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Pressure issue???

Old 12-26-2007, 01:40 PM
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Default Pressure issue???

Well my 4L60e seems to be having issues. I turned it on one day and found it was reving pretty high to get into gear. First gear seems fine, it is most noticeable when going into 2nd. Under normal acceleration car revs to about 3k rpms before finally shifting into 2nd. It seems when I just keep my foot on the gas it revs and then eventually pops into place. Under harder acceleration it doesn't seem to want to shift at all. Fluid level is fine, no burnt look/smell. It will always shift, just revs a lot to get there.

Trans has been rebuilt about a year and half ago and has a transgo shift kit and clutches and band have all been replaced.
Car has only been used for short distance driving, no WOT launches as I have yet to get a tune. In case it helps I also have a 2800 Vigilante stall and a trans cooler all hooked up.

Does this sound like only an issue with the pump or a stuck valve? Maybe a check ball wearing through???

Any help appreciated.
Old 12-26-2007, 01:48 PM
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If 1st gear is fine I would say it is possibly an issue with the servo itself. Possibly cross leaks at the stator.

How does it do going into 3rd gear and 4th gear?

g
Old 12-26-2007, 02:15 PM
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When i got on the highway it went into the other gears a lot easier, maybe a slight delay if anything. Hard to tell because soon as it happened I got it off the road ASAP. I only got it up to about 63 mph before the next exit.
Old 12-26-2007, 02:17 PM
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I didnt see where you mentioned , Are you getting and check engine light? And is the speedometer working?
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Old 12-26-2007, 02:29 PM
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No check engine light, I have had it go off before and had shifting issues in the past and it ended up being a pinched wire.

Speedo is working but is off right now. Previous owner had 3.42 gears put in and not tuned. That's why i have only used under normal acceleration. I didn't know it wasn't tuned for those gears and I gave it WOT and fried the trans which was the reason for my first rebuild.

Last edited by 95TXTA; 12-26-2007 at 02:37 PM.
Old 12-26-2007, 02:41 PM
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you need to have it tuned for gears first.
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Old 12-26-2007, 02:51 PM
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Originally Posted by performabuilt
you need to have it tuned for gears first.
I agree, but i'm concerned about driving it to where I need to go to get it tuned in it's present condition. I don't want to do any further damage. Any suggestions on what I can do to get it back to shifting smooth first?
Old 12-26-2007, 10:07 PM
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Update, car has been sitting for a couple days so I started it and took it for a drive to see how the other gears worked. At cold start it was fine, I only gave it light/gradual acceleration and all gears worked fine.

After a few miles on the highway and going through a bunch of stop lights, it finally started acting up shifting into second again.

I'm really hoping it's something that can be resolved without having to drop the entire trans so valve body and servo will be checked first. Any other suggestions?
Old 12-26-2007, 11:00 PM
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Do that and get back to us.

g
Old 12-28-2007, 02:08 PM
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Well i took the car to a mechanic who also works on transmissions. He drove it around and had his computer hooked up and says there is no second gear, it is going into 3rd after first. Valve body checked out, there is plenty pressure, however when the car is in drive and trying to go from 1st to 2nd the engine is just reving and both solenoids are staying on when one should be off in 2nd.

Solenoids have also been checked and are working properly in all other gears.
His guess is the servo or band but isn't sure because he says he has not seen the modifications that have been done to my servo before in his experience, so therefore he does not want to touch it. He stated the servo has some porting done to it and some extra plates (for extra pressure maybe?). Not sure what he is referring to because i have yet to see it myself. He has not looked inside the transmission, only dropped the pan to check valve body and pulled the servo. I'm not sure if the servo should just be changed or if it needs to be dropped and opened up which of course means more money. I have not been able to get a hold of the person who rebuilt it for me. I need some quick HELP!
Old 12-28-2007, 02:46 PM
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Ok skipping second Do you know if your getting 4th, And also you mentioned that the solenids are both staying on when it should shift to second , Is this being determined by looking at data on a scanner . If the scanner is showing both solenoids on unill the third shift and then they both go off you have and ecm issue, I have no idea what he means by the servo mods being strange there are only a couple things you can do , Please clarify what uou mean by both solenoids stay on in second is that what he thinks is happening or is that what the scanner showing , Both on till both go off?
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Old 12-28-2007, 03:16 PM
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Your exactly right, had scanner hooked up and both solenoids are staying on until going off in 3rd. As for fourth he said hard to tell but he did notice a drop in rpms as if it was shifting but then per his scanner the stall is not locking up. If 4th is ok then we should be able to rule out the band correct?

So if it is the ECM is it something that can be resolved by tunning or is my ecm just screwed?

One more thing in case it matters, he said he did check the solenoids out of the trans (not just per scanner) also and they checked out.

*EDIT...more info, he said in the 1-2 accumulator (sp?) there were two springs and in his experience there should only be one. He said it was one spring, the piston, and the second spring. I would assume this was an intentional mod but i'm just putting it out there in case it helps.

