More Amsoil Black Gear Oil

[Triple3 in Mo.]

I use Amsoil gear lube. Make my rear differential smoother and quieter than any other
gear oil I've ever used. Period. 75-140 SS Amsoil.
Use it, 75-90 SS, in my front diff as well.

 

[Rod Knock]

Just so are all on the same page. ECG installed the Rear diff $1300 and they used the Lucas 85w-140. They said to drive it for
1000 miles and then change it. The gear oil looked fine as I drained it. I replaced it with the Amsoil 75w-110 about 1000 miles ago.
Checked it today and it is what the pics show. I would never use Lucas but I felt I had to go with what ECGS said.

In my experience mechanics know very little about lubricants, and it strikes me as odd that they don't care to learn more.

I used Red Line 75W-90 to break in the front and rear diff on my 2022 Dodge Durango. Red Line has a super high concentration of anti wear additives for track use. If you feel that your rear diff hasn't broken in yet, then get some Red Line in your preferred viscosity and run it for 1000 or 2000 miles and drain it. I think that should do it and it should also save you a lot of hassle. Then use what you like. But if you want to be absolutely sure that you're on the right track, then do two more drains and fills with the same brand / viscosity lubricant.

 

[Gebo]

.... But if you want to be absolutely sure that you're on the right track, then do two more drains and fills with the same brand / viscosity lubricant.

Could I borrow a few dollars from you? You can Paypal me. LOL

 

[Foxtrot08]

@Gebo - Get some Delvac 1 75W-90 from Summit Racing at $39.99 a gallon and run it for a while, it stands up to heat pretty well. I assume you have an open diff. Then go back to AMSOIL.

Counter point:

Almost all automotive synthetic gear lubes off the shelf are built very similarly. Whether it’s a house brand or a major brand.

So if amsoil is burning up. Any other brand will as well. Boutique or major or house.

Something isn’t right. My guess is bearing.

 

[Rod Knock]

Could I borrow a few dollars from you? You can Paypal me. LOL

Times are depressingly hard for everyone, sadly. Valvoline 75W-140 or 75W-90 from Walmart would be another good option.

For example, Valvoline 75W-90 is on the PRI list for tested & approved military and other industrial use as Delvac 1 75W-90 which is what I use. Price & pedigree aren't always indicative of high quality.

PRI: https://p-r-i.org/pri-qpl/lubricant-review-institute/

PRI Approved Gear Oil List: https://media.p-r-i.org/assets/2023/03/14094605/LRI-QPL-3-13-2023-on-line.xls

Counter point:

Almost all automotive synthetic gear lubes off the shelf are built very similarly. Whether it’s a house brand or a major brand.

So if amsoil is burning up. Any other brand will as well. Boutique or major or house.

Something isn’t right. My guess is bearing.

You're absolutely right and to your point, the source of heat might be a bearing. My point is that maybe he shouldn't throw major $$$ at gear oil until he figures out the issue.

 

[Foxtrot08]

Times are depressingly hard for everyone, sadly. Valvoline 75W-140 or 75W-90 from Walmart would be another good option.

For example, Valvoline 75W-90 is on the PRI list for tested & approved military and other industrial use as Delvac 1 75W-90 which is what I use. Price & pedigree aren't always indicative of high quality.

PRI: https://p-r-i.org/pri-qpl/lubricant-review-institute/

PRI Approved Gear Oil List: https://media.p-r-i.org/assets/2023/03/14094605/LRI-QPL-3-13-2023-on-line.xls


You're absolutely right and to your point, the source of heat might be a bearing. My point is that maybe he shouldn't throw major $$$ at gear oil until he figures out the issue.

I wouldn’t throw money at boutique gear oil in his situation at all. Fix the issue. Other wise something like redline or HPL. All the rest of the “synthetics” will be similar. But the issue need fixed first.

My guess is something is wobbling. Mainly the input shaft bearing in my opinion.

 

[Rod Knock]

My guess is bearing.

I just remembered, a few months ago a wheel bearing went bad in my dad's semi. We cleaned it up, installed new bearing and sealing, and for good measure we ran a gallon of @High Performance Lubricants Differential Life Cleaner for 10K miles inside the diff and then drained it. The diff was fine, but the bearing made a mess and caused the seal to rupture and burst gear oil everywhere. The gear oil around the bearing turned to sticky tar. So you have a very good point there.

