[Adam Orth]

So, I couldn't find the answer to this question on this fine forum, so I suspect the answer is no. But, here goes. We have the 3.5 EB, but settled for the 3.31 axle because of availability. So, is it possible to retroactively upgrade our Transit to a 3.71? If so, what would be involved and how much of a massive hole would it put into my wallet?

We will soon need to tow a trailer with our Ford Transit high roof. We have the tow package, including the trailer brake.

Curb weight -- which doesn't include water, any belongings etc. -- of the trailers we are looking at run 4,000 at minimum. I'm looking stats for our van that show a maximum loaded trailer weight of 5,600. When we haul our trailer, it will likely, be for several thousand miles. I get that we could baby our van, and run light -- no water, one change of clothing, etc -- but I'm trying to figure our our options here.

Thanks for any help folks can provide!

 

[Damaskinos_of_Athens]

.
I am not s mechanic but:

I think all you have to do is swap out the rear differential, and those are only around a few hundred, maybe more if you want limited slip or locker or something. Plus labor .

Found this interesting discussion: http://www.viperclub.org/howto/faqs/what-are-the-benefits-of-a-rear-gear-swap.php

.

 

[orton]

First try the 3.31. Suspect the EB will handle the load.

 

[danketchpel]

So, I couldn't find the answer to this question on this fine forum, so I suspect the answer is no. But, here goes. We have the 3.5 EB, but settled for the 3.31 axle because of availability. So, is it possible to retroactively upgrade our Transit to a 3.71? If so, what would be involved and how much of a massive hole would it put into my wallet?

Thanks for any help folks can provide!

Yes, you can upgrade later and you would have the option to upgrade to a limited slip at the same time for more $$$ of course.

It's not a simple job and best handled by a reputable differential shop. If you don't get the backlash shimming right it will whine at certain speeds.

The 4x4 off-road guys change diff gear ratios all the time. You're probably looking at $500-600 in parts and labor, but you'd need to get a quote to be sure. You might want to scout out a reputable shop in your area just to check. I'd start by asking the local off-road 4x4 type shops who'd they recommend.

 

[6386]

The Ecoboost F-150 is rated to tow a great deal more than the Transit with an effectively taller rear ratio when you compare tire sizes. I suspect the towing limitations of the Transit are related more to the much smaller brakes and unibody vs having a full frame.

 

[Adam Orth]

Thanks for responding, guys. Researching a good shop and getting a quote, and then waiting to see how the 3.31 handles the load makes a lot of sense!

 

[Adam Orth]

By the way, Damaskinos_of_Athens, I worked my way through that interesting thread you linked and deciphered about a third of it, but I did come to understand that I would really like a Viper!

 

[joefromga]

It will handle that 5000 lb load easily. If it starts to wear out just replace it then.

It would probably be 1100-1400 with labor from a good shop.

 

[star gazer]

I tow a small Casita Trailer, 3500 lbs loaded, and carry heavy equipment that puts me a couple hundred pounds less than my max gross and it does very well. However my trailer is an aerodynamic egg shape so has almost no wind drag. If you are towing a larger frontal area travel trailer that might start to be a problem if you go much over, which would be easy to do from the sounds of it.

But like others have said, try it and see. Find a scale after you think you have it loaded the way you want, and with passengers, and see what it weighs.

Dean

 

[danketchpel]

Thanks for responding, guys. Researching a good shop and getting a quote, and then waiting to see how the 3.31 handles the load makes a lot of sense!

Please post back the price quote, I'm quite interested to know how much they quote.

The numbers I tossed out came from both another forum and I had gotten a quote for putting different gears plus a LS unit into a open diff for an Econoline a few years ago. I took out the cost of the LS unit.

 

[Adam Orth]

OK guys here is an update:

I talked with Jackson Powertrain in Jackson, Miss. When I called around in this area, they were the folks I was sent to. They hadn't actually worked on a Transit at the time I called, but have upgraded the gearing on plenty of Ford truck rear ends. He said they'd done about five the week previous, if I remember correctly. Anyway, over the phone he quoted $1,200 to $1,400.

I plan to stop by Powertrain in the next few days and talk a little about what I can reasonably hope to achieve with such an investment in terms of towing capacity. I'm thinking that alone might not get me the 7,000 I'm looking for.

I've also located a local scale and will go weigh my partially loaded Transit in the next few days.

 

[joefromga]

A 3.73 will handle that 7000 no problem.

