NV5600 and American 4" rearend temps

[badams1]

I have an 03 HO 305 six speed HD trail Tow 373 gear LWB with 14k miles on it. I Just recently pulled my 12klb 5th wheel over the mountains of Colorado and had some transmission and rearend maximum temperatures that I would like a comment on please. 95F + day and I am pulling 6-7% grades, the NV5600 transmission maximum temperature got up to 225F and the rearend got up to a max of 200F. No noise all and it all came down to 200F and 175F respectivly after I got level again at 65 MPH in cruise. Yes I did push it pretty hard with a Six Gun/spd loader at level 6 during the climbs with a Max pyro temp at 1200F, but this thing eats mountains like you would not believe. Am I getting out there too far with these temps?

 

[CumminsBu]

Are these temp with Fast Coolers and MAG-Hytec differential cover? Might be time for those. I would hate to learn something the hard way.

 

[Prairie Dog]

There's nothing wrong with those temps - their well within safe limits for those fluids.

 

[badams1]

Thanks Prairie Dog I needed to hear that! I love this truck and am really impressed with its towing performance.

 

[kbarlow]

With the same conditions as you with Fast Coolers but no box I have seen 194 in the transmission using 5th gear on the climb. The highest pyro was 1127.



Cheers Ken

 

[badams1]

I have the filter kit with a magnet inside so I can't use the fast coolers and the temp probe is on the other side. If 225F at the most extreme conditions is ok with the extra power on then no damage done using synthetic Royal Purple Syncromax. A PAO lubricant can stand 225F without any deteration of lubrication. I just wanted to know what the extreme temperature limits are for both ends. Thanks!