3-4 shift problems won't shift till let of gas or play with throttle
03-07-2015, 10:21 PM
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3-4 shift problems won't shift till let of gas or play with throttle 3-4 shift problems won't shift till let of gas or play with throttle Then it shifts harshly
Park to reverse and park to drive jerks also
Been searching on 3-4 but haven't seen clear cut answer
Trans was just look over by auto shop clutches where all new it's pretty much a fresh rebuilt
I'm current tuning in SD mode
Has shift kit and 3600 stall from hpscanner not getting any codes
Any help will be appreciated
Park to reverse and park to drive jerks also
Been searching on 3-4 but haven't seen clear cut answer
Trans was just look over by auto shop clutches where all new it's pretty much a fresh rebuilt
I'm current tuning in SD mode
Has shift kit and 3600 stall from hpscanner not getting any codes
Any help will be appreciated
03-08-2015, 11:05 AM
#2
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By "won't shift" I assume you mean that you hit the rev limiter. This indicates either that the 3/4 clutch is slipping or the tune is not correct. Is your PCM tuned for the 3600 stall?
If you have HP Tuners, try reducing the WOT Shift MPH by 5%; ideally also put that value into the Partial Throttle shift table for the 100% throttle position and blend it into the lower throttle values.
For the jerks when shifting out of Park, I would first suspect the transmission mount.
Another possibility for the harsh shifts and jerky engagement is that the line pressure is too high. Perhaps the rebuild shop adjusted the PCS for higher pressure and overdid it. (IMHO, just blindly adjusting the PCS set-screw indicates a lack of understanding how the trans works.)
You can check the line pressure with an inexpensive trans pressure gauge ("ATD 5550" on Amazon for $34). The line pressure in Park/Neutral with a shift kit is typically 75psi warm and a bit higher when the trans is cold.
If you have HP Tuners, try reducing the WOT Shift MPH by 5%; ideally also put that value into the Partial Throttle shift table for the 100% throttle position and blend it into the lower throttle values.
For the jerks when shifting out of Park, I would first suspect the transmission mount.
Another possibility for the harsh shifts and jerky engagement is that the line pressure is too high. Perhaps the rebuild shop adjusted the PCS for higher pressure and overdid it. (IMHO, just blindly adjusting the PCS set-screw indicates a lack of understanding how the trans works.)
You can check the line pressure with an inexpensive trans pressure gauge ("ATD 5550" on Amazon for $34). The line pressure in Park/Neutral with a shift kit is typically 75psi warm and a bit higher when the trans is cold.
03-08-2015, 12:10 PM
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No it's not tune to my stalled
What needs to be changed ? I have the ability to make changes
I check the force motor current section and wasn't stock values
Lower value higher pressure which isn't need with mechanism increase such as shift kit
I resetted then back to stock
I'm getting mix info I read one place where 3-4 wot isn't possible till you let off alittle
I assumed that was only for 700r4 TRANS is this true still for 4l60e also or no some say yes others say no
What needs to be changed ? I have the ability to make changes
I check the force motor current section and wasn't stock values
Lower value higher pressure which isn't need with mechanism increase such as shift kit
I resetted then back to stock
I'm getting mix info I read one place where 3-4 wot isn't possible till you let off alittle
I assumed that was only for 700r4 TRANS is this true still for 4l60e also or no some say yes others say no
03-08-2015, 12:22 PM
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Used a spread sheet found on HPtuner forum I did that last night I adjusted shift speed according to rpm gear ratio and tire height well half of the number 12.75
To get my shift speeds
After that I went to part trottle I just added New 100% TPS mph speed amd I blended it in like you said
I'm take another drive because if I'm at like 60% trottle I would need to be going over 156 to engage 3-4 shift
So I'm pay closer attention to the mph and TPS and see if it actually shifting before I jump to mechanical assumptions as yesterday wasn't really paying attention especially havent driving it in 2 years and frustration lol
To get my shift speeds
After that I went to part trottle I just added New 100% TPS mph speed amd I blended it in like you said
I'm take another drive because if I'm at like 60% trottle I would need to be going over 156 to engage 3-4 shift
So I'm pay closer attention to the mph and TPS and see if it actually shifting before I jump to mechanical assumptions as yesterday wasn't really paying attention especially havent driving it in 2 years and frustration lol
Last edited by zachary3; 03-08-2015 at 12:30 PM.
