Rear Drive oil

[Kilroy]

Hi All,
What is your favorite rear drive oil.   I am about out of my Amsoil and need to change the oil.   What do you think?
Kilroy

[donaldcc]

   my last change was prohonda hypoid gear oil 80w90.  Works fine, seems easy.

[fudgie]

Valvoline Synthetic I got at Auto Zone. grey bottle.

Check that----Mobile 1

[Thunderbolt]

of the correct viscosity should be fine.

[hubcapsc]

From the manual...
Hypoid Gear Oil, SAE #80...

I had been using those little eyedropper sized bottles from Honda, but last time I just went
down to Advance Auto Parts and bought a much larger bottle of something that matched
what the manual specifies...

-Mike

[fordmano]

RoyaL Purple (full synthetic) and it's smells better than most others and it's a "PRETTY" color (says the wife).

I run a bit heavier weight than factory spec but anything factory spec or heavier should be fine (it's your dime).

[Mildew]

Supertech every 25k

[Tropic traveler]

Mobil 1 full synthetic. 

[Westsider]

Any synthetic -- change every oil change--(3k)--doesnt take much /cheap ins. for what it does....

[Robert]

Redline or Mobile one 75w/140

[Hoser]

Anything that is GL-5 rated is good to go.  Hoser

[Kilroy]

Is there any reason why we should not mix say Amsoil and Mobil 1 if they are both synthetic and the same weight?

[John U.]

I don't think there's any reason not to mix them even if they aren't both synthetic and the same weight. Oils will mix quickly when being churned up by the rear end gears.  If they are both GL-5 oils, no problem.
Consider how semi-synthetic motor oil is possible without mixing different oils.

[BradValk48237]

Have used Valvoline 80 in the rear end of my hondas since the 90's (first bike with a driveshaft was 81 CB900 Custom) and Valvoline 20 w 50 in the engine of every bike I've owned. Never had trouble....
But I change the oil every 2500-3000 miles and at the beginning of the season... I also change the rearend at the beginning of every season.....I think that is the secret...... Just flushing out the crap.



JMO...

B

[98valk]

Amsoil 75w80

honda requires an 80W, a higher weight is not needed and just lowers mpg slightly.
80W is the same requirement for the much heavier GL1500, never read of any failures in the goldwing community.

I see some are using a 75w140. I'm curious as to why?

from what I have found out is that Ford for one, has for their trucks installed and require 75w140 now, however the yr before the same truck and rear they required 80w90. Well it seams the 75w140 is only for a lifetime fill to met some EPA reduce oil change program. A 140w actually can increase rear differential operating temp.
there are many discussions like this one http://www.thedieselstop.com/archives/ubbthreads/73EandD1/showflat.php-Cat=&Number=1628532&page=83&view=collapsed&sb=5&o=&fpart=1.htm
on other sites.

comments?

[Tropic traveler]

The 75W140 that Ford wants in their diffs is full synthetic with all the benefits of lower friction that full synthetic brings. 
I sell a bunch of it. 

[Robert]

I use 75/140 I find cooler operating temps, smoother. In the Valk and the other vehicles I put it in too. Redline makes a oil called shock proof that is higher rated than the 5 yet maintains the lower friction. I have used that too.

[98valk]

The 75W140 that Ford wants in their diffs is full synthetic with all the benefits of lower friction that full synthetic brings. 
I sell a bunch of it. 

I beleive the 80w90 they did require was also syn. The only reason I can find from various ford diesel web sites, for them going to the 140 is to claim lifetime fill and that it has nothing to do with better protection or for a new differential design. Have u any other info on this?