Last edited by 95TXTA; 12-28-2007 at 04:03 PM.
Old 12-28-2007, 11:59 PM
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Hi Earnest. Just saw the post. Sorry I did'nt see it sooner. Tell the guy doing the diagnostics that the "funny things" in your tranny are part of the Transgo 4L60E-HD2 shift kit that I installed when I built the unit. The "big washer thingy" under the servo cover is used to adjust the band clearance. The 1-2 servo spring and piston setup are also part of the shift kit. Tell him when he is done to put it back the way he found it. The 1-2 ("A") and 2-3 ("B") shift solenoids are suposed to operate in the following order with OD selected:

1st= "A" & "B" on,
2nd= "A" off "B" on,
3rd= "A" & "B" off,
4th= "A" on "B" off

The shift, TCC, and 3-2 solenoids are powered from the same source (PCM ign fuse) which is the pink wire going into the tranny plug. The PCM grounds the solenoid that it wants to engage for a particular shift. My guess is the "A" solenoid ground (light green wire to the tranny plug) is grounding somewhere, keeping the "A" solenoid on when its not supposed to be. Shake out that harness and see if something different happens. Take a look for more pinched wires. Most likely your problem will be something in this order.

Mec
Old 12-29-2007, 01:13 AM
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Originally Posted by Greaseymec
Hi Earnest. Just saw the post. Sorry I did'nt see it sooner. Tell the guy doing the diagnostics that the "funny things" in your tranny are part of the Transgo 4L60E-HD2 shift kit that I installed when I built the unit. The "big washer thingy" under the servo cover is used to adjust the band clearance. The 1-2 servo spring and piston setup are also part of the shift kit. Tell him when he is done to put it back the way he found it. The 1-2 ("A") and 2-3 ("B") shift solenoids are suposed to operate in the following order with OD selected:

1st= "A" & "B" on,
2nd= "A" off "B" on,
3rd= "A" & "B" off,
4th= "A" on "B" off

The shift, TCC, and 3-2 solenoids are powered from the same source (PCM ign fuse) which is the pink wire going into the tranny plug. The PCM grounds the solenoid that it wants to engage for a particular shift. My guess is the "A" solenoid ground (light green wire to the tranny plug) is grounding somewhere, keeping the "A" solenoid on when its not supposed to be. Shake out that harness and see if something different happens. Take a look for more pinched wires. Most likely your problem will be something in this order.

Mec
From the sounds of things I would have to say there may very well be and eletrical problem ,If the PCM is keeping both solenoids on then its definatly not a mechanical issue. But very unusual . I think if this is the case more study should be done in the tuning. I would definatley agree on the shift kit put it back as you found it , One problem at a time and that could not cause the issues you have
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Old 12-29-2007, 12:41 PM
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Good deal, thanks to everyone for all the replies and info. I'll definitely relay the info and hopefully that's all it will be.

I'll keep everyone posted on the results for future reference.
Old 12-29-2007, 01:25 PM
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Well I talked to him and he had already put the trans back up but the same as before with exception to the 1-2 accumulator extra spring. For some reason he thought it would make a difference?

Regardless it should still work with one I know but he said while the car was up in the air he truned it on and gave it gas and it is shifting. I guess he is implying that without any load it's holding and able to shift.

Not real concrete if you ask me because as I said before when I drove it over it worked fine for a while as well.

As far as the wiring he said he had not found any issues with it grounding out or being pinched. On his scanner no codes were being given. He said he drove it around and manually shifted and it was working, but shifting into 2nd was not firm at all.....

Last edited by 95TXTA; 12-29-2007 at 02:18 PM. Reason: new info
Old 01-02-2008, 08:20 AM
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Need more help! Here is the short version.All electrical possibilites have been ruled out. Still having trouble going into second. Is it safe to say something went wrong with the band at this point?
Old 01-02-2008, 08:32 AM
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Well if the shifts are soft into 2nd you are left with BAND, ACCUMULATOR OR SERVO as all remaining possibilites if it definatley not electrical. But I still dont understand unless you were mistake in and earlier post how both solenoids arestaying on untill it shifts to third since that would definatley be and electrical problem, The trans will never shift to second with both solenoids on
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Old 01-02-2008, 09:28 AM
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You are right about the solenoids and I agree. That's why I am trying to make sure I get all the possibilities because i'm getting the feeling this guy is just trying to make some extra bucks off me.

When I asked about that he said when he put everything back and tried it again it was working just very softly. Doesn't make sense I know, but in case it is not electrical I wanna see what he is trying to get at.

Apparently the 1-2 accumulator checked out and he was unsure about the servo as it was moded in a way he had not seen (extra plates and 4 holes drilled?), but then again he said the pressure checked out as well, so to me he is implying it needs to be opened up and have the band looked at....
Old 01-02-2008, 09:33 AM
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As long as both the solenoids are staying on and the A (1-2) solenoid is not going off to make the 1-2 shift you will not have second gear. I would reverify this is whats happening , If the scanner is showing both on then suddendly both off without the A off B on required to make second then you absolutly have a strange electrical or tuning issue.

Now adressing the servo the shims ajust the band clearance for second and are from the transgo kit. The holes or slots i the cushion retained are to help eliminate part throttle slam caused by the plate there becoming hydraulically locked solid in place also a transgo mod. I dont think you ever answered but how does the 3-4 shift feel that will give a good indication of the condition of the band?
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