4l60E 4th shift pressure 96PSI

[HellKnightHicks]

Is it safe to run 96PSI on the forth gear shift?

3>4

[bmc1025]

07 Tahoe has 3-4 shift at 90 psi 0 torque reduction 0.0 for the shift time, the force motor current tables are slightly different.

[HellKnightHicks]

I had mine set to 96psi before with a crappy a$$ junk yard tranny in it..

I have 5 pinion planiteries and all that good stuff now.

Sonnex 4th Billet Servo, Vett 1-2
HD2 All washers installed. ....

[bmc1025]

WHen I get home tonight I Will post up the factory tune out of the Tahoe the pressures look like a good starting point most of the shift times are very long under part throttle and get quicker under hard trottle. I prefer all 0s or .2 if it shifts to hard and then. Then you have to play give and take with the pressures and TM. I'm no professional by any means proceed with caution. Posting from my phone sorry

[HellKnightHicks]

I get confused over reducing shift times to .2 or 0.0 Mine are 0.0 right now. Why .2

[bmc1025]

.0 makes it shifts as quick as mechanically possible or the way the shift kit is designed. If it feels good and solid but not abrupt leave it. You can add time to the lighter throttle areas and make it more cadillac like for dd or if your wife wants to drive

[joecar]

Is it safe to run 96PSI on the forth gear shift?

3>4Ramp it up from 0 psi @ 0 ftlb to 96 psi @ ~300 ftlb, and then level out at 96 psi.

[joecar]

Shift kit: set shift times to 0, this prevents the PCM from correcting the shift times programmed in by the 4L60E-HD2 kit.

[HellKnightHicks]

Is there a reason that we have to start at 0.0

I like to feel the engagement of the gear even when my foot is not on the pedal

[joecar]

Is there a reason that we have to start at 0.0

I like to feel the engagement of the gear even when my foot is not on the pedalNo, no reason... you can start with say 10 psi and fine tune.

[bmc1025]

Here is the stock TCM file for my 07 Tahoe17808

Keep in mind this is a 6000LB SUV with a 4l60E and a 5.3 .

Take a look at (D8301) 3>4 Shift Pressure it is all 90 and the (D3104) 3>4 Torque reduction is 0. (D3101) 3>4 Shift Time is 0.0. Don't pay any attention to the other shift times, as this is a soccer Mom SUV.

The Base Pressure for the 3>2 downshift (D8203) is set at 90 across the board also.

[joecar]

Here is the stock TCM file for my 07 Tahoe17808

Keep in mind this is a 6000LB SUV with a 4l60E and a 5.3 .

Take a look at (D8301) 3>4 Shift Pressure it is all 90 and the (D3104) 3>4 Torque reduction is 0. (D3101) 3>4 Shift Time is 0.0. Don't pay any attention to the other shift times, as this is a soccer Mom SUV.

The Base Pressure for the 3>2 downshift (D8203) is set at 90 across the board also.

How does the 3->4 shift feel at low/mid throttle...?

The stock truck 4L60E did not have the larger area 2nd servo, so that's one way to provide sufficient clamping.

[bmc1025]

Believe it or not it is not harsh at all. It must be restricted in the VB. The 3>2 shift is harder, but I would describe it only as almost firm.

I would assume this is actually a 4L65E or 4L70E but I have not had one of these exact transmissions apart. I also think you are correct about the 2nd servo piston. My wife's s-10 has the larger servo and 2nd is much more firm, shifting up and down. I have to use a little TR to soften the shift at lower throttle.

[Brad Kimbler]

Believe it or not it is not harsh at all. It must be restricted in the VB. The 3>2 shift is harder, but I would describe it only as almost firm.

I would assume this is actually a 4L65E or 4L70E but I have not had one of these exact transmissions apart. I also think you are correct about the 2nd servo piston. My wife's s-10 has the larger servo and 2nd is much more firm, shifting up and down. I have to use a little TR to soften the shift at lower throttle.

Its hard to get a firm or hard 3-4 shift, I usually build 3-5 4l60es a month for 10-11 sec cars as well as stock builds..I totally block off the 3-4 accumulator and DOUBLE the valvebody feed, this makes it noticeable, but still not hard to bad whatsoever. As far as the tune...Turn it up in my opinion...If I'm doing a stock truck with stock trans tune, I will usually highlight the entire 4th gear shift table and add 10-20 at least, even on my built transmission, its not a hard shift...Just make sure you DO NOT have the converter locked during a shift..most OS prevent this from happening but I have seen it able to lock during a 3-4 shift and that's very damaging to the trans, most of the time your better off eliminating 3rd gear lockup anyway. As far as billet servos...eh...I favor the corvette second gear servo and stock 4th gear servo . The stock 4th gear servo is plenty IF the mods are done during as build as I mentioned, or if you go into the tune and add to that 3-4 shift table. Oh and as far as maxing the shift table out, I wouldn't do that, just add to it, if the pump sees too much pressure to often the pump rotor has been known to crack preventing any movement. Now if you pull the trans andf add a billet pump rotor...go for it..

[bmc1025]

Oh and as far as maxing the shift table out, I wouldn't do that, just add to it, if the pump sees too much pressure to often the pump rotor has been known to crack preventing any movement. Now if you pull the trans andf add a billet pump rotor...go for it..
It is already maxed out from the factory in the Tahoe.

