Trans guys help me out.
06-09-2007, 04:54 PM
#1
Launching!
Thread Starter
iTrader: (8)
Join Date: Apr 2005
Location: TN
Posts: 203
Likes: 0
Received 0 Likes
on
0 Posts
Trans guys help me out. I have a built 4l60e with vacuum mod and 4000 stall. I got it to shift at part throttle but it will not shift at WOT. It will pull hard and go all the way to the rev limiter and then it feels like it slips. I have it shifting at 6200 rpm.
06-09-2007, 06:15 PM
#2
Whats your rev limiter set at , Bear in mind shifts are not instantanious, You must allow time from command to actual shift, ussally depending on the trans build and the power of your car which affects the rate the RPM increases with a well built trans with tight clearances this would be aprox 200 to 500 RPM though again this number can vary according to build and power out put
Originally Posted by Kiss_My_99SS
I have a built 4l60e with vacuum mod and 4000 stall. I got it to shift at part throttle but it will not shift at WOT. It will pull hard and go all the way to the rev limiter and then it feels like it slips. I have it shifting at 6200 rpm.
__________________
06-09-2007, 06:34 PM
#4
Launching!
Thread Starter
iTrader: (8)
Join Date: Apr 2005
Location: TN
Posts: 203
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by performabuilt
Whats your rev limiter set at , Bear in mind shifts are not instantanious, You must allow time from command to actual shift, ussally depending on the trans build and the power of your car which affects the rate the RPM increases with a well built trans with tight clearances this would be aprox 200 to 500 RPM though again this number can vary according to build and power out put
Rev limiter is set at 6800. I have tried to set the shift rpm to 6000 but it still does not work.
Trending Topics
06-13-2007, 12:22 PM
#13
Launching!
Thread Starter
iTrader: (8)
Join Date: Apr 2005
Location: TN
Posts: 203
Likes: 0
Received 0 Likes
on
0 Posts
I know that the shift is being comanded so that rules out the tune. What do I need to look at now? The PT shifts feels soild and fast. Please help!! I'm about ready to brun this thing.
06-13-2007, 01:10 PM
#16
Ok I dont know what the general shape of your trans is but there can be anywhre from a 200 to I have seen 600 rpm lag between actual comand and when the shift ocurrs depending on the conditions and the set up of the trans internally . If you have the ability I would drop the shift point to around 5600 and work from there. if it makes the gear try and raise it just a little at a time. Though the electronics are at the speed of light the reaction of the trans is not , If that dosent do it try dropping to 5400 if it wont make the shift there then I would say theres some internal trans issue . Also if in the tuning the line presure has been increased try returning it to stock also .
__________________
06-13-2007, 01:38 PM
#17
Launching!
Thread Starter
iTrader: (8)
Join Date: Apr 2005
Location: TN
Posts: 203
Likes: 0
Received 0 Likes
on
0 Posts
Ok I just scanned the car at WOT. I set the shift rpm to 5400 and the mph table is set to 0. Both 1-2 and 3-4 solenoids are on.At about 4900 RPM 3-4 goes off and then at 5200 RPM right back on. Then at 6300 RPM 3-4 back off . Car does not shift.
06-13-2007, 02:11 PM
#19
Launching!
Thread Starter
iTrader: (8)
Join Date: Apr 2005
Location: TN
Posts: 203
Likes: 0
Received 0 Likes
on
0 Posts
They are not used the trans has vacuum mod done to it. They are set to stock. What coul;d be wrong on the inside? If you let off the gas when you waNT IT TO SHIFT IT WILL.
Last edited by Kiss_My_99SS; 06-13-2007 at 02:19 PM.
06-13-2007, 02:23 PM
#20
Oh yes I forgot you have the modulator. Well Im not sure what could be wrong but the reason I suggested presure is it is possible for the line to go high enough to push so much fluild to the solenoids that they become flooded, Which simply means they cannot vent fast enough. So the gears wont change, You can still ajust the line but its a bit more difficult. You will need to drop the pan and remove the MOD then turn the screw in center of the mod where the hose goes counter clockwise aprox I turn . Then put it back and see what happens, I am not a big fan of the vacc mod for this reason , But it may be worth a try . Sounds like the only possibility left , Other than perhaps a wrong feed hole to the solenoids being drilled to large during the build which can also cause solenoid flooding
__________________