Tranny question

[Guest Richard D]

Hello all, my driver Reatta at 143,000 miles has developed a tranny problem that occurs about twice a week. Under slow or normal acceleration the 2-3 shift will cause a shudder, letting off on the gas it goes away. The fluid is bright red and smells ok and can't feel any debris when rubbed between my fingers. Should I 1, have the fluid completely changed including the T/C or 2, just a normal oil & filter change, or 3, the tranny is worn out drive it until I can afford a rebuilt or 4, put more miles on the 71 Skylark. What would a new/rebuilt tranny cost with labor? The Skylark seems to be a target for rusted out econoboxes, and it is still original except for carpet so I am not crazy about making it a daily driver

Edited January 25, 2011 by Richard D (see edit history)

[padgett]

I'd start with adding a can of Seafoam TransTune (at many FLAPS).

[Guest Richard D]

Padgett, That would be my second can in 6 months, I should drain about a quart out first, yes? Level is full, first can seemed to help.

[padgett]

Have noticed a hard/odd 2-3 shift usually if I let off the gas just before the shift on several 4T60s, one for over 100,000 miles.

[sfair]

When Seafoam dislodges some, well whatever it works on, where does it go?

Into the valve body?

[padgett]

Should wind up back at the filter but would depend on where it came from. The usual valve body problem is more gummy residue/sludge than objects. It can make servos stick. OTOH debris from the bands would go to the filter first.

caveat: I have seen a few apart but have never rebuilt a 4T60.

If Seafoam has already been used, the next action wouldbe to replace the fluid and filter.

[Guest Richard D]

are a 4T60 and 4T60-E interchangable? Would I need a different ECM for the -E?

Thanks

[padgett]

the 4T60 is hydraulic except for the sensors and TCC, the 4T60E is all electronic and controlled by the ECM. Very different.

[Barney Eaton]

depending on the speed you are running at the 3-2 downshift, it could be the torque converter is not unlocking. It is usually more of a problem when you are slowing to a stop when you really notice a problem.

[Guest Richard D]

Thank's Barney, It always does it when accelerating, but I will take all the advice I can get.

Padgett, That is what I thought, so if I do find a deal it has to be 88-90 4T60.

[padgett]

The later the better, GM reman is best. Were a constant string of TSBs on "improvements" of the 4T60/440T4.

[DAVES89]

Is the tranny shift issue you describe on the first shifts of the day? Then the rest of the day does the car shifts as it should?

If that is what is happening I would think that a transmission drain and fill with a new filter may be a first option.

Certainly a lot cheaper the a replaced transmission situation...

[jgmck]

I had the same symtems and changed the coil pack and the controller (think that's the right term) and the problem went away.

[sfair]

would depend on where it came from.

Exactly, that is why snake oil in a high mileage transmission is a bad idea!

A person has no idea what gets loosened, cleaned, dislodged and where it ends up.... next thing you know the transmission starts to slip 200 miles from home and you now have a major league problem.

[Guest Richard D]

Thank You all, I am going with a complete fluid and filter change and see where that takes me. If the tranny is worn it looks like I will have this one rebuilt. The only rebuit/overhauled ones I can find are the 4T60-E

Regards

Richard

[Guest 88atta]

Found this little tidbit on-line in Wikipedia; Turbo-Hydramatic 440-T4

A breakdown of THM440T4 is: Turbo HydraMatic Model 440 - Transversely Mounted - 4 Speed Fully Automatic transmission

Quote:

One unique feature of this transmission is its use of both a modulator valve and a throttle valve (TV) cable. Most transmissions either use one or the other to control shift points and shift smoothness. On the Turbo 440-T4, the TV cable exclusively controls the shift points, while the modulator valve controls the shift feel. This feature makes it very easy for a home, "shadetree" mechanic to adjust the transmission shift points with minimum effect on the shift feel. Unquote. "The 440-T4 was later renamed the 4T60". Could it be a cable or modulator problem?

Edited January 27, 2011 by 88atta (see edit history)

[Guest 88atta]

Richard D,

Any luck with that fluid and filter change? We've all been rooting for you!

[Guest Richard D]

I am having it done tomorrow, the transmission shop says they can change between 90 and 95% of the fluid without pulling the torque converter. The device has a large clear cylinder with a disc to keep the old and new fluid seperate as it sucks out the old and puts in the new. With a new filter $110.00. Will post tomorrow.

[Guest 88atta]

When they drop the pan to change the filter, try to physically check the pan yourself (if they will let you) for anything other than just normal fluid residue. Good luck.

Edited February 3, 2011 by 88atta (see edit history)

[Ronnie]

I guess I'm kinda old school but something doesn't sound right about them sucking out old fluid while replacing the new, knowing the pan has to be dropped to replace the filter. Let's see now...

Option 1-

Pull the pan and replace the filter first... naw that wouldn't work because there wouldn't be any old fluid to suck out while putting in the new. :confused:

Option 2-

Suck out the old fluid while filling with new fluid first... naw that wouldn't work because you would have to drain the new fluid when you drop the pan to replace the filter. :confused:

Option 3-

Suck out the old fluid and put in the new at the same time. Then tell the customer you changed the filter... that will work. :eek:

Sorry to be so negative and skeptical. I hope it works out for you.

[Guest 88atta]

Ronnie is right unless they plan to drain and drop the pan, change the filter, and somehow hook up that cylinder device to change the fluid in the torque converter with it. Better keep a close watch.

Edited February 3, 2011 by 88atta (see edit history)

[padgett]

I could see using a plastic pan to replace the original while flushing. Might have to start the engine and pump until clear, just do not know enough about the flow even looking in the FSM. Anyone know more about how the torque converter is fed/drained ?

[wws944]

Some flush machines hook into the cooler lines. Here is one that feeds fresh fluid into the filter hole:

Automatic Transmission Flush Machine By CTS Inc.

+1 on checking the pan for debris. If they do a flush (e.g., thru the cooler lines) without doing a pan drop, they are only doing half the job.

[Jim]

I sent Richard an email with my thoughts on replacing or rebuilding his transmission and then read these posts.

The posts I found most interesting are the ones about the coil pack/module being bad and the modulator etc. I recommended to Richard and recommend here, going to a local type transmission shop, not a dealer or a chain shop, and see what they think.

[Guest 88atta]

wws944,

Great info; would suggest all members review the above link thoroughly to include the video. I defiinitely learned something and I'll attempt to find a facility that offers this equipment and type service. If you have ever had transmission problems and a rebuild, and you start asking a few questions, you would learn that the majority of the tranny fluid is within the the torque converter and tranny body. I think we have a mind-set that it is like having your oil changed. When you go in for a normal transmission fluid and filter change, the portion that is drained, only about 25 to 30% of the fluid, is in the pan so normally that is the quantity that is changed or added back; not good.

[Guest Richard D]

Well they removed the pan and filter, cleaned out the friction material from the bottom of the pan. Measured the amount of fluid that was in the pan and added it to the fill tube. Then hooked device to cooler lines and once fluid coming out was clean started car for two more quarts to run through while running through gear selector (PRNDL). I think they used around 15 quarts. So far all is well, will keep you all posted.