Hey folks,

Went on our first trip with our F350 and travel trailer (guessing 8000lbs) last weekend and noticed that I couldn't keep it in OD (4 speed tranny) at 60MPH on the Interstate. It felt like it was on the edge of 'lugging' and I thought it would have been constantly been downshifting at any incline, so I just drove in 3rd.
It was happy in 3rd, but it took a while to get used to the 2600RPM growling at me. Not a big deal I know....just turn up the radio.
It's a RWD with 3.73 ratio, so I'm thinking of possibly changing it out to 4.30. This truck is our tow vehicle only (the odd city excursion) and it will be parked over the winter, so the marginal loss of MPG isn't an issue.

Our previous tow vehicle was an '01 Suburban 2500 8.1L 4.10, and it would tow our 6500lb trailer in OD (4 speed) on Interstates nicely at around 2100RPM. I know the trailer weight is and apples to oranges comparison, but I'm wondering if the gear change on the Ford could get me back to what the 'Burb delivered.

Another consideration is that we live in mountain country and we'll be doing some climbing this summer.

Also, maybe towing in OD isn't a good idea with the 4 speed anyway?
Any idea on the $$ to do a gear change? Because it's a RWD I'll only have the one to do.

Any advice would be greatly appreciated.

Mike

 

its no problem to tow in Od if the engine can manage it..

sicne you said the vehicle is purely a tow vehicle, i'd make the jump right to 4:56..

huge increase in power to the ground, and i bet your truck stays in OD in all the biggest of hills.

 

Hey folks,

It's been a while so I thought I'd check in.
After doing some more towing with the truck and got to know it a bit better I was in fact towing in OD as much as I could.
I put a ScanGuage II in and watched my tranny temp and it tended to stay at around 190* with it going up to 225* for a couple of the longer climbs.

Anyway, we just bought a smaller trailer and it should weigh in at about 1000lbs less when loaded so I'm thinking the 3.73 will do OK.

Decided to call a couple places to price out a diff gear swap and one of them said $1100(CAN) and the other called back to say it'd be $1900 because the carrier for the 'posi' would have to be changed as well.....a bit over my head.
I was a bit shocked considering it's a RWD, but maybe that's what things cost these days

Because it's an '01 with the 4 speed and no Tow/Haul function I'm thinking perhaps a 5 Star Tune may be the best investment.

Any comments?

Cheers,
Mike

 

Oh, yeah. 5 Star tune will make you smile. Not only will you get more power, he will adjust shifting behavior to better meet your needs.
Make sure you talk to Mike in person so he can make it perfect for you on the first shot.

 

first off, what size turd ya got under the hood?

 

It's the 6.8L.

 

A tow tune from 5 star will help. My tow tune actually doesn't allow the truck to shift into OD until around 60mph. A gear change is not cheap, labor runs the price up very quickly. Since the truck is dedicated tow vehicle and it sounds like you tow around 60-65mph you could go a little steeper with 4.56 gears if you do decide to go the gear route.

 

I changed the rear gears in my '99 V10 2WD to 430s from 373s and it really woke this truck up for towing. I have the stock 16" wheels and tires. I tow a 7,000# RV trailer with it and it was the best investment I have made for towing. It put the engine in the sweet spot RPM wise when towing and it doesn't drop down a gear on hills anywhere near as much as it used to. It cost me just about $1,000 to make the swap.