Like the title says, what do you think? Do they extend the life of good transmissions and condemn ailing ones? I'm debating getting one for my 545RFE.
What's Your Opinion on Transmission Line Boosters?
- Thread starter mphilleo
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Never heard of them. Headin to google now
Ok. Google helped. The trans cooler is not a high pressure line. The higher pressures are in the trans and valve body. I do not see how restricting the flow to the cooler would make a trans last longer.
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Depends on many factors.....Health of the unit, Health of the pump, Is the cooling system up to the task? More pressure equals more heat!
I don't build many 545RFE's but I've built quite a few of it's big sister...The 68RFE, I use the Sonnax line booster kits on every one!
I don't build many 545RFE's but I've built quite a few of it's big sister...The 68RFE, I use the Sonnax line booster kits on every one!
I do not understand what these boosters do.
I think the money is better spent on a large transmission cooler.
I think the money is better spent on a large transmission cooler.
They're supposed to increase the transmission line pressure, resulting in faster, crisper shifts without a tuner (and the RFEs would defeat a tune). Theoretically, this results in reduced clutch wear if yours aren't slipping already. That's when they're not do good.
See, I have a 2008 Commander with the 545RFE and towing package, so what isn't an issue for me since I mostly DD it. I do have an occasional annoying firm or hanging (not slipping) shift I'm hoping to improve. I'll probably do a filter change and series of drains and fills first though. I was trying to see what others thought first, though.
See, I have a 2008 Commander with the 545RFE and towing package, so what isn't an issue for me since I mostly DD it. I do have an occasional annoying firm or hanging (not slipping) shift I'm hoping to improve. I'll probably do a filter change and series of drains and fills first though. I was trying to see what others thought first, though.
Originally Posted By: clinebarger
Depends on many factors.....Health of the unit, Health of the pump, Is the cooling system up to the task? More pressure equals more heat!
I don't build many 545RFE's but I've built quite a few of it's big sister...The 68RFE, I use the Sonnax line booster kits on every one!
I've used that line booster before. It does absolutely nothing for line pressure. It's a waste of money unfortunately. Line pressure is still at 160. However with a properly built 68RFE you can go to 225-250.
Depends on many factors.....Health of the unit, Health of the pump, Is the cooling system up to the task? More pressure equals more heat!
I don't build many 545RFE's but I've built quite a few of it's big sister...The 68RFE, I use the Sonnax line booster kits on every one!
I've used that line booster before. It does absolutely nothing for line pressure. It's a waste of money unfortunately. Line pressure is still at 160. However with a properly built 68RFE you can go to 225-250.
Originally Posted By: clinebarger
Depends on many factors.....Health of the unit, Health of the pump, Is the cooling system up to the task? More pressure equals more heat!
This statement ends the whole thread without the line boosters in the equation. "How long will my transmission last?"
That said, if something is on it's last leg, I don't think much can be done at this point..
Depends on many factors.....Health of the unit, Health of the pump, Is the cooling system up to the task? More pressure equals more heat!
This statement ends the whole thread without the line boosters in the equation. "How long will my transmission last?"
That said, if something is on it's last leg, I don't think much can be done at this point..
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Originally Posted By: Farmer
Originally Posted By: clinebarger
Depends on many factors.....Health of the unit, Health of the pump, Is the cooling system up to the task? More pressure equals more heat!
I don't build many 545RFE's but I've built quite a few of it's big sister...The 68RFE, I use the Sonnax line booster kits on every one!
I've used that line booster before. It does absolutely nothing for line pressure. It's a waste of money unfortunately. Line pressure is still at 160. However with a properly built 68RFE you can go to 225-250.
My mechanical pressure gauge disagrees with you......LOL
If you are trying to read the line boost via a scan tool, It will read the same as stock.
The Sonnax line booster is placed between the TCM & Pressure Transducer, The TCM will now see a lower pressure vs commanded PCS duty cycle. The TCM will now command increased PCS duty cycle to compensate for the false readings.
Of coarse this will not produce 250 psi of max forward line pressure that a 68RFE behind a 900# torque modified Cummins will require, Nor was it ever meant to. But it WILL produce the 20-25 psi increase.
Originally Posted By: clinebarger
Depends on many factors.....Health of the unit, Health of the pump, Is the cooling system up to the task? More pressure equals more heat!
I don't build many 545RFE's but I've built quite a few of it's big sister...The 68RFE, I use the Sonnax line booster kits on every one!
I've used that line booster before. It does absolutely nothing for line pressure. It's a waste of money unfortunately. Line pressure is still at 160. However with a properly built 68RFE you can go to 225-250.
My mechanical pressure gauge disagrees with you......LOL
If you are trying to read the line boost via a scan tool, It will read the same as stock.
The Sonnax line booster is placed between the TCM & Pressure Transducer, The TCM will now see a lower pressure vs commanded PCS duty cycle. The TCM will now command increased PCS duty cycle to compensate for the false readings.
Of coarse this will not produce 250 psi of max forward line pressure that a 68RFE behind a 900# torque modified Cummins will require, Nor was it ever meant to. But it WILL produce the 20-25 psi increase.
Originally Posted By: clinebarger
Originally Posted By: Farmer
Originally Posted By: clinebarger
Depends on many factors.....Health of the unit, Health of the pump, Is the cooling system up to the task? More pressure equals more heat!
