Dodge Cummins Diesel Forum banner
  • Hey everyone! Enter your ride HERE to be a part of this month's Ride of the Month Challenge!

1 - 11 of 11 Posts

·
Registered
1997 5.9 12v 3500 Dwr
Joined
·
73 Posts
Discussion Starter · #1 ·
What happens if I drop 4K gsk and 60 lbs valve springs for extended towing. More specifically my NV 4500 won’t tow heavy in fifth gear as everyone knows. So I have to drop down the fourth however I have the 4.10 gears which maxes me out at 60 miles an hour at 2750 rpm at which point the truck will not give me any more.. so if I run 3500 rpm at 72 mph in 4th .. I was concerned about EGT’s but people are saying running higher RPM put some more air in and they’re saying they’re EGT‘s cool down at higher RPMs??

Anything I’m not thinking through here any issues running in the 3200-3500 on highway for better speeds? Any other upgrades that should accompany this?
 

·
Premium Member
Joined
·
2,526 Posts
You MIGHT start puking oil from your crankcase vent tube sustaining RPMs that high for long periods of time. What size tires? How heavy of a load? My stock 3.54s have served me well in the past.


Sent from my iPhone using Tapatalk
 

·
Registered
1997 5.9 12v 3500 Dwr
Joined
·
73 Posts
Discussion Starter · #3 ·
You MIGHT start puking oil from your crankcase vent tube sustaining RPMs that high for long periods of time. What size tires? How heavy of a load? My stock 3.54s have served me well in the past.


Sent from my iPhone using Tapatalk
running lt 235/85r16 so a bit bigger but when you talk about puking oil are you saying that I could increase oil pressure too much or overheat the oil in which case for the oil pressure gauge oil temperature gauge be helpful? Towing heavy as in 15-17 up to 20k on a 3-4 hr drive once to a couple of times a month
 

·
Registered
Joined
·
2,097 Posts
What happens if I drop 4K gsk and 60 lbs valve springs for extended towing. More specifically my NV 4500 won’t tow heavy in fifth gear as everyone knows. So I have to drop down the fourth however I have the 4.10 gears which maxes me out at 60 miles an hour at 2750 rpm at which point the truck will not give me any more.. so if I run 3500 rpm at 72 mph in 4th .. I was concerned about EGT’s but people are saying running higher RPM put some more air in and they’re saying they’re EGT‘s cool down at higher RPMs??

Anything I’m not thinking through here any issues running in the 3200-3500 on highway for better speeds? Any other upgrades that should accompany this?
I had a 6b in a hagie sprayer (just sold it) anyway it ran 2950rpm all day with no troubles. I dont think I would want to run 3500 rpm for long periods of time. Cummins 8.3 engines had a habbit of breaking rod bolts and kicking rods out the block in high rpm apps ( 2750 rpm) around 3000 to 4000 hrs was when troubles started happen. We had them and they always used oil running that way. I dont know but I would think the 5.9 might do the same at such high sustained rpm.
 

·
Registered
1997 5.9 12v 3500 Dwr
Joined
·
73 Posts
Discussion Starter · #5 ·
I really don’t wanna buy a new truck I should’ve bought a 6 speed in the first place just the 12v had a place in my heart but I didn’t realize the speed... but I just really want to go a little faster than 57 mph when towing heavy... people say not to tell and 30th other people say they pull in fifth all the time so the end of the transmission has 260k on it I’m a need to upgrade my clutch anyway I’ll probably run it in 5th and let it die when it dies and rebuild it with the South Bend
 

·
Premium Member
Joined
·
2,526 Posts
There is a “fix” for 5th. It requires a full rebuild though because it includes an updated fully splined main shaft. Torque King is the only legit one. It involves 5th being pressed on the shaft. That would be the only way I’d tow in 5th seeing as mine back off and I didn’t have it for a good year and a half.


Sent from my iPhone using Tapatalk
 
  • Like
Reactions: 24hrsparkey

·
Registered
1997 5.9 12v 3500 Dwr
Joined
·
73 Posts
Discussion Starter · #7 ·
There is a “fix” for 5th. It requires a full rebuild though because it includes an updated fully splined main shaft. Torque King is the only legit one. It involves 5th being pressed on the shaft. That would be the only way I’d tow in 5th seeing as mine back off and I didn’t have it for a good year and a half.


Sent from my iPhone using Tapatalk
will that allow me to build anymore power in 5th? It’s notoriously weak for power in 5th as well as high egts
 

·
Registered
Joined
·
18,429 Posts
Torque King is the only legit one.
I disagree. The fully spline shaft & gear was perfected by Standard Transmission & Gear. Over 20 years ago the advertisement was "I got the shaft at Standard Transmission".
 
  • Like
Reactions: Stox225

·
Premium Member
Joined
·
2,526 Posts
I disagree. The fully spline shaft & gear was perfected by Standard Transmission & Gear. Over 20 years ago the advertisement was "I got the shaft at Standard Transmission".
I guess I should have elaborated more. Torque King has the correct fix. Their manual goes into detail on how to install 5th on the main shaft. It shows cross sections and everything.

Standard has the best customer service. I called them with an issue I had rebuilding my transmission, and I didn’t even get my parts from them.


Sent from my iPhone using Tapatalk
 

·
Premium Member
Joined
·
2,526 Posts
will that allow me to build anymore power in 5th? It’s notoriously weak for power in 5th as well as high egts
I don’t know. I would think more fuel and air is how you get more power. I’ve never had power issues in 5th. Especially when the turbo spools.


Sent from my iPhone using Tapatalk
 

·
Registered
1997 5.9 12v 3500 Dwr
Joined
·
73 Posts
Discussion Starter · #11 · (Edited)
I don’t know. I would think more fuel and air is how you get more power. I’ve never had power issues in 5th. Especially when the turbo spools.


Sent from my iPhone using Tapatalk
Yeh I feel like the 2 trucks I’ve had have had problems building power in 5th only I don’t know if I’ve had 2 trucks with similar problems or what hat problem would be guess I’ll have to do some research. Where you running a plate? Maybe I’m having a lack of fuel if that high output ? Could it be a lack f fuel either via plate or pump I have food power everywhere else?
 
1 - 11 of 11 Posts
Top