3.42 gears

[Steve Robinson]

I am looking at a new truck with a manual trans but the gears are 3. 42 and I plan to tow a 25ft trailer. My concern is the gears are too high for towing/backing etc. Anyone using these gears and towing with a stick? I probably should hold out for 3. 73 or 4. 10 if I can get them. What do you think?

 

[RVTRKN]

I am looking at a new truck with a manual trans but the gears are 3. 42 and I plan to tow a 25ft trailer. My concern is the gears are too high for towing/backing etc. Anyone using these gears and towing with a stick? I probably should hold out for 3. 73 or 4. 10 if I can get them. What do you think?

Towing heavy should require 3:73 or higher? look at my sig, sometimes I wished I had 4:10, but do a lot of service in town and needed the extra MPG. I would not order one with 3:42.

 

[Steve Robinson]

These are "on the lot" trucks and I agree, the 3. 42gears aren't the best for towing. I think I will continue looking. Thanks for your insight.

 

[HBarlow]

Yep, I agree with the above. 3. 42 gears are a bad idea for anything more than passenger service.

It's been my experience that RVers tend to move up to larger and heavier trailers over the years. The 3. 42 gear will be adequate for towing a light weight 25' trailer but even then, if you get into a situation where you have to back the trailer up hill and have to repeat several times to get the trailer into a tight spot, you'll overheat the clutch and cause glazing or early failure.

You're the man who's going to hand over the cash or sign the note. Hold out for what's best for you, not for some foolish sales manager who doesn't know which end of a truck to hook a trailer to and thought 3. 42 gears would be a great idea when he was ordering inventory.

 

[AClayton]

I have 3. 55's in my truck with 285 size tires..... which would closely mirror the effects of a new truck with stock tires and a 3. 42's. Even when hooked to my lightweight 12' Work/Utility cargo trailer which weighs in at about 6k lbs, I wish I had the lower gears. Unloaded,the truck is very efficient and even with my mods I can easily obtain high teens in mileage... ... ... provided I keep my foot out of it and keep speeds at or around the 65mph mark. It is very easy to lug these engines because they have so much low-end torque and do generate the power at above idle conditions to successfully pull a trailer... ... but the DRIVER needs to downshift to keep the R's at the 1600 to 2200rpm range. So many beginner's and even a few experienced driver's will fall into the category of thinking their truck is down on power or the thought of humiliation for having to downshift their truck is a bad thing..... when in fact,it only makes our Cummins engines last longer by keeping oil psi up,EGT's down,transmission and engine temps in control and even makes the A/C work better.



Get the 3. 73 or 4. 10's! You'll be more satisfied!



Alan

 

[Steve Robinson]

Thank you for your helpful information guys.

 

[therabbittree]

you can always put it in 4 low to back up. . i use 4 low all the time. . I run 3. 07 gears...

 

[Powder Extreme]

The older Dodges all had 3. 54 rear ends (for the most part) and always seemed to tow and haul just fine. The top gear of the manual transmission, be it 5th or 6th is still pretty numerically close to what it's always been. The new 6sp auto is the only transmission with a deep overdrive. With the increase in HP / TQ I don't see why it would be necessary to go with a lower (numerically higher) rear end?

 

[67guzzler]

Yup. I agree. I think the G56 and the 68rfe call for a totally different analysis of the rear end selection.

I think that the G56 allows for the 3. 42 ratio as it has a final ratio of . 74 vs the . 63 of the 68rfe. Because it's a stick, you can pick the gear you want so effectively, though it does somewhat, the 3. 42 doesn't impact performance the way it would with the 68rfe. The biggest challenge will be getting the rig moving when towing very heavy.

This is why almost ALL the G56's on the lots have the 3. 42 while almost ALL the 68rfe's have the 3. 73. There are some 4. 10's with the 68rfe and some 3. 73's with the G56 but not many... .

 

[KLauber]

I have the 6spd and the 3. 42 gears. In Greenville SC with steep hills and a 25 ft work trailer that weighs 9700 empty and 15K plus when loaded, I have no problem getting started or pulling hills. Engine and drive train are fine with this set up. Plus when you're unloaded you can cruise at 70MPH at 1800 RPM. Of course operator knowledge and terrain have a lot to do with safe and efficient use of the truck. Harvey is worried you might burn out the clutch backing up a hill. Where do you live? Where will the truck be run?

