2nd Gen Non-Engine/Transmission Royal Purple ?

[TravisG]

I am switching over to Royal Purple in the diffs and was wondering which to use the 75w/90 or the 85w 140. I tow a little and it is pretty cold up here in Green Bay from time to time.

My next quesion is do I rin the same in the front and rear or is there a difference? Thanks in advance.



BTW- I have a Dana 70 in the read and a 60 up front. I would like to do the transfer case in a couple of weeks to if you guyz have any suggestions about that too.

 

[Bob V]

I would run the 75w/90 unless you start towing heavy in hot weather. I recomend the RP syncromax for the TC

 

[Matt42]

I tow a 27 foot TT in temperatures of 100 to 130. I use Royal Purple 75W-90 in the front, and 85W-140 in the rear. That's per the DC TSM for my usage and climate.



No major parts have fallen off, pinion gears have not shot thru covers. Yet.

 

[ANG012]

I would run the 75/90 in both front and rear. I think it is too cold up your way to run 85/140 in the winter time. The 85/140 is for towing close to max weight in the hot weather.

 

[steved]

I run 85w140 RP in the rear year round. Doesn't seem to really affect it anything. I wouldn't recommend running a dino gear oil... but RP is synthetic.



I also like what RP synchromax did for my tcase.



I should also add that my dad runs 95w140 in his D80 and it seems to have really made a difference over dino oil.



steved

 

[MErickson1]

I'am running 75/90 in front and back, aswell as the synchromax in the tc.



I'am really happy with it.

 

[TravisG]

Sorry it has taken me so long to respond, I am working on the road w/ no internet access. Got the R. P. in. Cruising r. p. m. 's are down and the truck seems a lot happier flyin down the road. Now that I got all the fluids changed I have got a leak where the driveshaft yoke goes into the rear diff. GREAT!!!! How hard is this to change or is it not a real big deal. Doesn't seem to be to much of a leak but I will keep an eye on it. Thanks a lot for all the responsed fellas. Shows how great the TDR really is.

 

[apat]

Is RP 75/90 suitable for a LSD rear? Is there an additive required?

 

[Bob V]

If you have a second gen with limited slip the RP is all you need, no aditive required. No aditive is required for the 3rd gen trucks no mater what fluid you use.

 

[jleons]

jIM10477

Hello

I HAVE BEEN USING RP SINCE 2001. Run RP-75/90 in both diff's and synchromax in TC for over 220,000ml with no problems - EVER.

Thanks,

JL

 

[HEMI®Dart]

What's the bottom line on RP...

Is Royal Purple a semi-synthetic?



Is it top tier PAO synthetic like Amsoil?

 

[jleons]

Jl

Hello

RP is a true synthetic product. I recently retired with 35 years as a Heavy Equipment Manager. I have tried, "THEM ALL". There is no better lube product.

Check them out @ Roytal Purple.com.

Thanks,

JL

 

[Vaughn MacKenzie]

Yes RP is a top-shelf genuine synthetic. I would vote for 75/90 because that's what I ran (Amsoil) in the rear and towed with it and also pulled a flatbed in 105-108 weather with no discernable deterioration. After 30,000 miles there was NOTHING on the magnet, pretty amazing.



Vaughn

 

[John]

I haven't verified what I have heard from two, usually in-the-know individuals but...



I was informed that Royal Purple synthetics were not "True" synthetic lubricants. Both led me to believe Royal Purple was akin to hydro-cracked Castrol. One of these days when I get around to it I will look deeper into this.

 

[steved]

In all my conversations with RP, they assured me they were 100% synthetic much like Amsoil and Redline.



While I did have a bad experience with RP's Synchromax in my NV5600, I attribute that to possibly being a quirk of the transmission and not the oil.



I have nothing but positive things to say about their gear oils... in one instance I ran 85w140 MaxGear in a mower gearbox... in a yard where the best i could get out of the tractor was the low side of high range with moderate throttle, I was able run the high side of high range at little more than an idle after changing nothing but the gear box oil. That made a believer out of me!



They were originally made for the heavy industry and only recently dabbled into the automotive industry...



steved

 

[WDixon27]

i just noticed this weekend that pepboys now has 75/90 (i think) max gear on the shelf, that's what i have in my nv4500 and it's working great, whatever was in there when i bought the truck sucked

 

[HEMI®Dart]

I was informed that Royal Purple synthetics were not "True" synthetic lubricants. Both led me to believe Royal Purple was akin to hydro-cracked Castrol. One of these days when I get around to it I will look deeper into this.

John,



I read or heard the exact same thing somewhere. That's why I asked.

 

[JKaptchinskie]

Has anyone used the power steering fluid from RP? What do you think of it?

 

[Vaughn MacKenzie]

Interesting John, hope you find the info.



steved you're not the only one to have bad results using Syncromax in a NV5600.



Vaughn

 

[Texas Diesel]

I haven't verified what I have heard from two, usually in-the-know individuals but...



I was informed that Royal Purple synthetics were not "True" synthetic lubricants. Both led me to believe Royal Purple was akin to hydro-cracked Castrol. One of these days when I get around to it I will look deeper into this.

Not true, it is true synthetic. I use Royal Purple in everything, all three trucks, BMW motorcycle, boat, lawn equipment (2 cycle).



I have used Synchromax in my 5600's for years. The only time I heard of a problem was a guy runnning it in his 5600 and towing ~28,000 GVWR with serious HP mods. I had 2 5600's fail under warranty with OEM fluid, the 3rd replacement got Synchromax the same day I got it back. 2 years later I sold it, and it was working perfectly, and last I heard it still was ok.



I use 75W90 in the diffs and the OEM friction modifier as needed to quiet the clutch packs. I use 75w-90 MaxGear in my 5 speed as well. There is a story here about another brand of oil causing bad shifting, but will stay on topic.