I don't build many 545RFE's but I've built quite a few of it's big sister...The 68RFE, I use the Sonnax line booster kits on every one!
I've used that line booster before. It does absolutely nothing for line pressure. It's a waste of money unfortunately. Line pressure is still at 160. However with a properly built 68RFE you can go to 225-250.
My mechanical pressure gauge disagrees with you......LOL
If you are trying to read the line boost via a scan tool, It will read the same as stock.
The Sonnax line booster is placed between the TCM & Pressure Transducer, The TCM will now see a lower pressure vs commanded PCS duty cycle. The TCM will now command increased PCS duty cycle to compensate for the false readings.
Of coarse this will not produce 250 psi of max forward line pressure that a 68RFE behind a 900# torque modified Cummins will require, Nor was it ever meant to. But it WILL produce the 20-25 psi increase.
I tend to concur with Farmer that this line pressure booster is a waste of money.
Agreeing that a line pressure booster does provide increased line pressure (depending on the spring rate in use), however this increased line pressure does nothing (borrowing a word from Farmer) to the varying actuating pressures of the respective clutch pistons (of various speed) as these clutch actuating pressures are generally very far lower than that of factory set line pressure.
Transmission supply line pressures are not actuating pressures of combinations of various clutch housings/pistons of various (gear) speeds.
Originally Posted By: Farmer
Originally Posted By: clinebarger
Depends on many factors.....Health of the unit, Health of the pump, Is the cooling system up to the task? More pressure equals more heat!
I don't build many 545RFE's but I've built quite a few of it's big sister...The 68RFE, I use the Sonnax line booster kits on every one!
I've used that line booster before. It does absolutely nothing for line pressure. It's a waste of money unfortunately. Line pressure is still at 160. However with a properly built 68RFE you can go to 225-250.
My mechanical pressure gauge disagrees with you......LOL
If you are trying to read the line boost via a scan tool, It will read the same as stock.
The Sonnax line booster is placed between the TCM & Pressure Transducer, The TCM will now see a lower pressure vs commanded PCS duty cycle. The TCM will now command increased PCS duty cycle to compensate for the false readings.
Of coarse this will not produce 250 psi of max forward line pressure that a 68RFE behind a 900# torque modified Cummins will require, Nor was it ever meant to. But it WILL produce the 20-25 psi increase.
I tend to concur with Farmer that this line pressure booster is a waste of money.
Agreeing that a line pressure booster does provide increased line pressure (depending on the spring rate in use), however this increased line pressure does nothing (borrowing a word from Farmer) to the varying actuating pressures of the respective clutch pistons (of various speed) as these clutch actuating pressures are generally very far lower than that of factory set line pressure.
Transmission supply line pressures are not actuating pressures of combinations of various clutch housings/pistons of various (gear) speeds.
Originally Posted By: zeng
Agreeing that a line pressure booster does provide increased line pressure (depending on the spring rate in use), however this increased line pressure does nothing (borrowing a word from Farmer) to the varying actuating pressures of the respective clutch pistons (of various speed) as these clutch actuating pressures are generally very far lower than that of factory set line pressure.
Transmission supply line pressures are not actuating pressures of combinations of various clutch housings/pistons of various (gear) speeds.
The Chrysler "RFE" series transmissions DO NOT operate in that manner, They don't even have a "Actuator Pressure Circuit"
Main Line Pressure is applied directly to the clutch apply pistons by the shift solenoids, The Solenoids are NOT modulated by the TCM either, They are "ON" or "Off" (Though the LR/CC Solenoid CAN BE modulated by the TCM in 2nd-6th gear for converter clutch operation).
The VPS/PCS (Pressure Control Solenoid) of course IS modulated by the TCM.
Agreeing that a line pressure booster does provide increased line pressure (depending on the spring rate in use), however this increased line pressure does nothing (borrowing a word from Farmer) to the varying actuating pressures of the respective clutch pistons (of various speed) as these clutch actuating pressures are generally very far lower than that of factory set line pressure.
Transmission supply line pressures are not actuating pressures of combinations of various clutch housings/pistons of various (gear) speeds.
The Chrysler "RFE" series transmissions DO NOT operate in that manner, They don't even have a "Actuator Pressure Circuit"
Main Line Pressure is applied directly to the clutch apply pistons by the shift solenoids, The Solenoids are NOT modulated by the TCM either, They are "ON" or "Off" (Though the LR/CC Solenoid CAN BE modulated by the TCM in 2nd-6th gear for converter clutch operation).
The VPS/PCS (Pressure Control Solenoid) of course IS modulated by the TCM.
Some units (The Allison 1000 for example) do use clutch actuation pressure that IS separate from Main Line Pressure. This eliminates the need for hydraulic Accumulators/Compensators.....I believe this is the type of control system your referencing here Zeng?
Then there are units that use a "Actuator Feed Limit" just for Solenoid & shift valve operation & is regulated to a lower static pressure mechanically, However.....Main Line IS used for actual clutch actuation (The 4T60E, 4L60E, 4L80E are examples).
Then there are units that use a "Actuator Feed Limit" just for Solenoid & shift valve operation & is regulated to a lower static pressure mechanically, However.....Main Line IS used for actual clutch actuation (The 4T60E, 4L60E, 4L80E are examples).
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