transmission and rear end fluid?

[CoastyAV8R]

I'm getting ready to change my differential fluid and transmission fluid as I approach the 27,000 mile mark. I am wondering what the best oil would be for the diff and transmission? I have heard all the hoopla about Amsoil and was wondering if it is worth the $$ and the trouble of finding it? I am going to put synthetic in both and was curious on the brands and types the rest of you use.



Thanks,

Pat

2001 QC ETH 4X4

 

[Extreme1]

Amsoiled. Look in your yellow pages. The trucks come from the factory with a synthetic in the diff.

 

[RJOL]

I'm going to put Royal Purple 85W-140 in my differential, when I change it. .

 

[Mombo]

Rear/Gear Oil

Ever since my days as a sprint car owner (dirt tracks), I have used "Mobil 1" Synthetic Gear Lube in all of my rears. The sprint car had a Halibrand quick-change gear box in the rear. Using the synthetic allowed you to remove the gears with your fingers. With regular gear oil, you would get second degree burns. That's racing use. I would seem that towing loads would get the same benefit. It's always worked for me. Also,

the engine oil temp in the sprint car dropped 100 degrees when I went to Mobil 1. As soon as my truck reaches 10K miles (the break in) I will use Mobil 1 regularly.

 

[RustyJC]

Originally posted by Extreme1

The trucks come from the factory with a synthetic in the diff.

Mine apparently didn't. The owner's manual very clearly recommended getting the 90W standard hypoid lube out and changing to a 75W-140 synthetic for towing. I went with the Royal Purple 85W-140 full synthetic and it works great. Didn't even have to add any friction modifier for the LS - it's built into the lube.



Rusty

 

[LSMITH]

I use the Mobil 1 in both diffs on mine. I use the cheapest ATF+3 I can find for the transmission. Your choices in synthetic ATF+3 are really limited, you may only be able to get one or two kinds around you if you look. I am not sure the ATF is worth it if you drive a lot, I change mine 3-4 times a year, and the synthetic is 4 times or more the cost of the dino ATF. In my case it is simply to expensive to use unless I extend the drain interval and I am not comfortable with that. Take a look at how and when you use your truck, make your decision based on that.

 

[georgej]

Your transmission will require ATF+4 and to avoid any warrantee hassles I'd have the dealer service it the first time! You should replace the dino fluid in the rear end with 75-140 sythetic if towing.



George

 

[Big-D]

Differential Change

Where is the best place to purchase Royal Purple 85W-140? With my LS will I need to add modifier also?

Thanks!

 

[CoastyAV8R]

Thanks for all the replies, I guess I forgot to mention I have the 6 speed transmission with the ETH package, so the ATF 4 probably wouldn't fit the bill. What weight of oil do you guys use for the transmission? I have the service manual so I know what it recommends, is that what you guys are using?



Thanks again,

Pat

 

[redneckdr]

synthetic lubricants

alternatives to amsoil and mobil 1

redline: www.redlineoil.com

Royal Purple: www.synerlec.com

 

[RustyJC]

Re: Differential Change

Originally posted by Big-D

Where is the best place to purchase Royal Purple 85W-140? With my LS will I need to add modifier also?

Thanks!

I got mine at NAPA. It has friction modifier built in - I haven't had to add any supplemental Mopar friction modifier, and I don't have any LS chatter. With my Dana 80 with the stock cover, 3 quarts actually overfilled it (according to the owner's manual) by about 1/4"!



While you're at NAPA, pick up the HIGH TEMPERATURE Permatex RTV gasket maker - the gray stuff - if you're using the stock cover. That apparently is what Dana uses, and it works fine.



Rusty

 

[BV]

Royal Purple

Here is a corrected url to Royal Purple or their main home page



I'm going with RP since it can be purchased locally.

 

[redneckdr]

royal purple

oops, sorry about that i went back and corrected it.

 

[Big-D]

Thanks Rusty JC. I'll stop by NAPA tomorrow.

Dave