Transmission problem 3/2 shift
Thread Starter
On The Tree
Joined: Jun 2005
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From: Bribie Island
Transmission problem 3/2 shift I have a vacum modulated 4l65E that usually handles 600+ hp at the wheels needing only the 3-4 clutches replacing now and then.
But on a number occasions I have minced these clutches at part throttle and at full throttle during kicking back to 2nd gear . I know this because when it goes back to third there is nothing there.
A local tranny builder thinks the clutch piston needs to bleed off more quickly by installing a larger orifice /exhaust
he thinks they are still holding onto third while powering in 2nd..
What do you all think, and is there a better fix for this?
Cheers
But on a number occasions I have minced these clutches at part throttle and at full throttle during kicking back to 2nd gear . I know this because when it goes back to third there is nothing there.
A local tranny builder thinks the clutch piston needs to bleed off more quickly by installing a larger orifice /exhaust
he thinks they are still holding onto third while powering in 2nd..
What do you all think, and is there a better fix for this?
Cheers
Do you know if in the build he retianed the square aux spring set in third. While the bleed off is a possibility , Its also posible your getting HI RPM centrifical apply . Basically fluid that is trapped in the piston area gets pushed against the side of the drum and walks up the walls and this can apply enough force to partially apply the 3-4 clutch an cause it to burn. If also possible the 3-4 clutch feed is so large and the presure going so high at WOT that the normal leakage is enough that it cant bleed off fast enaough as he says and they are remaining applied. I would ask him about the AUX springs though.
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FormerVendor
Joined: Oct 2006
Posts: 3,123
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From: D-F/W
Yep those auxiliary helper springs are trouble in a high rpm / high horsepower environment. In addition to remoing those springs it is recommended to install the spring packs that are included inthe Trans Go HD-2 reprogramming kit. These will drastically reduce and in most cases eliminate the 3/4 clutch failures in these units.
You are correct to think that the clutches are failing during hard pulls in 2nd gear. As Frank stated they are quite possibly applying in high rpm pulls.
I would not necessarily open the bleed hole, some builders block that hole.
Good Luck.
g
You are correct to think that the clutches are failing during hard pulls in 2nd gear. As Frank stated they are quite possibly applying in high rpm pulls.
I would not necessarily open the bleed hole, some builders block that hole.
Good Luck.
g
Thread Starter
On The Tree
Joined: Jun 2005
Posts: 111
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From: Bribie Island
Thanks for the info, Im sure thats whats happening,
When It goes Im at about full throttle and then going into 3rd I am usually back at about 30 -50% throttle ,had me thinking it was not enough line pressure burning them on the way to third.( modulator)
ah,but as I said it appears they are still applied going into 2nd.
The Transgo reprogrammer, is that the cable thingo that changes a message to start empting the fluid earlier or something??
When It goes Im at about full throttle and then going into 3rd I am usually back at about 30 -50% throttle ,had me thinking it was not enough line pressure burning them on the way to third.( modulator)
ah,but as I said it appears they are still applied going into 2nd.
The Transgo reprogrammer, is that the cable thingo that changes a message to start empting the fluid earlier or something??
Last edited by Tonner; Jul 10, 2007 at 09:37 PM.
FormerVendor
Joined: Oct 2006
Posts: 3,123
Likes: 3
From: D-F/W
Originally Posted by Tonner
The Transgo reprogrammer, is that the cable thingo that changes a message to start empting the fluid earlier or something??
Hope that clears it up somewhat.
g
Thread Starter
On The Tree
Joined: Jun 2005
Posts: 111
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From: Bribie Island
Yes Thanks for the help, The trans Builder is away for a few weeks on a rally, he normally uses the Transgo gear & he hops over to the states now and then and visits Gil Y. so I just remember him saying.
Thanks again
Edit: just found the link,http://www.txchange.com/transgo.htm
To use this kit we would need to return all transmission tuning to factory settings for this to work correctly, ?? would that be the case.
Thanks again
Edit: just found the link,http://www.txchange.com/transgo.htm
To use this kit we would need to return all transmission tuning to factory settings for this to work correctly, ?? would that be the case.
Last edited by Tonner; Jul 10, 2007 at 09:50 AM.
Thread Starter
On The Tree
Joined: Jun 2005
Posts: 111
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From: Bribie Island
Just got word that we do have this kit installed, maybe I need to have the tranny tuned settings brought back to standard, they are probably still set for the previous tranny when it was cam only.
