, however, I'm still feeling the strange 2-3 shift, which leads me to believe that I may need to do the valve body spacer plate mod in order to remedy the issue.

Pull the transmission pan and locate the 10mm bolt as shown:


Remove the bolt and bracket assembly. You will have to remove the filter in order to get the bolt all the way out. Note the roll pin:


Use pliers and pull out the roll pin. Now the plunger can come out. I had to gently pull using pliers:


Once it comes out it looks like this, a plunger with grooved sleeve and a spring:


Find an appropriate spacer that is 1/8 to 3/16 thick and is .500 (1/2 inch) in diameter. Luckily I found a few flat washers that worked. I stacked 3 together to get the appropriate thickness. The washers go in between the spring and the plunger as shown:


Now just re-assemble. Now move the TV cable a click or two forward away from the firewall. I use a phillips screwdriver to push the 'button' on the cable. I guess my thumb isn't strong enough. You should now have more throttle travel with firmer shifts under light throttle.

 

[TurboBuRick]

Seems less line pressure down low is what we need. Helps in my case anyway. If I understand it right,adding the washers will increases line press. Letting out the tv cable is contradicting the mod. 6 of 1 half a dozen of another. That's why I have not done it myself. I have a ck spacer and valve body. Had to let tv cable way out when I installed these. Otherwise she don't like to shift. I can actually change shift points with tv adjustment. I have to run it loose on the street and tighten it up when racing.

Hard to have the best of both worlds.

After dual feed 2-3 wot shifts are not as hard on mine either. No flair but no lunge. I would like to address this as well.

RL

 

[onebadsix]

Thanks for the pictures , I dont think that is my problem with bind on the 2-3 shift . My trans is dual fed , I think RL is on to something . My minimum line pressure is at 100 lbs . if i move a click or two on the cable towards the throttle body it lowers my minimum pressure down to 95 or so . im hoping that will help without screwing something else up . I also have two diffrent lenghts of throttle springs , i have the longer one in now which is 2.050 in length the shorter one is 1.900 , i may try the shorter one, see if that changes any thing , also this is cz valve body with snow on the ground i cant do any testing , for a when i put the car away with a newly rebuilt trans i felt the slight bind
thanks again for the pics

 

[gnon18s]

Could someone explain the "dual feed"? My 2-3 shift has always seemed like it slipped or flaired at part throttle just cruising around but at WOT shifts firm and perfect. Its a fresh trans built by Dynotech performance (the owner has since passed away and the buisness dissolved). Im not sure if i have this "dual feed" your talking about??

 

[mikestertwo]

Could someone explain the "dual feed"?

The direct clutch piston is divided into two sections separated by a seal. There is an inner and outer section area. When the trans is in 3rd gear, oil is fed only to the smaller inner section to apply pressure to the clutch pack. When the trans is in reverse oil is fed to both inner and outer sections of the piston to apply pressure to the clutch pack. Using both sections of the piston increases the surface area which will apply more pressure to the clutch pack. Dual feeding is a way of modifying the oil passage so oil is fed to both inner and outer sections of the clutch piston when you are in 3rd gear. It basically consists of plugging the reverse feed line and removing the seal from the center section of the piston.