Advice on 6-speed fluid change needed

[mconstable]

hey everyone, been searching on this one, but have only found bits and pieces, so thought I'd ask for opinions on a synthetic for the 6-speed,(or non-syn... give opinions)... and at what mileage to change? I tow often... thanks in advance... Michael

 

[rbattelle]

There is no factory-spec change interval for the NV5600. I changed at 15000, and will again at 30000, then probably every 30000 after that.



I used Pennzoil synchromesh, which is non-synthetic. If you want a synthetic, I think Amsoil would probably be a good choice. Or Redline MTL. Others will chime in on this.

 

[Vaughn MacKenzie]

Go Redline

I've tried both Amsoil 5W30 Series 3000 and Redline MTL. I liked the Redline quite a bit better and felt better running it since it's designed for transmission (high pressure, shock loading and shear forces additives). It's also the correct weight. It's a No Brainer choice IMO. At 30,000 miles the stock stuff was pretty nasty. This was all on my 2001.



I have Redline ready to put in my 2003. Royal Purple makes a lube too but after reading the spec sheets and seeing it was quite a bit lighter than the Redline I opted for the Redline MTL.



Vaughn

 

[Slow Six]

I just changed mine out before Christmas at about 25000 miles. I had a lot of junk in the oil, there was even a small piece of metal. I jacked the rear end up to get the transmission more level and got inside and cleaned the bottom of the transmission case. I am glad I did this change as soon as I did so that all this junk isn't floating around the transmission. I used Redline MTL. I've put on about 5000 miles since the oil change and I think the shifting has improved. I used the Redline in my 94 and had good luck with it.

 

[Joseph Donnelly]

At 5600 miles I changed the lube to Pennzoil Synchromesh manual trans fluid from Autozone @$5. Shift quality noticeably improved, probably because of the brass powder in the original lube. Redline MTL seems to work well too. . . time will tell what is best. Lube like Pennzoil meeting the Mopar spec is best for waranty, if that matters.

 

[Mad Bomber]

Trans oil

Red line MTL90 was recommened by Peter @ South bend I took his advise

 

[lil red cummins]

is redline MTL90 a 90W oil?



i thought our trannies used 5W-30. am i wrong?



jim

 

[Mad Bomber]

Oil

I don't belive it is Red line also makes a 90W for the NV4500

 

[Joseph Donnelly]

I was referring to Redline MTL 70-80 weight.

 

[amsoilman]

Well, I installed the Amsoil lube in my NV-5600 around 2,000 miles. I now have over 23,000 and it shifts very nice... ... ... ... ... ... ... ... ... even in the cold temps we are now haveing. This AM it was 10 F. and the transmission shifted like it was the middle of July!



Wayne

amsoilman

 

[TexEdwards]

penz is a parrifin based oil I personaly would avoid it

 

[Casey Balvert]

I find it interesting the NV would fill their transmission with dino (if the factory fill is in fact dino) and then DC warrantees the transmission for 100,000 miles. If synthetic lube was so much better for this particular transmission, why not put it in at the factory and reduce the warrantee costs? I would think the guy designing and building them would know what is best for his stuff. I must be missing something. Can anyone confirm that the DC approved Synchromesh is in fact NOT synthetic?



Casey

 

[rbattelle]

Originally posted by Casey Balvert

I find it interesting the NV would fill their transmission with dino (if the factory fill is in fact dino) and then DC warrantees the transmission for 100,000 miles. If synthetic lube was so much better for this particular transmission, why not put it in at the factory and reduce the warrantee costs? I would think the guy designing and building them would know what is best for his stuff. I must be missing something. Can anyone confirm that the DC approved Synchromesh is in fact NOT synthetic?



Casey

The Pennzoil is definetly not synthetic... I assume it would read as such on the bottle. Nor is the Mopar stuff. Nowhere in the service manual is synthetic specified for the transmission.



TexEdwards,

What, exactly, is wrong with parrifin-based oil? And I don't mean "my uncles brothers cousins sisters dog used parrifin-based oil once, and was spontaneously decapitated as a result"... I mean what's wrong with it? If NVG says it's good for this transmission, I tend to side with them.

 

[amsoilman]

This is directly taken from my owners repair manual.



NOTE: DaimlerChrysler recommends using Mopar

lubricants or lubricants of equal quality.

NV3500 - Mopar Manual Transmission Lubricant

NV4500 - Mopar Synthetic 75W85 Manual

Transmission Lubricant

NV5600 - Mopart Manual Transmission Lubricant





Wayne

amsoilman

 

[rbattelle]

Originally posted by amsoilman

This is directly taken from my owners repair manual.



NOTE: DaimlerChrysler recommends using Mopar

lubricants or lubricants of equal quality.

NV3500 - Mopar Manual Transmission Lubricant

NV4500 - Mopar Synthetic 75W85 Manual

Transmission Lubricant

NV5600 - Mopart Manual Transmission Lubricant

I stand corrected! NV4500 owners need synthetic, but not NV5600 owners. Sorry!

 

[draymorris]

I like my Amsoil. Like Wayne said - it shifts like it is warm even when it is cold.



As far as using an oil that is "heavier" or "lighter". Isn't true that viscosities are based on standard test (SAE or ISO)? Amsoil or Redline or any other mfg would be taking a great risk using an oil that is not the viscosity that they show. If additives make the oil viscosity change, I don't beleive they could show 70-90 on the bottle if they already put something in it to make it a 140 weight.



No offense to anyone on any of these topics - I am just stated my point of veiw.



Also, regarding the factory specs on lubes. I have some strong opinions on "factory specs" We have an injection molding facility. We have 5 injection molding machines - on is very large and hold 440 gal of hydraulic fluid. The pump mfg recommends a different oil than the machine mfg, the oil company recommends different from them, and the filter mfg will tell you something a little different from all of them. SOOOOO ... think about this... . is the engineer that is in charge of specifying the lube is the 5600, 4500 etc, a lube specialist, gear specialist, someone who is neither and was given the task of asking an oil salemans what he would recommend based on blueprints. Each company operates in its own way. The true story behind an OEM spec is very hard to find. Personnally, I have had the best luck with the filter saleman on my hydrualic oil - he WANTS your pumps to last a long time so that he can brag about his filter. Same with the oil salesman. The machine mfg - they actually told me that they make over $3 million in spare parts sales annually - I don't think they care about my pumps as much. I know that if I lose a pump and tell them I think it was premature, the first thing they want to know is what kind of maintenance program I have - not what kind of oil do I use - they try to place the blame on me, in other words. As for the pump OEM, - he is so far from the real world, he just specs an oil and moves on to the next project. Engineers are not always right! ( We have a few employeed here)



Again, no offense to anyone!



I think the best thing a person can do is listen to others advice, try different things and in time you will know what works best for you - but be careful of the motives behind some advice.



I will get off my soap box now.

 

[rbattelle]

Originally posted by draymorris



SOOOOO ... think about this... . is the engineer that is in charge of specifying the lube is the 5600, 4500 etc, a lube specialist, gear specialist, someone who is neither and was given the task of asking an oil salemans what he would recommend based on blueprints.

Engineers are not always right! ( We have a few employeed here)

These are excellent points... I had not thought about the fact that the 5600 engineer who spec'd the lube in the 1st place may not have been a lubrication engineer at all. Or particularly bright, either!