3.31 gears at 40,000 lbs gross.

mkirsch wrote:


No confusion about it.

A taller rear gear keeps you out of the overdrive gears when towing, so you are not burning up the overdrive clutches. You use the overdrive gears for cruising empty.

There is no law saying you HAVE to use every gear in the transmission. That's old 3-speed thinking. Remember in those days you topped out at 1:1. There was no such thing as overdrive.

Modern trucks have the horsepower and plenty of gears in the transmission to accommodate taller gear ratios.

But hey, if you want to redline at 5MPH in 1st gear, and turn 2500RPMs at 65MPH in 10th, by all means, get a set of 4.30 or 4.56 gears

Not exactly. You have to cut gears when you have a tall rear gear ratio leaving with fewer gear options when going up hills versus not having to cut gears with a shorter ratio leaving you with more gear options. Since shorter rear gear ratios put less of a strain on the trans, you can tow in the higher trans gears giving your more gears available for when the load gets harder like going up hills.

In the case of the OP, he has three overdrive gears and is still using the overdrive clutch hub in 8th since it is still an overdrive gear. He would have to drop in into 7th at around 2k rpm to get out of the over-drive clutches. For my 6-speed which has 2 overdrive gears, I would have to drop down to 4th to get out of overdrive putting me over 2,200 rpm at 65 mph. Since the shorter rear gear puts less stress on the overdrive clutches, you can use them in more situations when towing versus taller gears without putting as much stress on the trans.

BTW, didn't watch the video until just now. Love the Ford dash setup!
But what stood out was it appears that either 9th or 10th gear is effectively useless at the speed you were driving (about 63-64mph).
Less than 100rpm split between gears at almost "highway" speeds doesn't really have nay practical benefit IMO. That calcs to about a 200rpm split at around 80mph, still not enough to write home about except to say you have the "most" gears!

I'm not one to bash on the "more is better" theory when it comes to trans gears, but unless there is a benefit down lower in the ratios somewhere that the 10th gear could have a greater benefit, seems like 9, or even 8 speeds is about all that is practical for a light duty diesel truck.

And in other news, your 34" tires have about a 33" effective rolling diameter. Based on a known final drive ratio, known trans gear ratios and the rpms and speed observed in the video. Not that it matters, just an observation.
Common thing really. My "37s" roll at approx effective diameter of 35" and the half worn "35s" I have on another truck roll closer to 33" (with low/no load, "comfortable" pressure in the tires for both trucks).

Ole 4x, the eternal antagonist....
Shiner, you realize you’d have better luck explaining it to your desk, the water cooler or some other inanimate object.
4x understands exactly what you’re saying and likely agrees with you, because he’s that smart. but there would be no fun or back and forth dissertation if he didn’t just keep on feigning ignorance....

ShinerBock wrote:

4x4ord wrote:

ShinerBock wrote:

4x4ord wrote:

Lynnmor wrote:
Obviously some don't care, but hopefully an intelligent discussion won't use the who cares attitude. Some want the best for their equipment, there is no need to talk down to them.

I wouldn’t say “who cares?” But I think it is an honest question to say “why would a person care?” Will the Ford driveline last longer transmitting 200 hp at 2400 rpm than it will transmitting 200 hp at 2000 rpm?

Yes, the transmission will have a much greater chance of lasting with shorter gears. Just about every 6R140 through our nine Ford dealerships with burnt or grenaded overdrive clutches was with a taller gear ratio and/or heavy oversized tires.

If what you’re saying means anything it would lead me to wanting 3.31s in an f450. You need to think about what you just wrote.

Shorter gear ratio = higher numerical number. Taller rear gear = smaller numerical number. This is the basics of truck ownership(especially if you own HD trucks) and I am not sure how you are getting confused.

No confusion about it.

A taller rear gear keeps you out of the overdrive gears when towing, so you are not burning up the overdrive clutches. You use the overdrive gears for cruising empty.

There is no law saying you HAVE to use every gear in the transmission. That's old 3-speed thinking. Remember in those days you topped out at 1:1. There was no such thing as overdrive.

Modern trucks have the horsepower and plenty of gears in the transmission to accommodate taller gear ratios.

But hey, if you want to redline at 5MPH in 1st gear, and turn 2500RPMs at 65MPH in 10th, by all means, get a set of 4.30 or 4.56 gears

4x4ord wrote:

ShinerBock wrote:

4x4ord wrote:

Lynnmor wrote:
Obviously some don't care, but hopefully an intelligent discussion won't use the who cares attitude. Some want the best for their equipment, there is no need to talk down to them.

