I was told by my local tranny guru NOT to tow in OD, never have but have seen threads in which many people do, I have burnt a 700r4 towing in OD.

Whats the concensis on this ?

By the way, I am speaking of my sig truck, 4L80E with mods, thanks.

Do not tow in O/D.

Thanks Mike.

Do not tow in O/D.

With the 4l80?

With the 4l80?

Correct.

80 & 60's. Just knowing from plowing snow, that it's a big what not to do. Drive by the trans shops in the winter and that's all you see. Landscapers plow trucks. Even just having the gear selector in OD vs D/3 will roast it. Even if it never actually comes out of 1st/2nd gear.

So what is the optimal highway speed for 4.10's without using OD? Won't 60-65mph overwork the engine?

slow lane...

OD=Overdrive...not tow haul

that being said, the 4L80E can handle more than it's credited for...

I have always towed in OD, never an issue. When plowing it was always in D as well. Plowing snow commercialy for 10 years with no issues.
I have almost 130,000 on my 480 in my 98.

Dad has almost 400,000 kms on his 4L80e and it is still stock. He does not pull in OD, will an empty trailer, but not with a load. Also when coming to a stop we pull the shifter down to 1, then when its time to shift, bump up to 2, then 3. That way it is not trying to start in 2nd and slip more under load. Grandpa was told years ago to do this with the old TH400, and it is still original as well in the old gasser. I do the same with my 6.0/4L80e, and between the 3, we have never done any tranny work. So it has worked for us. If someone here has anything to say about that, by all means. But that is my experience.

Dad has almost 400,000 kms on his 4L80e and it is still stock. He does not pull in OD, will an empty trailer, but not with a load. Also when coming to a stop we pull the shifter down to 1, then when its time to shift, bump up to 2, then 3. That way it is not trying to start in 2nd and slip more under load. Grandpa was told years ago to do this with the old TH400, and it is still original as well in the old gasser. I do the same with my 6.0/4L80e, and between the 3, we have never done any tranny work. So it has worked for us. If someone here has anything to say about that, by all means. But that is my experience.

The trans will start in 1st gear even if you leave it in drive from a standstill. I have manualy shifted older cars for years with no issues as well. I was more beating the crap out of them though.

I tow in OD with the tow/haul button pushed in.

I tow in OD with the tow/haul button pushed in.

Ditto.

Most of my towing is done at 75mph. I don't think that I could tow at that speed without OD.

Anytime that I tow or even hit it at all I make sure that the tow/haul button is on though.

As long as the tranny is not hunting (continually switching from
locked to unlocked converter, or 3rd to 4th) OD is fine, these
trucks were equipped with this tranny because it could handle it.

There is a tow haul switch. The question I am asking you is what are gaining vs risk over the long run?
Wrap your mind all over this 4L80-E. I will say that good maintenance overall will keep the ghosts from coming out of the closet and haunting.

I towed with my overdrive on and only got 285,000 miles out of my transmission. Granted it wasnt the overdrive that went out.

I think that tookielee was right. as long as it is in overdrive and not switching back and forth, as that is when the clutches are wearing (assuming its not slipping)