 

[Greasymechtech]

Time for any 75w140 from Mobil1, Valvoline, Redline, Supertech, Lucas, or RoyalPurple...
Pretty sure your local autopart stores have a good selection since wallyworld can be hit/miss with inventory and selection.

If you don't think Amsoil worked as well as you expected, then don't use it.

I've seen plenty of diffs drained and too many looked like black ink. Since it was factory fill, never worried about it.

If you're stuck on the 75w110 grade, then consider Redline, Ravenol, or Driven.

 

[Gebo]

Counter point:

Almost all automotive synthetic gear lubes off the shelf are built very similarly. Whether it’s a house brand or a major brand.

So if amsoil is burning up. Any other brand will as well. Boutique or major or house.

Something isn’t right. My guess is bearing.

What bearing?

 

[Gebo]

Please suggest what I need to suggest to my mechanic. Remember, ECG did the rear diff and my mechanic did everything else.

We replaced "everything". I know he had to use a press.

What other bearings are you guys talking about? Is input shaft part of drive shaft?

 

[Rod Knock]

What other bearings are you guys talking about? Is input shaft part of drive shaft?

Were new bearings installed and were they OEM?

 

[Foxtrot08]

What bearing?

Input shaft bearing is my first guess. This would be the drive shaft bearing.

Axle bearings are my second guess.

 

[Gebo]

 

[Gebo]

Were new bearings installed and were they OEM?

Yes

 

[Gasbuggy]

Hmm. One brand looked good at 1000 miles and one didn't. I'd send a sample to a lab and switch back to Lucas and see how it looks in another 1000.

 

[Snagglefoot]

One thing I noticed is the that boutique oil fans tend to change their rear diff oil a lot. Here is a shot of some rear synthetic diff oil ( Motomaster ) that was in from 150,000 to 200,00 miles on the odometer. It came out black, as I would fully expect.

It’s due for a change next year at 50,000 miles and five years on my Chevy 14 bolt. Currently it has 240,000 miles and it’s the original diff.

If your diff oil is coming out as golden honey, you’re probably changing it too often. In the new GM 1/2 ton trucks, changing dif oil is not even a required maintenance procedure.

 

[Snagglefoot]

I would use an infra red temp gun on the diff if the OP thinks it’s heat that turned his Amsoil fluid black. The early colour change could also have caused by a coating of black heat affected fluid inside the axle tubes left over from when the first diff failed.

 

[Pablo]

You have a mechanical issue that occurred after your first 1000 miles. Either one of the new parts or a part that you didn't change is failing/has failed. Or possible some type of contamination/intrusion as noted in the axle tubes.

I, and many customers use SG. Some 100,000+ miles. Does not look at all like the fluid you drained.

I need to re-read what was changed. And who did the fluid change?

Plus it's not a bad batch. I would know by now, and I'm not saying the chances are zero, but it's never happened.

 

[Gebo]

You have a mechanical issue that occurred after your first 1000 miles. Either one of the new parts or a part that you didn't change is failing/has failed. Or possible some type of contamination/intrusion as noted in the axle tubes.

I, and many customers use SG. Some 100,000+ miles. Does not look at all like the fluid you drained.

I need to re-read what was changed. And who did the fluid change?

Plus it's not a bad batch. I would know by now, and I'm not saying the chances are zero, but it's never happened.

I changed the fluid. I have used this gear oil for 30 years and I change it around 50K.
I'm just looking for help. I ain't bashing Amsoil.

What is confusing me is when I changed out the Lucas at 1000 Miles it looked "normal." So it appears what
happened, happened the second 1000 miles. I am very confused.

 

[4WD]

I changed the fluid. I have used this gear oil for 30 years and I change it around 50K.
I'm just looking for help. I ain't bashing Amsoil.

What is confusing me is when I changed out the Lucas at 1000 Miles it looked "normal." So it appears what
happened, happened the second 1000 miles. I am very confused.

Find a big parking lot and get someone else to circle you … both directions …
General maneuvers etc … I have had rear ends fail and they can get noisy …
You might use some ST conventional and not waste ASG until this is solved …