Engine/Transmission (1998.5 - 2002) NV 5600 repair

[Gary - K7GLD]

I know this question has been asked, but ill ask it again what kind of life can I expect from mine?.



I dont really tow very much. My trailer weighs around 10K. My GCW is close to 20K when fully loaded during summer months when I travel to the northwest.



Summer trips are usually around 4k loaded.



Mac

Way too many variables for a trustworthy reply!



The transmission SHOULD generally last as long as the engine, if it's operated and maintained according to spec. Unfortunately, SOME of the printed specs have been shown to be not entirely accurate - the most pertinent, is the issue of lube level for proper lubrication of all internal parts - especially the upper-rear mainshaft support bearing - entirely adequate if lubed properly, and long hard pulls in OD are avoided - but prone to overheating and early failure if those conditions are NOT met!



Some of us have recognized those lapses in documentation, and fill the transmission over the specified level by a couple of quarts or so, and make sure that the OD is engaged only on moderate loads and out in the flat lands. The low RPM power the Cummins provides is deceiving - especially after a few power mods - and what SEEMS to be an easy and normal load as far as the *engine* is concerned, can easily exceed what the transmission itself is designed carry in steady operation. Using the proper gear for the load and grade goes a LONG ways to extend transmission life!



Respect the transmission, and service it well, and it probably will last as long as the engine...

 

[Wyomingcowboy]

Way too many variables for a trustworthy reply!



The transmission SHOULD generally last as long as the engine, if it's operated and maintained according to spec. Unfortunately, SOME of the printed specs have been shown to be not entirely accurate - the most pertinent, is the issue of lube level for proper lubrication of all internal parts - especially the upper-rear mainshaft support bearing - entirely adequate if lubed properly, and long hard pulls in OD are avoided - but prone to overheating and early failure if those conditions are NOT met!



Some of us have recognized those lapses in documentation, and fill the transmission over the specified level by a couple of quarts or so, and make sure that the OD is engaged only on moderate loads and out in the flat lands. The low RPM power the Cummins provides is deceiving - especially after a few power mods - and what SEEMS to be an easy and normal load as far as the *engine* is concerned, can easily exceed what the transmission itself is designed carry in steady operation. Using the proper gear for the load and grade goes a LONG ways to extend transmission life!



Respect the transmission, and service it well, and it probably will last as long as the engine...

What he said!

I'll also add that 8 qts. is what Blumenthal's recommends for a transmission without fast coolers or filter set-ups. Blacksheep recommended I try 11 qts. , as he did, this summer when I was trying to see if an oil change would fix my problem. (Look at the pics and you'll see the fried friction rings..... no oil change could fix that!:-laf) I immediatly ran a trailer for about 1k miles with the 11 qts and blew alot of it out the breather tube and all over the trailer. I really wish I had measured the amount I drained when I pulled the transmission last fall, but I got in a hurry and didn't. Anyways, 11 is too much IMO. I will go with the 8 as suggested by Blumenthal's.

And to repeat what Gary says..... treat it right (NO SPEED SHIFTING!) and It *should* last as long as the engine.



p. s. Go in through the cab and top of transmission to add the oil. It's only a few more bolts to mess with and then you don't have to fight with trying to add through the silly fill hole. Plus, you may find some change or some other goodies under the console!

 

[macdaddy]

What he said!

I'll also add that 8 qts. is what Blumenthal's recommends for a transmission without fast coolers or filter set-ups. Blacksheep recommended I try 11 qts. , as he did, this summer when I was trying to see if an oil change would fix my problem. (Look at the pics and you'll see the fried friction rings..... no oil change could fix that!:-laf) I immediatly ran a trailer for about 1k miles with the 11 qts and blew alot of it out the breather tube and all over the trailer. I really wish I had measured the amount I drained when I pulled the transmission last fall, but I got in a hurry and didn't. Anyways, 11 is too much IMO. I will go with the 8 as suggested by Blumenthal's.

And to repeat what Gary says..... treat it right (NO SPEED SHIFTING!) and It *should* last as long as the engine.



p. s. Go in through the cab and top of transmission to add the oil. It's only a few more bolts to mess with and then you don't have to fight with trying to add through the silly fill hole. Plus, you may find some change or some other goodies under the console!

I take it your talking about filling it through the shift tower?.

Man I just got the dam thing to stop leaking, I do however fill it with the truck leaning (Left side up on blocks).



Mac

 

[Wyomingcowboy]

Ya, the shift tower is what I mean. Where is it leaking from?

 

[JesseJ]

Wyoming, I had the same issue holding the shaft. When I rebuilt my NV4500 I could engage two gears so nothing would move, then just hold the case, can't exactly do that with the 5600. I got it as tight as I possibly could using a big wrench to fit the nut, whacking the wrench with a hammer, with rags stuffed in the gears to try and keep things from rotating. I ended up using a chisel for a few good extra whacks, but also used some blue loctite on the nut for extra insurance.

 

[DMcLeod]

Thanks, wc, for posting details on your rebuild. It's been an interesting read for me, and the pics are great. I'm all ears to what's going on inside that box and what conditions tell you it's time for tear down. I've always had a "catch" when going from 1 to 2 and 2 to 3 (I purchased the truck with 60k, now it has 130K?). This last winter, it's been more pronounced when shifting from 2 to 3 and now 3 to 4, especially when cold. I can no longer shift into 1st (and usually can't shift easily into 2nd) from a stop. I have to ease the clutch out a little in 3rd, and then I can slip it into 1st to start out, say with a load. If it can't get into 1st at a stop, what part is probably bad inside? 1st gear syncro? I'm going to change oil again (10,000 on this Amsoil MTF now) to see if things improve for me a bit. I'd love to tear into it like you did, but I lack a few tools, time, experience, etc. Might have to take a road trip someday to Oklahoma City.

