Engine/Transmission (1998.5 - 2002) NV5600 & Synchro's

[AKDrifter]

I have a transmission oil change coming up in another 7k miles I am going to add a bottle and give it a try before I drop the oil and get another opinion; maybe others should give it a try. .

I'm at the same crossroads here and will also try the FM for my trip to AK and back next month. I've beeen waiting 89,000 miles for the shifting to loosen up, this does'nt seem to be a huge risk to take for an easier shifting trans.



Paul

 

[MrDiesel]

I finally changed mine today to Amsoil w/ the LS additive. Only thing is I know (or think) I need some clutch work, and till I get it checked out I don't drive it much. But I'll try to keep you posted...

 

[Fogie]

According to Quad 4X4 the synchros in the NV4500 are stamped steel with carbon fiber for the center ring. This is the NVG OEM. The reason for the GL-4 is for the carbon fiber center ring. I rebuilt mine a year ago, and carbon fiber came out, and then carbon fiber went in. No brass in the NV4500.

 

[steved]

I got thinking about this... this may explain why certain gear oils seem to work better than others... some gear oils already have the LS Modifier in them... make sense?? Depending on how much they actually had... might make a difference between oils...



steved

 

[Buffalo]

Awhile back, I remember reading that TDR member Joseph Donnelly tried a manual transmission fluid from Torco & reported a fairly substantial improvement in shifting quality, in his '04, NV-5600.



Personally, I've tried Pennsoil Synchromesh with no significant improvement in shift quality.



The last fluid change, I tried Specialty Formulations, MTL-P (www.specialtyformulations.com), which, I heard about on "bob is the oil guy.com". It has improved the shift quality, slightly, in comparison to the others I've tried.



Joe F. (Buffalo)

 

[steved]

Awhile back, I remember reading that TDR member Joseph Donnelly tried a manual transmission fluid from Torco & reported a fairly substantial improvement in shifting quality, in his '04, NV-5600.



Personally, I've tried Pennsoil Synchromesh with no significant improvement in shift quality.



The last fluid change, I tried Specialty Formulations, MTL-P (www.specialtyformulations.com), which, I heard about on "bob is the oil guy.com". It has improved the shift quality, slightly, in comparison to the others I've tried.



Joe F. (Buffalo)

I believe Pennzoil Synchromesh is the factory fill IIRC. I agree, I changed mine at 50k and it only made a slight improvement for a short time... I used PZ synchromesh.



I got a case of Royal Purple Symchromax sitting waiting for me to get off my butt to change... anyone else running RP??





steved

 

[Hohn]

The factory fill is a Texaco formulation, not Pennzoil.

Pennzoil just happens to be about the only off-the-shelf lube that meets the MS-9224 or whatever it is spec that the 5600 needs.

The factory lube is VERY hard to find in Texaco bottling. You can buy it in MOpar bottling for $20/qt or something like that. Ripoff.


Personally, I'll be trying the Torco lube next change.

jh

 

[Gary - K7GLD]

Just a reminder, that there is at least SOME potential that the stuff that improves shifting, may well NOT be properly performing it's basic function of gear and bearing lubrication. Sometimes "fixing" one problem ends up creating another, worse one...



FWIW

 

[steved]

Just a reminder, that there is at least SOME potential that the stuff that improves shifting, may well NOT be properly performing it's basic function of gear and bearing lubrication. Sometimes "fixing" one problem ends up creating another, worse one...



FWIW

While I agree with this statement, the additive in question is used in differentials with bearings and gears similar to the NV5600... for what it is worth.



It's not like adding STP to the 5600... or using some other "snake oil" in a bottle.



Just a thought,

steved

 

[Gary - K7GLD]

While I agree with this statement, the additive in question is used in differentials with bearings and gears similar to the NV5600... for what it is worth.



It's not like adding STP to the 5600... or using some other "snake oil" in a bottle.



Just a thought,

steved

UMMmmmm - not entirely certain about that similarity of gear types and operation Steve - the Hyphoid type differential gears (if that's what they still call them) involve a fair amount of slippage at the gear teeth engagement surface - a "wiping" action that is quite a bit different from the action in transmission gears - and at least one reason differential lubes aren't also used in transmissions - different operating conditions and lube characteristics...



At least that's the way I understand it.

 

[NVR FNSH]

Personally, I'll be trying the Torco lube next change.



jh

How's the MTL/Lubegard combo holding up?



Brian

 

[nps]

How's the MTL/Lubegard combo holding up?



Brian

I've got it in my transmission and tcase. Holding good so far. IIRC, Hohn says the Lubegard wore off after a few months, but mine has been in for about 6 months and still shifts good, both up and down (with the Ebrake I find myself downshifting more that I used to so I can keep the RPMs up).

 

[Hohn]

How's the MTL/Lubegard combo holding up?

Brian

It was short-lived.

Last month I changed the fluid to RP synchromax.

Instantly the shifting was MUCH improved.

2 weeks later, the improvement was MUCH less-- about what new MTL would have done, I suppose.

Torco is next.

Oddly enough, the MTL & RP I've tried has been MUCH better than the factory stuff for shifting-- the worst was Pennzoil. It was so bad I changed it after 5K.


I have high hopes for Torco... ... .

 

[steved]

It was short-lived.



the worst was Pennzoil. It was so bad I changed it after 5K.

I'm changing mine soon again too... I feel the same, it really didn't improve much if anything... I got RP synchromesh to put in...



steved

 

[NVR FNSH]

Best price I've found for Torco RTF is http://www.onoffroad.com/Merchant2/...RTF&Category_Code=TORCO-AUTOMOTIVE-LUBRICANTS



Unfortunately, I don't have any dealers near by.



Brian

 

[Bob Cochran]

How much do you put in? It would appear that to much might hurt something in the 5600 and to little may not work.



I just read what I posted above. Must have thought what a DUMMY. I ment how much Mopar Limited Slip Differential gear oil additive do you put in, that sounds much better.

 

[Froadin]

Everything I have tried so far always shifts better at first, then starts getting worse overtime.

The Redline took a few miles before it started shifting better.

The RP was next, and it shifted better right off, but still wore out fast.

Went back to stock (dealership did this under warranty for something else), this helped for a while as well, but still got bad.

I haven't tried the amsoil yet though, so I will waste me money on that next. Soon too, as it is not shifting very well right now, AGAIN.

 

[Tomeygun]

I haven't tried the amsoil yet though, so I will waste me money on that next. Soon too, as it is not shifting very well right now, AGAIN.

Thats what I have in my NV4500, And I like it. .



Only rough in the cold morning

 

[kscheffler]

I still use the OEM fluid, brought two cases for $10 per bottle, since this cost is comparable to the others. I only notice that after 15 to 20k that the transmission gets "sticky". It just seem that some of you are experiencing a change in the after market stuff in a short time. This is not my experience with the OEM it goes after a long period of time. So maybe the OEM (Texaco) juice is working as designed. Anyway just my observations I have 3 more changes before I run out of OEM. .

 

[rivercat]

I have only used Amzoil MTF and it seems ok. I find the smoothest shifts to be either without the clutch or double cluched. Everyone try that-Press the clutch to pull out of gear then let off for a sec then press to put into higher/lower gear. Could be lag in the heavy inards-just something we have to live with. You cant expect a true TRUCK to drive like a sports car and just suck into gear everytime and quick too.