75w140, 80,212 miles, '99 Ford F350

[Rob_Roy]

The following results are from the factory-filled 75w140 in rear differential of my recently purchased '99 F350. This truck has the Sterling 10.5" rear axle with a traction-lok carrier. Analysis by Schaeffer's.

Copper-2
Iron-1315

Chromium-2
Aluminum-2
Lead-0
Moly-5
Phos-2015
Zinc-187
Magnesium-10
Calcium-28
Sodium-23
Silicon-165
Potassium-5

Water-none
Sulfur-6
Oxidation-41
Nitration-7
Visc CST-22.64

 

[Pablo]

Seems severe to us BITOG 5ppm Fe freaks - but really pretty standard fare for many cars on the road. Don't forget the extreme load protection is FeS compounds....it's not that bizarre that Fe ends up in solution.

Sheared just a bit.

 

[Tempest]

Sulfur = 6??

Just what exactly is protecting the gears??

 

[Bror Jace]

Yes Pablo, typical ... but that doesn't make it right.

I can't wait to ditch the oil in my S2000's diff ... I presume it's the factory fill. It only has 15,000 miles on it ... but I'm itching to try my borate-chemistry Chevron 80W-90 in there.

 

[unDummy]

Definitely overdue for a change.

 

[Steve S]

Al .1
chrom.2
iron.986
copper.1
lead .1
tin .0
moly.1
nickel.6
manganese.10
silver .0
titanium .11
potassium.4
boron .246
silicon .80
sodium .9
calcium .4
magnesium .3
phosphorus .2916
zinc.38
barium.1
sus visc .101.2
flashpoint*f 385
insol .0.4

This UOA is Redline 75w/140 from a 2002 Ford Powerstroke 2wd with a posi rear end ,64,000 miles on the unit 40,464 miles on the oil. Blackstone labs UOA. This is from my wifes F 250. I wonder if the iron is from the posi clutch material . I'll have to search .

 

[Doug Hillary]

Hi,
Rob & Steve S - A typical condemnation point for Iron is 1000ppm. Often this "replace" limit is 1500ppm

A major contaminant can be water and I note that this is not mentioned. The viscosity has me puzzled a little too

All other points look good except Silicon Rob which typically has a limit around 130ppm if wear metals are "high". Limits for a specific component should be obtained to be accurate - as should a VOA

 

[Rob_Roy]

Hi Doug, thanks for the feedback. I wondered if the silicon could be from the sealant used on the differential cover?

 

[Steve S]

Thank you as well Doug.

 

[Colt45ws]

If you have a track lock the iron could definitely be from that. Like a Trans clutch pack you have steel discs separating clutch discs.

 

[Rob_Roy]

Yes, my truck does have a Trac.-Lok differential.

 

[Steve S]

Originally Posted By: Colt45ws
If you have a track lock the iron could definitely be from that. Like a Trans clutch pack you have steel discs separating clutch discs.
I wonder if there is iron in the clutch material?

 

[Jim Allen]

Don't forget, this is factory fill so all the break-in and manufacturing contamination is still in there. Question, was the oil all silvery looking?

 

[Doug Hillary]

Hi
Rob - Yes the silicon may be from sealant or the VO

If the diff has a cleanable breather this should be checked too

In OZ it is common place to remote mount breathers to avoid water and dust ingress

 

[Rob_Roy]

Originally Posted By: Jim Allen
Don't forget, this is factory fill so all the break-in and manufacturing contamination is still in there. Question, was the oil all silvery looking?


There was some silver material in the oil that first drained out, but the oil was mainly drark brown in color. The magnetic fill plug did have a lot of metallic material.

Originally Posted By: Doug Hillary
Hi
Rob - Yes the silicon may be from sealant or the VO

If the diff has a cleanable breather this should be checked too

In OZ it is common place to remote mount breathers to avoid water and dust ingress


This truck has hose that goes from the diff. up to the inside of the frame rail and is terminated with some sort of plastic fitting. I made sure the vent wasn't plugged and left it alone. The truck is "back to work" with fresh 75w140 synthetic.

-Rob

 

[Johnny]

Did you put TRC fluid in there?

 

[Rob_Roy]

Originally Posted By: Johnny
Did you put TRC fluid in there?


Unfortunately Texas Refinery does not make a 75w140 gear lube. They do offer an 80w140, but I could not justify a 45 lb pail just for this 3.5 quart change. I ordered some 75w140 AMSOIL through Gary Allan.