I wouldn’t say “who cares?” But I think it is an honest question to say “why would a person care?” Will the Ford driveline last longer transmitting 200 hp at 2400 rpm than it will transmitting 200 hp at 2000 rpm?

Yes, the transmission will have a much greater chance of lasting with shorter gears. Just about every 6R140 through our nine Ford dealerships with burnt or grenaded overdrive clutches was with a taller gear ratio and/or heavy oversized tires.

If what you’re saying means anything it would lead me to wanting 3.31s in an f450. You need to think about what you just wrote.

Shorter gear ratio = higher numerical number. Taller rear gear = smaller numerical number. This is the basics of truck ownership(especially if you own HD trucks) and I am not sure how you are getting confused.

ShinerBock wrote:

4x4ord wrote:

Lynnmor wrote:
Obviously some don't care, but hopefully an intelligent discussion won't use the who cares attitude. Some want the best for their equipment, there is no need to talk down to them.

I wouldn’t say “who cares?” But I think it is an honest question to say “why would a person care?” Will the Ford driveline last longer transmitting 200 hp at 2400 rpm than it will transmitting 200 hp at 2000 rpm?

Yes, the transmission will have a much greater chance of lasting with shorter gears. Just about every 6R140 through our nine Ford dealerships with burnt or grenaded overdrive clutches was with a taller gear ratio and/or heavy oversized tires.

If what you’re saying means anything it would lead me to wanting 3.31s in an f450. You need to think about what you just wrote.

4x4ord wrote:

Lynnmor wrote:
Obviously some don't care, but hopefully an intelligent discussion won't use the who cares attitude. Some want the best for their equipment, there is no need to talk down to them.

I wouldn’t say “who cares?” But I think it is an honest question to say “why would a person care?” Will the Ford driveline last longer transmitting 200 hp at 2400 rpm than it will transmitting 200 hp at 2000 rpm?

Yes, the transmission will have a much greater chance of lasting with shorter gears. Just about every 6R140 through our nine Ford dealerships with burnt or grenaded overdrive clutches was with a taller gear ratio and/or heavy oversized tires. The same goes with our fleet which is why we don't put tall gearing on the trucks that haul or tow often. The instances of failure are even greater on the oil field repair trucks that we have to put heavier mud tires on.

Most u-joints can handle the abuse, but the trans cannot and it is better to get a shorter rear gear if you are towing that heavy on a frequent basis. There is a reason why shorter gears can tow more and it isn't just because of higher rpm or torque multiplication. It also has a lot to do with driveline stress and longevity when towing heavy. It probably isn't going to affect you because you don't keep your truck that long, but it might affect the next owner.

The high level of stress on the driveline occurs at low speeds in first gear, especially when my trailer is on soft ground and I’m trying to get going in 4wd . My 2011 had much less torque and way less gear multiplication yet a much better “feel”. With my 2011 I could put the truck in gear hooked to this same load and touch the throttle and in no time the torque converter “hooked” up and the engine felt connected to the wheels. As the Powerstroke has gained torque over the years the engineers seem to be more and more concerned about protecting the driveline. To get this trailer moving in soft ground the torque converter never seems to lock up. The engine revs to 1500 rpm before the truck starts moving and even once underway it feels like the crankshaft is twisting a big rubber band.

4x4ord wrote:

Lynnmor wrote:
Obviously some don't care, but hopefully an intelligent discussion won't use the who cares attitude. Some want the best for their equipment, there is no need to talk down to them.

I wouldn’t say “who cares?” But I think it is an honest question to say “why would a person care?” Will the Ford driveline last longer transmitting 200 hp at 2400 rpm than it will transmitting 200 hp at 2000 rpm?

The fact that many are saying who cares, shows they do not understand what’s going on in a transmission with different rear end gearing. And because of that, trying to explain it would be like me explaining it to my wife. She would just never get it.

Lynnmor wrote:
Obviously some don't care, but hopefully an intelligent discussion won't use the who cares attitude. Some want the best for their equipment, there is no need to talk down to them.

I wouldn’t say “who cares?” But I think it is an honest question to say “why would a person care?” Will the Ford driveline last longer transmitting 200 hp at 2400 rpm than it will transmitting 200 hp at 2000 rpm?