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

[steved]

Hohn:



How is the Lucas additive doing... still shifting good???



steved

 

[steved]

So how is the LSD additive holding up so far... it has been a while.



steved

 

[Scrappy]

Any updates? I tried the Lubegard (2 bottles) additive with my fresh factory lube and it was better for a little while but it has degraded back to the way it was.

 

[CFAR]

Normally I hit 2nd, then go into 1st. Same with reverse. Of course if you put it into 1st, then take it out, it goes right back in, if you take it out of 1st and then let off the clutch, then try to go into 1st it's hard, unless of course you go into 2nd first. Same deal with reverse. All of my upward gears seem notchy, 1st, 3rd, 5th, Rev.



About 80 on this batch of Penzoil.



No complaints with the 6 sp, except maybe, lack of parts when it needs a rebuild. I also have the short shifter kit, which amplifies the nochty-ness.

 

[steved]

I bought two bottles of the Lucas Trans additive today... it states right on the bottle "will improve hard shifting"... I'm also going to run a little bit in the tcase as well...



It also states to add a bottle to the transmission then top off with 15w40 or 10w30... ? Hmm, that sounds interesting to me... I could see using some synthetic 5w30 and a bottle of this stuff instead of synchromesh...



steved

 

[steved]

OK, took the plunge...



Drained and filled the transmission (fourth time in 2 weeks), the tcase, and the 11. 50 rear last night...



Used a bottle of the Lucas in the transmission and half a bottle in the tcase (didn't want it too thick since there is only two quarts of ATF in there to dilute it), and 85w140 synthetic in the rear... here are my results with the transmission:



Shifting: still "clicks" in and out of gear, but all the stickiness is gone... shifts a whole lot better than even the redline by itself... the redline drained crystal clear (should have since it only had about 1k miles on it)... felt bad draining $50 in new oil, but...



Temperatures: This was the most notable thing... before the Lucas, transmission temps would climb to 190* in 10 miles of driving 65mph... now, I drove 50+ miles to work today (35 miles of that was 70mph highway) and the temperature was just above 150*... initial readings indicate close to a 40* drop in operating temps!! Now, don't get me wrong, this was a single run... If anything, the Lucas really lengthens the time it takes for the transmission temps to rise. I got a 2100 mile trip on thursday, so we shall see what it does over the long haul... plus back and fourth to work the rest of this week yet...



So for an initial report, I'm impressed with the Lucas/Redline MTL mix...



steved

 

[WestTN]

It just might be the gears are being slowed too quickly to mate properly. I'm planning to try this in my truck. It has shifted rough for 107,00+ miles.

 

[steved]

OK, well the temperature thing... while it takes longer for the temp to reach "hot", I'm not sure that it won't eventually reach that mark... might take several hundred miles to do it, but I feel it will eventually top out at the original "hot" temperature... I just find it funny how much longer it takes to get there!



So far, the transmission is shifting better than it ever has... 300 miles to date... longer than the first change of Royal Purple lasted!



steved

 

[CFAR]

OK, well the temperature thing... while it takes longer for the temp to reach "hot", I'm not sure that it won't eventually reach that mark... might take several hundred miles to do it, but I feel it will eventually top out at the original "hot" temperature... I just find it funny how much longer it takes to get there!



So far, the transmission is shifting better than it ever has... 300 miles to date... longer than the first change of Royal Purple lasted!



steved

Did you have your temp gauge installed with the stock lube? Do you have fast coolers installed? I just realized that my temp probe went in when I put on the fast coolers. So I have no data on stock lube/no Fast Coolers. Mine, unloaded won't go above 160 with the penzoil. loaded I've hit 225 at about 70mph. If I slow down the temps fall.

 

[steved]

Did you have your temp gauge installed with the stock lube? Do you have fast coolers installed? I just realized that my temp probe went in when I put on the fast coolers. So I have no data on stock lube/no Fast Coolers. Mine, unloaded won't go above 160 with the penzoil. loaded I've hit 225 at about 70mph. If I slow down the temps fall.

