Transmission skipping or 'fall-out' ?

[dangerous]

All is still the same.... I plan on a Converter next - as it is $110 +- at Autozone. Also - I may try to go by Aamco Transmissions and see if they will diagnose/give advise for a fee... Chevrolet wanted $300 and to tear into it at minimum.

[Quickpatch]

Originally Posted by dangerous

All is still the same.... I plan on a Converter next - as it is $110 +- at Autozone. Also - I may try to go by Aamco Transmissions and see if they will diagnose/give advise for a fee... Chevrolet wanted $300 and to tear into it at minimum.

Thanks a million for the update. I find it amazing that Chevrolet has no help or insight. I have been working this problem for a year. I am not even sure if it is a transmission or engine problem. My vehicle does not have the problem when the engine is running cold. It has to warm up and run about 12-15 miles. This seems to indicate that it could be a closed loop situation. Possibly something causing the computer to run in limp mode. (or cold/thick fluid?) So far I have done complete tune with wires, fuel filters and motorvac (combustion chamber cleaning) The problem started as jerking during "light throttle at the top of hills" only and has progressed to "a miss, or shake, at very light throttle" over 15,000 miles. I bought a obd program for my laptop, but so far have not seen a smoking gun.

[EA6BMECH]

Originally Posted by Quickpatch

Hello, I am having this exact problem with a 99 5.7 van. I also had my fluid changed. It started at 105,000 for me. I do not see any more posts after you performed the work above. Did this solve the problem? Which item do you think fixed it. Any help would be greatly appreciated.

After reading this stuff and I'm not a tranny expert, it is starting to sound like to me the Torque converter. I have a 91 Nissan V6 and under a load in 1st gear, it shutters pretty bad, but i deal with it. I also had a 90 Mazda van V6 and I think it takes the same tranny the Nissan did. Same thing. At 179K I had the Mazda tranny rebuilt and they rebuilt the torque converter. Well long story short, they had to go back in and replace the converter.

As for feeling some rumbling leveling out on the hiway, don't discount your engine doing some of the mischief. That TPS can make the throttle twitch and make the tranny act a little crazy. I noticed that in my '00 Camry. Feels like it sort of jumps in and out of converter lock. I now don't think it's the tranny doing it, but the engine giving it some weird feedback. Just my 2cents.

[NoEcm]

Originally Posted by sjcrft

My 97 Does The Same at 50+ Mph ,Tranny Shop Said It was Lockup Torque Conv ,Replace or just deal with??(it feels like bumps in the road)

See if the following has any relevance to your situation:

CHUGGLE-SURGE ON TCC APPLY - NO DTC'S - 5.7L 4L60E

[Quickpatch]

Originally Posted by NoEcm

See if the following has any relevance to your situation:

CHUGGLE-SURGE ON TCC APPLY - NO DTC'S - 5.7L 4L60E

Very interesting. Thanks for the info. This sounds like what my van is doing, but my van is a 99. Every bit of information helps. It does it when I am on the highway doing 65 mph. It does it at the same places in the road every day on my commute. This forum has been a great help. I will pass on any helpful information I find.

[RahX]

you can try putting a higher friction fluid in there instead of the Dex/Merc 3 fluid. use a atf +4 or mercon V fluid. its the same stuff, wont damage your transmission, but itll add a bit more friction to the fluid so the clutches dont slip as easily. i know on F series trucks the TCC likes to slip when the trans fluid gets some mileage on it and a flush with mercon V takes care of the problem easily. its worth a shot and cheaper and easier than putting in a torque converter.

[dangerous]

ECM - I checked out the bulletin and that appears to be for pre 97's... I asssume (I know - don't snicker ) that that should have been applied to mine - as it is a 1999.

In the tests we ran, there was no indication of a engine issue, although I recall what one post noted that wires. etc can create this issue.

I will follow up when I replace the Tourqe converter......

[Quickpatch]

Originally Posted by RahX

you can try putting a higher friction fluid in there instead of the Dex/Merc 3 fluid. use a atf +4 or mercon V fluid. its the same stuff, wont damage your transmission, but itll add a bit more friction to the fluid so the clutches dont slip as easily. i know on F series trucks the TCC likes to slip when the trans fluid gets some mileage on it and a flush with mercon V takes care of the problem easily. its worth a shot and cheaper and easier than putting in a torque converter.

I am going to try this. A common denominator has been transmission fluid changes. One person did say they used an additive that worked. (I don't like additives much) The additive probably thickened the fluid. Am I correct in thinking that these transmissions shift electronically, which means the lockup torque converter can not be unplugged for testing purposes?

[RahX]

you can unplug the solenoid but its kind of a pain. we used one type of additive at the shop but i dont know what it was. said it had parafins in it, which is a wax, and i dont know if i would use it in my vehicle. but as far as the fluids go its a pretty good idea and it might buy you some time

[dangerous]

OK - latest update. I have been lazy - I had another car to drive - so the Sub has just been sitting. I did buy the Torque COnverter , front tranny seal and rear engine seal . Today a friend was to come over and do teh Converter for me - but he got tied up.

Since I am ina hold pattern, I heard Aamco gave free External Diagnosis w/a computer. I went and they checked the tranny - said all is fine with the tranny. hmmm. I would assume that if a customer is there and says he has problems, I am sure they would not want to turn away business - so I feel good to hear the diagnosis. He offered to say that it could be an engine issue.

So I stopped by Chevrolet for a check - they want me to come back Monday so a technician can drive with me while watching with a computer. Thyat will cost $80. will keep all posted.

[dangerous]

I returned the parts I was going to install on the tranny. As mentioned - Amoco felt it was an engine related issue. Chevrolet said the same (most likely). The Chevy transmission guy went for a 20 minute ride with me. He drove and indeed felt it. His assessment was to replace the plugs/wires, etc. first. BTW - he did that at no charge ! Way cool.

I did the wires and plugs. Previously I installed Delco wires ($100+-) and new plugs and cap about a year or so ago. I repurchased new ones but went with Borg Warner Cap, Wires and AC Plugs. When I took the cap off - I was stunned to see each contact post heavily corroded and was igniting a bit off center to each post. The wires fit a bit looser at the cap than the AC wires, but they were only like $50+-). BTW - they were exchanged as the Delco had lifetime warranty.

The car idles much better. The 'tranny' stumble I had been eager to get rid of is ...'mostly' gone. Sometimes I wonder if my mind is playing games on me - sometimes I feel a slight stumble - othertimes - I am thinking - its all gone. The more I drive it the better I feel the situation is resolved properly.

Either way - the wire/plugs and cap were indeed the best first solution (rather than the solenoids). I have been driving the car now for a few weeks and I hardly think about the issue anymore.

If someone tries this and it does not work and they want to replace the solenoids like I did - if you are on a budget - give me a shout - for a decent minimal offer - I will send the solenoids - as they had no affect on my issues and I do believe they are still good).

Remember Amoco did a free test - Chevrolet was really cool too. Both used test equipment - and even for $70 test fee - at Chevy - that would have been worth it. Chevy noted that the transmission appeared to be shifting at all appropirate points correctly. Thanks to all for the help - hope this closing comments assists someone else. - Good luck