Synthetic Fluids

[BigMike]

It's time for me to change the front and rear axle fluid on my truck. I tow a 11k 5er frequently in the summer. Should I be thinking of putting a synthetic fluid in my axles, especially the rear. If so, what should I be looking for and who can do it?

 

[GLASMITHS]

Big Mike



You are on the right track. I have a 3500 wwith Dana 80; whick I believe you also do since it is stick. The owners manuel says that if you tow heavy loads you should use synthetic, and I believe it is 75/140, it could be 85 though, check for sure. I am at present using Amsoil; however from everything I can read on the subject, redline is the best period. Hope this helps.



Oh, do you have the Magtec cover. It sure takes the work out of procedure. It also hold twice the amount (8qts)

 

[CumminsAholic]

Yes, I think you should look into synthetics. They're a little more $$, but in my opinion it's well worth it. You'll have cooler temps and maybe better mileage. I personally like Amsoil. I run it in everything I have from my truck to my snowmobiles. www.amsoil.com Check them out. A lot of auto places carry it. If you're planning on going with everything amsoil then it'd probably be cheaper to become a preferred customer. I think it's $10 for 6 months and you get things WAY cheaper (dealer cost) direct from Amsoil. After the 6 months is up you can renew it for $20 a year if you want to. Just thought if you were interested you could sign up and save a little, if it's just for the 6 months, you'd save way over $10 in your first purchase of stuff for your truck.

You should be able to change it yourself. It's not hard, can be a little messy sometimes.

Corey

 

[GLASMITHS]

The reason I made the remark about Amsoil, is that I read on some forum about tests of oil and oil filters, that Amsoil was not approved by GM for the LT1 engine. However, I have used Amsoil in the past and just got my preferred customer card so I can buy cheap. If you decide to go with Amsoil make sure you do this. Its a lot cheaper

 

[Ramafid]

I use Mobil 1 products (synthetic) and would swear by synthetics for the axles. My rear diff fluid still looks new at 35K miles compared to looking awful at 5K with non-synthetic. I think most if not all rental trucks (class 8 ) use synthetic in the axles. IMHO they wouldn't spend the extra money if it wasn't worth it.

 

[LSMITH]

Definately put the synthetics in the axles, and do both of them. I use Mobil 1 also, 75-90 in both axles. I did pick up at least 1 MPG by going to the synthetics. Rear axle temps also dropped from about 190 to 165 on an average commute so it is doing what it was advertised to do.

 

[Sled Puller]

Amsoil was not approved, but I bet it was not DIS proved either!



No way did they test it. They don't make any money off of it.



Amsoil will warranty their product.



Gene

 

[JSmith]

MGM what Amsoil fuids

do you use in your diff`?s I run Amsoil in the engine but thats all. What about the transmission(auto)?In the diff`s with Amsoil will a friction modifier be needed?I read a post where someones rearend chattered or clunked after changing fluids,thats why I am asking.

Thankyou for your reply.

 

[Sled Puller]

Absoulutely!



The Series 2000 line in the gear lubes does not need any modifier.

Change it out, do several tight figure 8's, if it chatters, ad 1/2 a bottle of modifier.

99% of my customers did not need the extra modifier.





I tell people to change the auto over first, it helps keep the heat down, makes them live longer.

Gene

 

[snake]

I changed the front and rear axle fluid two days ago. I used Amsoil Series 2000 75W-90 gear lube.