05 S-Crew 5.4,4x2, 3.73. 35" tires. 95k miles

Towed my toyhauler into the mountains for the first time this weekend and wanted to share the experience/performance of the F150 and solicit advice and opinions. The 21ft toyhauler fully loaded is around 8000 lbs.

On the flat, no issues, truck pulls strong. This particular location, has a lot of single lane and windy uphill (relatively steep 6%) roads that make it difficult to keep momentum (lots of 30mph turns). OD off. There were times where I felt like the truck should have more to give. I'm not trying to charge up the hill at 65, but I'd like to be able to maintain 45. There were times it felt like I was losing ground and the truck seemed to downshift into second a little later than it should have. Full throttle and I just felt like I should have been able to maintain a little better. Question here is the experience I described normal for those conditions? Engine temp was constant, pushed 4k RPM's when it did drop down to 2nd. Would a tuner with a Tow profile help.

2nd issue- When pulling into the campground, I had a short (75 yards) steep hill to climb. There were some nice speed bumps about half way up that I slowed for, and then missed my left turn. I stopped and back up a few feet to make the left and to my horror, I could not move forward. I dropped down to 1st, nothing, 2nd nothing. Finally in D, ever so slowly it inched forward and got me moving. Is that normal? Never ideal to come to a dead stop on a hill, but I really thought I should have been able to pull out of that a little smoother.

That experience really made me nervous as I've got some trips planned that will see me going through the I-15 Cajon Pass and the I-8 between San Diego and the Imperial Valley, both with 6% grades. I can live with 35mph with the hazards flashing, but can't live with the idea of not making it up a hill, especially if I were to have to stop for some reason (traffic, accident, whatever).

I'd appreciate any advice, aside from the "you need a diesel".

 

The 35's are killing you... Killed my towing also.. 1000 mile round trip with OD "OFF" towing 7500lbs..

 

I suspected as much. They were on it when i bought it. They look awesome, but that's about it.

 

Downshifting manually could cause the issue you noted on the hill.

When you downshift manually in an F150, it will not lock up the converter completely. Not sure why, it makes not sense to me and this is the first truck I've had that does that.

However when you shift back into D it should have been more normal driving experience.

That is a big load for that truck at 8000 #

 

when I went from 33's to 35's without towing ...I could feel the loss of hp.. got to re-gear...

 

I think if you re-geared 4.56s or 4.88 that towing experience woukd be good/decent?

 

This ^^^^ or drop back down to stock tire size..

 

Regear is a must if you plan on towing with those 35's.

 

How much does the toy hauler weigh loaded down with everything?

 

I have not weighed it on the scales, but with bikes and water and beer etc, I estimate it might get as high as 8500. Planning to wait till almost at destinations to fill fresh water, save almost 1000 pounds. Getting ready to google it up, but I take it re-gearing is no small feat. Might be worth getting on cragislist and finding some stock tires. Wouldn't be a huge deal to swap them out for the two or three times I tow longer distance in mountains.