4th gear towing?

[dizdak]

took the play truck out over the weekend, tow weight of truck and trailer approx 9500lbs give or take, about a 40 mile ride with a good 20 miles of it wide open hwy, noticed running 5th gear at 55-60 it was putting smoke out pretty heavy, running at about 1700-1800 rpms, down shifted to 4th gear, smoke cleared up but rpms were at about 2400 running the 55-60, and the engine temp seemed to stay around 210... is running at those rpms good or bad for the motor on a haul like that?

 

[riotwarrior]

You won't have a problem with running in 4th. If you run 5th towing better make sure yer not too heavy as it's IMHO not a good gear to tow in.

These engines from those whom know here can bounce all day at the governor speed of the engine at about 3400 RPM with NO ISSUES.

You did right by what you did FYI

JM2CW

Al

 

[dizdak]

good deal, thanks... i didn't "think" it would hurt it but figured i would ask the IDI pro's, just for a little reassurance..

 

[fordf350man]

always remember with any transmission, if its an overdrive transmission, that final overdrive gear is for fuel milage, not towing or hauling

 

[redneckaggie]

i dont pay attention to what gear im in per se, i just drive where the engine doesnt feel like it is lugging. depending on how heaily loaded i am that could be 3rd 4th or 5th at 50-60 mph

 

[towcat]

i dont pay attention to what gear im in per se, i just drive where the engine doesnt feel like it is lugging. depending on how heaily loaded i am that could be 3rd 4th or 5th at 50-60 mph

as long as I can maintain 2000rpm minimum, I will any gear either. those who say you can't use 5th, haven't driven the wide open expanses of nothing I look at all day long. my F450 handled 5th gear for 980k/mi and went through three transmissions. two due to repeated oil starvation thanks to leaky PTO's and one due to a cracked bellhousing. none were from overloading 5th gear. do bear mind my gross weight was 14k to 18k routinely.

 

[dizdak]

i have used 5th when towing a lighter load at about 70mph, FL being flat you hit open road and can run pretty good..my only issue with running 70 with the heavier load is the temp slowly creeps up and i don't like to see the gauge go much past that 210-215 mark...

 

[The Warden]

I tow in 5th gear all the time on flat ground...if the EGT's aren't too high and the engine isn't lugging, there's no problem at all with running in 5th gear. Diesels have more low-end torque, and IMHO that's one of the beauties of the design. At the same time, at least with my IDI, I usually have to downshift to 4th if I"m loaded going up a hill.

Compare that to the one time I towed with a gas engine...if I looked at the gas pedal funny, it would downshift and bring me to 5000+ RPM's

 

[iverger]

took the play truck out over the weekend, tow weight of truck and trailer approx 9500lbs give or take, about a 40 mile ride with a good 20 miles of it wide open hwy, noticed running 5th gear at 55-60 it was putting smoke out pretty heavy, running at about 1700-1800 rpms, down shifted to 4th gear, smoke cleared up but rpms were at about 2400 running the 55-60, and the engine temp seemed to stay around 210... is running at those rpms good or bad for the motor on a haul like that?

I agree with the others, you can run in 4th all day long. However, at just 9500lb gross? That is bearly loaded and your in a fairly flat area. You should not be experiencing smoke at 1800rpm unless you running foot to the floor, which shouldn't be the case. Has your pump been turned up a little to far? Is your timing set correctly? Just a few things to consider.

 

[79jasper]

I'm really surprised no one asked what gears he has...

The 02 f550 7.3 psd at work can hardly keep 65 with an empty TA bumper pull. Zf-6 and 5.xx something gears. Pulling the skidloader, sometimes I'll be redlining 2nd gear by the time I get to the top of a moderate hill.

 

[GOOSE]

My cclb srw is about 7600lbs with full tanks and a heavy toolbox. I am guessing that the truck and trailer you were towing was 9500lbs and your total gross weight was around 17,000lbs, is this correct? If that is the case, 3:55 gears will definitely leave you wanting.

I have 4:10's and grossed about 15,500-16,000lbs to Michigan and back for last years rally. I used 5th when ever I could get away with it, had no problem maintaining 70mph on flat ground. Grades had me into 3rd gear routinely and one pass in particular had me red lined in 2nd at 3800rpms for literally a few minutes. Towing heavy on the open highway is a whole new experience if you haven't done it before. I have plenty of faith in my 5th gear and my idi running high up on the tach, you will be swallowed up and spit out if you don't.

 

[dizdak]

Yes sir Goose you are right, pull truck, trailer , and play truck total gross probably in the 17k lbs range.. And yes 3.55 gears still, and also running 265/75 tires which are slightly larger than stock i beleive.. and YES to the wanting a little more get up and go when towing.. down here, if you can't run 70mph in most areas you quickly get a line of traffic behind you..
Also it was asked if my pump had been timed correctly, no it hasn't.. When we installed it the person who helped me do it has a timing meter but it stopped working when we were trying to time it.. Also i still have to install a PYRO to monitor the EGT... But that is in the plans, along with re-gearing when i get my new tires and wheels.. Also according to Banks i can get the 3" down pipe for $92 + shipping which is also fixing to be ordered..

 

[hesutton]

What was the pyro doing when your were in 5th gear? My guess is they were climbing up there. Like others posted, I will drop a gear and increase RPM if the IDI is struggling on a grade. Better to go slower with higher RPM that to try and hold a gear that's too tall for the situation and lug the engine and shoot the EGT's through the roof. They like RPM when working hard. It keeps the EGT's in check and the coolant temp down.


Heath

 

[OLDBULL8]

Geez; I thought I was in the 6.9L IH & 7.3L IDI Diesels forum, must be something wrong with my puter. How did I get in the Towing and Hauling forum?

 

[dizdak]

mods can move it if they choose to, i posted where i do my reading and checking on things..