Transgo Vacuum Modulator problems
01-27-2007, 12:17 AM
#1
Teching In
Thread Starter
Join Date: Jun 2006
Posts: 10
Likes: 0
Received 0 Likes
on
0 Posts
Transgo Vacuum Modulator problems Lost 4th gear about a month ago and decide to bullit proof the tranny ordered all the goodies beast sunshell the alto and kolene transgo shift kit and
VAC MOD. Had my 33 year gm world class trans builder pull and it and rebuild it for me. He followed the directions to a tee reinstalled the tranny and I have had nothing but problems. First of all it is constantly defaulting into 2nd gear, it will not down shift into 1st unless i manually do it with the shifter,and because of constantly starting off in 2nd im seeing tempatures of 250 degrees. Also the diode that came with the kit was constantly setting current codes for the epc solenoid, so we dropped the pan threw out the diode and installed the epc and left it in the back of the pan. That has fixed the coding problem but not the shifting issue. when it shifts into 3rd I can feel the converter lock up ( a tci 3k)but as soon as it shifts into od it unlocks and im not even really sure it is shifting into od (3:73 gears and im running 3200 rpms at 60 mph in od thats just not right). There does not seem to be any vacuum leaks .When at wot it seems to work fine. I'm lost on this any help would be greatly appreciated...........
VAC MOD. Had my 33 year gm world class trans builder pull and it and rebuild it for me. He followed the directions to a tee reinstalled the tranny and I have had nothing but problems. First of all it is constantly defaulting into 2nd gear, it will not down shift into 1st unless i manually do it with the shifter,and because of constantly starting off in 2nd im seeing tempatures of 250 degrees. Also the diode that came with the kit was constantly setting current codes for the epc solenoid, so we dropped the pan threw out the diode and installed the epc and left it in the back of the pan. That has fixed the coding problem but not the shifting issue. when it shifts into 3rd I can feel the converter lock up ( a tci 3k)but as soon as it shifts into od it unlocks and im not even really sure it is shifting into od (3:73 gears and im running 3200 rpms at 60 mph in od thats just not right). There does not seem to be any vacuum leaks .When at wot it seems to work fine. I'm lost on this any help would be greatly appreciated...........
01-27-2007, 09:03 AM
#2
I do not believe that the vacmod is your problem with no 4th and the problem with 1st. It sounds like you have an issue with the 1-2 solenoid. This solenoid is on in first gear and also needs to come back on in 4th. The vacmod only controls line pressure not the actual shifts. It sounds like your builder should go back over his work. I think he missed something. Vince
