Life with the new 6 Speed Manual

[Dave3500]

What's that old saying?...........................With friends like that, who needs enemies! I know there just messin w ya!

 

Think my Dad used to say that,

Dave

[KATOOM]

I'm not so sure I agree here with the same level of concern.....  I really dont think the friction or stress placed on the crank with the clutch pushed in during starting is something to really worry about.  In saying that, I remember there being a lot of discussion years ago about how much "better" it is to start with the clutch in.....and remain holding it in until the oil pressure registers.  That being so to alleviate any added load on the crank having to turn the weight of the transmission internals and those internals also pushing through cold gear lube.  So which is it?.....  Personally I'm not sure it matters much either way.  If I remember correctly the load thrust bearing on these engines is located on the 6th main journal which gets supplied by the oil pump almost instantaneously.  If the crank didn't receive lubrication as quickly as it does and instead took the 10 seconds it takes to register oil pressure on the gauge, the crank and rod journals wouldn't last a year.  So why would the thrust bearing last any less?

[oldbeek]

As a fleet manager, I found synthetics in gear boxes and differentials had a much higher pay back (better  mileage and durability) than synthetic in the engine. Synthetic grease in heavy equipment also pays for itself. I now run synthetic everywhere except the engine. I don't use it in my engine because I don't run enough miles to justify it.

[Dave3500]

Actually, now that you mention it, I'm doing the same in my truck. W the Rotella if I open the fill cap & look inside it looks like a new engine, so perfect there! But my Wife's & our  DD's require syn so I run it in both applications, I like the longer drain intervals.

 

Thanks,

Dave

[rancherman]

Probably no  'right or wrong'  in  this instance.

But,  I look at it as  common sense type  engineering principles.

On horizontal  crankshafts,  the rod and main bearing  are also horizontal.  Plus the  fact there is only   ~ 3-5 thousandths  clearance  in the  crank and  bearing  surface.  The  cohesive bond  on the oil,  between the  journal and bearing  is  strong.  Meaning  there should always be  a  'wedge' of  oil   'chasing' the   'tight' spot.  

Our engines,  when @ rest,  the crank is  on the bottom of the main journals.  The  gap  is  wide  at the top, which is also  where the oil comes  from. (those  galleries will also have oil just sitting there,  even w/o pressure     Our  oil galleries  do not  empty out upon shut down...  vacuum and  the  bond of oil in a small passageway   keeps it  in place.

Rods will probably all be  'down' against the rod journals,  and  the 'gap'  below  the journal will also be filled  with  oil. 

Now,  In the case  of   the thrust bearing,  which is  totally  vertical,   there is almost zero  'wedging'...  except for the  tiny little  indentation which may hold  a  miniscule amount of   oil.    When  the  clutch is  jammed  to  start the engine,  it's placing  equal amounts of pressure  forward on the  crank.    This little ring  of  bearing surface   has  been  squeezed  pretty  tight,  and  what's left of the film  is   pretty  thin.  With  little or no  'reserve' to  help  'chase' the  tight spot.  The  'tight spot' in this case  is  the entire circumference of this  surface.       The little film is much  thinner than  what is  available  to  supply lube  in  the  rod or main bearings  (remember the  'gap'?)  The only time this bearing will ever  see 'new pressurized'  oil will be long after the  engine  is  running,  oil pressure is  up,  and FOOT IS OFF  THE CLUTCH.  I say this,  because  the  oil will definitely go out the  front side  thrust bearing..  it'll be the easiest path.

So,   when it's all added up,    and the facts  are crunched,     I doubt  most    owners  will ever see  any benefit  from not holding the clutch while cranking...  but  I  guarantee you,  for  guys such as me,  (the ones  that   rebuild  engines  for  their  2-3 lifespans)    the  inevitable  has taken  place:  the  thrust  area  on the crank itself is  taking a beating..    Most of the time,  a  regrinding will  clean it up..  I have no idea  what kind of  surface treatment  Cummins  uses  on their  cranks..  and  if   regrinding  is  a long term fix  or  short term  disaster! 

This crank degradation will not leave  anyone on the side of the road!   It  may however   cost  a little more  when the engine is  rebuilt:  Either  more machining  costs to re-do the  crank itself, or  in worse case scenario a new crank will be  needed.  This is the class of  consumer I fall into!   Shoot,  10 years from now,   my 12v  engine may be powering  a tractor,  stationary pump.. who knows?

 

Ok,  ONWARD HO!     If our  trannies  were filled with   90-140 gear oil,  I'd say  YOU BET!   there is gonna be  more of a load  upon our  starters for sure.   Especially when it's below 0 F.        The almost  Mazzola  weight  oil  that's spec'd for these  trans  is  not even a fly in the ointment.    But  I don't see any changes  in  the  way  those little  'wedges'  is going to change  based on a little rotational loading of the crankshaft.

All of the accessory drives  are immediately  loading the crank... in fact,  there is quite a  loading just to 'drive' the cam!    But again,  the  crank's defense is  that little  wedge.

 

So,  to answer your question on who is right, who is wrong..  I'm  going to  say 'both'.

Is there  benefits to  not using the clutch?  yup..  LONNNNGGG term!

'will it   benefit  me'?     probably not.  It'll be  the  guy digging these out of  the iron pile for rebuilding who'll thank you.