 

[brownbear]

You can run in fifth gear, use a little more fuel for a lot cheaper than swapping gears for a grand or two.

Fifth doesn't even sound like it it's reving much more anyhow..

 

[Adv]

I called my local 4x4 shop a few weeks ago. I want larger tires but still need to tow. They were concerned about the potential problems with the traction control and ABS. If I matched the right gears set with the appropriate size larger tires he 'thought' it would all work out but wasn't completely sure. He said it was a common rear axle and quoted me $700-800 over the phone with Nitro gears and re-using the bearings.

 

[danketchpel]

That price of $700-800 is much closer to the prices I was getting when searching around for the same thing for an Econoline van. The $1,400 price sounds very inflated unless there's some sort of upgraded locker included.

I don't seen any issue with ABS/Traction control as long as all 4 tires are the same size. Both of those systems work off an encoder ring near the brake rotor and simply detect wheel rotational speed vs the other wheels.

Your speedo reading will might be off unless the current ones pick up off the wheel encoder rings instead of the trans.

 

[Adam Orth]

Hi guys, here is an update. The advice I got here -- that our van with its 3.31 read-end would likely have no trouble with a 5,000-pound dry-weight trailer -- was echoed by a well-recommended shop I located. Since then, we purchased a 27-foot, 2285 Lance travel trailer (4,600 pounds dry weight) and I hauled it from Florida to Massachusetts and from there across our great land to California without any towing issues. As I think I said earlier, our van has the tow package, which includes trailer brakes, towing gearing and a heavy-duty hitch. In addition, we had sway bars installed for the trailer. I kept it at the speed limit the whole way and never over 65 mph-- that's just how I roll -- and climbed the Sierra's up to 8,000 plus feet at about 45 to 50 mph, but only because I saw no reason to stress out my engine. The trailer and van track well together, handled gusting winds while crossing Texas with ease and the brake system never felt overwhelmed. We could not be happier and I just wanted to thank everyone here for taking the time to help us out.

As an aside, I never got above 12 miles per gallon while crossing the United States and I spent a lot of time just below or above 11 mpg. That's mostly highway miles as I was on a tight schedule, except for a detour in Arizona to hike with an old buddy.

Also, I don't recall what the quote was for changing the rear end. I did get a rough number over the phone. I just went over my notes and didn't find it. Sorry.

 

[pjz]

$1,200 - $1,400 does seem pretty high for a regear even in super expensive CA. Paid just under $1,000 per axle for my jeep at that was at a high end shop. Could have paid a bit less, but didn't want to worry about it.

Agree with the others. Try it first and see how it tows. May not be a big issue at all with the 3.31s.

Good luck!

 

[joefromga]

It will tow just fine but I think the mileage would be better towing with the 3.73 because 6th gear is so low that you're in higher boost the whole time.

I got a quote for 1100 for a regear.

 

[Kevin L.]

This thread looks a couple months old, but I'll chime-in since I've been wondering the same thing (about aftermarket gears). Quick background: I too had been looking at options to tow a travel trailer with my T-150 Wagon with the 3.7 engine. I read countless comments that said it would be fine. As a result, I bought a trailer that weighs 3450 dry. I tow it almost completely unloaded and even removed one of the batteries to save weight. My finding is that while the towing experience is very stable behind the T-150, I have almost no power. Going down the highway, I often struggle to get it over 50, often shifting back and forth between 4th and 5th, just to hit 55. Going up grades is obviously a struggle as well.
My issue may be that I have the 10-passenger Wagon with the heavy seats, and those are filled with two adults, plus six kids. We're not talking a ton of weight in passengers... maybe 600-700 lbs total... but I wonder if the excess weight of the seats is holding me down. I just feel like the power range on the freeway is VERY lacking and I wish I knew if changing the gears would really help very much, plus whether or not it would screw up other things such as the vehicle computer, the ABS system, etc.
Has anyone actually gone through with the gear change? Are there other performance enhancements to try first? I don't have the Eco Boost (not sure if it would help a whole lot), but I've wondered about aftermarket upgrades that could possibly boost HP.

 

[CrewVanMan]

Your T-150 Wagon should have come with the 3.73 ratio so your change would be to go with a 4.10 ratio. With the lesser power of the 3.7L V-6 you just don't have the torque to pull the load. That is where the 3.5L EcoBoost and the 3.2L Diesel work the best.