I normally run royal purple, 5 quart capacity plus 1. I'm gonna run some pennzoil synchro mesh for my new re build break in then change over to something different. So I know to run synchro mesh, but I've heard of guys using redline and other stuff. 

What is y'alls recipes? 

I haven't seen a whole lot of synchro mesh options out there. 

Let's say that Dodge Dealer is now filling both NV4500 and NV5600 with ATF+4 transmission fluid. Since neither fluid is no longer manufactured.  If your worried about specs then Dodge dealer choice of ATF+4 is telling me there is not much to the spec other than its got to thin fluid for shift quality. 

 

This is an interesting thread on the subject.

 

 

I have always run the Penzoil sychromesh. Sure are a lot more thoughts on what to run in them these days.

Heck, even the GetRag 360 was 10w-30 engine oil. Then the G56 in the common rails is ATF+4 as well from the dealer. 

 

 

Red Line 75W 80 synthetic is the best performing transmission oil I have tried by a long shot so far.  I decided to use it in the wife's truck since it has a fussy 3rd gear synchronizer.  It REALLY improved how the wife's truck shifts through the gears.  The Amsoil MTF works well too but is a bit thinner in viscosity.  I mixed the Amsoil MTF 50/50 with SAE 50 synthetic transmission oil in my truck which is not real cold weather friendly on the first start of the day but once warmed up or in warm weather works very well. 

Peter aT Southbend said Red Line MTL. The other Red Line isn't the one that one is for the NV4500 not the NV5600

Edited March 17, 20196 yr by Mad Bomber

There's lots of different opinions floating around out there and here, I've read. From all these oils I really haven't seen a common trend on what everyone is using, it usually 3-4 different oils and biased. 

I just get so confused lol. So I figured I'd make my own thread, and since I trust all the knowledge on this site, maybe I could get on board with a brand/weight.

 

So far I only can come to the consensus that synchromesh oil is what I should run. But I'd like more options... and it's hard to find sometimes. 

 

Also gonna do the same thing with t-case. But I know it's just atf so that's pretty simple. Just gotta choose a brand, lol. 

It looks like cost is not a real big issue due to low miles traveled (140k) For me it is, plus mostly they are towing miles. I use 15/40 diesel engine oil, 326k original tranny. I would not use any ATF. I also never overfill. I change every 36K miles. Keep it clean and full and these trannys go a long time.

 

Any ATF+4 for the t-case is fine. Be sure and pull the fill plug first and make sure it is not overfull or discolored by tranny oil. The biggest down fall of any manual tranny with 4x4 is running them low, due to leakage into the t-case. On a 4x2 any leak from the tranny is obvious.

Amsoil, thats what I ran in my 05 when I had it. Amsoil goes in the 5spd too. Shift quality is good and the right stuff for the job. 

I've ran the Amsoil Syncromesh in my 05 since it had 15K miles on it. It has 140K now and shifts great. 

Geez that stuff is expensive!

So is a trashed trans. 

3 minutes ago, Dmaney said:

So is a trashed trans. 

And that will really cost you a lot more.

I'm not sayin I wouldn't buy, just sayin its pricey. 

Yeah, but there isn't much truth there either. Being I'm one of the rogue owners that bailed out and went out on a limb to prove that there are much more options.

What are you running @Mopar1973Man ?

15 minutes ago, Stanley said:

What are you running @Mopar1973Man ?

 

Mobil 50 SAE GL-4 Synthetic Transmission fluid. Same stuff used in Eaton Fuller 10 speed transmissions. I'm at 110k miles and still going... No shift issues even with winter temperatures down to near -30*F and shift like butter. Be aware 50 weight oil is actually 90 weight Gear Lube much thicker. Like 75w-85 for the NV4500 is like 10w-30 engine oil.

 

 

 

 

Have to remember @Mopar1973Man is running a NV4500, little different animal. That being said what he's using works great for him. Just personally I'll pay 4 or 5 bucks a quart more for the fluid that was made for my trans. If $20 makes or breaks me on a trans oil change every 100k then I probably shouldn't own a Cummins. 

I still got serious doubt of how different it is being now Dodge dealer is now loading either NV5600 or NV4500 with ATF+4. Even the G56 in the 3rd Gens are now ATF+4. Must not be too special eh?

 

Don't have to warranty any NV4500 or NV5600's. Seriously think they care? As far as the G56 there are lots of mixed reviews on what oil "should" be in them. Seems I've read where Mercedes and Chrysler don't see eye to eye on that one. But I like my old second gens and will cross the G56 bridge another day.