Engine/Transmission (1994 - 1998) Question For The NV4500 Experts....

[Hammer]

Today I had to do a remove and replace on my U-Joints as I have been chasing a intermittent drive line vibration. Anyway,the short version was bad u-joints and the driveshaft needed to be dropped so the work could be performed and thats where the my question comes from.



When dropping the driveshaft and sliding it out of the transfer case I had a big time flow of fluid comes flying out of the tailshaft like the transfer case was waaaaayyyy overfull. Knowing I had checked the fluids underneath back in October I knew it was up to the sight plug and the transmission was also. We stuck a yoke into to keep the fluid from running out while we addressed the bad u joints,then went back to the case to see what was up. I decided to just remove the sight/fill plug and allow the excess to drain off into a clean drain pan so we could figure out what was up. The transmission fluid from the transfer case was mixed with Syntorque from the transmission and the transmission was low. The transmission however had no mixture in it and was all Syntorque.



So I changed the fluids and refilled both until we can remove the transfer case next week and see whats up. I am wondering if maybe the seal in between the transfer case and transmission has failed,but if it did,wouldn't it pass fluid both directions and not just one way?. I am confused and figured someone has had this issue and would like some input. Thanks... ... ... Andy

 

[Signal73]

Fyi it would have to make its way through both seals, one on the NV, one on the transfer case. neither one is under pressure I cant see how they would mix Another note, I know on the auto's there is a weep hole between the tc and trans, so you know when you puke a seal. Not 100% on the manual though, worth a look. when I drop my shaft I get some fluid out, nothing like you describe though.

 

[kenny61]

Its been awhile but on my 96 from memory... . There is somethng in the manual about not worrying about the seal betwen the trans and transfer case. And i think if there is a seal its on the transfer case. which is fairly easy to take out and check. with that said are you sure about the mixing of the fluids? if it was an open passage they would go back and forth not stay in one unit and not transfer back to the other. personally I would just drain and refill both units and keep checking it to see whats going on. Is it possible somebody else did work on the truck and did a fluid change improperly?

 

[Hammer]

And i think if there is a seal its on the transfer case. which is fairly easy to take out and check.

Yes it is the transfer case seal and the case has to be removed to change it. No biggie just more of a bad timing deal than anything else.

with that said are you sure about the mixing of the fluids? if it was an open passage they would go back and forth not stay in one unit and not transfer back to the other.

Yes I am certain its mixed as we dumped all of it into a clean yellow drain pan. You could smell both fluids in the murky mess. The gear lube on a stick truck will pass into the transfer case and will not pass the other way. The local 4x4 shop here told me the transfer case seal usually dries out with age and will develop a crack. With 180k on my truck I was told I did good and feel fortunate that no real damage was done.

personally I would just drain and refill both units and keep checking it to see whats going on. Is it possible somebody else did work on the truck and did a fluid change improperly?

Both units were drained and refilled and when we drop the transfer case Monday and fix the seal they will checked and done again. I am curious to see how much,if any,transfers between them in a week. As for the shop messing up,nope since the last people to change the fluids under there was EEP in Thornville,OH and the mechanic who did the work was very,very cautious with my truck as they always are when they work on it. I had just checked them back in October myself as part of my normal winter prep and they were full and normal.



Jim. .

You are correct on the automatics and the weep hole. When they have a seal fail they leak out on the ground instead of into the t-case according to the local 4x4 shop. Its always something here lately with this truck,LOL. Seems like each time I get thinking about a new ride Big Red finds a way to make my wallet beg for mercy,LOL. Its a shame the transmission is OK though,it would give me a reason to rid myself of the stick and do the manual valve body auto like I want... ..... Thanks for the replies gang..... Andy

 

[JohnG]

Jeeez, who would take out a 5 spd for an Auto. . and why?? I'll never own an auto transmission ever again. . too many flailing parts and too much $$ to fix. . lol. . JG

 

[Hammer]

Jeeez, who would take out a 5 spd for an Auto. . and why?? I'll never own an auto transmission ever again. . too many flailing parts and too much $$ to fix. . lol. . JG

Who Would you ask?????

I would and its NOT any cheaper to build a stick transmission than a automatic. I have as much in my 5spd as most guys do their automatics. Plus,the 5spds also have as many parts to fail as the automatics as nothing is perfect. I have tired of rowing gears,and with my knees wiped out,anyway I can make my truck more enjoyable to drive I will. I'd much rather have a full tilt manual valve body automatic over my 5 spd anyday.



Maybe at one time you could make a claim for the 5 spds being the better route,but,with better parts available now for the slushbox crowd I'd say they are now on equal footing... ... Andy

 

[tony597fitter]

Who Would you ask?????

I would and its NOT any cheaper to build a stick transmission than a automatic. I have as much in my 5spd as most guys do their automatics. Plus,the 5spds also have as many parts to fail as the automatics as nothing is perfect. I have tired of rowing gears,and with my knees wiped out,anyway I can make my truck more enjoyable to drive I will. I'd much rather have a full tilt manual valve body automatic over my 5 spd anyday.



Maybe at one time you could make a claim for the 5 spds being the better route,but,with better parts available now for the slushbox crowd I'd say they are now on equal footing... ... Andy

I'm with you Andy. I'll take a built auto over this cruddy 5spd. anyday. I have just under $3500 in it, a rebuilt Blumenthals NV4500 with 1 3/8" shaft and a SBC dual disc.

If I had to do it over again I would have bought an Auto.

 

[Signal73]

Heck I converted my 95! I do not tow with that truck, just wanted better times on the track

 

[JohnG]

Oh Well...lol

Guess you guys told me... lol. . :-laf (Thought I'd get a rise outa somebody). . I still think a 5 spd will last longer and not break as often, but I could be wrong. . maybe I'm just too old to know better. . Stick w/ a few big gears as opposed to a bunch of springs and tiny oil passages and ball bearings for check valves. . and I KNOW I can't fix one on the road... lol

A stick will usually give you some warning when it's sick. . every auto I ever had break, left me stuck somewhere. . #@$%!