Ken

 

[KLauber]

Plus the granny

The older Dodges all had 3. 54 rear ends (for the most part) and always seemed to tow and haul just fine. The top gear of the manual transmission, be it 5th or 6th is still pretty numerically close to what it's always been. The new 6sp auto is the only transmission with a deep overdrive. With the increase in HP / TQ I don't see why it would be necessary to go with a lower (numerically higher) rear end?

Plus the granny 1st gear is mostly used only when pulling a load! The 3. 42 is adequate for the task with the manual 6 Spd. I've never been so impressed by its capabilities with a heavy load, plus with the exhaust brake, going down hills are just plain fun!



Ken

 

[HBarlow]

I have the 6spd and the 3. 42 gears. In Greenville SC with steep hills and a 25 ft work trailer that weighs 9700 empty and 15K plus when loaded, I have no problem getting started or pulling hills. Engine and drive train are fine with this set up. Plus when you're unloaded you can cruise at 70MPH at 1800 RPM. Of course operator knowledge and terrain have a lot to do with safe and efficient use of the truck. Harvey is worried you might burn out the clutch backing up a hill. Where do you live? Where will the truck be run?

Ken

You don't have a problem YET, Ken but you will. It won't be long until you'll be back lamenting the fact that your dual mass flywheel and clutch assembly have failed. You are increasing the stress on the DMF/clutch assembly with 3. 42 gears and hastening failure.

 

[67guzzler]

No offense, Harvey, but it's just not true. Over 90% of the G56 trucks sold are 3. 42. You can downshift to take the stress off the driveline at any time with a stick. There is no cause and effect between the rear end ratio and the dual mass flywheel failing. There is, however, such a relationship between too much HP / Torque and the DMF / Clutch failing. But blanket statements like the one you made are simply in error.

 

[Powder Extreme]

You don't have a problem YET, Ken but you will. It won't be long until you'll be back lamenting the fact that your dual mass flywheel and clutch assembly have failed. You are increasing the stress on the DMF/clutch assembly with 3. 42 gears and hastening failure.

LOL, be worried Ken, you might only get 240,000 miles out of your clutch instead of 250,000

 

[HBarlow]

Wishful thinking guys, wishful thinking.

I owned an '01 HO six speed with a 3. 54 gear set. I ordered it deliberately that way having no plans at the time to upgrade to a heavy fifth wheel. 3. 54 gears worked great pulling an 8500 lb. Airstream and later Avion but when I bought a 14,000 lb. Travel Supreme fiver the truck became a dog.

Launches clearly stressed the clutch and reversing the heavy trailer up a grade into a challenging parking spot stressed the clutch even more. Sure, when you're talking about towing at highway speed it is possible to shift down a gear or two and keep it rolling but there is no way to downshift and increase torque multiplication factor and load starting torque at launch. First gear is all there is.

Many TDR members have reported DMF flywheel clutch assembly failures in as little as 60,000 miles. If you doubt me do a search in old threads or call and ask the owner of Southbend Clutch how many conversion kits he has sold for DMF equipped trucks in the last five years or so. 3. 42 gears make it even more likely that early failure will occur.

 

[Powder Extreme]

Wishful thinking guys, wishful thinking.

I owned an '01 HO six speed with a 3. 54 gear set. I ordered it deliberately that way having no plans at the time to upgrade to a heavy fifth wheel. 3. 54 gears worked great pulling an 8500 lb. Airstream and later Avion but when I bought a 14,000 lb. Travel Supreme fiver the truck became a dog.

Launches clearly stressed the clutch and reversing the heavy trailer up a grade into a challenging parking spot stressed the clutch even more. Sure, when you're talking about towing at highway speed it is possible to shift down a gear or two and keep it rolling but there is no way to downshift and increase torque multiplication factor and load starting torque at launch. First gear is all there is.

Many TDR members have reported DMF flywheel clutch assembly failures in as little as 60,000 miles. If you doubt me do a search in old threads or call and ask the owner of Southbend Clutch how many conversion kits he has sold for DMF equipped trucks in the last five years or so. 3. 42 gears make it even more likely that early failure will occur.

