SeniorXJ

-So all the new parts are goin into my HP d30 this week & i have a question... what the best gear oil to get for the 30, with a brand new eaton, chromoly shafts, & cryod 488's?? I want a full synthetic but am unsure of the weight to use??

Thanks!!

TonyB

The cheap Coastal/Rotella **** at WalMart. If you or anyone else can see a measurable difference between that and the 10+ dollar stuff, please show/tell me.

freegdr

use a good qualiity oil not the cheap crap 85w or better as this is not a fluid you change very often i found synth at pep boys not to expensive seems to be working pretty good

SamSissine2

I put in the royal purple 75w-90, had great results from any Royal Purple product.. Definitely more expensive but I think worth it in the end..

If you are changing your oil very frequently though because of trail riding and water concerns I wouldn't go this route.

Dakota5605

X2 on the Royal Purple, don't mess around after you did all that work to your axle give it the best. 75-90w unless your in high temperature enviroment then use the 120-140w

Rock Toy

Use a 75-90 gear lube that is not to expensive, Do the gear break in, short drives, like 20-30 miles, not lugging or winding out, with cool down periods for about 100 miles. When you get around 500 miles on the new gears drain the oil and check for metal in oil and visually inspect the R & P, if it is good replace diff cover and fill with Redline.

TonyB

Why do people say you need to "break in" gears and then change the oil. Is this the same thing you all do when you buy a brand new vehicle off the dealer lot? I've never done that in any of the vehicles i've done R&P swaps in. Change it, add oil, don't change it again till something breaks/want to change ratio's again.

Ianf406

amsoil 75w-90... severe gear... good stuff!

SeniorXJ

-Seems 75w-90 is the winning weight to get. The 30 will have all new seals including outters so i hope nothing gets into it for sure!! Thanks guys!!

Rock Toy

I guess because most good manuals call for it. Maybe you are good enough that you are 100% sure that there is no way you could possibly have got something wrong. I'm not, so I'll do it the way my manuals say. As for the new car, I don't have the same equipment that major axle builders that supply to the auto companies have, but I did buy a Ford Mustang that had a bad R&P, but since it was new they paid to fix it, not me. Breaking in the gears is pretty inexpensive when you look at what it could end up costing.

TonyB

But why doesn't everyone "break in the gears" whenever they buy a new car? Do you think the people that built them broke them in for you?

Rock Toy

How would I know? The last motorcycle I bought had a break-in period of 500 miles for the engine and the driveshaft and rear axle. Like I have stated if you don't think you could make a mistake don't break your gears in, I just think it is a good idea, because I'm buying mine and my money doesn't come easy.

TonyB

Show me in a....say Ford 150 or Mustang or Chevy Cobalt owners manual where it says to do what you're saying. You know, vehicles they sell millions of.

Rock Toy

TonyB, what is your problem? I have stated that my manual ask for a break in period!
I have also stated that if you don't want to do a break in period don't. I'm finished with this, I don't have to show you anything.

SamSissine2

Easyyyyy.... I think this may have been misunderstood.. I dont believe he meant anything by it Rock. He is just talking through his thoughts.. Hate to get this thread closed for this..

I understand both sides and just see it as a preference thing.. My Harley asks for the drains on everything after break in and I would do the same on my autos.. Just common sense to me..