What weight gear lube ?

[ROGER/DODGER]

I thought I would check with all the masses that read this and find out what weight gear lube to use in the Dana 80. I live in the Tucson area and pull a TT

4000 mi. a year on vacation. I want enough protection, 75/90 or75/140 ? It will have a Mag HyTec cover next week.

 

[TwoSlick]

Roger,



With the larger cover installed, your oil temps will run significantly lower. I would normally recommend the Amsoil Series 2000, 75w-90 synthetic for this application. I cannot speak for Redline Oil or Royal Purple, but I suspect their 75w-90 synthetics would do the job as well ... .



I think the 75w-140 will actually be too thick with the increased fluid capacity and will give you too much viscous drag (frictional losses).



TooSlick

 

[John]

I'm using the Amsoil Series 2000 75W-90 gear oil in both differentials. Prior to that I had Red Line 75W-140NS in my rear differential (with the appropriate amount of friction modifier... the Red Line NS series has NO friction modifier added). Both brands of synthetics and gear oil weights have worked very well for me. BTW, I have also used Red Line 75W-90 gear oil in both differentials. Additionally, I didn't experience any mileage penalty when I was using the 75W-140.

 

[drag racer]

I pull a 10k race car trailer regularly between Phx and Tucson. Started out with Valvoline conventional 85W-140, then switched to Mobil 1 75W-90. I think the lighter weight is fine as long as its synthetic. I also noticed the Mobil 1 takes much longer to heat up (runs cooler for a while) than the heavy weight stuff, although the terminal temperature of both is about the same.

 

[EricBu12]

I use the LE Lubricants brand of lube that is a 80w-90. I have the mag-hytec also and love it

 

[John Berger]

I had good luck with Amsoil 75W-90. You might want to go with the 140 because of the amount of towing you plan on doing.

 

[Pete Peterson]

Roger, for the area that you live in and if your going to tow the heavier fluid might be the wise choice. The Amsoil series 2000 75/140 will protect your gears as well as anything on the market and probably better than most fluids can. Plus you don't need to add any friction modifiers to this fluid as you do with most others. Either way spend your money the way you want, you earned it... ..... Pete

 

[fj40charles]

I use Amsooil Series 2000 75W-140 gear oil. At room temp. this oil flows better than conventional 85-90 gear oil. Not sure about

it being to vicious and hurting mileage. I would use it if pulling

a TT.



Charles

 

[musclefixer]

You guys didnt mention anything about the friction modifier. .

Do you need to add any if using synthetic????

Thanks for your help... ... .

Jesse.

 

[fj40charles]

Musclefixer,



If you use the Amsoil series 2000 75-140W gear oil, you don't

need the friction modifier. I have read some posts where some

members said they needed it. I've put over 4,000 miles (3,000 miles towing) since I changed the gear oil and have not

experienced anything abnormal.



Charles