I am pulling 10,000 up 6% grades and need to drop into 4th gear at times and is running around 45-50 mph and turning 2800+ rpms. Seems a little weak to me. I think my 8.1 pulled just about as hard.

 

You have larger tires, so that doesn't help your issue. Can you leave it in 5th and hold steady at a lower rpm, or does the rpm steadily drop? I have an 07 with 285/70s, and when I tow around 8000 up those grades, I have to drop to 5th, but it holds steady between 55 & 60.

 

Even before Smarty I could accelerate up grades like that pulling 10,000 lbs of coal. I'm still using stock wheels and tires.
5.9 or 6.7?

 

There is something definitely wrong. You should be able to pull that 6% grade in fifth gear with no problem.

 

Where do you live, and what elevation?

 

Gauges? FP/ RP? EGT's?

When's the last time you changed your fuel filter?

I don't think that the 305's will make that much of a difference. Maybe if you have 3.73's, but not if you have 4.10's...

 

Thanks for the responses.I am pulling up to the rim near payson here in AZ. I have the 5.9 with fresh fuel and air filters. It seems to run good and I can pull most hills in 5th but I do need to drop to 4th from time to time. It did pull a bit better with the smaller tires and I think I'll go down to 295s when these wear out.
It will keep dropping if I don't down shift. I down shift around 45 and then it will pull back up to 50mph but am turning some Rs.
I wonder what gear the autos would be in since their 3rd is the same as my 5th with the same 3.73 gears.Would they be down to 2nd..I guess?
The exhaust temp sits at around 1250 until I down shift and then it goes to 1350-1400.

 

This seems a bit strange to me.

I can pull that sort of grade towing 20,000# in fifth and my truck is Bone Stock.

Also, I'm curious why your EGT's would rise AFTER you downshifted?

I'd expect your EGT to get hottest in 6'th when you start to lug and drop after you downshift and get more RPM back?

Hmmm, strange.

 

Sorry but I have a hard time swallowing this one. 20,000lb trailer up a 6% grade in 5th with a stock engine in a Mega Cab.
What sort of a 20,000lb trailer are you towing and where at.
Most triple axle 5th wheel toy haulers are max GVW at around 17,500-18,000lbs.
Sorry but I ain't believing this one.
But thanks for the input.

 

I have a tripple axle, and the gvw is 21k..

 

Thats a long haul if your heading up from Rye to Payson. Or are you talking from Payson to the Forest Lakes area?

 

How many miles on your truck?? Even modded my 06 was a dog for the first 10K

 

I figured they can get a lot heavier. Just the ones I have looked at were 17-18,000. So can your truck pull 60mph up 6% grades when your loaded?

I have 25,000 miles on her and I think most of the grades from Phoenix up to Forest Lakes are 6% but I would bet they get closer to 7% in some places.
The truck is not sick. It runs great I just thought it would have just a bit more. I do remember that with the stock tires it would really jump at freeway speeds when I nailed it. It did take some away going to the bigger tires.

 

From Payson to Forest lakes I can hold 5th and she drops to about 52 at one spot. It must be the Rye hill I drop to 4th on. I would bet that hill is more than 6%. There are a couple of steep hills going up to the rim.

 

Well I'll be pulling the same hills with same load except with 2 extra people this weekend but have loaded a Smarty Jr on #2 tow setting so lets see how see pulls now.