No, didn't have the guage in with the stock fluid... no coolers either... temp sender is mounted in a plug that we brazed low into the passenger side PTO cover...



The Royal Purple ran the coolest... ran 175*s at 65mph (unloaded)... but it didn't work out for me...



I'm running around 160* (just a little above the 150* mark) right now with the Redline/Lucas mix... I don't know if it would still be climbing if I stayed on the road, but it should be at max temp in 50+ miles...



When it was just redline, it ran 190* unloaded at 65mph, and just shy of 230* with over 6k on the trailer. Additionally, the Redline would be at 190* in less than 15 miles of highway driving...



I'm going to pop the cork on the transmission tonight and check the fluid level... also going to do it right after I get home to see if the fluid is foaming...





steved

 

[CFAR]

Maybe it doesn't matter, but 190 unloaded seems high, but then again you don't have coolers, and I don't remember what the claim is on their temp lowering ability.

 

[steved]

Maybe it doesn't matter, but 190 unloaded seems high, but then again you don't have coolers, and I don't remember what the claim is on their temp lowering ability.

I saw an old thread where they (fastcoolers) claimed only 10*, but from what I have seen others post, it seems like they provide more like 20* of cooling... I'm thinking of getting some heat sinks and simply bolting them to the PTO covers... :-laf



I was told by Royal Purple that 190* was well within operating temps for their oil which I think he mentioned 400* as the maximum for the RP synchromax.





steved

 

[JasonCzerak]

I bought two bottles of the Lucas Trans additive today... it states right on the bottle "will improve hard shifting"... I'm also going to run a little bit in the tcase as well...



It also states to add a bottle to the transmission then top off with 15w40 or 10w30... ? Hmm, that sounds interesting to me... I could see using some synthetic 5w30 and a bottle of this stuff instead of synchromesh...



steved

hmm, I might try this as well. My shifting stiff ness came with the ConFE. I had a vibration for the longgest time, figured I broke something on the stock clutch (hard launch). the new ConFE didn't fix it. So either I have bad u-joints still, or a jacked transmission.



Do you guys with ConFE's get a vibration in the throttle and clutch peddle at high RPM's and loads as you go to grab the next gear?



My down shifts are actully BETTER withy the ConFE, but the upshifts will slow you down.



I do have difficulty getting into 1st and reverse and sometimes 2nd



off to lunch and to get some of that fluid. napa,. here I come

 

[blacksheep4x4]

Some of the things said on this post make me wonder if this transmission wasn't made to be run with automatic transmission fluid in it. I personslly have a NV5600 in my '03 that gives me hell sometimes whe trying to shift in to reverse. The shifting really gets bad after towing a trailer for a long distance. Then a few days later if the truck hasn't been used for towing it eases up and starts shifting better. I bought a rebuild kit for this trans (haven't had the time to put it in yet) and the rebuild kit comes with some strange looking brass syncros. The have a coned shape to them and a real gritty feel. I am tempted to try auto fluid in it and see what happens. What do you guys think about doing so?

 

[jwernert]

When I get in the truck cold, it will shift into any gear no problem. After I've driven a few miles it gets worse. I've had times lately when I couldn't get it into any gear including 4,5,&6. On those days I can let the clutch out or blip the throttle and get it to take 3rd or 2nd. After it goes into a gear, then I can get it into reverse. I changed the fluid to penzoil about 15k or so. I never had the trouble before it has slowly gotten worse since I changed the fluid. My truck has 115k miles. Down shifting while the truck is moving isn't a problem. So do I need new fluid or just add the Lucas treatment?

 

[steved]

Some of the things said on this post make me wonder if this transmission wasn't made to be run with automatic transmission fluid in it. I personslly have a NV5600 in my '03 that gives me hell sometimes whe trying to shift in to reverse. The shifting really gets bad after towing a trailer for a long distance. Then a few days later if the truck hasn't been used for towing it eases up and starts shifting better. I bought a rebuild kit for this trans (haven't had the time to put it in yet) and the rebuild kit comes with some strange looking brass syncros. The have a coned shape to them and a real gritty feel. I am tempted to try auto fluid in it and see what happens. What do you guys think about doing so?

