switching to Synthetic?
 

Hey guys-
Moved up to Alaska this year from the Pacific NW. Its been cold here (-6F) and its time for changing all the fluids. I was thinking about changing everything over to Synthetic. Whats your thoughts on switching (changing out diffs, trans (NV4500), and crankcase) and what oil do you all use. My 96 is just about to turn 65K on the odometer and doesn't have any leaks or other issues. Its run Delo all its life and I was looking at the Amsoil. It seems cheaper than the Rotella, and I can get everything at the same location (changing the transmission from Syntorq to Amsoil MTG).
Whats your thoughts?

Thanks

Truck runs and starts easier with synthetic in the cold climates.
I think it is worth every penny.
Plus, I picked up 2mpg switching all my fluids out to synthetic.

Everything but....
 

Change out all the fluids except the tranny. The Syntorq is already a synthetic and has a bunch of propietary stuff in it to keep the brass synchros from coming apart. I use Rotella 5w-40 synthetic in the winter, works great. Use the AFT+4 in the transfer case (it's synthetic as well) and Redline 75w-90 in the diff's. I also use Redline PSF in the power steering and bleed the brakes every year cause it's cheap insurance. For coolant I went with the Global stuff made by Fleetguard. just my .02

I like Mobil 1 I live in the Yukon so very similar conditions as Alaska

It should not be a question of should I change? It should be How quickly can I change? As stated the manual trans already has its own special synthetic oil and the only other oil approved for the NV4500 (that I know of) is the one from Amsoil which is 2 1/2 times less money than the factory oil. I recommend changing at 50,000mile intervals.

I've been using the Amsoil with no problem.
I know GAmes (member on here) has been using the Amsoil for hundreds of thousands of miles with no problems.
If you search, Royal Purple and Redline make a GL-4 tranny fluid also.

Thanks for the responses guys. I think the amsoil is Amsoil MTG for the transmission. Is this what everyone else uses? This is what Amsoil says-

Ideal for NV-4500 Transmissions
MTG is a thermally stable, extreme pressure formulation that resists heat, oxidation, acid build-up and varnish. It is the ideal gear lube for high temperature applications, including the New Venture NV-4500 transmission, which retains heat due to its cast iron housing and is often subjected to heavy loads and high torque from turbo-diesel engines.

AMSOIL MTG is the replacement fluid for GM part #12346190 and Chrysler part #4874459 (Chrysler specification #MS-9070).

Also what gear oil is everyone using? They have a 75/90, 75/110, and a 75/140. They also have a 75/90 extended life.

Thanks again guys.

Here's what I'm running:

NV4500:
http://www.amsoil.com/catalog.aspx?code=MTGQT-EA

Transfer case (right on the label it says it's approved to replace Chrysler +4):
http://www.amsoil.com/storefront/atf.aspx

Front and rear diff:
http://www.amsoil.com/catalog.aspx?code=AGLQT-EA

just an FYI, after switchign too synthetic, i developed a few drips. it does start nicer, but got tired of trying to find the leaks.

I've known a couple of guys whose switch to synthetic engine oil with high miles turned into a leak horror story.
Apparently the synthetic has a solvent type action that cleans out sludge that's blocking leaks.
Beware if you have high miles.

Check your tranny fluid, it might not need changing. I dumped my tranny fluid when I put a dual disc clutch in my dually. The oil came out a nice honey colour. I put the redline manual tranny fluid in it. Wasn't long after that my 3rd, 4th and 5th gear synchros virtually disappeared. I eventually lot fifth gear (thats an unrelated issue), I put in another nv4500 from a 94 in it that had over 400k km on it, dropped the oil out of that, still a nice honey colour. The redline in my original was black. After seeing that, I will stick with the Castrol stuff. I'd consider Amsoil if I were to change it again, but I wouldn't drain good Syntorq to replace it with Amsoil. JMO.