NV5600 2nd to 3rd gear grinding

[SSalzer]

A buddy of mine has an '02 with the NV5600 6 speed (same trans as in my '05). He's having a problem with a little grinding from 2nd to 3rd. I searched the 2nd Gen forums and seems like there's a lot of that going around. Has the trans changed for our trucks, or is it just that they have more miles on theirs? I haven't really found many posts about the 3rd Gen's. Mine still shifts like butter. Also, we just put a SB ConFe in his. No grinding for the first 3 weeks it was in. Just a coincidence?

 

[steved]

Has he changed the fluid in a while? Mine will do that exact thing if the fluid has any miles on it... I change the fluid and it goes away. And its typically only the 2nd to 3rd gear shift...

 

[SSalzer]

It started happening right after the fluid change. We changed it the same day we did the clutch. Didn't happen before that. We're thinking syncro's?

 

[steved]

What oil was used? (It sounds like the wrong oil was used)

I was also going to say a sticky pilot bearing, but that *should* cause issues in all gears.

 

[JKreiss]

Are there anymore developments on this issue. Just changed the fluid with 130k. Using Amsoil synchromesh, never did it before but now the 2nd-3rd shift grinds as it goes in. Any thoughts?

 

[macdaddy]

What? No Amsoil sales pitch yet!!!!!!!!!





Mac

 

[blacksheepdiesel]

The least expensive thing to try is a different fluid. I use and recommend Royal Purple Synchro Mesh? I think that's the right name.

Godspeed,
Trent

 

[JKreiss]

Thanks for the help Trent. I sure would hate to have to change the fluid out again, it's a hell of a lot cheaper then transmission work though. I'm going to give it maybe 50 miles or so and see what it does. I'm not taking any chances, if it keeps up i'll try something different.

 

[blacksheepdiesel]

Make sure and put 6. 5 qts in through the shift tower. The extra fluid helps lubricate the rear output bearing.

Godspeed,
Trent

 

[Prairie Dog]

Make sure and put 6. 5 qts in through the shift tower. The extra fluid helps lubricate the rear output bearing.



Godspeed,

Trent

How exactly do you do that? I mean, how do you get the boot off and what does a guy find lurking under there?

 

[zzman]

Had mine rebuilt because I put the wrong fluid in it.

The syncros was the first thing to go. Then busted gears.

I put atleast 1 qt extra in mine now, amsoil at this time.



Hey Prairie Dog,

When you get both boots off, just take the star screws out and remove the shifter.

 

[JKreiss]

Thanks Ron, what fluid took out the transmission? I'm using the amsoil manual synchromesh transmission fluid. Had Redline in it before... at least that's what i was told was put in it. When i drained the fluid it looked liked a milky yellowish fluid

 

[blacksheepdiesel]

Prairie Dog,

Yep, it's just some screws on the rubber boot and then 4 bolts on the shifter assembly. Make sure to have a rag ready to put under the shifter so you don't drip oil on your carpet. Then just dump the fluid in.

Godspeed,
Trent

 

[steved]

First, while Redline MTL, RP SynchroMax, and Amsoil MTF are all synchromesh fluids; they all vary slightly in viscosity with MTL the "thickest", RP the "thinnest", and Amsoil somewhere in between. I found that my particular NV5600 does better with a thicker fluid (Redline MTL) and shifts the poorest with RP SynchroMax... I have even went as far as blending a quart of MT90 with the 7 or so quarts of MTL for even better feel.

Secondly, I read your statement "When i drained the fluid it looked liked a milky yellowish fluid"; and immediately think you got water contamination. I have put over 150k on different Redline MTL fills, and it drained looking like it was just put into use... never like what you described. You might want to investigate that further... like a blocked vent.