03-08-2015, 01:52 PM
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At WOT it won't shift until both the WOT Shift RPM and WOT Shift MPH are reached. Therefore I set my WOT Shift MPH about 10% lower than the calculated value.
I'm sure a WOT 3-4 shift is possible, although like you, that would far exceed any speed I care to reach. For high throttle 4th gear operation a billet 4th servo piston is highly recommended, and they you might as well put in a 2nd servo piston too.
If you log with HP Tuners scanner you, you can log for slippage, although it is often easy to see from just the MPH and RPM graphs.
I'm sure a WOT 3-4 shift is possible, although like you, that would far exceed any speed I care to reach. For high throttle 4th gear operation a billet 4th servo piston is highly recommended, and they you might as well put in a 2nd servo piston too.
If you log with HP Tuners scanner you, you can log for slippage, although it is often easy to see from just the MPH and RPM graphs.
03-08-2015, 04:59 PM
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Yes I did that
Can you take a look at my log ?
No don't need to WOT to 4th just want to trans to shift right as it doesn't feel right at all
If it's not one thing it's another
Did a cruise under 50 mph
Shift smooth 1-2 and 2-3 then it just revs up and untill I let off gas it shifts into 4th and it just repeats that if I'm in the right mph it just go back and forth from 3-4 with lifting on off throttle to I gather more speed and it stays in 4th
Can you take a look at my log ?
No don't need to WOT to 4th just want to trans to shift right as it doesn't feel right at all
If it's not one thing it's another
Did a cruise under 50 mph
Shift smooth 1-2 and 2-3 then it just revs up and untill I let off gas it shifts into 4th and it just repeats that if I'm in the right mph it just go back and forth from 3-4 with lifting on off throttle to I gather more speed and it stays in 4th
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03-08-2015, 08:43 PM
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I will do that when I get a chance
There like 10 miles now on rebuild everything was replace and upgrade
1-2 and 2-3 pulls hard I must say but 3rd and 4th rpm seem high
There like 10 miles now on rebuild everything was replace and upgrade
1-2 and 2-3 pulls hard I must say but 3rd and 4th rpm seem high
03-08-2015, 09:11 PM
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Does same thing at low speed part trottle just revs till letting of gas then goes to 4th
Starts at mid vid
Last edited by zachary3; 03-08-2015 at 09:16 PM.
03-08-2015, 10:55 PM
#14
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I don't have much experience looking at other people's log files, but your RPM seems to have little relation to MPH! I can see the huge spike where you hit the rev limiter; the RPMs doubled in a fraction of a second.
It therefore seems pretty clear to me that your 3/4 clutch is slipping badly.
It would be good to know what the actual line pressure is while you are driving (hint hint about the gauge). Low line pressure could cause it to slip, but it currently looks like the last rebuild left a big leak in the 3/4 clutch circuit.
I'm not an expert, I could be wrong, but that is what it looks like to me based on your description and the log file.
It therefore seems pretty clear to me that your 3/4 clutch is slipping badly.
It would be good to know what the actual line pressure is while you are driving (hint hint about the gauge). Low line pressure could cause it to slip, but it currently looks like the last rebuild left a big leak in the 3/4 clutch circuit.
I'm not an expert, I could be wrong, but that is what it looks like to me based on your description and the log file.
03-09-2015, 11:14 AM
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03-09-2015, 03:11 PM
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I see well I got VE tables roughed in to +/- 5 just going to get dyno tune so i just re enabled my maf among other things I needed to update back to stock settings but I'm going to drive it and see what happens
03-10-2015, 02:04 PM
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so took another drive and but it in D aka 3
and once it shifts into 3rd it just revs so im sure its more 3-4 clutch slip because I feel like I have no 3rd as it doesn't accelerate much
when I put into 4th OD it does accelerate but its just not putting the power down just revs higher just get it moving
1st to 2nd doesn't seem strong 3rd as wheel I hardly notice it really sometimes
also converter isn't locking
and once it shifts into 3rd it just revs so im sure its more 3-4 clutch slip because I feel like I have no 3rd as it doesn't accelerate much
when I put into 4th OD it does accelerate but its just not putting the power down just revs higher just get it moving
1st to 2nd doesn't seem strong 3rd as wheel I hardly notice it really sometimes
also converter isn't locking
Last edited by zachary3; 03-10-2015 at 02:10 PM.