I too owned an '01 6spd ETH HO QC Dually 3. 54 gears, I put just shy of 100k on it, it wasn't until I turned the power up drastically that had any issues with the clutch. I owned a 14,000lb 5th wheel at the time, and a GN that I'd regularly load to 20k. Once I changed injectors, intake, turbo, exhaust, and put stacked boxes on it, I started slipping the clutch while towing. But I was putting out over 500hp to the ground, kinda gotta expect the clutch to not hold when towing.

Peter at Southbend hooked me up with a new clutch, no problems after that.
I don't blame the stock clutch for it slipping though, I was putting out well over twice the hp it was designed to hold. At stock HP and even partially modified it held just fine for many thousand miles.

The Southbend was awesome, anybody looking for a clutch I highly recommend them!

*edit My '02 PLOW truck HO 3. 54 still has the original clutch at 150k miles. I tow with it as well, around 12k. Mildly modified with an EZ box and straight pipe, probably around 300hp.

 

[GaryOwen]

Was looking at the Trailer Life Magazine Towing Guide and noticed there is a substantial difference in tow rating with the 3. 42's. Info for a 3500 Crew Cab Long Bed 4WD DRW are as follows:



transmission ___ Differential ___ Tow Limit



Manual ___ 3. 42 ______ 11350

Manual ___ 3. 73 ______ 13350

Auto _____ 3. 42 _______ 9450

Auto _____ 3. 73 ______ 13450

Auto _____ 4. 10 ______ 17850



Not sure if the info is accurate, but it appears you shouldn't tow as much with the 3. 42's.

 

[HBarlow]

I too owned an '01 6spd ETH HO QC Dually 3. 54 gears, I put just shy of 100k on it, it wasn't until I turned the power up drastically that had any issues with the clutch. I owned a 14,000lb 5th wheel at the time, and a GN that I'd regularly load to 20k. Once I changed injectors, intake, turbo, exhaust, and put stacked boxes on it, I started slipping the clutch while towing. But I was putting out over 500hp to the ground, kinda gotta expect the clutch to not hold when towing.

Peter at Southbend hooked me up with a new clutch, no problems after that.
I don't blame the stock clutch for it slipping though, I was putting out well over twice the hp it was designed to hold. At stock HP and even partially modified it held just fine for many thousand miles.

The Southbend was awesome, anybody looking for a clutch I highly recommend them!

*edit My '02 PLOW truck HO 3. 54 still has the original clutch at 150k miles. I tow with it as well, around 12k. Mildly modified with an EZ box and straight pipe, probably around 300hp.

You either missed my point or, are trying to change the subject. I never mentioned clutch failure with my '01 six speed and 3. 54 gears, only my dissatisfaction with its performance on load starting with a heavy fiver.

The failures I confidently predicted and stand by are with DMF and clutch using 3. 42 gears on ISB6. 7 trucks.

 

[HBarlow]

Was looking at the Trailer Life Magazine Towing Guide and noticed there is a substantial difference in tow rating with the 3. 42's. Info for a 3500 Crew Cab Long Bed 4WD DRW are as follows:

transmission ___ Differential ___ Tow Limit

Manual ___ 3. 42 ______ 11350
Manual ___ 3. 73 ______ 13350
Auto _____ 3. 42 _______ 9450
Auto _____ 3. 73 ______ 13450
Auto _____ 4. 10 ______ 17850

Not sure if the info is accurate, but it appears you shouldn't tow as much with the 3. 42's.

Gary,

Thanks for providing that. I don't subscribe to TL any longer so hadn't seen it.

As you stated, the towing capability seem to be severely hampered by 3. 42 gears with a manual and even moreso with the MOPAR six speed automatic.

 

[67guzzler]

You either missed my point or, are trying to change the subject. I never mentioned clutch failure with my '01 six speed and 3. 54 gears, only my dissatisfaction with its performance on load starting with a heavy fiver.

The failures I confidently predicted and stand by are with DMF and clutch using 3. 42 gears on ISB6. 7 trucks.

There is no causal relationship between rear end ratio and clutch / DMF failures. There is such relationship between horsepower / torque and the DMF / clutch failing.