Are the Fast coolers for the NV-5600 worth it for someone who doesn't tow heavy? I want to keep my truck for quite a while, with the NV-5600 parts becoming scarce, I want to do whatever I can to prolong it's life.

~Rob

 

not sure....never ran withtout the coolers, they were installed when i bought it. my tranny temp gauge will still get to 150* on a long highway trip running a steady 75-80mph tho. the added 2-3 quarts of fluid is probably the best benefit rather than its actual cooling capacity.

im getting ready to drain my fluid for some amsoil synthetic tho...that will really extend tranny life.

 

I had the Amsoil synthetic in mine but didn't like the way it shifted. I drained after only 7 or 8000 miles and put the Redline MTL synthetic in. It shifts a whole lot better. Just thought I'd mention it. Most others also like how the Redline MTL shifts as well.

 

may have to look into that?

what does the MTL cost?

 

If you do get MTL make sure to keep us posted about tranny temps. Mine ran HOT after putting the Redline in. Drained it after a few thousand miles. Went in nice and red came out ice tea brown.

I just stick to OEM now.....Temps stay in check well.

 

It was somewhere around $6-7 qt best I can recall. Local Napa got it for me (franchise store), don't know if company owned store can get it.

On the color when drained, I don't know about that, mine has only been in for a few thousand miles so far. Stk fluid at at 100k was very clean. Amsoil was equally clean, but only 7-8000 on it. Redline came highly recommended to me by folks on DTR and TDR.

 

Rob....it coudn't hurt.....

As for oil....the place I used to work at in Texas, we ran Amsoil in a NV-4500HD after a clutch install (Con FE). It was ok at first...but then you couldnt get it into rev, kept missing gears and got REAL notchy. To the point your arm was real sore after driving. Was it the oil? Was it the Con FE (pilot bushing misaligned)? Who knows.....

Amsoil is some of the best oil out there. BUT i have read seveal people running it in the NV series trans and the shifing goes to crud. The trans has a tag on the PTO cover that calls for some Synt Castrol oil. I hear this is good stuff...and places i have talked to that rebuild these NV's say dont run anything but it. If i change my fluid, even with all the connection to people that can get me Synt oil, i will run the factory Castrol oil in my trans. NOW engine, D-80, D-60 and T-case......I got some good stuff in that already!

 

My experience exactly with the exception that I put in an OFE at the same time as the Amsoil change. I do believe, however, that the notchy shifting and difficultly shifting to reverse and first was due to the fluid and not the clutch or install.

A couple of reasons:
1) after I changed clutches again to the SBC DD, shifting was the same. After a little while of driving with the DD I drained the Amsoil and put the Redline MTL in and shifting was much improved.
2) others who have run the Amsoil manual tranny fluid have agreed that their shifting suffered and became notchier.
3) clutch was professionally installed though I helped and SBC provides an alignment tool.

 

i will be switching out to some redline soon. i run the royal purple stuff in there now and i hate the way it shifts. fights me into reverse and 5th alot

 

With the fluidamper on there my shifting has gotten glossy smooth using the redline mtl. I always go into 5th before reverse and have trouble getting into gear from a stop but that changed with the clutch and it remained the same with the old unknown fluid vs the new redline mtl. But properly timed shifts are very smooth now despite the colder weather.

You can also get Redline oils from Jegs for $8 a quart.

 

how many of you guys do the overfill on nv5600's?

i think the stock tranny holds 5qts, add 2 gts for my fast coolers, but i still put an extra quart in. i noticed it helped alot at first...but i still have hard shifts when i rev it out past 3200rpms...if i time my shifts early (2700-3000rpms) i hardly ever miss a gear...but it pulls so hard in the upper rpms now its hard to shift early.

 

I have the Amsoil MTG in mine and it shifts better than it did before. Never been changed though.

 

when you over fill the tranny how do you get that much fluid in it to begin with and how do you keep it from coming out the vent???

 

fill from the top of the tower...only takes a few minutes to disassemble, or put the truck on jackstands on one side only to tilt the tranny over fill from the top PTO cover bolt.