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 Is my transmission dead?

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austin296
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PostSubject: Is my transmission dead?   Mon Oct 31, 2016 9:50 pm

So I built a car from scratch using a 1998 Riviera for the donor motor & trans. The Riv was running strong, even though it had right around 200k miles when I pulled it. No mods to the engine yet and the car only weighs 2300lbs, so its a lot less abusive on the trans.

I drive it pretty hard. When I was driving yesterday, I launched from a dead stop and it wouldn't shift out of first gear. I hit the rev limiter and had to let off the gas completely before it would shift to second. On the remainder of my drive home, it did the same thing at part throttle a few times and seemed like it didn't want to make the shifts(either really soft or a little too hard) for all of the shifts, even at light throttle.

Any suggestions other than pulling the trans for a rebuild?

Here is a pic of the car if anyone is interested:

https://drive.google.com/file/d/0B93HqBsSfCQnNjNRN3YxaVdsZkU/view?usp=sharing
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LARRY70GS
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PostSubject: Re: Is my transmission dead?   Tue Nov 01, 2016 9:19 am

Being that it is an electronic transmission, lots of things can go wrong. What does the fluid look like?

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Abaddon
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PostSubject: Re: Is my transmission dead?   Tue Nov 01, 2016 9:47 am

+1 check fluid first.
#2 thing that usually goes wrong with the 4t65e are the shift/pressure solenoids. The pressure solenoid being the worst of them all. Had to replace that solenoid in both of my 4t65e cars.
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albertj
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PostSubject: Re: Is my transmission dead?   Tue Nov 01, 2016 9:59 am

austin296 wrote:
So I built a car from scratch using a 1998 Riviera for the donor motor & trans. The Riv was running strong, even though it had right around 200k miles when I pulled it. No mods to the engine yet and the car only weighs 2300lbs, so its a lot less abusive on the trans.

I drive it pretty hard. When I was driving yesterday, I launched from a dead stop and it wouldn't shift out of first gear. I hit the rev limiter and had to let off the gas completely before it would shift to second. On the remainder of my drive home, it did the same thing at part throttle a few times and seemed like it didn't want to make the shifts(either really soft or a little too hard) for all of the shifts, even at light throttle.

Any suggestions other than pulling the trans for a rebuild?

Here is a pic of the car if anyone is interested:

https://drive.google.com/file/d/0B93HqBsSfCQnNjNRN3YxaVdsZkU/view?usp=sharing


Maybe, maybe not.

You may find the following to be informative (I think it is informative but not necessarily correct):

https://www.facebook.com/GM3800Tips/posts/543953862420447

So... how is your o2 sensor?  And I think the author of the Facebook posts is way to pessimistic about the 4T65E.  My opinion is the engineering was great but the job 1 build was not consistent.  My 4T65E has run for a couple hundred thousand miles after an informed overhaul -- what happened was the lockup clutch quit, so since I had to have the transmission torn apart anyway to fix that I had the transmission overhauled -- put in a Transgo kit,  a post-2002 hardened final output shaft,  and the no-longer-readily-available Raybestos Blue clutch disks.  Other than maintenance fluid/filter changes with Dex VI (NOT Dex III!) I have not had to talk to the transmission since.  By the way, once you switch to Dex VI NEVER go back to Dex III no matter what anyone says because if you do your transmission will die a horrid clutch-fragging throttle-body-clogging death.  

Continuing: When you did this pull did you change the transmission fluid?  Sometimes dumb stuff happens to used transmissions that sit and then suddenly get put into service. I wonder if your transmission is starved for fluid. You might have/should have changed the filter and the fluid in the pan when you installed it. If not, consider doing so; if the fluid is anything but new-looking pink/maroon, definitely do the change. I have my fluid power flushed every 45-55 K miles but I think I'm the only person in the western hemisphere to do so; the person who does it for me ABSOLUTELY knows what he is doing and I don't really want anyone else, other than the guy that rebuilt it for me, touching my transmission for any reason whatsoever.

Further thinking out loud: you may want to manually adjust the line pressures back to stock (especially if you moved them for your custom install) or check them, and use a Tech II to reset the shift tables.   By "may" I mean that if you have appropriate experience with the 4T65E transmission as installed, and you have edited parameters for it, then you don't need me (us) to tell you this, and you don't need me to tell you that depending on the life that transmission had before your install and the circumstances of your install, although your problem *could* be mechanical --  it is as likely as not electronic, if you did not keep the sensors that the transmission reads to stay in adjustment, or perhaps had issues with faking it out by putting parts in to keep the needed data in the proper ranges.  The electronic issues can be fixed but will take some work and "engineering."

