Hi guys, Been doing quite a bit of reading on here about upgrading gears for towing. My Ex is used 75% of the time to tow my 9300lb travel trailer. I also tow a 3500lb boat a few times a year.
My VIN says I have the 3.73, but who knows since I bought her used in 2009. I have only added the RAS so my suspension is stock. Currently I have stock tires also.
I have a few questions for those who have swapped gears on their Ex's:
If I go up to 285 tires what gear ratio would you suggest?
Since I may upgrade the gears would you suggest limited slip, posi, etc.?
If I stay with the stock tire size what gear ratio would you suggest?
How much would fuel efficiency change?
How would my Ex drive when not pulling the TT?
As usual any input is appreciated.
Thanks, Joe

 

For 285 tires with a V10, 4.30 gears are your best return for your efforts/money. Get the Detroit TrueTrac in the rear and thank me later.

With stock tires, you should be good with the 3.73 gears or 4.10

I'll let someone else answer the fuel economy question.

Without a load, it would be pretty peppy off the line with either 4.10 or 4.30 gears and stock to 285 tires. Your top end would suffer a bit, though.

 

I have 4.30's on stock tires. That is the only way the X should've been offered. I towed my 9200lb loaded trailer with 3.73's and it was a terrible combination. I also ran 285 BFG AT. It will raise the gear ratio a bit to about 4.20 if you have the 4.30's. I would go so far as to say 4.56's would be a great gear even with stock tires.

Mileage will go up about.5 towing and about 1 around town. Unloaded hey will suffer at around .7. So I would go with either 4.30 or 4.56.

 

I'm in the same boat and have been contemplating the same issue.


What engine do you have? How has the tow experience been for you so far with the trailer and the 3.73s?

 

I have the V-10. I have towed this camper up and down he east coast, from Florida to Maine and have been satisfied. MPG was around 7.5- 8.0.
Two years ago I made a trip out to Cooperstown and had a few steep hills to climb, it was a horrible experience, trans and engine temp shot up, engine had to rev like crazy and could not get out of second gear.

 

Thanks for the input. Once I learned more about the Excursions towing capabilities I started to wish I had the 4.30 gears. I believe a swap to 4.30 gears is my only solution.
I guess my next step is to start looking for a good shop to do the work.
Any idea what a gear swap would cost?

 

For a 2wd, you are looking at about $1200.

4wd will run you around $2500

 

It depends on what 285 tire you want. A 285 75 16 is 32.56 inches tall, perfect with 4:30's. A 285 70 17 is 32.8 inches tall, which is what I have and 4:30's are perfect. A 285 75 17 is 33.82 inches tall so I would recommend 4:56's for that combo.

 

Since you are pulling that big heavy TT 75% of the time and you are considering 285 tires (I'm assuming 285/75R16) I would recommend 4.56 gears. That combo will have you just a little deeper than the great 4.30 ratio and will deliver excellent towing performance. For your 25% unloaded miles you will drop maybe 1 MPG or so, I would expect that your towing mileage would increase by the same amount.
I have pulled a 9500lb TH with stock sized tires and 3.73s, 32" tires and 4.88s and 35.28" tires and 4.88s. And now pull an 11K TT with the same 35"s and 4.88s. The 32"/4.88 combo was like a locomotive, but the unloaded MPGs suffered some, lost about 2.5. The towing mileage has gone from the all stock 6 to 7 MPG to 9 with the locomotive combo and now with headers and tunes and the 35"/4.88 combo and 11K TT we are seeing 8 to 9.5 MPG towing. My all stock unloaded mileage was 14-ish and now I'm getting 12.5 on the highway but some of that drop is from the big tires and 4" lift. About 90% of our EX's miles are towing miles these days.
And if you are looking to add a traction adder then the Detroit TrueTrac is the one to get.
I would also recommend that you look into 5Star's custom tunes, I use their 87 and 89 Octane Performance tunes while other guys here towing similar weights like the Tow tunes better, either way they are the second best performance mod after gears you can do for your V-10.

 

Listen to Tom. helped me when i re-geared and i could not be happier.

 

x2

Drove this truck in person recently and could not believe how much power the V10 has when geared the right way.

 

My tire choice is 285 75 16