Engine/Transmission (1998.5 - 2002) RP Synchromax 50k report

[Texas Diesel]

Got a new 6 speed installed at 51k miles, the first TWO went south due to multiple gear grinds.



Here is a picture of the gelled OEM lube and the brass CHUNKS that used to be synchronizers laying in the bottom.



https://www.turbodieselregister.com/user_gallery/displayimage.php?&photoid=2213&width=2



The same day I got the new 6 speed installed I brought it home and installed a PTO filter and Fastcooler and filled it with Royal Purple Synchromax.



I just turned 50k on the new 6 speed, it shifts better than new and is extremely easy in and out of gear with NO grinds. The lube came out looking like new and there were almost no brass shavings, a big improvement over the other 6 speed.



I know the warranty issues with not using OEM (lifetime!?) lube. I know others have used Synthetic MOTOR oil. My feeling is MOTOR oil is for MOTORS and transmission lube (Synchromax) is for TRANSMISSIONS.



The point to this is that there are better choices for your transmission than OEM.

 

[mbaston]

I just put it in mine... . good to see some confirmation

 

[Rman]

I've got 30k on my transmission with synchromax... still shifts great. I'm about to change it though to check everything and install a filter... where's the best (i. e. cheapest) place to pick this up? I bought it locally from a RP distributor and feel like I got ripped off. I'd rather buy it from a dealer and atleast support a business.

 

[Texas Diesel]

For quart quantities this place is hard to beat.



http://www.rpmoil.com/index.php/welcome.html?sid=ApG3Z1rMZtgia5Tc



Make sure you put your filter on the passenger side.

 

[NIsaacs]

Synchromax

I have a 91. 5 D-250 that I bought new in late 91. It now has 293,000 miles on the original clutch & Getrag trans. I have used 15/40 Rotella regular engine oil since the first oil change. The book said to use 30w engine oil if you need to add any, that it was also a lifetime oil. I can not for the life of me understand why the factory says that?? The only reason I can figure, is they would rather the original oil was in the trans, than what was used in tranmissions for years & years, 80/90w. I now have an 01 with the 6-speed. I changed the oil at 36,000 miles with the factory mopar stuff. I am scared to use the 15/40 Rotella in this one. It shifts with no problems and the oil looked good when I changed it out. I have 53,000 miles on it now.



"IF IT AIN'T CUMMINS POWERED, IT AIN'T A TRUCK"



"NICK"

 

[Rman]

gotta love that, free shipping! oh wait... handling what's the diff? That seems to be the best I can find also. I'll search a little more than give I guess.

 

[smittybuilt]

fixing to install some rp in my six speed and was wondering about this filter thing. can anyone tell me more.

 

[Rman]

Geno's carries a filter kit, it's cheap, like 30 bucks If I remember. It simply bolts over the passenger PTO and "filters" the oil slung to it by the gear assembly. This is why you put it on the passeneger side as noted above by TD. From what I've read it really does filter out quite a bit of stuff, for 30 bucks I thought I'd give it a try at the next oil change.



check it out here

 

[TPlasek]

I have 52k on RP 80W-90 in my NV 4500. I change it about every 25 K. All 4 of the main bearings went out in my 5 speed at 104k so I changed over then.

 

[cumminspwr01]

Does the filter from Genos increase fluid capacity?

 

[Texas Diesel]

Yes, they say 8 ounces. A Fastcooler on the opposing PTO cover adds even more oil capacity