Differential break-in mileage

[westex39]

What is the differential break-in mileage for my Suburban? I don't do any towing or drive in mountinous terrian. I plan to drain the GM 75W-90 out and go with the Amsoil series 2000 75W-90.
The gearing is 3.73 with the G80 Eaton locking type.

Thanks

 

[MolaKule]

I have worked closely with our differential rebulders regarding run-in, longevity, etc. I have worked on their metallurgy and lubrication problems in exchange for work.

The mechanics say never to tow anything for the first 6,000 miles and change fluids at the first 12,500 miles. After that, they suggest changing fluids every 30,000 miles unless you tow, and if you do tow, change fluids every 15,000 miles.

In terms of lubricating fluid wear analysis and metallurgy, I concurr.

Secondly, you might want to investigate the Schaeffer's blends, Redline Lubricants or the Mobil 1 fluids. My personal experience is that the Series 2000 fluids are not up to the task with respect to cost.

Many believe that the Redline transmission and differential (gear lube) fluids are primo.

BTW, I currently have two Suburbans ('92 4X4 and '89 2X4) but can't afford the new ones.

I think my next vehicle will be a Nissan Frontier 4X4 6-cyl with extended cab and short bed.

[ January 16, 2003, 01:13 PM: Message edited by: MolaKule ]

 

[MolaKule]

Westex,,
Also see this thread right below ya:

http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=16;t=000118

 

[Mike_dup1]

I can do it relate my experience

At work my last vehicle was a 1999 K2500 Suburban with 4.10 LSD rear, Survey Crew.

When I retired in October 2002 it had 94,900+- miles on the odometer. My truck pulled an arrow board tandem trailer weighing about 1 ton + the truck was loaded to the hilt and I could only carry pasengers in the front seats. Back seat and rear where full of equipment. My employer determined maint. and provided us with a 800 number and a maint. schedule. No where on that schedule did it allow any rear differnential service and none was done to it while I drove it. Never had any problems at all. All that was ever down was routine 5000 mile oil changes, R&R brakes and new tires at 75,000 miles along with an alternator, + fuel filter and pump at 90,000. The fuel pump went because of the incomptence of the dealer who failed to recognize the fuel filter was going bad and claimed the truck ran ok. They ignored our complaint that it stumbled on hills and long pulls. Dropping the 45 gallon fuel tank on a 3/4 ton 4X4 suburban was a job with a full tank and the skid plate.

btw
Our trucks were leased thru GM and wheels. Mine was tangier Orange with black wheel flares, deep tinted glass and custom cloth interior (plain jane with top of the line cloth interior).

[ January 16, 2003, 01:39 PM: Message edited by: Mike ]

 

[metroplex]

Since your new truck will have new ring gears, use the proper procedure for breaking in new gears and new differentials.

That is, drive 15 miles, let the whole thing cool down. Then drive some more miles, allow to cool down. This way the gear is heated and cooled properly.

Once you get to 500 miles, you can start to subject it to more abuse.

But yes, change the oil as soon as you can - 1000 miles if you must. For towing, use Redline 80W-140 from the start. It has a break-in additive and is formulated fro use in limited slip differentials. The synthetic will NOT break down from the excessive heating that takes place w/ breaking in new differentials and gears. Conventional oil, OTOH, can break down and cause more problems. I try not to work out the differential + gears from the start.

But for street driving, Redline 75w-90 is great.
For racing/towing, Redline 80W-140 is better.

Don't get the "NS" lubes, they do not have the limited slip additive or break-in additive. The LS additive is useful in reducing friction and heat even in non-clutch type LSDs such as a Torsen or TrueTrac. Heat reduction/friction reducition is important but for clutch based LSDs, use half of what the manuf recommends to obtain better lockup performance or just use a gear lube that's formulated for use in LSDs.

But if you want to use a 75W-90 or 80W-90 lube, check out Schaeffer's #267 Moly supreme gear lube. Its a synthetic 80W-90 blend but its specs SURPASS that of every other 75W-90 or 80W-90 on the market. Its closer to a 75W-140 or a 80W-140 than a 80W-90 in terms of its viscosity reading at 40C.

Its loaded with moly so you know its all good.

[ January 16, 2003, 02:22 PM: Message edited by: metroplex ]

 

[westex39]

Thanks for all the replies. I'm getting ready to call the Schaeffer dealer in town right now. I will also check out the Redline too.
Again many thanks.

Westex