camper disapointment

[jtate]

well this past week i put 6new tires on the truck and 4 new ones on my 30ft fifth wheel camper. ive never pulled my camper with this truck, which is a f350 7.3 n/a with 355 gears. from a dead stop to 50-55mph not a problem, but from 55 to 65 it takes forever. thats on flat ground, i would hate to see on some simple hills. do any of you folks pull a 30' camper with a n/a truck? i know its not turboed as of yet , but shouldnt this be a piece of cake for this truck? im not trying to win a race to get to the camp ground, but would like to be able to stay up with the speed limit and not have to weld the go petal to the floor to do so. what are some of your opinions and causes for this?

 

[Diesel JD]

The 3.55 gears and no turbo is hurting you here. How heavy is your 5'er? Are you sure your fuel system is good and the IP is timed right? Otherwise it may be down on power for real.

 

[zpd307]

x2 on the fuel system. mine has been changed out and it has more power than before. i have 186,000 on the truck, the ip and injectors were tired. it seems wierd that you would have 3.55s in a dually.....

 

[david85]

Are you in 3rd or overdrive to accelerate from 55-65?

 

[RLDSL]

That 3/55 rear is shooting you in the foot, and if you had that thing in OD it would be a wonder it could get out of it's own way
Before I got my turbo, I could tow my 5er in direct and keep it wound up and it'd pull fine. I could keep up with most of the big trucks going through the mountains, can't ask for much more, but OD was a no no unless going downhill... and that's with a 4.10 rear

 

[6 Nebraska IDIs]

Holy cow man, where did you get someone in their right mind to put a 3.55 gear in that thing, or was that the factory not thinking ahead? That in itself will rob you of an unbelievable amount of power. For example, my brother had 3.08's in his 68 Mustang and it drove ok but just wouldn't run the 1/4 mile very fast. He opted for a set of 3.80's and HOLY CRAP it was like we ditched the 289 Cobra and dropped it a 427! It dropped the quarter mile time by almost 2 seconds and the butt dyno was feeling an easy 50hp gain being transferred to the wheels.

 

[Dsl_Dog_Treat]

3:55 and C-6's came paired together.

Yup, those and N/A make it slow.

4:10/ ZF-5 N/A on a 29.5 fiver is slow.
Throw a turbo on there and you'll think ya hopped into a different truck.

Been there, wont go back.

 

[flatlander]

my 85 pulling our 34' nomad (7600 net, 9400 gross) would pull at 60 ok, I'd lose speed climbing hills. It'd take a long time to get to 65 and only if it was a flat stretch. That truck has C6 and 3.55 gears. I'm guessing that what you have is what you have.

 

[funnyman06]

My truck has 3.55s and C6, crusing cross country i ended up going just 55, it was more than worth it in the end. I wasnt even close to as heavy as you were but the truck and trailer were loaded, my lowest speed was about 45 going up the hills and at 55 i could maintain 18 mpg with AC on, did 300 miles through texas at 65 and was only getting 16. I gave up trying to go the speed limit. But in a 350 pulling a 5er you really want 4.10 gears.

 

[dansvan]

Weren't these trucks built when the national speed limit was 55? If so looks like the engineers did their job.

 

[Compu Doc]

I had a 28ft TT I towed with my truck. It is a 1991 ambulance that weighs 10K empty. The TT loaded was probably 8K but do not know as i never had it weighed. My truck is a 7.3 non turbo with 4.10 gears in the rear and has an E4OD transmission. I have pulled that trailer up the Adirondack mountains at about 50MPH going up hill in OD.

I also have a flat bed car trailer that I have pulled a 15K load on one time up the Adirondack mountains and the slowest I went up hill was 45MPH in OD. On the flats I could hit 65-70 easily. If your going to be towing and do not want to turbo the truck then change the gears to 4.10.

 

[jtate]

the po of the truck told me it had 355's, but after looking at the sticker in the door jam it has a d5 axle which is a 410. i tried pulling both ways, in od and out of od. out of od it was easier to keep the speed but sounded like it was screaming for me to come down on the rpm's. in od you basicly had to keep it almost to the floor. it has a set of new injectors that i put in about 4 months ago, and the pump has 233,000 miles on it. i know its time for a new pump, but after being laidoff of work for a couple of months its kind of next to impossible to pull off right now. i have a snap-on timing meter that ive tried setting the timing with and it just doesnt make any difference in how it performs, or i just dont know what the h im doing lol. there is just nobody close enough to me that can show me how to use the meter that i have. most people use a pulse timing meter, when i use luminosity probe.

 

[david85]

So much for the 3.55 gear bashing

As I've tried to explain several times before, differential gearing doesn't matter as much as final drive ratio once you are moving. If RPMs are below 2000 in top gear, then you can downshift to the next one down to get the extra RPM, gearing and Hp. Anything above 30 MPH and you will have access to a wide enough drive ratio even with 3.08s, let alone 3.55s.

That pump is well overdue, but at the very least you might be able to bump the fuel up a little if your timing is within spec. Internal clearences tend to increase as they age, thus reducing your actual fuel flow settings. What is your tailpipe smoke looking like right now? if you aren't seeing anything, then I would suggest turning it up by one flat and see how it does.

 

[hesutton]

With 233,000 miles on the IP, you're right, it's time for another injection pump. That coupled with a turbo and you'll be a happy camper (pun intended)!

Heath

 

[jtate]

So much for the 3.55 gear bashing

As I've tried to explain several times before, differential gearing doesn't matter as much as final drive ratio once you are moving. If RPMs are below 2000 in top gear, then you can downshift to the next one down to get the extra RPM, gearing and Hp. Anything above 30 MPH and you will have access to a wide enough drive ratio even with 3.08s, let alone 3.55s.

That pump is well overdue, but at the very least you might be able to bump the fuel up a little if your timing is within spec. Internal clearences tend to increase as they age, thus reducing your actual fuel flow settings. What is your tailpipe smoke looking like right now? if you aren't seeing anything, then I would suggest turning it up by one flat and see how it does.

david85 at 70 mph my tac reads 2500rpms , if i cancelled od then i would be close to 3000 . that is way to high to be comfortable with .