can I have some recommendations on different brands of gear lube to use in my diff's that are available at your local...auto zone, advance, car quest, Napa, o'rileys, etc.... <br><br>oh I have the factory &quot;anti-slip&quot; so what do I need to look for on the bottle to make sure I don't mess anything up?

 

Alot of guys use Mobil, Amsoil is by far the most used syn. I think. Someone in your town is a dist., or you can get it from the amsoil website. I use Lubrication Engineers 90 w.<br><br>Mike

 

[quote author=Marine link=board=7;threadid=15787;start=0#148448 date=1055394013]<br>Alot of guys use Mobil, Amsoil is by far the most used syn. I think. Someone in your town is a dist., or you can get it from the amsoil website. I use Lubrication Engineers 90 w.<br><br>Mike<br>[/quote]<br><br>Nope no Amsoil around here...ordering from Sleddy tomorrow b/c I can't get any deals on syncromesh around here for my tranny. But for the diffs I want something I can just walk into the parts house and buy.

 

The was a dyno oil test in the TDR magazine, a couple of years ago. Lubrication Engineers gear lube gave 7 more hp than the next closest, which was a synthetic, I believe.

 

I went to Atwoods and bought a 2 gallon jug of Mystic gear lube. It is approved for GL-2 through GL-6 and says it's for servicing limited slip axles. Then I added the little bottle of Chrysler additive for about $8.00. Someone else makes a similar additive (Eagle?), but I haven't found it around here.<br><br>I know it's probably not as good as the fancy stuff, but seems to be working fine.

 

I run Royal Purple in both of my diffs. It's available at your local Napa and some high performance shops.<br><br><br>Tony

 

I too have the RP 75/140 in the diff. Didn't add any modifier goo. Seems to be fine, but I think my lsd function had already quit me by the time I changed the oil.

 

How often do yo change your diff oil?

 

Auto Drone has Mobil 1 for 6.99 a quart. They also have the friction modifier but did not see a price. I've only put a few miles on since the change to Mobil 1, did the figure eights in a parking lot and so far so good without the friction modifier. I believe you can get extended service from the synthetics as well, but not sure how much. I read (on this website) every 24,000 for conventional fluid, and every 12,000 for &quot;severe duty&quot;. Kevin

 

[quote author=blafleur link=board=7;threadid=15787;start=0#148796 date=1055464467]<br>How often do yo change your diff oil?<br>[/quote]<br>On my older trucks with Dana's and Limited Slips I always changed at 15-20,000 on the rear and 30-40,000 on the front. I would say that if you go over 30,000 your limited slip clutch pack is probably toast. I always used Mobil 1 synthetic on the front (non-limited slip) and Valvoline Dino on the rear with the specified Mopar LS additive. I could never get my limited slip to work properly with synthetics. BTW the only &quot;symptom&quot; of a limited slip problem that I ever had with synthetics was simply that it would not &quot;hook-up&quot; properly. Daily driving was no problem.

 

[quote author=Nevada link=board=7;threadid=15787;start=0#148849 date=1055478458]<br> I would say that if you go over 30,000 your limited slip clutch pack is probably toast.<br>[/quote]<br><br>I just changed my rear diff tonight.......167,000 miles...bet its the first time its been changed (3rd owner, 2nd bought it when it was 1 yr old)..... put some additive in it and did some figure 8's in my field.......however it was dark so I couldn't see if it was working or not....it &quot;felt&quot; like it was still spinning both like it normally does.

 

You might want to change it again in 5000 miles. Jack up each side of the truck at the read to drain the axles.<br><br>Mike

 

You are severely limiting your options when you say that it has to be available locally. Good luck. Mobil 1 is about the only diff lube worth something that is available as widely is you would like.<br><br>To get the really good stuff, you have work to get it. Amsoil, RP, Redline, etc.<br><br>The Redline Shockproof is about the toughest gear oil you will find anywhere. I am going to wait a little more before I dump out my Mob 1 and put it in.<br><br>As for friction modifier, don't add any until you've test driven the truck. ONly add if you get bad chatter.<br><br>Others are good as well, but I have had superior results with Redline products in all my vehicles.<br><br>HOHN

 

If you don't won't to go with the Mobil 1 the use Royal Purple. Personally I agree with everyone else. Don't limit yourself to local precurment only. It's worth having it shipped to you if you won't to maintain the Diff's properly. I myself use AMSOIL and according to DC you DON't add any modifiers to the rear Diff of the 2003 rearend. : :

 

Lubrication Engineers in Ft Worth is a good choice. One of the highest quality lubes you can run. One of the best channel points for the cold weather guys too. <br><br>Secondly, I like the Torco. Torco is the choice of many racers and NASCAR guys looking for the last little bit of HP. Mark Williams of custom rear axles and ring and pinion fame uses a re-labled Torco oil for all his stuff. Yo will find his axles behind the meanest Top fuel and Sportsman class cars all over the world.<br><br>Some of the other lubes in this thread came in a DISTANT last place during HP drag tests and temperature comparisons. Many may not understand HP drag testing or disagree with the data or methods of collection so the names of the worst lubes have been left out.<br><br>Most clutch type gear carriers are addressed by the lubricant blenders now as HOHN stated above.<br><br>Don~<br><br><br><br><br>