[HellKnightHicks]

1-2 is easy to get a firm crisp shift.... 2-3 is harder to accomplish. 3-4 you can make noticable but not crisp.

I think the size and weight of the vehicle is a contributing factor as well.

1-2 will slam even with Tq Management and the stock pressure tables.

2-3 i start at somewhere arround 25 PSI and work up to max 96 by arround 275flbs

3-4 is maxed at 96 PSI all the way across


Its hard to get a firm or hard 3-4 shift, I usually build 3-5 4l60es a month for 10-11 sec cars as well as stock builds..I totally block off the 3-4 accumulator and DOUBLE the valvebody feed, this makes it noticeable, but still not hard to bad whatsoever. As far as the tune...Turn it up in my opinion...If I'm doing a stock truck with stock trans tune, I will usually highlight the entire 4th gear shift table and add 10-20 at least, even on my built transmission, its not a hard shift...Just make sure you DO NOT have the converter locked during a shift..most OS prevent this from happening but I have seen it able to lock during a 3-4 shift and that's very damaging to the trans, most of the time your better off eliminating 3rd gear lockup anyway. As far as billet servos...eh...I favor the corvette second gear servo and stock 4th gear servo . The stock 4th gear servo is plenty IF the mods are done during as build as I mentioned, or if you go into the tune and add to that 3-4 shift table. Oh and as far as maxing the shift table out, I wouldn't do that, just add to it, if the pump sees too much pressure to often the pump rotor has been known to crack preventing any movement. Now if you pull the trans andf add a billet pump rotor...go for it..

What about 13 vane rotor? Im not running the stock 10 vane.

[Brad Kimbler]

1-2 is easy to get a firm crisp shift.... 2-3 is harder to accomplish. 3-4 you can make noticable but not crisp.

I think the size and weight of the vehicle is a contributing factor as well.

1-2 will slam even with Tq Management and the stock pressure tables.

2-3 i start at somewhere arround 25 PSI and work up to max 96 by arround 275flbs

3-4 is maxed at 96 PSI all the way across



What about 13 vane rotor? Im not running the stock 10 vane.
13 vanes are worse about breaking, the extra vanes are slots in the same diameter rotor as a 10 vanes, so 3 more slots thin out areas on the rotor...The main stress point is converter installed depth not being deep enough into the rotor, also running a extra quart low or over filled as welll can cause pressure spikes, damaging the rotor...this is not a super common failure..over the past few years I have seen 4 broken stock rotors, one of those being my build, this is why i only do performance builds with billet rotors now.. I'm not trying to make anyone paranoid, just trying to help give 60es a good name ...1781217813

[HellKnightHicks]

Circle D torq converters come with a kit to make sure that you properly shim the TC into the tranny.

Most everybody seems to hate 4l60e's I got 222000 out of mine in my white truck... In my blue one i got around 200,000 before it blew... Not a bad tranny... Coolers really seem to help them stay alive... even those little dinky stock coolers make one heck of a difference.

But you gotta either build it yourself or find someone who is good with trannys... Preferably local.

[HellKnightHicks]

Here is the stock TCM file for my 07 Tahoe17808

Keep in mind this is a 6000LB SUV with a 4l60E and a 5.3 .

Take a look at (D8301) 3>4 Shift Pressure it is all 90 and the (D3104) 3>4 Torque reduction is 0. (D3101) 3>4 Shift Time is 0.0. Don't pay any attention to the other shift times, as this is a soccer Mom SUV.

The Base Pressure for the 3>2 downshift (D8203) is set at 90 across the board also.

Would be nice to be able to control the down shift pressure but the Express Van OS doesnt have a table for that... The only thing thats close would be the temp adjust.
Wonder if it cold be indirectly controlled from thoes temp adjust tables.

[bmc1025]

If I had some free time I would hook up my gauge and test it out. It will be a while before that happens though. Is any of your down shifts too soft?

[HellKnightHicks]

Idk really havent checked them to be honest.

I have a pressure gauge on mine.

She hits 250+ on the 3>4 shift or while the TCC is locked sometimes.

[joecar]

If you're putting an appreciable level of torque (above 400 ftlb) and/or you're spinning the engine higher than stock (~6000 rpm) then the 4L60E needs various internal upgrades (the transmission thread at LS1tech has some good threads on which components)...

with these upgrades, various people have got good results, but it does take knowledge/experience as Brad's info above indicates.

[joecar]

+1 very important: do not lock TCC during shifts.

[HellKnightHicks]

Has a full HD-2 Kit with the high rev release spring set.
https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0CAcQjRw&url=http%3A%2F%2Fwww.superchevy.com%2Fhow-to%2Ftransmission%2F1309-rebuild-a-4l80e-transmission-with-the-transgo-hd2-kit%2F&ei=HemJVOzQFoOfNvCLgrgI&bvm=bv.81456516,d.eXY&psig=AFQjCNFENBaYx3Yb_6cZvDYg526ILJDfvw&ust=1418410643723988

5 pinion planiteries
Beast sunshell.
Z-Pack
500 Boost Valve
Sonnex OD servo
Vett Servo
Full HD-2 Maxxed out