4.10's Installed
Record Breaker
Joined: Feb 2009
Posts: 1,661
Likes: 1
From: Virginia Beach
What sucks is that gears and diffs are impossible to do correctly without the right tools. Even still, I would not want to try it for the first time on my truck. Gears are something I would pay to get installed.
Rookie
Joined: Mar 2009
Posts: 69
Likes: 0
From: Upstate NY
DON'T FEAR THE GEAR boys!!! Not to knock anyone, to each their own, but I don't see the point in changing from 3.92's to 4.10's? The change is so minimal, it doesn't seem worth it, when you factor in the cost. Now, 3.55 to 4.10 I can see; it still blows my mind that all these dealers are ordering these trucks with 20's and 3.55 open diffs... This is going to take a while, so bear with me and hold on tight!
I have quite a bit of experience with gear changes, as I've run 3 different gears in my '05. Stock was 3.92, I went to 4.88 (screwed up big time, as they don't make 4.88's for the 8" IFS
), now I am 4.56. I'm also running 275/55/20s (32 inch dia) and 265/70/17s (31.6") in the winter. Here is the real data with my 32's; I also have this all in a spreadsheet and graphs if anyone wants it:In top gear, the difference from 3.92 to 4.56 is 500 rpm; from 3.92 to 4.88 its around 700 rpm. I actually like the 4.56 better than the 4.88, as the 4.88 was tachin out a bit. If I remember correctly, with the 33" 20's, you were right around 2000 rpm @ 80mph, and 1750 or so at 70mph. The 500 rpm increase is just what the doctor ordered with the previous generation Hemis; now with the VCT, the need might not be as great, but the non VCTs need more RPM.
So, if 0.60 of gear gains you 500 rpm, 0.2 (3.92 to 4.10) gets you around 170 rpm in top gear, is it worth it? The difference is even less in the lower gears, as proven by the math and graphs.
My biggest beef is that the 545RFE should be a 645RFE by now, then you could run your 3.92s or 3.55's better. 1st and 2nd gears are way too deep at 3.00 and 1.67; in a 6 speed they should be 3.67, 2.33 etc, as they have 4 gears before the 2 O/Ds instead of the 3 gears now. This gear deficiency is very noticable when towing, as my truck was a dog, but is much better now. When empty and hot rodding, it isn't as critical.
The biggest problem is that you with a good highway gear (3.92), you are asking the engine to pull to 45mph+ at redline in 1st and 75mph+ in 2nd. Even when driving normal, it doesn't shift out of 2nd till 45mph, then into 3rd for 5mph and then thru the 2 O/Ds. So basically you are using 1st, 2nd and 5th. With the 4.56's, you are actually using 3rd gear much more, so it acts like a true 1-2-3 -4/5 tranny! With towing, it is much more pleasureable, particularly that you can lock into 4th for 2500 rpm at 65 or 5th at 2200 rpm.
The downsides to the 4.56:
-1 mpg loss on average;
-when hot rodding, the truck feels faster with the 3.92s, as the engine has enough nutt to pull 1st to 45 and 2nd to redline.
-Cost: per axle: $240 or so for the gear set, $150 or so for the bearings, crush collars etc. Lots of labor, 4-8 hours per axle.
With the new "range select" function on the tranny, the truck is probably much more driveable than the old ones, as you can lock into the gear you want, instead of hunting around. Y
To you guys talking about only using 4.56s on 35"+ tires, you should drive my truck with the little 32's... Don't fear the gear (add your own word here)...
Record Breaker
Joined: Feb 2009
Posts: 1,661
Likes: 1
From: Virginia Beach
DON'T FEAR THE GEAR boys!!! Not to knock anyone, to each their own, but I don't see the point in changing from 3.92's to 4.10's? The change is so minimal, it doesn't seem worth it, when you factor in the cost. Now, 3.55 to 4.10 I can see; it still blows my mind that all these dealers are ordering these trucks with 20's and 3.55 open diffs... This is going to take a while, so bear with me and hold on tight!
I have quite a bit of experience with gear changes, as I've run 3 different gears in my '05. Stock was 3.92, I went to 4.88 (screwed up big time, as they don't make 4.88's for the 8" IFS), now I am 4.56. I'm also running 275/55/20s (32 inch dia) and 265/70/17s (31.6") in the winter. Here is the real data with my 32's; I also have this all in a spreadsheet and graphs if anyone wants it:
In top gear, the difference from 3.92 to 4.56 is 500 rpm; from 3.92 to 4.88 its around 700 rpm. I actually like the 4.56 better than the 4.88, as the 4.88 was tachin out a bit. If I remember correctly, with the 33" 20's, you were right around 2000 rpm @ 80mph, and 1750 or so at 70mph. The 500 rpm increase is just what the doctor ordered with the previous generation Hemis; now with the VCT, the need might not be as great, but the non VCTs need more RPM.
