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View Full Version : What gear oil?


Droopy76
December 27th, 2009, 12:16
I just finished installing my new 4.56's and I am getting ready to slide the 8.25 under the Jeep. I was just wondering what would be the best gear oil to run for the break in period?

Wayne Sihler
December 27th, 2009, 14:07
I ran the cheapest brand name oil i could find.It may have been the Valvoline 80w90 brand at Advance or AutoZone. Don,t over heat the gears,short trips & cool down.Get it out after 500 miles---

Wayne

TomMcD
December 28th, 2009, 00:07
Per Factory Service Manual, 75W or 80W - 90 SAE GL5 gear lubricant for normal use. And 80W - 140 SAE Synthetic for towing or other severe use. Using cheap stuff should be okay while breaking in, your choice what you leave in there long term.

Break in procedures should be supplied by the company that made your gears, follow them. If you don't have them, call the company and ask. A good rule of thumb is 10 trips of 20 or 30 minutes driving a different speeds. No hard acceleration, or other high stress use. Let it sit at least an hour between trips to fully cool down. After 300 to 500 miles drain it.

Cool extra trick, if you can get your hands on some high strength magnets put them in the bottom of the case before you seal it up. This will help keep the metal that wears off the gears during the break in out of your bearings. When you chair your oil, clean off the metal particles.

The Chryco 8.25 takes just under 5 pints or 2.5 quarts iirc.

kastein
December 28th, 2009, 06:42
Cool extra trick, if you can get your hands on some high strength magnets put them in the bottom of the case before you seal it up. This will help keep the metal that wears off the gears during the break in out of your bearings. When you change your oil, clean off the metal particles.
X2. If you have any old computer hard drives, you can get at least two super-strong rare earth magnets out of each one. Use your angle grinder (or tiny tiny torx bit, like a T9 or T7 usually) to remove the lid of the drive, use it again to remove the silver section around the back end of the "head arm", then use a vice and a pair of vice grips to flex each piece of each of the plates till the magnet comes unglued. Careful with them, they are VERY strong, you should be able to simply stick them to the inside of the diff cover in a spot where they won't hit the carrier/gears but you can epoxy them down as well if you want.

Johnnie Walker
December 28th, 2009, 12:23
During break in I would use the 75w/80w-90 after I would use Amsoil SevereGear 75w-140