Thinking out loud a little more - I wonder if your transmission is overheating? On the Riv, if you put the climate control in "Automatic" the air conditioner runs almost all the time, which would run one of the radiator fans almost all the time and in turn tend to cool the transmission (transmission fluid goes thru the radiator).

Anyone else chime in on this?

Albertj
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austin296
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PostSubject: Re: Is my transmission dead?   Tue Nov 01, 2016 9:59 pm

Larry/Abaddon,

Fluid looks pretty good. It is light pink, still fairly clear. Before I bought the car (Feb-2015), the previous owner used it as a daily driver and followed all recommended maintenance intervals. Not sure when the fluid/filter was changed, but I'd venture it was within the last 10k miles.

Is there any way to test the shift/pressure solenoids?

Albert,

I changed some of the fluid... After I retrofitted the wiring harness, I got overzealous and started(and revved) it without having the trans cooler lines connected... got to replace a few quarts of fluid. Per my comment above, the car was driven daily in 2014-early 2015. From June-2015 through now, I've only put about 1500miles on the car, but I wouldn't think that is enough sitting around for things to get funny.

Regarding line pressure, I have HP Tuners and adjusted the settings roughly to what AA posted here:
http://rivperformance.editboard.com/t3619-shift-points?highlight=shift I thought some of his numbers were too aggressive, so I made it a little tamer than his.

I kept all the stock sensors for the engine/trans.

Regarding the overheating, I doubt it. I put a 180 degree thermostat in it and the radiator is mounted high, directly behind the seats. I've never seen the engine temp go over 185 degrees. I'd imagine the trans is around the same temps.


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austin296
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PostSubject: Re: Is my transmission dead?   Tue Nov 01, 2016 10:03 pm

Here are some pics to show the radiator/engine placement:

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Abaddon
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PostSubject: Re: Is my transmission dead?   Wed Nov 02, 2016 8:31 am

austin296 wrote:
Is there any way to test the shift/pressure solenoids?




Not really, no. The PWM solenoid is what controls overall fluid pressure based on what you have it tuned to. Over time, gunk gets built up on the screen on the end of the solenoid. The gunk will actually move inside the bore of the valve body, which causes slip shifts, and then hard shifts, etc. Eventually, the solenoid will completely fail mechanically, and cause a whole bunch more symptoms. If the trans has been doing this long enough, it will set a code in the PCM that won't set an SES light. I forgot the exact code, but I believe it's a "Max shift Adapts" (or close to it) code.

The side cover of the tranny has to come off to access the solenoids. You don't even have to remove the pan. Just the left side axle, and the side cover. Don't even bother trying to clean the solenoid if you're going in there. Just replace it. I think I did a Write-up on replacing that solenoid....

Cool ass buggy/car btw thumbsup
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albertj
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PostSubject: Re: Is my transmission dead?   Wed Nov 02, 2016 9:22 am

austin296 wrote:
Larry/Abaddon,

Fluid looks pretty good. It is light pink, still fairly clear. Before I bought the car (Feb-2015), the previous owner used it as a daily driver and followed all recommended maintenance intervals. Not sure when the fluid/filter was changed, but I'd venture it was within the last 10k miles.

Is there any way to test the shift/pressure solenoids?

Albert,

I changed some of the fluid... After I retrofitted the wiring harness, I got overzealous and started(and revved) it without having the trans cooler lines connected... got to replace a few quarts of fluid. Per my comment above, the car was driven daily in 2014-early 2015. From June-2015 through now, I've only put about 1500miles on the car, but I wouldn't think that is enough sitting around for things to get funny.

Regarding line pressure, I have HP Tuners and adjusted the settings roughly to what AA posted here:
http://rivperformance.editboard.com/t3619-shift-points?highlight=shift  I thought some of his numbers were too aggressive, so I made it a little tamer than his.

I kept all the stock sensors for the engine/trans.

Regarding the overheating, I doubt it. I put a 180 degree thermostat in it and the radiator is mounted high, directly behind the seats. I've never seen the engine temp go over 185 degrees. I'd imagine the trans is around the same temps.




This all helps.  I'm thinking about this some more and I may call the guy that built my transmission. He does not lurk on this forum that I know of.  Now that I am informed by your comments above: mechanical issue along the lines of Abaddon's guess (PWM solenoid and/or dirty valve body).  I would also connect a Tech II or other scanner that takes real-time logs out on a 20-30 minute mixed drive, then desk-check the log to see if any of the sensor readings were BS.

By the way, disconnecting the transmission lines at the radiator is how you change the fluid completely in the "sealed" AW automatic transmission in a late model Volvo, after Ford's changes. In some ways it is easier although changing the filter is more messy. If one knows what one is doing one can install a drain bung such that changing the filter is less messy. Whether one should do so is an open question in that community.

Albertj
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