So, if 0.60 of gear gains you 500 rpm, 0.2 (3.92 to 4.10) gets you around 170 rpm in top gear, is it worth it? The difference is even less in the lower gears, as proven by the math and graphs.
My biggest beef is that the 545RFE should be a 645RFE by now, then you could run your 3.92s or 3.55's better. 1st and 2nd gears are way too deep at 3.00 and 1.67; in a 6 speed they should be 3.67, 2.33 etc, as they have 4 gears before the 2 O/Ds instead of the 3 gears now. This gear deficiency is very noticable when towing, as my truck was a dog, but is much better now. When empty and hot rodding, it isn't as critical.
The biggest problem is that you with a good highway gear (3.92), you are asking the engine to pull to 45mph+ at redline in 1st and 75mph+ in 2nd. Even when driving normal, it doesn't shift out of 2nd till 45mph, then into 3rd for 5mph and then thru the 2 O/Ds. So basically you are using 1st, 2nd and 5th. With the 4.56's, you are actually using 3rd gear much more, so it acts like a true 1-2-3 -4/5 tranny! With towing, it is much more pleasureable, particularly that you can lock into 4th for 2500 rpm at 65 or 5th at 2200 rpm.
The downsides to the 4.56:
-1 mpg loss on average;
-when hot rodding, the truck feels faster with the 3.92s, as the engine has enough nutt to pull 1st to 45 and 2nd to redline.
-Cost: per axle: $240 or so for the gear set, $150 or so for the bearings, crush collars etc. Lots of labor, 4-8 hours per axle.
With the new "range select" function on the tranny, the truck is probably much more driveable than the old ones, as you can lock into the gear you want, instead of hunting around. Y
To you guys talking about only using 4.56s on 35"+ tires, you should drive my truck with the little 32's... Don't fear the gear (add your own word here)...
I have quite a bit of experience with gear changes, as I've run 3 different gears in my '05. Stock was 3.92, I went to 4.88 (screwed up big time, as they don't make 4.88's for the 8" IFS
), now I am 4.56. I'm also running 275/55/20s (32 inch dia) and 265/70/17s (31.6") in the winter. Here is the real data with my 32's; I also have this all in a spreadsheet and graphs if anyone wants it:In top gear, the difference from 3.92 to 4.56 is 500 rpm; from 3.92 to 4.88 its around 700 rpm. I actually like the 4.56 better than the 4.88, as the 4.88 was tachin out a bit. If I remember correctly, with the 33" 20's, you were right around 2000 rpm @ 80mph, and 1750 or so at 70mph. The 500 rpm increase is just what the doctor ordered with the previous generation Hemis; now with the VCT, the need might not be as great, but the non VCTs need more RPM.
So, if 0.60 of gear gains you 500 rpm, 0.2 (3.92 to 4.10) gets you around 170 rpm in top gear, is it worth it? The difference is even less in the lower gears, as proven by the math and graphs.
My biggest beef is that the 545RFE should be a 645RFE by now, then you could run your 3.92s or 3.55's better. 1st and 2nd gears are way too deep at 3.00 and 1.67; in a 6 speed they should be 3.67, 2.33 etc, as they have 4 gears before the 2 O/Ds instead of the 3 gears now. This gear deficiency is very noticable when towing, as my truck was a dog, but is much better now. When empty and hot rodding, it isn't as critical.
The biggest problem is that you with a good highway gear (3.92), you are asking the engine to pull to 45mph+ at redline in 1st and 75mph+ in 2nd. Even when driving normal, it doesn't shift out of 2nd till 45mph, then into 3rd for 5mph and then thru the 2 O/Ds. So basically you are using 1st, 2nd and 5th. With the 4.56's, you are actually using 3rd gear much more, so it acts like a true 1-2-3 -4/5 tranny! With towing, it is much more pleasureable, particularly that you can lock into 4th for 2500 rpm at 65 or 5th at 2200 rpm.
The downsides to the 4.56:
-1 mpg loss on average;
-when hot rodding, the truck feels faster with the 3.92s, as the engine has enough nutt to pull 1st to 45 and 2nd to redline.
