I have a 2003 F250 SC Superduty V10 with 4R100 transmission and 3.73 gears, 83,000 miles, owned since new. I towed my race car with an open trailer and my nearest track is 88 miles one way. With the open trailer I'll towed to the gate of the track and will comsume only a 1/4 of a tank and I can cruise at 70-75 easy. Now I owe a new trailer, is an enclosed V nose 24ft dual 5200lbs axles etc. I went to the same track, it take a bit to get moving and them gears (3.73) makes it feel like the motor is working harder to get up hills etc. I take it off the over drive for hills and slight hills in the higway. I can get it to tow in overdrive at 65mph with cross wins etc. When I got to the track it consume half a tank. By my calculations this joker gave me 6.65 mph to the galon!!! I don't like it how it tows it does not have the hump like when I tow it with the open trailer due to is lighter and less win to deal with. I installed air bags to help not to sag at the back.

I went to Randy's ring and pinion and did the calculation with the OEM tires etc and compare it to 4.30 gears. The results are that with 4.30 gears and .071 overdrive it will cruise on 70mph at 2240 which I think is not bad. Anyone here has the same truck and tranny and 4.30? How does it ride? I just hate this going up hills and have to drop gear to 3rd and sometime to second. Any info I'll apprecited. By the way I search this but all I can find was 4.30 with 5 and 6 speed.


Edgar

 

Plz delete wrong room

 

I was told that this is the room to put this in V10 forum, so where do I post this at??

Edgar

 

You are in the correct place Edgar. You have a V10, so you posted on the V10 forum. All good.

Anyway there's a big weight and wind difference between open and enclosed trailers so I'm not surprised by the lower performance.
Realistically you should be driving slower speeds: it's easier on your truck and trailer, it's safer, and if you get the right gear/rpm you can probably improve your MPG.

But if you're dead set on changing rear end gears and running high speed in overdrive through hills and wind, then I'll stop now and let other guys advise you.

Good luck.

 

Is not that I want to go higher speeds, I have to get up there so I can cruise at 65mph, if I drive at 65mph or 60 then the truck slows more and doing 50mph and a slight hill then it starts hunting gears. I just want to drive without worring flooring the pedal to get it to run 60-65mph and it burns fuel like there is no end. If gears keep me from flooring the truck and easier to the motor and drive train then the gear swap is the ticket. Thank for the advice.

Edgar

 

I think you will be pleasantly surprised with 4.30 gears, it's a good combination when you have a 2V V10 with a 4 speed transmission. I owned two 2V F350 V10s with 4.30 gears.

Denny

 

with the stock tires 4.30's are the ticket. The V10 loves to rev. Headers will help here too. I had a 99 with a complete Borla system(I really wish they made headers again) with 430s and it was much peppier than my 02 with 3.73's.

 

I totally agree with these guys!
We bought our V-10 EX to pull travel trailers, 9500 lb toyhauler first now an 11000 lb 41' TT. EX had 3.73s gears originally and it suffered on any amount of uphill pull, always dropping out of OD and killing the MPGS. I first installed a set of Banks headers, they gave a nice seat of the pants performance boost across thE entire RPM range and +1 or so MPG. Here is a comparison between the factory exhaust manifold and the Banks headers, which one do think breathes better?


The factory Y pipe is also kind of restrictive too, the new one that came with the Banks kit looks a little better.


Next I swapped in 4.88 gears, WOW! Pulled like a locomotive with stock sized tires. Now it would hold onto OD on all but the bigger hills and that really pushed the MPGs up. Over the same route, pulling same trailer, same weight at the same speeds (60-63 MPH) with the 3.73s we averaged 6.5 to 7 MPG, with the 4.88s and headers we saw 9.0 MPG mostly due to being able to hold OD better at the higher RPMs and power at that point.
Tire change came next, went from the stock 31.5" to 35.25" highway treads. This dropped the effective ratio down to 4.39, pretty close to the "ideal" V-10 tow ratio os 4.30. I knew I was going to 35"s that's why I went to the 4.88s.
The taller tires dropped the towing mileage down about .5 MPG.
Custom tunes from 5Star Tuning came next, I went with the 87 Octane Econo, Tow and Performance as well as 89 Octane Tow and Perf. After some experimentation I have found that my style of driving and how I like to tow that the Perf tunes work better for me than the Tow tunes do, personal preference. The trans tuning really improves the drivability and I have found the Perf tunes allow it to hold onto OD much longer on uphill climbs without lugging the motor, makes me a very happy camper!
Now with all of the above changes and pulling our new 11k TT using the 87 Perf tunes we have regularly gotten 9.0 MPG and with the 89 Perf tune have seen 9.25 MPG.
I'm very pleased with my current situation, the new TT is 10' longer and 1500 lbs heavier. The EX is lifted 4" over where I started, went from 31.5" 265 tires up to 35.25" 305 s, 3.73 gears to 4.88s, now running tunes AND we are enjoying a 30%+ towing MPG increase. Lovin my V-10!

 

Hi there guys. Well the combine weight including the truck loaded top off with fuel etc and trailer loaded is 14,085 lbs (3.73:1). I have not been able to order the gears yet due to the fact is a bit confusing. My truck is a 2003 Super Duty SC V10 two wheel drive with the stock height tires. Everyone recommends the Yukon Gears, but here is the deal. Is the rear end on my truck a 10.25 or a 10.50 rear end. If I input this in summit it says 10.25, if I go to Randy's site and input the info it says it is a 10.50 but if I input the 10.25 it says it is for 1999 and below, so which one is it. Can anyone direct me to the right gear to choose. I'm going with the 4.30:1. Thanks for any info:


Edgar

 

My 01 is 10.5. I went with 4:30 gears to replace my 3:73's. and made a world of difference. My truck and 5th wheel is approx. 18,500 lbs. Used the gears from Randy's Ring and Pinion and made sure I got the bigger pinion bearing for the 10.5. I would call them and ask them what you need.

 

The rear end is a 10.50 but you can use either the 10.25 or the 10.50 gear set, you just need the appropriate install kit.

 

So I can't use the same bearings that are on the truck right now. Meaning just change pinion and the gear or is it that the pinion bearing is different from one each other. Thanks for the response:

Edgar

 

The pinion shaft is smaller on the 10.25 and they use a different pinion bearing. Stick with the bigger pinion shaft used on the 10.5

 

I understood the smaller pinion gave you a bigger bearing which led me to believe the 10.25 wouldn't be a bad idea ( or some such reasoning that made sense at the time ) , that and the LSD unit was much cheaper, i went along with what my gear guys suggested and no trouble thus far.

You'll like the gears after you get over the cost , for that matter, same goes for the headers and tuner, they work well together

 

Yes....bigger pinion bearing on the 10.25 shaft......I stayed with the bigger pinion shaft for the 10.5 because of my towing.