Lets talk gears for a second.
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Joined: Jul 2007
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From: South Georgia/East Florida
If you stay with current trans setup, go with 4.10 gears, if you go to a 545rfe then the extra OD will give you good mileage on the highway and I'd go all the way to 4.56s...
Professional
Joined: Nov 2012
Posts: 187
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From: Michigan
I have an 02 4.7 with the 3.92's and I updated the trans to a 5 speed, no trip to the dealer needed. If you want the 5 speed update go snag a TCM from a 2002 grand cherokee 4.7 and it will bolt into your truck and give you the magical 5th gear. If your serious about it I'll get the part number off of mine so you get the right one.
Before you go and start swapping gears are you sure its not your driving style? Using cruise control on anything other than flat highway is just plain brutal on these trucks, even more so after the TCM swap. When your on the highway and it needs more power the first step is unlocking the torque converter, if that isnt enough the truck will shift into 3rd gear. For you thats only one gear, not a big deal, but on my truck the trans skips 4th gear and goes right to 3rd. Its a bit of a jump and very noticeable.
I do a ton of highway driving, if you use cruise control all the time you are much better trying it without. With a little common sense and a steady foot you can make it up some pretty big hills while maintaining speed and getting better gas mileage over the course of the trip too. If you know you wont make it up without a lot more power push the OD off button, it makes the transition much smoother, especially when towing. Pushing OD off will also lock the torque converter in 3rd gear which is much better for gas mileage and trans temps.
You mentioned being used mostly for work and hauling, if you are on hilly highways or towing heavy loads keep your trans the way it is. If changing driving habits isn't enough you might have to re-gear, the 3.92's get the job done for me but if I hauled more I would go with 4.10's or 4.56's.
When I tow my snowmobiles on long trips I put in the stock TCM to return my trans to a 4 speed and bring up the rpm's in overdrive. This does help with cruising and small hills, I can maintain speed easily on flat ground and with a careful right foot I can keep it in overdrive on most hills. On larger hills or with heavier loads you will need to spend a lot of time with OD off, which isn't a bad thing.
If you have any more questions let me know.
P.S. There is a little trick for 02 4.7 owners and early 03 owners to make the trans shift a little harder on heavy throttle, its a lot more fun than the soggy stock shifts and hasn't caused me any trouble in 10,000 miles.
Before you go and start swapping gears are you sure its not your driving style? Using cruise control on anything other than flat highway is just plain brutal on these trucks, even more so after the TCM swap. When your on the highway and it needs more power the first step is unlocking the torque converter, if that isnt enough the truck will shift into 3rd gear. For you thats only one gear, not a big deal, but on my truck the trans skips 4th gear and goes right to 3rd. Its a bit of a jump and very noticeable.
I do a ton of highway driving, if you use cruise control all the time you are much better trying it without. With a little common sense and a steady foot you can make it up some pretty big hills while maintaining speed and getting better gas mileage over the course of the trip too. If you know you wont make it up without a lot more power push the OD off button, it makes the transition much smoother, especially when towing. Pushing OD off will also lock the torque converter in 3rd gear which is much better for gas mileage and trans temps.
You mentioned being used mostly for work and hauling, if you are on hilly highways or towing heavy loads keep your trans the way it is. If changing driving habits isn't enough you might have to re-gear, the 3.92's get the job done for me but if I hauled more I would go with 4.10's or 4.56's.
When I tow my snowmobiles on long trips I put in the stock TCM to return my trans to a 4 speed and bring up the rpm's in overdrive. This does help with cruising and small hills, I can maintain speed easily on flat ground and with a careful right foot I can keep it in overdrive on most hills. On larger hills or with heavier loads you will need to spend a lot of time with OD off, which isn't a bad thing.
If you have any more questions let me know.
P.S. There is a little trick for 02 4.7 owners and early 03 owners to make the trans shift a little harder on heavy throttle, its a lot more fun than the soggy stock shifts and hasn't caused me any trouble in 10,000 miles.
Thread Starter
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All Star
Joined: Dec 2012
Posts: 895
Likes: 56
I have an 02 4.7 with the 3.92's and I updated the trans to a 5 speed, no trip to the dealer needed. If you want the 5 speed update go snag a TCM from a 2002 grand cherokee 4.7 and it will bolt into your truck and give you the magical 5th gear. If your serious about it I'll get the part number off of mine so you get the right one.
Before you go and start swapping gears are you sure its not your driving style? Using cruise control on anything other than flat highway is just plain brutal on these trucks, even more so after the TCM swap. When your on the highway and it needs more power the first step is unlocking the torque converter, if that isnt enough the truck will shift into 3rd gear. For you thats only one gear, not a big deal, but on my truck the trans skips 4th gear and goes right to 3rd. Its a bit of a jump and very noticeable.
