Of course, a throttle-induced two gear WOT downshift is one of the greatest sensations one can get with an automatic. But it's held to be pretty destructive to the 4L60e. I'm wondering - would it be less damaging to ease the shifter into, let's say, second from fourth, being careful to rpm match it, and then to nail it and upshift manually? In some traffic situations there's enough time to do this, and the Transgo kit allows manual selection of any gear at any speed. Which would be harder on the tranny, and why?

 

How can you RPM match with an auto. With the manual you must have the clutch engaged to "match the rpm" then let off to engage. With the auto it is engaged at all time with the t/c.

 

True, although prior to going for an OD to 3rd gear change manually on the highway I have 'eased' into the throttle a bit before doing so and it was almost an RPM match, though not quite as matched as one could do with a manual.

 

You just give it throttle as you shift it ... the slippage in the T/C allows for it, especially if it is a higher stall.

 

messing with ur shifter does more damage then it will ever do to itself

 

I'd stomp the gas and drop it into second, by the time the rpm gets up there the trans will have completed a downshift into second (or first if your mph is low enough). It might take some practice to get your timing right.
Then when you upshift at wot it obviously won't actually shift when you move the lever unless your above the vcm's programmed wot shift point.

I'm not sure what two situations you're talking about. But I would say downshifting and then nailing the gas would not be good for anything, acceleration or the trans.

 

i know exactly what you mean- i'll be cruising in od and nail it to hit 2nd gear or in 3rd it'll shift to first. i also sometimes manually shift it down to 2nd and then nail it.

i would think letting it go from 3 to 1 would be harder on the trans than actually slowing down and shifting it to 1, then throwing it back in od and letting it upshift itself.

like you said, the car really hits hard and feels really fast when you go 3 to 1st so just don't do it all of the time, maybe save that for when trying to impress somebody or scare your girlfriend or something. i try to limit myself from doing it all of the time but sometimes i can't resist. 2.73's= 1st gear kickdown at 35mph! feels like you got punched in the back of the head if it doesn't spin!

im curious what a trans builder (like a sponsor) has to say about this.

 

dunno if this has anything to do with what is being discussed (lol) but thought id mention it. (a4) sometimes i will be driving in 2nd gear and il take it up to 40 at normal speed.. i noticed if i let the car drop back down to 30mph by itself, and then i nail it, the rpms jump to 6k and it takes off like a ****. is this what you were saying was destructive to 4l60e's? an can someone tell me what i am doing to my car when i do this?

 

Ok, let me try to explain myself a little better ... the first scenario is leave it in D (fourth) and floor it. The second is to manually downshift it into second and then floor it. I've heard that the automatic 4-2 (or 3-1) WOT downshift is really hard on these trannies and was wondering if doing it manually and then flooring it would be better (or worse).

 

i think that manually shifting it at any given point is bad for these trannies.

i do it all the time though

 

I did it all the time on my 93 and it's still alive (over 80k miles). I never did it with my 01 and it's been rebuilt once now (33k miles).

I think that you COULD do more damage shifting manually, but if you did it right, then it prolly wouldn't hurt it much (if at all).

 

A 4 to 2 downshift is easier for a 4L60-E to do than a 3-2 downshift. It is a single event of disengaging the 3-4 clutch pack. Downshifting from 3 to 2 has to release the 3-4 clutch pack and engage the band at the same time. There is a valve specifically for doing this just to make sure it doesn't let the engine over-rev trying to pull that off.

Keep in mind that mechanically the 4L60-E is only a 2-speed auto with overdrive.

 

OK, makes sense ... my question is, is there any difference on the impact to the tranny between doing it automatically at WOT or shifting it manually first and then going WOT?

 

Oh, yeah baby!

 

listen to James B. he is right.
if the tranny shifts on its own, all its doing is releasing the 3/4 clutch

if you manually shift, the tranny is releasing the 2/4 band and applying the overrun clutch to shift into third
then to go to second releases the 3/4 clutch, and then re-apply the 2/4 band
and it tries to accomplish all this in the time it takes you to move the shifter

so the transmission does less work(hence less wear), if you let it shift on its own
after that, there is no difference