Hello, a long time since i've been here but I need some quick advice please.
My 2001 F350 has finally given up the ghost (transmission) and I need a new truck soon. I have done some reading on axle ratios and I'm still confused, so I'm turning to the forum in the hopes of getting some advice from fellow ford owners.
My current truck is 5.4L gas engine with 4.10 axle, carrying a 3000lb Bigfoot camper. I occasionally tow a small utility trailer, but nothing more than 800-1000lb with only 100lb tongue weight. I've been very happy with this setup, BUT my truck only has 100,000 miles and the differential had to be rebuilt last month, and now the auto transmission is slipping in 4th gear, and very hard shifts between 1st and 2nd (at the wrong RPM) so I think it's toast (I had it serviced 2 weeks ago and there was metal in the filter).
I'm wondering if maybe the 4.10 puts too much torque on the powertrain, thus why perhaps both differential and tranny are shot after such low mileage? I've seen alot of these trucks with a 3.73 (?) axle and wondering if this might be a better choice.
Even if that were true I think the new offerings with the 6 sp torqueshift transmission will be much better suited. The 5.4L was not exactly a powerhouse either in 2001. (260HP-350 ftlbs torque) One advantage of the 6 speed is that need for low rear gears is no longer applicable. The 6.2L is the current standard on the SuperDuty series and is available in a 3.73 or a 4.30. Either one will seem like a racecar compared to the 2v 5.4L.
ScottG wrote: The 4:10 puts less stress on the power train
X2
I run in a jeeping club. All of us have some sort of gear change. 5.38's are common, 4.88's come in a close second. The bigger the ratio, the less chance you have of breaking a tranny, driveline, ujoints, clutch or torque converter. 3.73 would put the most strain on the parts mentioned. Just put a decent rear-end cooler cover on. That will help keep the gear oil cooler.
Also worth noting, a lot of small gas V8's don't like being under load/towing/haling in overdrive. Some even tell you in the owners manual not to haul in OD. Heats the tranny up, and causes failures. Make sure to get a good tranny cooler on your next rig. Personally, I'd say just fix and upgrade the tranny in that one. Don't just rebuild it. I'm assuming it's paid for....
I have a Jasper Racing tranny called a MonsterBox in my truck. Been a heckuva good tranny, and I beat on the poor thing a lot. but I did get the biggest tranny cooler I could get, a TruCool Max.
yes the truck is fully paid for, with new brakes and new front end suspension last year as well... I'm just thinking that it's bleeding, and getting close to needing new tires as well.
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Thanks so far for the input, much appreciated...
fla-gypsy wrote: Even if that were true I think the new offerings with the 6 sp torqueshift transmission will be much better suited. The 5.4L was not exactly a powerhouse either in 2001. (260HP-350 ftlbs torque) One advantage of the 6 speed is that need for low rear gears is no longer applicable. The 6.2L is the current standard on the SuperDuty series and is available in a 3.73 or a 4.30. Either one will seem like a racecar compared to the 2v 5.4L.
Well said, and saved me a lot of typing.
The first gear of the new 6 speed is a lower ratio, so it is easier on the drivetrain while starting out.
The 4.10:1 drive ratio as noted above is easier for the engine to turn than the 3.73:1 rare ratio, and a 3.35 like used in the F-150 is even higher torque requirement to turn it. But the new Ecoboost engine has 350 foot pounds of torque thanks to it's turbocharger, and does not ping like a carbureted engine might because there is only air going into the cylinders to be compressed, and can not ping until the fuel is introduced at the critical moment before firing off in the power stroke.
I wish they would hurry up and start offering a Ecoboost in the F-250/350 series. Ford seems to be putting them in everything else they make.
So yes you are better off with the new 6 speed and the 3.73 rear axle ratio will work fine as well. Just keep changing that rear axle fluid every 25,000 miles and transmission fluid every 15,000 miles.
fla-gypsy wrote: Even if that were true I think the new offerings with the 6 sp torqueshift transmission will be much better suited. The 5.4L was not exactly a powerhouse either in 2001. (260HP-350 ftlbs torque) One advantage of the 6 speed is that need for low rear gears is no longer applicable. The 6.2L is the current standard on the SuperDuty series and is available in a 3.73 or a 4.30. Either one will seem like a racecar compared to the 2v 5.4L.
Actually you have it backwards.
Check the maximum GCWR for the same truck with the same engine and with 4.10 or 3.73 rear ends. The truck with the 4.10 gearing will be rated 30% higher.
Don't know about Ford but with Chevy the 6-speed trans used with the gas engines has 4 under drive and 2 over drive gear ratios. The 4th gear under drive ratio is not enough to compensate for a 3.73 rear end. However the 5th and 6th gear overdrive gear ratios do compensate for a 4.10 rear end.
The purpose of the gearing is to keep the engine inside its power band as much as possible and with the Ford gas engines maximum torque is at 4500 RPM. Taller gearing means more frequent downshifting while driving with a load.
fla-gypsy wrote: Even if that were true I think the new offerings with the 6 sp torqueshift transmission will be much better suited. The 5.4L was not exactly a powerhouse either in 2001. (260HP-350 ftlbs torque) One advantage of the 6 speed is that need for low rear gears is no longer applicable. The 6.2L is the current standard on the SuperDuty series and is available in a 3.73 or a 4.30. Either one will seem like a racecar compared to the 2v 5.4L.
Actually you have it backwards.
Check the maximum GCWR for the same truck with the same engine and with 4.10 or 3.73 rear ends. The truck with the 4.10 gearing will be rated 30% higher.
Don't know about Ford but with Chevy the 6-speed trans used with the gas engines has 4 under drive and 2 over drive gear ratios. The 4th gear under drive ratio is not enough to compensate for a 3.73 rear end. However the 5th and 6th gear overdrive gear ratios do compensate for a 4.10 rear end.
The purpose of the gearing is to keep the engine inside its power band as much as possible and with the Ford gas engines maximum torque is at 4500 RPM. Taller gearing means more frequent downshifting while driving with a load.
You have misunderstood my reply. We are saying the same thing. By lower, I mean a larger numerical rear gear. The 6 speed transmission has a greater multiplier in the low range and allows for smaller numerical rear gear to acheive the same result. A 3.73 with the 6 speed tranny has greater torque applied to the rear wheels than a 4.10 rear driven by a 4 speed based on the ratios of the current offerings with a 6 speed.
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