Gear lube recomendation chrysler 8 3/4

[pjc360]

Just finished putting together a chrysler 8 3/4 rear axle to put in my 91 half ton short bed four wheel drive truck, I live in idaho where winter is brutal and summers get hot. In the past I have always ran valvolone synpower 75w-90 and in fact I have synpower 75w-90 in the front axle on my truck which is a dana 44.
I was considering running amsoil severe gear in this 8 3/4 and the reason why is because it's a chore to completely drain the oil from this axle, you have to pull the axle shafts out and drop the third member to completely drain it.
I could use a suction method but it wouldn't get all of it out. Anyways I want to run a good synthetic oil in this axle.
Right now my local Napa auto parts has valvoline 75w-90 gear oil on sale for 9.99 a quart. They also sell amsoil severe gear 75w-90 at 15.99 a quart. This axle takes just shy of 3 quarts to fill, so I'll be buying 3 quarts. The amsoil would cost me 48 dollars and the valvoline would cost me 30. Is the amsoil worth the extra 18 dollars? Or would the synpower work just fine. What oil would you reccomend? Chrysler reccomends an 80 to 90 wieg oil for the 8 3/4.
I'm willing to buy the amsoil, but if the valvoline will do just as good then I don't mind saving 20 bucks.

 

[Donald]

+1 Amsoil SVG.

 

[SwedishRider]

+2 Amsoil SVG.

 

[oilboy123]

Lots of people poo poo Amsoil being too expensive with short oil changes etc. Fluids in axles, transmissions, transfer cases etc are time consuming, and not cheap to have done either.

I feel Amsoil makes stellar transmission, and gear lubes. For the cost difference why not run one of the best?

I would rather pay more for quality, and run it longer.

 

[Kuato]

Becoming a preferred customer will get you the Severe Gear 75w90 for $11.55 a quart plus shipping on the Amsoil site, well worth it IMO.

If you contact Pablo, he might even be able to do better.

 

[oldhp]

Open or posi-trac? Factory posi I would use plain 75W90 gear goo with Mopar posi additive. The OEM style clutch packs don't like synthetic lube.

 

[HTSS_TR]

For oil you will be okay to stay with name brand such as Mobil, Pennzoil, Valvoline ... No need for expensive boutique oil.

For ATF, Gear fluids ... Amsoil is 1 of the best if not the best, and since you're not change these fluids every year the extra cost over 3-5 years is no more than 1 Starbuck Latte a year.

 

[pjc360]

It's a non sure grip. If the amsoil is worth the extra 20 dollars I'll get it.

 

[dnewton3]

The Valvoline is an excellent gear oil, and is registered as an SAE J-2360 lube. (as are many others.)

You asked if it's worth spending the $20 for the Amsoil; that's very "iffy" IMO.
SVG is an outstanding lube; I'll not deny that. But are you going to get any difference in treatment from the added expense; is Amsoil going protect or last that much longer? The Valvoline is a great fluid, and it will probably last 100k miles or more (as long as it's not submerged, but that is true of any axle).

This topic is not unlike many concerning engine oils; is product "x" worth the added expense?

In this case, I doubt it.

Info for J-2360; this is a VERY robust and hardy standard (MIL spec based) that focuses on real world application testing results and not simply meeting GL-5.
For reference reading in your spare time:
http://standards.sae.org/j2360_201204/
http://drivelinenews.com/tips/the-value-of-sae-j2360-a-global-standard/
http://www.pri-network.org/wp-content/uploads/2012/10/QPL-lowres-110420.pdf
http://drivelinenews.com/videos/sae-j2360/

and the list itself ...
http://p-r-i.org/other-programs/automotive-qpl/lubricant/
(see the link for the excel file listing; it's kept up to date)

What I have found is that there are some very interesting qualified product, including many dino oil choices that also meet the very same standard as the syns!


Yes - I've seen the "white paper" that Amsoil did regarding gear oils. The SVG is a fantastic product. But this is a question about ROI. What do you get for your money spent?

Why do I like the J-2360 listing? Because while GL-5 assures me what's in the bottle, the J-2360 is a performance spec; it tells me how the lube actually does in the gear-case!


Here's the real way to look at this ...
What is the standard you need to protect your rebuilt axle? Probably any GL-5 would suffice.
But J-2360 fluids go above and beyond; there is a performance assurance with these.
Do you "want" Amsoil? Some folks do.
Do you "need" Amsoil? No way; the J-2360 products will protect to a level far greater than you're going to need. So way pay the extra $20 for the Amsoil when J-2360 is well more than adequate?