I do a ton of highway driving, if you use cruise control all the time you are much better trying it without. With a little common sense and a steady foot you can make it up some pretty big hills while maintaining speed and getting better gas mileage over the course of the trip too. If you know you wont make it up without a lot more power push the OD off button, it makes the transition much smoother, especially when towing. Pushing OD off will also lock the torque converter in 3rd gear which is much better for gas mileage and trans temps.
You mentioned being used mostly for work and hauling, if you are on hilly highways or towing heavy loads keep your trans the way it is. If changing driving habits isn't enough you might have to re-gear, the 3.92's get the job done for me but if I hauled more I would go with 4.10's or 4.56's.
When I tow my snowmobiles on long trips I put in the stock TCM to return my trans to a 4 speed and bring up the rpm's in overdrive. This does help with cruising and small hills, I can maintain speed easily on flat ground and with a careful right foot I can keep it in overdrive on most hills. On larger hills or with heavier loads you will need to spend a lot of time with OD off, which isn't a bad thing.
If you have any more questions let me know.
P.S. There is a little trick for 02 4.7 owners and early 03 owners to make the trans shift a little harder on heavy throttle, its a lot more fun than the soggy stock shifts and hasn't caused me any trouble in 10,000 miles.
Before you go and start swapping gears are you sure its not your driving style? Using cruise control on anything other than flat highway is just plain brutal on these trucks, even more so after the TCM swap. When your on the highway and it needs more power the first step is unlocking the torque converter, if that isnt enough the truck will shift into 3rd gear. For you thats only one gear, not a big deal, but on my truck the trans skips 4th gear and goes right to 3rd. Its a bit of a jump and very noticeable.
I do a ton of highway driving, if you use cruise control all the time you are much better trying it without. With a little common sense and a steady foot you can make it up some pretty big hills while maintaining speed and getting better gas mileage over the course of the trip too. If you know you wont make it up without a lot more power push the OD off button, it makes the transition much smoother, especially when towing. Pushing OD off will also lock the torque converter in 3rd gear which is much better for gas mileage and trans temps.
You mentioned being used mostly for work and hauling, if you are on hilly highways or towing heavy loads keep your trans the way it is. If changing driving habits isn't enough you might have to re-gear, the 3.92's get the job done for me but if I hauled more I would go with 4.10's or 4.56's.
When I tow my snowmobiles on long trips I put in the stock TCM to return my trans to a 4 speed and bring up the rpm's in overdrive. This does help with cruising and small hills, I can maintain speed easily on flat ground and with a careful right foot I can keep it in overdrive on most hills. On larger hills or with heavier loads you will need to spend a lot of time with OD off, which isn't a bad thing.
If you have any more questions let me know.
P.S. There is a little trick for 02 4.7 owners and early 03 owners to make the trans shift a little harder on heavy throttle, its a lot more fun than the soggy stock shifts and hasn't caused me any trouble in 10,000 miles.
Do you have a part number?
Professional
Joined: Nov 2012
Posts: 187
Likes: 0
From: Michigan
I posted the part number in this thread, one guy mentioned using a 2004 tcm which isnt a bad idea since they update them so often.
https://dodgeforum.com/forum/3rd-gen...and-3-7-a.html
https://dodgeforum.com/forum/3rd-gen...and-3-7-a.html
Professional
Joined: Nov 2012
Posts: 187
Likes: 0
From: Michigan
There is no official update for the tcm on our trucks, only a tech who knows what he is doing will be able to trick the machine into updating your trans with the jeep update. If you really want the 5th gear the tcm swap is the way to go, it doesnt get any easier than that. But if you do a lot of towing at highway speeds and your already having trouble holding a gear this isnt the way to go for you.
Professional
Joined: Nov 2012
Posts: 187
Likes: 0
From: Michigan
The difference isn't noticeable until about 45mph where the TC lock up in overdrive currently, after the swap it wont lock up until over 50mph. The swap is great for empty highway driving, but when highway towing or in the city I prefer the stock 4 speed setup. They're easy enough to change out I swap mine back and forth as needed.
Thread Starter
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All Star
Joined: Dec 2012
Posts: 895
Likes: 56
Well hey, you're an alright guy there, DirtyDodge.
Got the new TCM in today. Installation was easy.
It feels like it shifts differently, like my buddies 03 hemi ram. It's nice.
Whats even nicer is the 5th gear! Here's a couple pics.
Previously @ 65 I was around 1800 RPM
Previously @ 70 I was around 2000 RPM
That's some real results right there.
Got the new TCM in today. Installation was easy.
It feels like it shifts differently, like my buddies 03 hemi ram. It's nice.
Whats even nicer is the 5th gear! Here's a couple pics.
Previously @ 65 I was around 1800 RPM
Previously @ 70 I was around 2000 RPM
That's some real results right there.
