Towing in overdirve

[91Bluestreak]

What all should be done to the trans (4L60e) to be able to tow with it in overdrive?
I towed a car home today with the truck and it sucks not being able to use overdrive and sucking alot of gas.

 

[Chevyguy78]

Nothing trannys arent built to tow in OD, ant tranny shop will tell you the same thing. Thats why its in Od for milage. You always tow in 3rd.

 

[TUCSONDUDE]

I only have 2 letters for OP 5char




....NO....

 

[96-1500]

Nothing trannys arent built to tow in OD, ant tranny shop will tell you the same thing. Thats why its in Od for milage. You always tow in 3rd.

x2. You could always throw the auto in the junkpile and put in an NV4500.

 

[88GMCtruck]

I tow with my NV4500 in overdrive.

 

[96-1500]

I tow with my NV4500 in overdrive.

Me too. Well, not my truck, but I do ('98 C3500 HD 6.5/NV4500)

 

[bggrnchvy]

Transmissions will tow in OD just fine, provided you have enough holding power in the clutch packs or clutch to apply power and not slip depending on your final drive ratio and GCVW.

That said the biggest hiccup with the 60e is it's car like .70:1 OD. That combined with limited 3-4 clutch pack holding power results in accelerated wear and possible slippage even locked in. Even going to a Z-pack to increase the surface area and effective holding power of the 3-4 pack doesn't alleviate the steep OD ratio which makes the shift out of lockup nearly all the time and even downshift regularly. You get the heat from the converter in non-lockup and the wear on the clutches from the downshifting.

You could regear the axle a bit deeper to make up for the OD but it's the opposite of what you're trying to do in lower cruise RPM.

IMO for your situation, run in OD on open flat ground and just run in 3rd anytime you need more power/compression braking.

I too run my manual (G56) in OD grossing 20klbs, but it's a manual and my OD is .79:1.

 

[silverado13]

Transmissions will tow in OD just fine, provided you have enough holding power in the clutch packs or clutch to apply power and not slip depending on your final drive ratio and GCVW.

That said the biggest hiccup with the 60e is it's car like .70:1 OD. That combined with limited 3-4 clutch pack holding power results in accelerated wear and possible slippage even locked in. Even going to a Z-pack to increase the surface area and effective holding power of the 3-4 pack doesn't alleviate the steep OD ratio which makes the shift out of lockup nearly all the time and even downshift regularly. You get the heat from the converter in non-lockup and the wear on the clutches from the downshifting.

You could regear the axle a bit deeper to make up for the OD but it's the opposite of what you're trying to do in lower cruise RPM.

IMO for your situation, run in OD on open flat ground and just run in 3rd anytime you need more power/compression braking.

I too run my manual (G56) in OD grossing 20klbs, but it's a manual and my OD is .79:1.

sorry buddy but i disagree, overdrive is just not strong, i crack up when i see these fbody guys with 4l60e camaros and trans ams doing a 150mph pull, which is really bad for the tranny becasue they are pulling in overdrive, thats why all the newer trucks are tow mode which stops it from going into overdrive

 

[88GMCtruck]

Tow/haul mode still uses overdrive, the trans just changes its shift behavior significantly.

Sent from TBI 454 HTC Droid DNA

 

[96-1500]

Tow/haul mode still uses overdrive, the trans just changes its shift behavior significantly.

Sent from TBI 454 HTC Droid DNA

x2. I believe it makes it a higher-rpm shift point? You can kind of replicate it with these trucks if you want by shifting manually gear to gear. I almost never have felt it necessary to do so, I usually just hold it in 3rd (with my 4L80E) and let the trans do what it wants automatically. Sometimes if I'm on a really long flat spot I'll throw it into OD, but not often. We live in hilly country here.