Engine/Transmission (1994 - 1998) Too much HP for the NV 4500? Help!

[LRamey]

I'm having problems with fifth gear!

Has anyone had problems with high HP with this transmission other then the fifth gear nut backing off? Will this transmission handle high HP in fifth towing?

Two weeks ago I bought a Standard Transmission rebuild. Had it installed and left for Denver pulling my 8500 lb. camp trailer. Had a tail wind all the way from Ore. to Colorado so put the hammer down, set the cruise at around 85 and let her rip.

Coming back I was fighting a 20 mph head wind so was running around 75 in fifth gear. Got to Boise ID. and all of a sudden it sounded like someone tossed some ball bearings in the gears.

Shifted to fourth & had to drive in that gear the rest of the way home! Standard trans. said it sounded like a couple teeth broke on fifth gear but didn't know why.

I do pull some long hills in fifth but when my EGT's get too high I shift into fourth. This is usually around 65 - 70 mph.

I think I'm running around 400+ HP & I push the thing hard, so is this my problem or did the transmission just have a problem to begin with?

Thanks for your thoughts.

Lonnie

 

[JTeague]

I had a similar combo on my 97. I never lost the 5th gear nut, but it did strip the splines out of the 5th gear hub (part on end of countershaft that engages 5th gear). I also started twisting the

input shaft off up front. Those were the only 2 probs I had with mine, otherwise it was bulletproof. What clutch are you using?

 

[Alaskaskiff]

I had a standard trans rebuild that grenaded 5th gear as well. My truck only dynos at 279 hp and I was only pulling a 5. 5K trailer. Total milage on transmission was 13K with about 300 miles pulling. Oil was factory spec Castrol.

 

[C. Harlan]

I could not keep my 5th gear nut on once I started bombing away... I finally got a quote for a fix on it, and for a few hundred more dollars, I got a brand new transmission, 6 SPEED, from Blumenthal's in OKC... . Just something to think about... its a direct bolt up, all you have to do is modify the center hub on the clutch...



-Chris-

 

[LRamey]

Ok, about the 6 speed. Is it really that much heavy duty? Because 6th gear isn't that much differant then 5th gear on my 5 speed. So if I have to drive in direct under heavy loads with either transmission then whats the differance? Just closer gears below direct. I guess if over drive in a 6 speed is a lot more heavy duty then my 5 speed I might consider it.

Thanks,

Lonnie

 

[WadePatton]

I think Mr. Donnelly has a 4500 in Sickly. If there are any necessaries for high HP operation - besides the clutch, he'll know. He' been over 600 forever and now well into the 7's. :--)



ON the NV5600--The early 6-speeds (like mine) have the 1. 25 input shaft. The later ones have the 1. 375 input shaft. I'd be sure to get the larger one. The sixer's are finicky about oil according to New Venture and DC (if you care what DC thinks). They are huge compared to a 4500.

 

[Got Smoke?]

Originally posted by WadePatton

I think Mr. Donnelly has a 4500 in Sickly. If there are any necessaries for high HP operation - besides the clutch, he'll know. He' been over 600 forever and now well into the 7's. :--)



ON the NV5600--The early 6-speeds (like mine) have the 1. 25 input shaft. The later ones have the 1. 375 input shaft. I'd be sure to get the larger one. The sixer's are finicky about oil according to New Venture and DC (if you care what DC thinks). They are huge compared to a 4500.

Well you all can see my dyno #'s in my sig... ... think my transmission moaned uncle a couple of times last month... I dunno... ... . never had any problems out of it before... ... I even slid my fuel plate back about 3 days after I dynoed... . if mine ever goes out I'm just gonna bite the bullet and upgrad to a six speed as I plan on keeping my truck for a VERY LONG TIME.



Wish I could find a way to adapt a 98-and newer 5spd gear shift on my 97 5spd.

 

[JJW_ND]

Can be made stong enough.

Just like the HP auto trucks have to use "special" parts to keep for breaking, stripping the spines might not be from to much HP but rather a standard quality part. They can be made to take the power.



There are several suppliers providing the fully spined shafts. Some line Oppie (input... output special shafts for autos) could speak to the quality and what can be done.





So I think a NVG4500 can be made to take the power, but then heat will be its next enemy as if you can run in 5th with big HP you will be generatoring lots of heat... . way more the the few quarts of ANY OIL can survive. There are ways to deal with that... just need to keep that in mind.



The NVG5600 are stronger, and do not have any of the NVG4500 OD gear issues. They are not problem free, but it is a stronger trans that you can pull in 6th day in an out.



Need to decide which is more cost effective!



jjw

 

[CFAR]

http://dodgeram.org/tech/transmission/nv5600_swap.htm

http://dodgeram.org/tech/specs/Ramspecs.htm



Here is some stuff about the two you might be interested in.



Penzoil makes sycromesh transmission fluid, $4. 99qt at Autozone



lol

 

[CumminsPower98]

6th gear in the NV5600 is nothing like 5th in the NV4500, it's in the main case and on the main shaft along with 1st, 2nd and 5th (3rd and 4th are on the counter shaft). There is no nut holding it on. Reverse on the other hand is the gear that is similar to 5th in the 4500 as it's in the extension housing and held on by a nut. I think some of the early 5600s had some trouble with reverse.

 

[Boomer II]

http://www.drivetrain.com/nv5600.html#NV5600-4WD 1994-1997

 

[Garry Verheyden]

Lonnie,

I have had over 400HP for 4 yrs now and I'm done with my 5 spd. I destroyed 3 clutches, Broke 1 input shaft, then had the 5 spd completely rebuilt about 25,000 miles ago. After I had it rebuilt I had a very slight groan in 5th gear. It was not noticeable to anyone else in my truck, but I am used to how my truck sounded. With 200,000+ miles on it, I have never had a 5th gear problem. But when I was on holiday in Sacramento on the way to Arizona the 5 spd grenaded on me. I lost every gear except 4th. Every time I broke something , it was on my holiday towing my 15,000 lb 5th wheel with my family.

Lots of people have over 400hp with no problems, but most of them aren't towing over 15. 000lbs.

I now have a 2002 6 spd in it and have only towed with it once. It still has a stock clutch in it so I cant beat on it to test it. It is not as fun to drive as the 5spd(more shifting and notchier shifting) so it is not quite as fast for acceleration. If you don't race anyone then this wouldn't matter. But I wouldnt trade back to the 5spd because i don't believe it is nearly as strong. The 5 spd looked like a little runt sitting besides the 6 speed. The 5 speed weighed 200lbs and the 6 speed was 6" longer and 380lbs. It is HUGE and i believe it will hold out much better with towing.

Garry.

 

[LRamey]

Gentlemen,

Thanks to all who replied to my problem. I guess some day I'll have to go to a 6 speed but I just don't have the 3 grand right now to shell out! Guess I'll just have to go easy on the old 5 speed!

Lonnie