2004 2500HD with NV4500

AA Hayes · May 13, 2014

I have a 2004 2500HD with the 6.0L and a NV4500

So my NV4500 rear casing has a pin hole in it and was leaking fluid.
i am curious about what my options could be at this point.

i have temporarily stopped the leak with some metal epoxy.

either i replace the case, with a new case, or replace my tranny.
i was wondering about putting in the allison 6 spd, but am not sure how it would mesh up with my truck. or putting a new nv4500 in it.
i noticed it makes a knock coming out of 2nd after i disengage the clutch and knocks again when i engage clutch into 3rd gear.
i was thinking this was due to running on low oil, so i got under the truck and saw a drip, found the suspect and temporarily fixed it. not sure how long it ran on low fluid so i am leaning toward a rebuild or new tranny because i dont want to have any serious issues on a long haul trip.
thoughts and comments please.

AA Hayes · May 13, 2014

ok so i may actually be my transfer case.
it was leaking close to the rear output shaft.
i will take some pictures and post them in day light tomorrow

Prokopchuk_9 · May 13, 2014

Pump rub. Look on merchant auto, they have pumped rub kits.

No you cannot run an allison, you could run a 4l80e. Sounds like syncro's are going to me, does it grind when you shift too?

AA Hayes · May 13, 2014

i dont have any grinding.
i want to stick with my manual tranny, so the 4l80 is out of the question.
i think i will do a fluid change and see how that does me.
what fluids should i run in my tranny and transfer case? it is a manual shit transfer case

I love this tranny and want to treat her well

Prokopchuk_9 · May 13, 2014

i dont have any grinding.

i want to stick with my manual tranny, so the 4l80 is out of the question.

i think i will do a fluid change and see how that does me.

what fluids should i run in my tranny and transfer case? it is a manual shit transfer case

I love this tranny and want to treat her well

I know, do NOT use anything else but the synchromesh AC Delco stuff from the dealer. It's pricy but trust me, I've heard horror stories guys using something else. Transfer case is just ATF...

Prokopchuk_9 · May 13, 2014

Only reason why I said 4l80 is cuz you asked for an allison. Which is an auto, but will not mount to a 6 litre.

AA Hayes · May 15, 2014

so who makes the 6 speed manual for the duramax and the 8.1?

sdeeter19555 · May 15, 2014

I know, do NOT use anything else but the synchromesh AC Delco stuff from the dealer. It's pricy but trust me, I've heard horror stories guys using something else. Transfer case is just ATF...

The NV4500 uses 80w90...the other NV variants (e.g. NV5600, NV3500, etc.) use synchromesh. I ran synthetic 75w90 for over 250k miles in my dad's NV4500...it stated the gear oil part number right on the tag, while my NV5600 stated "Synchromesh" on its tag.

Point being, make sure what you are supposed to run...as far as I know, all NV4500s are a gear oil, not synchromesh.

AA Hayes · May 15, 2014

from what i have read the best thing for the NV4500 is syntorque by castrol.
i am going to be putting the pump rub kit and a new tail housing on my truck, it is a 261HD do anyone know a good place to order these and which company makes a good kit.
i am living in northern ontario and the parts store i normally use is unable to order the tail housing for me.

AA Hayes · May 15, 2014

i would like to update to the aluminum case rather than the soft magnesium case

sdeeter19555 · May 15, 2014

from what i have read the best thing for the NV4500 is syntorque by castrol.

i am going to be putting the pump rub kit and a new tail housing on my truck, it is a 261HD do anyone know a good place to order these and which company makes a good kit.

i am living in northern ontario and the parts store i normally use is unable to order the tail housing for me.

Syntorque is different than Synchromesh...

You can't really buy Syntorque in the consumer market...you either buy it by the 55-gallon drum from a supplier, or buy it in smaller packages from some transmission rebuilders that simply repackage it from the 55-gallon drum for their customers. Either that, or you buy the quarts at $35/qt from the dealership. That's why I looked for another solution...

A synthetic 75w90 like Pennzoil Synthetic will work in place of Syntorque. The main concern with the oil type is the brass internals...a synthetic oil will have anti-corrosives that counteract the corrosive nature of the high sulphur anti-wear additive. They specify a GL-4, but a GL-5 will work.

This is bringing back memories from my Dodge days...

AA Hayes · May 15, 2014

yes i know syntorque is different than syncromesh. i am willing to pay the 30$/l from my near by dealer to know i am running a quality oil. from what i have read the syntorque was designed specifically for the nv4500. i love my tranny and want to treat her right, it is not like the fluid is a frequent thing to change. so for the 120 in oil i will be a satisfied man.

sdeeter19555 · May 15, 2014

... from what i have read the syntorque was designed specifically for the nv4500.

It was designed for final gear drives in the marine industry...not sure how they figured it was a good application for a trans, but...

I'm not sure what you get at the dealer is actually Syntorque either...NVG fills them with Syntorque, but I'm not sure that's what the dealer sells you for a refill.

AA Hayes · May 15, 2014

so anyways, about that transfer case tail housing and pump rub kit.

from what i have read the best thing for the NV4500 is syntorque by castrol.
i am going to be putting the pump rub kit and a new tail housing on my truck, it is a 261HD do anyone know a good place to order these and which company makes a good kit.
i am living in northern ontario and the parts store i normally use is unable to order the tail housing for me.