And  lastly,  'level of concern'.. to most:  on a  rating of  1-10,   probably  a  1.      For me,  it's  a  7-8.  Only because I'm the ultimate recycler!  

 

  Guys will argue to the death on   why running  synthetic oil  is the ONLY way to fly with these engines..  but in real life,  most guys  will put  on    2-300k miles  AT MOST  before the next owner will  be  appreciative/get the benefit  from it... 

Edited September 10, 2014 by rancherman

[Dave3500]

Hi all it's been awhile.

 

So I was towing my light camper home from Tybee Island, Georgia back to Ohio & blew out my driveshaft on the 1st long hill in Virginia. Sunday night. The truck is sitting in Wytheville, Virginia in a UHaul storage till I can get back down w a car hauler. As far as I can tell the trans locked up & sheared the bolts off of the rear yoke.

 

I had the top seal replaced before I left because it was leaking a little, but kept my eye on it, did not leak a drop, it had the 7 qt limit, so I don't get it! No vibrations in the truck before, so? I only put 3K on the swap since last Summer. She's a garage queen!

 

Dave

[Mopar1973Man]

Well you'll have to get it home and open it up so we can see what happened.

[Dave3500]

I was hoping that this was going to be the solution the the 4th gear hunt problem I was having. Now another tranny issue? Aren't these supposed to be bulletproof?

 

Dave

[TFaoro]

From my reading, the 6 speed can be hit or miss. Sometimes you get a great trans and sometimes they grenade. Lucky for you there are parts suppliers unlike 3-5 years ago when NV quit making parts for them. You should be able to have a reputable shop rebuild it for you.

[KATOOM]

I was hoping that this was going to be the solution the the 4th gear hunt problem I was having. Now another tranny issue? Aren't these supposed to be bulletproof?

 

Dave

Nothings bulletproof.....  But yes, generally the 5600 is a safe bet.  The only common issues that I can think of off the top of my head with that tranny is, they do better when overfilled for better bearing lubrication.  And making sure the correct fluid type is used.  There's quite of bit of discussion on this very topic too.....

[Dave3500]

Yes, it was overfilled & was using the syncro stuff. I've had much of the info directed towards me & I followed all the best of solutions, one of the reasons I was surprised the tranny locked up. I thought I lost my VP44 because on the last tank I didn't have enough 2-cycle.

 

Thanks,

Dave

[KATOOM]

Well let everyone know what happened when you get everything pulled apart.

[Dave3500]

Sure will, I'm still figuring out how to get the truck back here, still 400 miles away. Everyone that said they would help is not available!

[lrhull]

So my owners manual states the nv5600 is filled by the factory and does not need periodic fluid change. However if you do need to add or change you should use mopar 4874464. I have never changed the fluid. I don't now if previous owner ever changed the fluid. I do have a hard time finding a gear every once and a while and it defenently doesn't shift as easy as the vw jetta. I've thought about changing the fluid but I did that once in our dodge caravan and soon after it crapped out I believe because of changing the fluid. So I can't decide.

[KATOOM]

Factory manuals will usually state things like "lifetime" fluids for various driveline components but in reality the service life of a lubricating fluid is based completely on the temperature that fluid runs at.  Meaning, if you tow often and/or drive in triple digit weather often, or live in mountains, then you may consider that the fluid has probably gotten hotter than the desired maximum temps a time or two.  Or if there's a small leak and the fluid level drops to a point where heat becomes a problem due to lubrication issues.  If the driveline components never get overly hot, are never subject to water intrusion, and run under mild temps forever then eccentially the fluid should last forever.  At least 100,000 miles easy.  That obviously excludes the engine though.....

 

Point being is that there are reasons why you'd always want to keep an eye on the driveline component fluids.  That doesnt mean they need to be changed every "X" amount of miles but that you should and can assess how often you need to maintain something based on the driving conditions and how the vehicle is used.  Taking the approach that if you mess with it then something will go wrong simply means that you should have someone else perform the task.  Or should I say.....someone who knows what they're doing and doesnt mess things up.

Edited May 2, 2015 by KATOOM

[Hawkez]

So my owners manual states the nv5600 is filled by the factory and does not need periodic fluid change. However if you do need to add or change you should use mopar 4874464. I have never changed the fluid. I don't now if previous owner ever changed the fluid. I do have a hard time finding a gear every once and a while and it defenently doesn't shift as easy as the vw jetta. I've thought about changing the fluid but I did that once in our dodge caravan and soon after it crapped out I believe because of changing the fluid. So I can't decide.

I bought my truck with 100K on it.  I changed my transmission oil soon after and it did seem to shift better.  I would certainly suggest that it should be changed at some point and the oil level certainly needs to be checked.  It was really simple and I used an Amsoil product.

[Dave3500]

Agreed w Hawkez!

[Dave3500]

My problem right now is my truck is 400 miles away from home. The friend that has the truck & trailer is backing out, so still trying to figure out how to haul a 6,000+ truck home!

 

Dave

[Dave3500]

It's been over a week, and truck is still sitting in Virginia in in a UHaul lot. One starts to see who your friends are when One really needs help, tried to do the UShip thing but......

Will keep you posted, Dave!

[Buzzinhalfdozen]

I've been there before, sometime "friends"are hard to come by. Best of luck and keep us updated.