Have 2006 F-150, 2WD, 5.4 automatic with 3:55 limited slip rear end. I pull a 35' travel trailer 7,500 lb unloaded and 8,800 lb if I'm bring my own water. Most of the time we get the water when we arrive at the camp site. I'm thinking of changing the rear end gears to 4:10. I'm looking for advice for the pros & cons and what all I have to mechanically and to the computers. I would love to have a F-350 but that isn't in the budget right know. I will do most of the work my self to keep it affordable. Thanks in advance, Dale

 

Hello, DNG. I could be wrong, but I don't think anything needs to be done to the computer except to change the revs per mile value it stores in the VID section to correct the speedometer. You could have this done at a dealership, or, you could correct it yourself if you bought a programmer. The process is very simple.

But, you don't say that your truck is a 2WD. If so, you only have to change the rear axle gearing but if it's 4WD, you'll need to change the gearing on both axles. This essentially doubles the cost.

I can't help you with the "mechanical" end of it, but I know it's well within the skill of a DIY mechanic. I think there are books that can help you with the process.

The trailer you are pulling is really almost too much for your truck. 4.11 gearing would ease the strain on your engine and transmission, but I wonder about the tongue weight you've added to your truck. If your trailer is properly set up, the tongue weight should be between 880# and 1320#. Even with a Weight Distributing Hitch, you are probably over the GAWR rating for your truck on one or both axles.

- Jack

 

Recommend a new shim kit for new ring and pinion

 

That's really too much trailer for your truck regardless of axle ratio. You may even want to get 4.56's and a programmer with custom tunes.

FYI, there aren't 4.11's for Ford - technically they are 4.10's.

 

Yukon is the only brand that calls them 4.11

 

Hi Jack, It is a 2WD truck and yes I could use a F-350 but that isn't in the budget right know. Thank you for the information and I think it is something I will do myself and have the programing done at the Ford dealership when I'm having the spark plugs replaced under the agreement with the class action law suite about the spark plugs. Thanks again, Dale ;5170978]Hello, DNG. I could be wrong, but I don't think anything needs to be done to the computer except to change the revs per mile value it stores in the VID section to correct the speedometer. You could have this done at a dealership, or, you could correct it yourself if you bought a programmer. The process is very simple.

But, you don't say that your truck is a 2WD. If so, you only have to change the rear axle gearing but if it's 4WD, you'll need to change the gearing on both axles. This essentially doubles the cost.

I can't help you with the "mechanical" end of it, but I know it's well within the skill of a DIY mechanic. I think there are books that can help you with the process.

The trailer you are pulling is really almost too much for your truck. 4.11 gearing would ease the strain on your engine and transmission, but I wonder about the tongue weight you've added to your truck. If your trailer is properly set up, the tongue weight should be between 880# and 1320#. Even with a Weight Distributing Hitch, you are probably over the GAWR rating for your truck on one or both axles.

- Jack[/QUOTE]

 

I recommend you find a 4 wheel drive shop and pay them to do it. They change gears a lot and probably can do it better than a dealer and less expensive.
But, if you insist doing it yourself, there are some excellent utube videos that tell you how to do it. It's not for an amateur. But, if you study the videos and buy the tool that holds the pinion flange while you crush the pinion sleeve, buy an inch lb torque wrench so you can properly torque the pinion nut, buy a torque wrench to torque all of the large bolts and buy a dial indicator to check backlash, and you are meticulous, you have a chance of doing it correctly.

The shim between the pinion gear and the inside bearing establishes the pinion depth. This depth has to be correct to get the correct gear pattern. If the first shim you use is not the correct one, you will have to pull the inside bearing and try again. Assuming you replace all of the bearings while you are doing the gear change you can shave a little metal off the inside of the old bearing so that it will slide over the pinion shaft and use it to get the pinion shim correct. That way you don't have to press the new bearing on and off many times and possibly ruin the new bearing. There is a lot more to it than just replacing parts.

 

It's not very likely that Ford can reprogram for 4.10's. You will need an aftermarket device.

 

What are you pulling? A mobile home? How long is you're TT? I cringe pulling our 27' tt that weighs 6k fully loaded when there's a little wind...

 

Pulling a 35' Rockwood Windjammer, with the "V" in the front it pulls better then our 22' old one with a flat front. We try to stay out of the big winds, but can't always do that.

 

I've got 4.10's on my truck. I went from 3.31's. What a difference. It is like night and day.

I can say that 8800# is a lot for your truck. I've pulled a lot with mine, and it does not like accelerating, but I'm not drag racing my trailers around town. In fact, even when I'm cruising, I try to stay at the speed limit as it really saves on fuel when pulling a trailer.