OT - Can a 4L80E handle towing in OD?
 

I'm looking at a '96 Suburban 2500 4X4 with the 7.4L and 4L80E, 4.10 gears. Max tow rating for the vehicle is 10000 lbs, according to the specs I have seen. I will be pulling considerably less than the max, around 6500 lb. I know that you should tow in 3rd with the lighter duty 4L60E, but is the '80 sufficiently HD to handle towing in OD? Somewhat worried about the gas bill with this beast. I have had a couple of people tell me that I can get as much as 16 mpg hwy unloaded - do they mean downhill with a tailwind? Anyone else out there have experience with this rig? Seems like Craig223 bought one recently. I test drove it yesterday - ran pretty good, but oil pressure was around 20 in gear at idle, around 40-45 at 2500 RPM. Temp ran as high as 210* sitting at idle. Do these numbers sound OK for a 120K mile rig?

Anyone care to share their experiences?

Thanks!

Tom

Re: OT - Can a 4L80E handle towing in OD?
 

Tom

2002 Chevy suburban 1500 not towing gets 13.5 MPG in town and 18.3 on the road. Towing yeilds 9 MPG depending on traffic Temp runs 180-210.

1998 Chevy 3500 dually all around I see 9-11 MPG Temps as low as 160-170 under no load and 215-220 after towing in Summer at idle at a stop light. Press the gas to accelerate and back down to 160-170.

Hugh

Re: OT - Can a 4L80E handle towing in OD?
 

the 4L80E is an awesome transmission. Yes you can tow in OD. It is the 4L60E that unless modified will give you trouble.

Roby

Re: OT - Can a 4L80E handle towing in OD?
 

I believe there is a sticker on the drivers door jamb that will cover your question. As I recall, it wanted you to be in 3rd. I remember seeing the sticker on a 95 2500 4x4 with a diesel.

Re: OT - Can a 4L80E handle towing in OD?
 

Those gas milage numbers sound really optemistic. I had a 96 2500 pickup with a 7.4. In mixed highway and city I got 11.5 to 12. All highway 13 TO 14 unloaded. That's why I went diesel when I went 1 ton. The idea of less milage than my 2500 was scary.

Re: OT - Can a 4L80E handle towing in OD?
 

Just about every trans can be used in over drive .
The only reason they ever said not to , was because it will shift up and down too much making too much heat and frying it !! YOu need to manualy control your shifts when towing heavy with any auto trans . Once you get out on the highway , put it in OD and fly !! Just make sure YOU down shift it on th ehills before it does itself. That way there is a lot less slip and pressure on it ... ALso ,that fuel estimate is high ....Joe

Re: OT - Can a 4L80E handle towing in OD?
 

This is a good shop and a good site. I bought one of their 700-R4s for my last hotrod truck and it was awesome there is a lot of good info on different transmissions too.

http://www.transmissioncenter.net/

Roby

Re: OT - Can a 4L80E handle towing in OD?
 

I tow in overdrive everytime I tow. Gas is killin' me...thinking about going diesel. :cool:

Re: OT - Can a 4L80E handle towing in OD?
 

Its funny how much time, effort and money we will spend on our boats engine and not always on the tow rig! I spent some money on my tow rig a 98 Yukon. Made the motor into a 6.5 liter torque beast with addition of a 4l80e. With a good transcooler and the added engine torque you can pull in overdrive all day long. I now get about 17mpg in overdrive averaging about 70mph and I don,t have to slow for hills or grades and believe me we have some dooseys in California! Moral of this story. Don't forget the motor in the tow rig-Torque,Torque,Torque!
Raylar

Re: OT - Can a 4L80E handle towing in OD?
 

I run a '95 K2500 Suburban with the 7.4L and 4L80E trans, tow about 7000lbs total. I have always towed in OD with no problems, but like someone else here said, pull it down into 3rd manually when needed. Don't let the trans "hunt" for the right gear


That gas mileage figure is a bit optimistic 10-11 towing, about 13 best, not towing.