shift points
#1
06-28-2010 | 09:21 PM
Thread Starter
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Diesel Enthusiast
Joined: Aug 2009
Posts: 462
Likes: 18
From: portland oregon
shift points
so i'm going to adjust my shift points. tps controls o/d. any way to get around that. i think 48 to 50 is way to low for o/d to my liking. plus i was going to increase line pressure by 3 psi. tranny has 26,ooo on it with shift kit. good idea or bad? do not want to blow any seals
#8
06-29-2010 | 10:56 AM
Diesel Enthusiast
Joined: Mar 2010
Posts: 238
Likes: 34
Increasing your system pressure won't necessarily effect your shift points. That is more determined by rpm than by pressure. FWIW, there is more than one pressure setting and reading in the transmission. Depending on which port you test, there are various recommended pressures. You'll need a good pressure gauge and an ATSG manual to know what you are doing. Pressures in that manual are:
Rear servo: Min. 145-175 -- Max. 230-280
Accumulator: Min. 54-60 -- Max. 90-96
Governor: Min. 0 (@ idle) -- Max. 1 PSI per 1 mph
Overdrive: Min. 68-72 -- Max. 90-120
Each of these has its own test port on the transmission and needs to be tested at a particular RPM range and shift point.
The TPS can adjust the point where torque converter lock-up and OD hit -- most guys would benefit from maxing out the voltage of the TPS. Check voltage across the center pin to the TPS (use a volt meter, positive to the center wire, negative to a good ground, and a pin or paper clip pushed up into the center terminal as far as you can get it -- helps to pull the connector and shove the wire up where you can see what you are doing, then reinstall the connector). Voltage should be around 1.0-1.4 at idle, and ramp up a maximum of 4 volts at WOT.
Adjustment is made by loosening the two screws that hold the TPS to the bracket, then rotate the TPS unit on the screws (it only moves a small amount). As you rotate it, watch the Volt Meter and set it where you want it. If you cannot adjust it far enough to pull the desired volts (1.4 at idle) then you may have to knock out the small metal sleeves and/or drill out the holes in the TPS a bit to get more movement.
I did mine and I love the new shift points.
Rear servo: Min. 145-175 -- Max. 230-280
Accumulator: Min. 54-60 -- Max. 90-96
Governor: Min. 0 (@ idle) -- Max. 1 PSI per 1 mph
Overdrive: Min. 68-72 -- Max. 90-120
Each of these has its own test port on the transmission and needs to be tested at a particular RPM range and shift point.
The TPS can adjust the point where torque converter lock-up and OD hit -- most guys would benefit from maxing out the voltage of the TPS. Check voltage across the center pin to the TPS (use a volt meter, positive to the center wire, negative to a good ground, and a pin or paper clip pushed up into the center terminal as far as you can get it -- helps to pull the connector and shove the wire up where you can see what you are doing, then reinstall the connector). Voltage should be around 1.0-1.4 at idle, and ramp up a maximum of 4 volts at WOT.
Adjustment is made by loosening the two screws that hold the TPS to the bracket, then rotate the TPS unit on the screws (it only moves a small amount). As you rotate it, watch the Volt Meter and set it where you want it. If you cannot adjust it far enough to pull the desired volts (1.4 at idle) then you may have to knock out the small metal sleeves and/or drill out the holes in the TPS a bit to get more movement.
I did mine and I love the new shift points.
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#9
06-29-2010 | 03:07 PM
Thread Starter
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Diesel Enthusiast
Joined: Aug 2009
Posts: 462
Likes: 18
From: portland oregon
#10
06-29-2010 | 03:23 PM
Diesel Enthusiast
Joined: Jun 2010
Posts: 119
Likes: 10
From: Lower Alabama
Increasing your system pressure won't necessarily effect your shift points. That is more determined by rpm than by pressure. FWIW, there is more than one pressure setting and reading in the transmission. Depending on which port you test, there are various recommended pressures. You'll need a good pressure gauge and an ATSG manual to know what you are doing. Pressures in that manual are:
Rear servo: Min. 145-175 -- Max. 230-280
Accumulator: Min. 54-60 -- Max. 90-96
Governor: Min. 0 (@ idle) -- Max. 1 PSI per 1 mph
Overdrive: Min. 68-72 -- Max. 90-120
Each of these has its own test port on the transmission and needs to be tested at a particular RPM range and shift point.
The TPS can adjust the point where torque converter lock-up and OD hit -- most guys would benefit from maxing out the voltage of the TPS. Check voltage across the center pin to the TPS (use a volt meter, positive to the center wire, negative to a good ground, and a pin or paper clip pushed up into the center terminal as far as you can get it -- helps to pull the connector and shove the wire up where you can see what you are doing, then reinstall the connector). Voltage should be around 1.0-1.4 at idle, and ramp up a maximum of 4 volts at WOT.
Adjustment is made by loosening the two screws that hold the TPS to the bracket, then rotate the TPS unit on the screws (it only moves a small amount). As you rotate it, watch the Volt Meter and set it where you want it. If you cannot adjust it far enough to pull the desired volts (1.4 at idle) then you may have to knock out the small metal sleeves and/or drill out the holes in the TPS a bit to get more movement.
I did mine and I love the new shift points.
Rear servo: Min. 145-175 -- Max. 230-280
Accumulator: Min. 54-60 -- Max. 90-96
Governor: Min. 0 (@ idle) -- Max. 1 PSI per 1 mph
Overdrive: Min. 68-72 -- Max. 90-120
Each of these has its own test port on the transmission and needs to be tested at a particular RPM range and shift point.
The TPS can adjust the point where torque converter lock-up and OD hit -- most guys would benefit from maxing out the voltage of the TPS. Check voltage across the center pin to the TPS (use a volt meter, positive to the center wire, negative to a good ground, and a pin or paper clip pushed up into the center terminal as far as you can get it -- helps to pull the connector and shove the wire up where you can see what you are doing, then reinstall the connector). Voltage should be around 1.0-1.4 at idle, and ramp up a maximum of 4 volts at WOT.
Adjustment is made by loosening the two screws that hold the TPS to the bracket, then rotate the TPS unit on the screws (it only moves a small amount). As you rotate it, watch the Volt Meter and set it where you want it. If you cannot adjust it far enough to pull the desired volts (1.4 at idle) then you may have to knock out the small metal sleeves and/or drill out the holes in the TPS a bit to get more movement.
I did mine and I love the new shift points.
---AutoMerged DoublePost---
I did mine and I love the new shift points
Read more: https://www.dieselbombers.com/12-val...#ixzz0sH9GL800
What are they, thank you?
Last edited by motorboat; 06-29-2010 at 03:23 PM. Reason: Automerged Doublepost