-Cost: per axle: $240 or so for the gear set, $150 or so for the bearings, crush collars etc. Lots of labor, 4-8 hours per axle.
With the new "range select" function on the tranny, the truck is probably much more driveable than the old ones, as you can lock into the gear you want, instead of hunting around. Y
To you guys talking about only using 4.56s on 35"+ tires, you should drive my truck with the little 32's... Don't fear the gear (add your own word here)...
I am not changing anything on my truck, I just like the knowledge.
Veteran
Joined: Mar 2009
Posts: 298
Likes: 0
I agree. What is the point of changing from 3.92 to 4.10? And can you even tell the difference afterwards? I changed from 3.73 to 4.10 on a Chevy 1500 several years ago, and was seriously disappointed afterwards, because it made such a miniscule difference. It was just BARELY noticeable. I can't even see how you can feel the difference at all when going from 3.92 to 4.10. Maybe you can see a few hundred RPM difference at 80 mph, but thats about it.
I also would not use 4.56 gears with 37" tires, as was suggested earlier in this thread. Your truck is going to be geared way too high for highway use with that high of a gear and that tire size. Here is a picture of my Jeep at 70 mph. It has 4.88 gears, 37" tires, and the stock 4 speed OD automatic transmission.
And the overdrive transmission on our Ram trucks has an even taller overdrive than the Jeep does, so it would do better with even lower gears. The Jeep should have at least 5.13s with its 37" tires, and that is what I would recommend for a Ram truck as well. Those are big tires, and they need low gears.
I think its great that Bounty Hunter got the 4.10 gears for free, and that a friend did the install for him. Hell yes, if I had that kind of a deal I would snag it up in a hurry. The 4.10 gears are definitely going to help, by a very small amount. But for people that are paying retail for a gear swap, make the gear change enough that you are going to notice a difference. Just my .02.
MOPWR2U
I also would not use 4.56 gears with 37" tires, as was suggested earlier in this thread. Your truck is going to be geared way too high for highway use with that high of a gear and that tire size. Here is a picture of my Jeep at 70 mph. It has 4.88 gears, 37" tires, and the stock 4 speed OD automatic transmission.
And the overdrive transmission on our Ram trucks has an even taller overdrive than the Jeep does, so it would do better with even lower gears. The Jeep should have at least 5.13s with its 37" tires, and that is what I would recommend for a Ram truck as well. Those are big tires, and they need low gears.
I think its great that Bounty Hunter got the 4.10 gears for free, and that a friend did the install for him. Hell yes, if I had that kind of a deal I would snag it up in a hurry. The 4.10 gears are definitely going to help, by a very small amount. But for people that are paying retail for a gear swap, make the gear change enough that you are going to notice a difference. Just my .02.
MOPWR2U
Record Breaker
Joined: Feb 2009
Posts: 1,661
Likes: 1
From: Virginia Beach
This thread is making the decision to stick with the stock tires easier.
Figure 1000$ for new wheels, if they are cheaper ones.
1400$ for gears, bearing, etc and install front and rear.
1000$ for tires, if they are for 17 inch wheels.
3400+$ for looks? Not for me then. I will stay stock. I have no plans to off road nor do I need the look. Granted, if I had extra money to blow, sure, but right now the are 100 other things I could do with 3400$.
I think the 3.92's are just fine with the stock tires. I will make another judgment after I do some towing. I had 3.55's in my 2005 and pulled a 3000lb trailer up and down hills on a back road in Iowa and had no problems with pulling. I also had about 1000 lbs in the bed. The only problem I had was the brakes, but that is another issue. On that trip towing I got around 12 mpg, from New Jersey to Iowa.
What about warranty issues with bigger tires and gear swaps?
Figure 1000$ for new wheels, if they are cheaper ones.
1400$ for gears, bearing, etc and install front and rear.
1000$ for tires, if they are for 17 inch wheels.
3400+$ for looks? Not for me then. I will stay stock. I have no plans to off road nor do I need the look. Granted, if I had extra money to blow, sure, but right now the are 100 other things I could do with 3400$.
I think the 3.92's are just fine with the stock tires. I will make another judgment after I do some towing. I had 3.55's in my 2005 and pulled a 3000lb trailer up and down hills on a back road in Iowa and had no problems with pulling. I also had about 1000 lbs in the bed. The only problem I had was the brakes, but that is another issue. On that trip towing I got around 12 mpg, from New Jersey to Iowa.
What about warranty issues with bigger tires and gear swaps?