Update on Tranny Prob and towing in OD myth

[Can Can]

So you're basing the fact that 700r4s(or 4L60Es) suck because your brother

A) Towed a really heavy load in OD and then continued to drive another 400 miles/forums/images/icons/tongue.gif after he developed problems and

B) His second tranny let go because he went 75,000 miles without a tranny service.........


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Sounds to me like he got what he deserved..........

 

[87K54WD]

I didn't say the 700R4 or 4L60E suck. I was just adding to the discussion. If anything, my post probably shows how much abuse those trannies can take and still keep going. As for the 400 miles on a breaking tranny, you do what you have to do in the middle of the night; under a time constraint; and in the middle of nowhere. It got us home, and that was all that counted that night considering the tranny was still under warranty at the time. Regarding the 75K miles, he puts a lot of highway miles on his truck and those 75K came in a little over 2 years with not one tow. I would think the fluid should still be able to do its job considering most were highway miles and the fluid was only a little over 2 years old. Maybe it was a bad rebuild from the first repair ... who knows. I may be wrong here, but didn't GM start recommending 100,000 mile tranny service (fluid change and filter) in the late 90's anyway on their cars and trucks? Personally, I wouldn't go that long either on my tranny without some fresh fluid and a new filter. The longest I would personally go is about 30K. But, I think it goes to show that ATF fluid can last a lot longer than what most used to believe ... probably due to the refining of the molecular structure of the stuff. Don't we have Dexon/Mercon IV (?) now and of course the synthetics are out there now for ATF.

As for your personal comment, we all get what we deserve at some point in time in life.

 

[Calclips]

I don't know 100%, but I'm pretty sure that all that the tow/haul button does on the new trucks is electronically lock out 4th gear on the 4L60Es and 4L80Es.

 

[blazer72]

It does much more and does not lock out OD It does changed shift points both up and down. On our 01 2500 sub with the 8.1 it all so changes shock valving, By the way I got 17 MPG this weekend towing my 72 on a trailer, about 7500 lbs.

 

[89GMCSuburban]

They say not to tow in OD because it does several things...the pump in the trans doesn't flow enough fluid to keep the internals cool when pulling a heavy load at that RPM. Also, there aren't as many clutches in the OD pack as in the D pack. It can also lug the engine if the load is too heavy. I guess, in the end, it's all up to the operator.