Rubiconrod & ATP Pilot - - The running of the bulls is over and the report follows:

I will present some data hopefully in a format that is relevant to you. The pull was 600 miles round trip with the first 150 miles being into a T-storm leading front making the truck push into 20-22mph winds. This truck does NOT like going into a wind more than 5mph regardless if it is empty, towing, or ?? The degree I give (1st column) is from the Truck Apps indicating incline degree. What that relates to as 3:1 etc - I have no idea, but wish someone could advise.

Other info: New oil & FoMo filter - Castrol Edge Full Syn 5W-20. Ambient Temp: 73-81 deg F. Trans Temp: 201 deg F. (while pulling) OEM tires with 33,800 miles on them inflated to 78 lbs rear, 74 lbs front. Air Spring Bags set at 35 lbs. Fifth Wheel Trailer - Same as Rubicon's (color included)

0 deg - 65mph - 6th gear - 2000RPM (only when wind is less than 5mph)
1 deg - 65mph - 5th gear - 2500RPM (majority of my pull time)
2 deg - 60mph - 4th gear - 3000RPM
3 deg - 55mph - 3rd gear - 3500RPM
3 deg - 45mph - 3rd gear - 3000RPM
4 deg - 45mph - 3rd gear - 3000RPM
6 deg - 30mph - 3rd gear - 3000RPM (from a 10mph start - run for approx 1/2 mi)

You can see a pattern here regarding how I drive probably - I'm not in a big hurry, I will NOT pull faster than 65mph, and I don't push the RPMs trying to be 1st to the top.

My observation: 4.30 vs 3.73 gears gave noticeable improvement in gears 1-3 and slight improvement in 4-5th with no change in 6th. When pulling inclines 2-3 degrees it gained 1 gear higher vs 3.73 maintaining speed. The truck struggled less to maintain momentum with 4.30 vs 3.73's. The truck still likes to perform in hills better than on flat land. Gasoline mileage was 8.2 mpg in the Ozarks vs 7.8 mpg on flat ground.

Conclusion: While the truck does pull with greater resolve with 4.30 vs 3.73 gears, the result comes at a price of approx. 0.5 mpg in fuel efficiency. With 3.73 gears, same route, same 5th wheel, same weight; the overall operational efficiency was 8.4 mpg vs 7.9 mpg with 4.30's.

Prefice: After the first 100 miles of the pull I was reminded of what Lou Holtz said after ARK lost to AL years ago. "Our offensive play was absolutely horrible, but to their credit, our defensive team did their best to make them look good."

I was getting that feeling while watching the gas gauge drop faster than the odometer was turning!

Hope this info helps you in some manner. Yes - I'm glad to have the 4.30s. Wish I pulled more so a diesel would be justified. Economics is a terrible realization though.

 

thanks for the update. Keep us posted if you get more info.

I agree about the headwind making a big difference.

Going into a stiff headwind pulling my 5'er last time it dropped into 4th gear while trying to hold 65 mph a couple of times on flat ground.

I can see having a 300 more rpm in 5th gear helping, but I don't know if it is worth the cost.

At 65 mph I'm right at @ 2200 rpm in 5th, 2500 with the 4:30 gears would be a nice boost.

Since I have only a 2wd drive I would only have to do the rear...may consider it after the warranty expires.

 

ATP - With 3.73s this truck would drop into 4th trying to hold 60mph with a head/cross wind on flat lands (SE MO, NE AR). That is one apparent improvement with 4.30s, but jeez I was hoping a gas transporter would throw me a umbilical hose. (not that it was much better with 3.73s) I suspect a 2WD would be some better in that regard.

What gas mileage do you see pulling your '15 Wildcat on flat at 65mph?

Without dyno proof, it seems to me my particular truck does not perform much better over 3k RPMs than it does at 4k RPMs. I've read numerous threads with people saying things like, "these trucks perform their best when the engine is turning 4000-4500 RPMs because that's where the HP is produced." uhhh.... I'm interested in torque to the ground in gears 1-3, and then I'm interested in what it costs to run the truck at 55-65mph pulling a load for extended period of time.

My truck will make tons of noise (for a while) at 4500 RPMs, burn a lot of gas, and the only thing accomplished is getting my wallet thinner. - ok - I'm old now. (I may grow up one day). Point is - I'm interested in a solid engine/trans that is steady, low maintenance, and doesn't hold up traffic.

Hope you have a wonderful day.

 

Thanks for reporting back. Based on your results it would appear I would not be 100% satisfied after getting the gears done. I think I may go to the local dealership and see what kind of deal I could get on a diesel. I know one of the local dealerships has a 2014 with only 10k miles on it...

 

Haven't done a full tank pulling yet, to get a good average.

Just going by my ScanGauge, which is pretty close...with no wind:

8 mpg at 65
8.5 mpg at 60

only a little less than I got with my old 6000 lb Travel trailer.

 

ATP - that's right where my truck was before the gear swap. Thanks.
Hope you didn't get blown away last night in the storms. We're good up here.

 

Follow up...

775 mile round trip hand calculated 8.0 mpg at 65 mph using manual mode in hills switching between 4-5th gear.

Several trips now and including the last one up I55 with a few hills, I can report happy with no issues with my combo. (trailer weights 12,000 lb loaded)

I do feel using manual helps with my towing experience, using 4th and 5th in the hills kept the speed easly above 60 mph. If I let the auto do the work it would drop to 3rd when not really needed.

Now the steepest grade I faced so far, was the I10 bridge going over the Mississippi in Baton Rouge, Pulled up the bridge in 3rd with plenty of power left at 60 mph.

Off the line 1st is plenty low enough with the 3.73 rear due to the low first gear in the 6-speed auto.

Top speed 65 mph, but can easly go over 70 mph to pass when needed, even when locked in 5th manual without down shifting.

 

ATP - Thanks for the update. Sounds like you are doing well with the 3.73 gears and have found the right way to pull with it. I know the I55 stretch you referenced as well as the I10 bridge at BR. Haven't been back in the area for a while, but worked in the area for a few months after Katrina.

The hills I pull in are a bit steeper than that and have found the 4.30 gears do better than the 3.73 gears for me, but it's still not a diesel - and that's ok! Hope you have many enjoyable trips with your rig.

 

I know this is an old thread but I wanted to correct one of the part numbers listed in case anyone else needs them.

Rear: Part number BC3Z42095 is actually Rear: Part number BC3Z4209J

Prices seem to be a bit lower too.

Part Number: DC3Z-3222-C = $300.39
Part Number: BC3Z-4209-J = $389.21

 

Excellent catch Ray. The tech that wrote the number down must have slipped a 5 for the J. Today's price shown by Ford is $516.20 also.

Have a great day. I'm still happy with the conversion.
RK

 

Just for info, the prices I listed are from the oemfordpart website.

I'm glad to hear you're still happy with the conversion. I am looking to do this conversion too.

I pulled an enclosed 7X12 trailer packed with hunting gear and provisions for 4 hunters. We pulled out of NE Florida and headed up to Melvern Lake Kansas to bow hunt. We left there and drove over to NW Nebraska to rifle hunt. Needless to say, the 3.73 gears struggled with the slightest incline, even overpasses. The constant shifting was very annoying to the guys trying to sleep. I believe the 4.30 gears would have allowed the truck to stay in the same gear longer. This might have reduced the number of times it shifted on the smaller inclines.

 

did you try locking out 6th gear? also trying using manual 5th it will hold 5th over overpasses without all the shifting. Give it a try next time.