 

[Wyomingcowboy]

That sounds like maybe it's clutch time? I never had any issues getting into gear... . well, except for reverse and that wasn't bad. It sometimes took a pretty good shove and them the truck moved slightly, but looking at my pressure plate it might very well be that too. I'm going to put the old clutch back in due to money and it really doesn't look too bad. (So I have been told... . I have very little experience myself, but necessity dictated that I try this one myself. )

OKC is a LOOONG way from AK but I i would love to go down myself and see what these guys have goin' on down there. Sounds like quite the setup. I know they were impressed with the very fact I got mine apart. That was ditto'd by the outfit in SLC that rebuilds these. I guess I just got lucky! Other than rebuilding a transfer case in my '94 Chevy and other shadetree mechanic stuff I have had no expereince with these either. Being a member here, and having access to AllData and the great guys in OKC have helped me out more than I'll ever know. I would say a normal man's shop outfitted with a press could handle the job. (You better have access to a big-*** press just in case you need it and the only way you will need that would be if you need to tear down the countershaft. The rest is mostly bearing and bearing sleeves with the input/mainshaft gears sliding on and off.



Got a little long winded there... ... I would venture to say that your problem is clutch related as 2-3 are not using the same synchro; 1-2 are together, 3-4, 5-6, and reverse are. I would start with diagnosing that clutch before I even went so far as dumping $100 worth of fluid in it.

But by all means... do not take my word for it! I hope a bunch of others that know more than me chime in here too... ... good luck and keep us posted!

 

[Wyomingcowboy]

Well, it appears that my engine is going to be another week and I am getting very itchy to do something. My trans. is done and I really want to put it in and install the new exhaust. I had wanted to use the lift and install the transmission after the motor is in place so I won't have to lay on my back and also so the motor would go in easier. But, I WANT TO TURN SOME WRENCHES!!!

My question is this: is there a way to support the front of the transmission without the motor? The thing ways a ton (not literally, but you know what I mean) and even with the transfer case on it still is very unbalanced from the mount.

 

[Wyomingcowboy]

I got no answer here so in my downtime I decided to mount the transfer case to the transmission. Then I noticed it was a tad dirty so I decided to clean it. Then I didn't like how I got some solvent down inside so I decided to throw it in the spray cabinet and then tear it all down... ... . It took me 4 hours to tear it down and put it back together but it was clean as a whistle inside. (The 5600 was also very clean inside except the 2 fried friction rings. ) There was absolutely no wear that I could see on anything. The little friction cone inside looked brand new as did all the gears, shift forks, and even the plastic sleeves on those forks. It will still be next week before the motor is done so I'll pose the question again..... is there a way to support the front of the transmission without the motor?



TIA!

 

[MKreiberg]

You sure you want to stab the motor onto the transmission? I'd rather do it the other way- I think. Note that I've not had one of these out though.

but yeah, to answer the question I think it'd be a piece of cake to fab something to hold up the front of the trans, but like I said... you sure?

 

[Wyomingcowboy]

You sure you want to stab the motor onto the transmission? I'd rather do it the other way- I think. Note that I've not had one of these out though.



but yeah, to answer the question I think it'd be a piece of cake to fab something to hold up the front of the trans, but like I said... you sure?

No, I'm not sure, but I'm aching to do something! I know I could use a jackstand to hold it as that's what I used until the transmission came out, but I was thinking about putting it in overhead and supproting it from in the cab or something?

I know it sounds nuts, but like I said... I'm itching to do something!

 

[MKreiberg]

Ok - so my thought on supporting it is to run a piece of 1-1/2" - 2" steel pipe across the rear/top of the lower control arms, and ratchet strap it to the cross member to keep it from rolling/sliding forward... trans is supported on top of pipe & might throw in some 2x4's or something bolted to bell housing to keep the trans centered in frame, and then you've got a rolling chassis - less motor.

still don't know if its a good idea - so take me with a grain of salt - just thinking here.

 

[DPrew]

Wow, your brave. I know if my 5600 goes out I'll have my mechanic throw it in the back of my 06' 2500 and I'll be on a two hour drive to Fort Worth to see the folks at Standard Transmission. I'm glad that place is close by in case I need it.

 

[Gary - K7GLD]

I assume you don't have a transmission jack? I couldn't find any in my area when I pulled my 5600 a few years back - all the rental shops had was great big ones for larger vehicles. Fortunately, a neighbor biker was selling a bunch of stuff in a yard sale - and there was this neat 1500 lb. capacity motorcycle hoist/platform! Paid $35 for it, and then made a wooden cradle that fit the bottom of the 5600, with strap brackets to secure it - and it worked great!. Just a thought - might check with any biker buddies you know - I've loaned mine out to a local area friend to use, and worked well for him as well - too bad you're not closer...

 

[Wyomingcowboy]

I have actually got three transmission jacks! I have one that rolls real low on the ground. I used that one to get it out. And I have one that's made for using while a vehicle is up on a lift. That's the one i want to use as I'll have more room to move around and stuff. And I have another nifty little setup that mounts onto an existing floor jack. I'm looking at MKrieberg's idea and think that might work. It would make stabbing the motor on harder, but the transmission's done, the motor's not (and won't be for another week) and time is what I have an abundance of right now.

 

[Dieseldemon]

I have done a bunch of taking the engine out and leave the trans in just block and use a bottle jack to raise it and turn the engine to line the splines the only one that I could not do that with was an 06 as there was not enough room between the pan and xmember