I don't know about the auto fluid... they run it in the G56, but it might be designed for it also... the Lucas Additive, while targetting autos primarily, is made for both autos and manuals...



I was under the impression the synchros for the 5600 were "carbon fiber" like a clutch pack?? I have often wondered if there are several versions of the synchros... I have also wondered if the fluids are creating too much "bite" for the synchronizers to slip or if they are not creating enough "bite" for the synchronizers to "spin up" to the next gear's RPM??? The prior would explain why LSD additive seems to work so well, but the later doesn't...



And my transmission, while sometime beligerant taking 1st and reverse from a standstill, will usually "loosen" up when the fluid gets hot... it shifts the best with the fluid at max temp and worse when cold... when cold, I need to double clutch usually to smooth the shifts out. Once in a while it will "touch teeth" going into 5th, but it is usually just a "tap-tap" (enough you can tell you touched the other gear while it was still turning really slow) and drops right in...



I have been having mixed shifting lately and I am wondering if the pilot bearing is "sticky" and not allowing the transmission to spin free of the engine completely?? One day it will shift like a champ, the next the engine seems to drag the transmission down too quickly...



steved

 

[steved]

When I get in the truck cold, it will shift into any gear no problem. After I've driven a few miles it gets worse. I've had times lately when I couldn't get it into any gear including 4,5,&6. On those days I can let the clutch out or blip the throttle and get it to take 3rd or 2nd. After it goes into a gear, then I can get it into reverse. I changed the fluid to penzoil about 15k or so. I never had the trouble before it has slowly gotten worse since I changed the fluid. My truck has 115k miles. Down shifting while the truck is moving isn't a problem. So do I need new fluid or just add the Lucas treatment?

That's the exact opposite problem I have... mine shifts like trash when cold... at max temp it shifts good.



What you describe is exactly what happened when the Royal Purple took a dump on me... it got real sticky, not bad enough it wouldn't go into gear though, but you really needed to coerce it into the slot you wanted.



steved

 

[Texas Diesel]

Just a thought here. Perhaps the transmission fluid over heating is a problem. Cast iron is a poor conductor of heat.



Even with the Fast Cooler I get get to 250F in the summer pulling heavy. Bet that with out the fastcooler the temps would be higher, not sure how much though.



Fluid that works good then seddenly gets 'sticky' sounds like burned oil. Heat some in a pot and see how sticky it gets.



Since I added the Fastcooler I havnt had any trouble with fluid suddenly going bad. I've put almost 60k miles on a fluid change and still have good performance.



FTR I have a Fastcooler on the driver side PTO port and Genos - Eaton PTO filter on the passenger side. I ALWAYS overfill the transmission by a quart or so too.



It's pretty well known that DC sets the oil levels so that no fluid sits below seal level. They arent concerned with longevity (I suspect they actually dont want LONG life spans) they are worried about warranty costs associated with marginal seals. My axles get over filled too. If the seal is good then overfilling wont make it leak.



Several transmission rebuilders have told me to change the transmission fluid at 30k miles or once a year for longest life.

 

[JasonCzerak]

Added the Lucas stuff. The entire 24ox bottle. Things seem a LITTLE easier to push around, little more notchy, only got to drive like 4 or 5 miles after I installed it, including a run to 108 on the e-way.



Today it's raining out, so all I was doing was slipp and slidding around, so now real performace shifting. But I don't think things helped much in that regard today.



We'll see in the days to come.



BUT, it didn't get worse

 

[steved]

Just a thought here. Perhaps the transmission fluid over heating is a problem. Cast iron is a poor conductor of heat.



FTR I have a Fastcooler on the driver side PTO port and Genos - Eaton PTO filter on the passenger side. I ALWAYS overfill the transmission by a quart or so too.

I know RP told me their oil was stable to 400* IIRC... I never even got close to that...



I want to do the single fast cooler/filter combo too, but you can't buy just a single fast cooler... which are way overpriced for all they really are...



How do you overfill the transmission?? Through the top?



steved