Towing in Overdrive

[MillionMileMarch]

Hey Guys - It seems this topic would have been beat to death but I can't find anything on the OBS. I am towing a 5th wheel that weighs about 8,000 lbs loaded. And the little bit I have found on the subject says these trucks should never be in overdrive while towing. BUT, it I did that my top speed would be around 65 mph and that's turning close to 3000 rpms!! So my question is - is overdrive really off limits? I can pull around 65 at around 2100 rpms in overdrive and it doesnt feel like I am lugging the engine or trannie. I have 4.10 limited slip rearend - just need some help because I dont want to scream down the interstate doing 60 mph at 2800 rpms... Thanks Guys!

[vitalidle]

You should be fine as long as your tranny isnt looking for gears or constantly downshifting. If your running up any grades or in the mountains take it out of overdrive. Also get yourself a tranny temp gauge, so you can monitor the temps

[alabamafrog]

I have heard that it is okay as long as the truck is not "hunting" gears, shifting in and out a lot. I have to run mine in OD on the interstate to keep it below redline, I can tow at 80 mph in OD or 60 mph with OD off. I think on my tranny the OD switch only shifts it from 5th gear to 4th gear, the torque converter will still lock in either gear. I will be interested to hear what other think about it.

[MillionMileMarch]

Thanks Idle - I have read enough about these auto trannies to be dangerous. I'm scared to death the thing is going to melt anytime I have to use it.

[MillionMileMarch]

Originally Posted by alabamafrog

I have heard that it is okay as long as the truck is not "hunting" gears, shifting in and out a lot. I have to run mine in OD on the interstate to keep it below redline, I can tow at 80 mph in OD or 60 mph with OD off. I think on my tranny the OD switch only shifts it from 5th gear to 4th gear, the torque converter will still lock in either gear. I will be interested to hear what other think about it.

Yeah - I definitely have a gap with these 4.10 gears I either need to be doing 65 in OD or 55 in drive for comfortable engine revs. I don't go any faster than 65 pulling the 5th - the little tires can't handle it. Hope to hear a lot of opinions too!

[jfines@cox.net]

I tow a 14,000# 5er, And unless I am on flat land, I never tow in O/D. Sure you RPM's are higher. And you have to go slower. As I look at it, why should you be in a hurry with all that weight.

Also, by down shifting, you keep you EGT's a little lower. As said before, get gauges. I recommend both tranny and EGT.
With my rig I can hit 1,500* (turbo meltdown) real quick.

And I have 4.10's also

[vitalidle]

Yeah get yourself a tranny gauge and that will let you know if you need an upgraded or second cooler to keep the temps in operating range. Its cheap insurance if your towing.

[MillionMileMarch]

Originally Posted by jfines@cox.net

I tow a 14,000# 5er, And unless I am on flat land, I never tow in O/D. Sure you RPM's are higher. And you have to go slower. As I look at it, why should you be in a hurry with all that weight.

Also, by down shifting, you keep you EGT's a little lower. As said before, get gauges. I recommend both tranny and EGT.
With my rig I can hit 1,500* (turbo meltdown) real quick.

And I have 4.10's also

I definitely don't get in a hurry - I enjoy every second of towing with this truck but I also don't think, at least at my 5er weight, that I need to rev between 2500 - 3000 to do between 50 and 60 mph cruising down the interstate. It feels pretty comfortable at 2000 - 2200 at 65 in OD. I guess the temp gauge will solve the issue. What is your cruising speed and rpm on flat land?

[MillionMileMarch]

Originally Posted by vitalidle

Yeah get yourself a tranny gauge and that will let you know if you need an upgraded or second cooler to keep the temps in operating range. Its cheap insurance if your towing.

Do I have a trannie cooler stock?

Sorry for the ignorance guys...

[jfines@cox.net]

As long as your trans doesn't shift in and out of O/D frequently then it is fine. Atleast this is according to the guy who just rebuilt my trans.

as for the cooler, A big must, Our trucks have two stock, on in the radiator and a tiny one in front of the condenser.
To be safe, I went with the largest one I could get (40,000# rated) I figure it is safe cheap insurance to preserve my $3,500 tranny.