I need to change the rear and front diff fluids, I have the 3:92 with LSD. My question is does the synthetic gear oil have the 4oz of additive in it already for the LSD? No one at auto zone etc can tell me if its in there and it dosen't say on the bottle. Maybe I will just use regular gear oil and add the additive, I would like to use the synthetic do too pulling my tow hauler. Thanks for any input anyone has.

 

Most do not, i.e. Mobil 1. Some do, like Royal Purple. It should say on the bottle. I'd go with Mobil 1 and 4 oz of friction modifier additive.

Rob

 

As Rob said, most gear lubes do not come with the additive in it. Keep in mind, the lube that is recommended for these trucks is synthetic so I would shy away from the regular gear oil. Stick with the synthetic and you can pick up the additive fairly cheap, the MOPAR stuff (4318060AB) is around $8 from what I remember.

 

I use Amsoil Severe Gear oil and still add one bottle of additive.Won't hurt it one bit and keeps you have having to go back and add it if clutch packs get grabby.Any of the additives work fine.Dosen't have to be MOPAR brand.

 

Last gear swap for the 4.10s, the tech recommended non-synthetic oil with an additive. Based on a few 3rd Gen guy's recommendations, I went with Lucas Oil and Red Line additive. 2.5K miles later and I've had zero whine, chatter, or any problems.

 

I used Lucas oil in the rear end of my Porsche. I wasn't to happy with the way my car shifted so I emptied it a week later and it came out almost like a milk shake. Then I went with Amsoil and have had no problems.

 

Some Lucas products are snake oil.I wouldn't put it in my lawnmower.

 

True, a lot of the stuff they sell is a little "iffy" on their claims. The gear oil seems dead on though and since it doesn't claim to do everything is probably their one product that does just what it says. If that makes sense.

 

Ya went to auto zone this morning and re read the bottle and it says it has the additive in it. I use Valvoline in everything, I have used this product for years with no issues anyways I also called the company and they said if you tow heavy things you should also add the additive anyways.

 

Which one did you look at that says it includes it?

Rob