when NOT to use 5th gear?
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From: Greensburg,Ky
when NOT to use 5th gear?
The last 5speed I had went bad...I am guessing the nut holding 5th gear backed off.
The tranny made a horrible racket in 5th,but was quiet in 4th.
I was told that 4th is traight through and that 5th should not be used for loaded driving.
OK...at what point is a "Load" considered a.....LOAD?????
I really like my 97 with a 5 speed and I don't want this one to tear up on me.
Your opinions OH Opinionated ones?????
GCSS
The tranny made a horrible racket in 5th,but was quiet in 4th.
I was told that 4th is traight through and that 5th should not be used for loaded driving.
OK...at what point is a "Load" considered a.....LOAD?????
I really like my 97 with a 5 speed and I don't want this one to tear up on me.
Your opinions OH Opinionated ones?????
GCSS
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From: Scotts Valley, Ca
started at 152k on my 96 3/4 ton and had almost 170k when 5th backed out I would at times pull a dump trailer with load but went out going down the interstate with NO LOAD was an easy fix though. I have had my 97 5 speed dually 13 months about 235k on it started with 187k but have yet to pull anything with it.
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From: Laredo
Originally Posted by GCSS
The last 5speed I had went bad...I am guessing the nut holding 5th gear backed off.
The tranny made a horrible racket in 5th,but was quiet in 4th.
I was told that 4th is traight through and that 5th should not be used for loaded driving.
OK...at what point is a "Load" considered a.....LOAD?????
I really like my 97 with a 5 speed and I don't want this one to tear up on me.
Your opinions OH Opinionated ones?????
GCSS
The tranny made a horrible racket in 5th,but was quiet in 4th.
I was told that 4th is traight through and that 5th should not be used for loaded driving.
OK...at what point is a "Load" considered a.....LOAD?????
I really like my 97 with a 5 speed and I don't want this one to tear up on me.
Your opinions OH Opinionated ones?????
GCSS
Hmm
I dont use fifth gear under 2500 RPMS in fourth gear, anything less than 1500 rpms is luggin fifth gear and can cause the failiure..
Ive towed some heavy loads myself and have never had problems with the trans, Heaviest being a 28 foot big tex gooseneck tandem axle with a cat 416B 4wd backhoe with a closed cab.. Startin was no prob, stoppin on the other hand was a little trickier, i dont know the weight of it, but i do know that i didnt get to fifth for that haul, it was in town..
Rick
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From: Scotts Valley, Ca
you can change it by taking the tranfer case off on a 4x4 and removing the tailshaft housing but if you strip the 12 point bolt heads like I did then remove the whole thing and you can either buy the whole shaft with the fifth gear fixed from one of the aftermarket sellers on here or I bought the fix nut assembly from dealer it has set screws but they need to be 300 ftlbs torque look up the bulletin for the fifth gear fix or search threads for it mine is probably still on here from around May 2004
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From: Greensburg,Ky
Originally Posted by jlipskoc
Same for me, I'm on the original 5th gear nut. 3.55 gears/5pd. 160k now. Its all about not lugging it down low, the vibration will wear the end shaft nut back and forth causing slop in the gear and eventually it'll back off, fully splined is only the real fix IMO,
I never let her get below 1.9-2k rpms in 5th towing heavy. Empty in 5th, I never let her drop below 1600 or 55mph before i go to 4th.
When i tow heavy, its basically out of 5th all the time, unless its a flat ground area, or downhill. Anytime a hill approaches, down to 4th.
When I'm towing heavy in 4th, I like to keep speed slow anyways for best fuel economy and safety, 55-60 non insterstate with fairy easy straight roads, 60-65 insterstate. Rpm's are just perfect like this in 4th.
To me its easier on the drivetrain, lets the cummins breath, less egts with more rpm's, and better fuel mileage keeping it under 65mph.
I never let her get below 1.9-2k rpms in 5th towing heavy. Empty in 5th, I never let her drop below 1600 or 55mph before i go to 4th.
When i tow heavy, its basically out of 5th all the time, unless its a flat ground area, or downhill. Anytime a hill approaches, down to 4th.
When I'm towing heavy in 4th, I like to keep speed slow anyways for best fuel economy and safety, 55-60 non insterstate with fairy easy straight roads, 60-65 insterstate. Rpm's are just perfect like this in 4th.
To me its easier on the drivetrain, lets the cummins breath, less egts with more rpm's, and better fuel mileage keeping it under 65mph.
my truck has 207K on it and the tranny is as quiet as a church mouse!
GCSS
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Great advice given on don't lug it. You can see the difference in the shafts in my photo gallery, I went ahead and put in a fully splined main shaft when I installed my southbend clutch just for ease of mind as I was getting the truck ready for a very long trip pulling a big load and just for over all wanting to feel secure. My fifth gear had never made a noise either. Goodluck,,Rick
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From: Alabama
My nv4500 rattles like hell under much of any load in most gears. It didn't use to do that. I suspect that the power it's now making has contributed to that. I shift at low rpm, like 1500 just putting around town unloaded. If your definition of lugging is that it won't accelerate in that gear, then I don't lug it. I think a stock one might not accelerate though, so maybe I do actually lug it sometimes. Does it sound like my transmission is going?
If so, I have a spare nv4500 sitting around. How much would a good rebuild cost if I send it to them and they don't have to pull/reinstall it?
If so, I have a spare nv4500 sitting around. How much would a good rebuild cost if I send it to them and they don't have to pull/reinstall it?
DTR's Toad Wrangler
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From: N 48 25.707 W123 21.887
Well I lug mine down to 1100 rpm and have had no problems. But what is lugging and the load? If the foot is hard on the floor heat and torque are there. So one should let up on the throttle as you go into a pull. If you have a boost gauge watch it keep the boost low at low rpm.?Under heavey loading that is harder to do.That is when you have to get a hand on the paddle in the middle of the cab and paddle that cummins up the hill. When I pack my camper I stay above 1600 rpm in 5th
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From: Cummins Technical Center, IN
Guys, just remember to replace the mainshaft as well if you replace the 5th gear nut. The gears wear on the shaft, and without replacing the shaft, you'll have to fix it all over again.
jh
jh