dbrannon79
I'm getting there!
I need some input on where to start. on my 93 truck the trans has been shifting hard from 1st to 2nd after it's warmed up. when cold it shifts fine.
a little back story: This truck had it's trans rebuilt back in 2018 by the PO, at the time I purchased it, the trans only had about 2k miles on it since it's rebuild. During this process for reasons unknown the factory TCM was disconnected and a EZ-TCI controller was installed. from what I recall, the PO had told me that the trans was replaced and pieced together using parts from the old trans and this apparently was the reason for the aftermarket TCM. I have put about 2500 miles or so on it since I bought it.
The things I can physically see that were done (thinking a newer year trans was used) is the shift shaft was swapped so the factory linkage would connect to the old style column shifter. The connector was upgraded to the new style as the factory harness is a bolt on type.
I have read where @THEFERMANATOR has posted the differences many times and learned about the PCS (pressure control solenoid) are different from the 93 and the newer ones as well as the valve bodies with the TCC PWM solenoid cleaning cycle on the older ones. Here is a snip of one or his posts telling the differences..
Honestly I have no idea what the internals are, if they are of a newer trans or the older style trans, nor do I know if any upgrades were done in the process. I did verify this trans does have the tone wheel installed for the older style and it does send signal for both speed sensors, (the TCU is using the rear output sensor)
other than the hard shift from 1st to 2nd, all gears feel strong, no slippage, and the TCC lockup is much stronger than my 95 (feeling when it engages)
it's just the odd hard shift only when warm. the speed and RPM is normal when shifting too. I have the EZ-TCI set to shift as light as it will let me set it at and the low speed first shift is set to 10mph (as low as it will go). accelerating normally (not slow) it will shift at about 15ish mph and if I accelerate faster it will shift a little later and even harder from 1st to 2nd. all other gears shift smooth comparing to how my 95 shifts.
One thing that I also wondered is if the trans was filled with dex IV instead of Dex III. wondering if there is a oil viscosity difference when warm since when cold, shifting is fine.
I have already reached out to EZ-TCI asking for some data or charts to tell me what the controller commands for things like line pressure and shifting events so if I need to connect a pressure gauge and verify the trans is responding to what the TCU is commanding. There is no way to connect and see live data like line pressure on the TCU that I'm aware of. The handheld display will only show things like speed sensor, temp, and TPS data in live mode.
I figured I would reach out to your guys here for help before I drop the pan wasting what looks like clean bright red fluid and replace it with fresh dex III. I also bought a bottle of "Craigslist trans clutch rebuild" Lucas trans stop leak since it is supposed to thicken up the fluid and help with harsh shifting, but I have not poured it in yet.
Any help or advice would be appreciated. I think @Will said Humvee guys are running the EZ-TCI controllers on their hummers, maybe they have some insite on how their shifts with this controller or what the optimal setting would be for an everyday driver.
Diagnosing this I need to find out if it's something in the trans causing this or if it's the controller and this is how it will be. during this I would also like to see if the factory TCM can be connected back up since it's still in the truck with all the wiring intact.
a little back story: This truck had it's trans rebuilt back in 2018 by the PO, at the time I purchased it, the trans only had about 2k miles on it since it's rebuild. During this process for reasons unknown the factory TCM was disconnected and a EZ-TCI controller was installed. from what I recall, the PO had told me that the trans was replaced and pieced together using parts from the old trans and this apparently was the reason for the aftermarket TCM. I have put about 2500 miles or so on it since I bought it.
The things I can physically see that were done (thinking a newer year trans was used) is the shift shaft was swapped so the factory linkage would connect to the old style column shifter. The connector was upgraded to the new style as the factory harness is a bolt on type.
I have read where @THEFERMANATOR has posted the differences many times and learned about the PCS (pressure control solenoid) are different from the 93 and the newer ones as well as the valve bodies with the TCC PWM solenoid cleaning cycle on the older ones. Here is a snip of one or his posts telling the differences..
Honestly I have no idea what the internals are, if they are of a newer trans or the older style trans, nor do I know if any upgrades were done in the process. I did verify this trans does have the tone wheel installed for the older style and it does send signal for both speed sensors, (the TCU is using the rear output sensor)
other than the hard shift from 1st to 2nd, all gears feel strong, no slippage, and the TCC lockup is much stronger than my 95 (feeling when it engages)
it's just the odd hard shift only when warm. the speed and RPM is normal when shifting too. I have the EZ-TCI set to shift as light as it will let me set it at and the low speed first shift is set to 10mph (as low as it will go). accelerating normally (not slow) it will shift at about 15ish mph and if I accelerate faster it will shift a little later and even harder from 1st to 2nd. all other gears shift smooth comparing to how my 95 shifts.
One thing that I also wondered is if the trans was filled with dex IV instead of Dex III. wondering if there is a oil viscosity difference when warm since when cold, shifting is fine.
I have already reached out to EZ-TCI asking for some data or charts to tell me what the controller commands for things like line pressure and shifting events so if I need to connect a pressure gauge and verify the trans is responding to what the TCU is commanding. There is no way to connect and see live data like line pressure on the TCU that I'm aware of. The handheld display will only show things like speed sensor, temp, and TPS data in live mode.
I figured I would reach out to your guys here for help before I drop the pan wasting what looks like clean bright red fluid and replace it with fresh dex III. I also bought a bottle of "Craigslist trans clutch rebuild" Lucas trans stop leak since it is supposed to thicken up the fluid and help with harsh shifting, but I have not poured it in yet.
Any help or advice would be appreciated. I think @Will said Humvee guys are running the EZ-TCI controllers on their hummers, maybe they have some insite on how their shifts with this controller or what the optimal setting would be for an everyday driver.
Diagnosing this I need to find out if it's something in the trans causing this or if it's the controller and this is how it will be. during this I would also like to see if the factory TCM can be connected back up since it's still in the truck with all the wiring intact.
