Towing in overdirve

[great white]

X2, the only down side to a 4L80e is how long first is

And the hollow input shaft on pre 99 ish units.

Well, it's also not strong enough to stand up to a duramax, even a stock lb7 if pushed reasonably hard...

 

[silverado13]

do they make solid input shafts that you can just swap out?

 

[great white]

do they make solid input shafts that you can just swap out?

The earlier ones had a drilled passage down the center to pass oil for something. I can't recall at the moment if it was for pressure, lubrication or something else and my 4L80E shop book is a couple 1000 kms away right now.....

I believe the later ones drop in, but I'd have to look up what the passage was for before I could say if there was any negative effects....

 

[LoudnLifted88]

i always tow in 3rd in my 98 and im usualy in 4th in my 98sometime od

 

[96-1500]

i always tow in 3rd in my 98 and im usualy in 4th in my 98sometime od

Hold it, I thought it was an automatic?

 

[4x4incountryboy]

I was always of the understanding od is like another gear so to speak that kick out if under load....kinda like the passing gear drop down.... and once the load was off it would kick back in. That it is only bad for od if you can't keep it locked in...that would result in more heat and constant engaging and disengaging....???

 

[great white]

I was always of the understanding od is like another gear so to speak that kick out if under load....kinda like the passing gear drop down.... and once the load was off it would kick back in. That it is only bad for od if you can't keep it locked in...that would result in more heat and constant engaging and disengaging....???

Problem with od is the lock unlock of the convertor clutch. Get in the wrong conditions and it can shorten it's life or end it. You can be in OD and still be in and out of lock up without knowing it. The converter clutches are very small (relatively) and not meant to hold heavy load in a stock configuration. Just don't have the holding power. Often, even if you hold lockup, they slip with heavy load on a light duty transmission. Again: making heat, burning friction material and just generally bad for transmission health.

Theres other things at play in there that are of concern, but that's the main one and why it's recommended not to tow in OD...

 

[RyanR]

When I'm towing a litlle load, like a boat or fourwheeler, OD is fine. I have plenty of power to tow them items with the OD gear ratio and not over stress the tranny.... but when I'm pulling a really large load, like my old Lightning, 12 big *** light poles, etc, I leave it in 3rd to run in a higher drive ratio and keeps my rpms up a little so I'm in my power band and not just lugging around and burning the crap out of my clutches, over heating the torque converter, etc... to each is own though but I've never lost a tranny due to towing. Trans temp gauge is an angel sent from heaven if your gonna tow heavy items. I also run dual coolers and bypass the radiator reservoir. Arkansas weather is usually very mild and humid

 

[4x4incountryboy]

Problem with od is the lock unlock of the convertor clutch. Get in the wrong conditions and it can shorten it's life or end it. You can be in OD and still be in and out of lock up without knowing it. The converter clutches are very small (relatively) and not meant to hold heavy load in a stock configuration. Just don't have the holding power. Often, even if you hold lockup, they slip with heavy load on a light duty transmission. Again: making heat, burning friction material and just generally bad for transmission health.

Theres other things at play in there that are of concern, but that's the main one and why it's recommended not to tow in OD...

I agree, it boils down to common sense with a large load and a higer gear it makes sense that if large enough the tranny will slip. its actually how when testing machinery we warm up the transmission faster...put it in a high gear and aply the brake and throttle thus stalling the converter to warm the fluid faster to warm the fluid.... i really am not sure as to what i was really getting at with my post now that i really stop to think about it...i blame morning stupidty on that one

 

[rhino]

If you are even thinking about towing in OD install a Superior 4th gear billet servo...It's the easiest mod you can do. It's around $85.00. Hold a stock servo in your hand and see how it works, then hold a Superior servo, you will be amazed. In 4th gear, the band and 3/4 clutches are applied. I pull my boat it od, but do it smart. You can tell when its in a bind, just pull it down.