The PRI J-2360 listing shows that these lubes go through a barrage of testing that is performance based; well above the min GL-5 standards. These are based on field trials, and take into account vis retention, foaming, wear, etc. These lubes are likely to far exceed any capacity you would need. The ONLY question is one of longevity; would the SVG last longer in service? I doubt it, because any J-2360 will last a LONG, LONG time and you'll probably OCI again before the lube is worn out.


Take this completely out of a lubricant context, and let's make up some mythical example ...
Let's pretend you need a pump to move water in your large pond for a fountain.
You determine that you need 10 gpm from a pump that will last 5 seasons.
You find a qualified list of pumps from an unbiased research institute; it tests to a military standard that provides a minimum of 15 gpm in a period over 10 years.
Then later you find a pump that will deliver 18 gpm over 12 years, but it's more expensive, and is not on the qualified list; it's not been tested to the same standards.
Which is the solid choice? When the "qualified" pumps are already "over" capacitized, why spend even more money on a high-end product that you'll not ever glean the added expense from?


Maybe SVG would do better; maybe it would not. But any J-2360 is going to give you outstanding performance, and many of the qualified lubes are at nice low prices.

Why spend money that you don't need to, when J-2360 is well more than good enough?
This is not a question about what's "best".
This is a question about what's well more than good enough, for a nice low cost.
I seriously doubt you'd ever get any performance advantage from SVG that you'd be able to discern above J-2360 fluids.
If you want a syn for longer OCIs, there are plenty of syn J-2360 lubes (such as the Valvoline, among others) for less than SVG.

 

[Lubener]

Supertech, Valvoline or Pennzoil 80W-90 dino. I wouldn't pay the extra for anything else, no benefits gained in my opinion.

 

[pjc360]

Longer oci is a pretty big benefit of running synthetic imo, and that's why I run them, specially in this axle, it's not as easy as pulling a cover to drain the oil on these 8 3/4 axles.
The synpower gear oil has served me well in the past, and I'm not rich, The 20 bucks id save buying the synpower over the amsoil could go into my fuel tank.
The synpower 75w-90 can go 100 thousand miles?

 

[dlundblad]

Synpower (*and any gear oil) also qualifies for AAP codes if you have one local to you. I bought 4 quarts of 77w-140 cheaper than what I could have bought Supertech at.

 

[Greasymechtech]

Any full synthetic GL5 75w90 will work fine.
It depends on what you want. Group III or IV? Burger or filet mignon?

Price seems to always be the argument in every thread. Enjoy your walmart economy.

Amsoil it!

 

[pjc360]

I want to try the Amsoil just because I have never tried it before, and I have heard great things about it. On the other hand I'm confident the synpower would serve me well too. And I'd save 20 dollars. I might just flip a coin, heads for synpower tails for amsoil. The axle in my truck did burn up while I was running synpower 75w-90 in it but I don't think it was the oils fault. It was a chrysler 9 1/4 and they are infamous for thier oinion bearings issues and crush sleeve issues.
That's why when my 9 1/4 burned up I decided that I would get an 8 3/4 to replace it.

 

[901Memphis]

Have you considered Redline? I rate them equal to amsoil in my book.

 

[pjc360]

Ya I've considered redline, the main reason I haven't ever tried it is because it's not in any of my local stores. I usually buy what's in the part store, ive never ordered oil online of any kind before. Mainly because I hate waiting for stuff in the mail.

 

[dnewton3]

Originally Posted By: pjc360
I want to try the Amsoil just because I have never tried it before, and I have heard great things about it. On the other hand I'm confident the synpower would serve me well too. And I'd save 20 dollars. I might just flip a coin, heads for synpower tails for amsoil. The axle in my truck did burn up while I was running synpower 75w-90 in it but I don't think it was the oils fault. It was a chrysler 9 1/4 and they are infamous for thier oinion bearings issues and crush sleeve issues.
That's why when my 9 1/4 burned up I decided that I would get an 8 3/4 to replace it.



I am pleased to know that you realize blaming a lube for mechanical defects and poor design is not a credible thing to do. The failure of your old axle is not likely caused by the Synpower.

Nothing wrong with trying Amsoil if you have some detailed manner in which you're going to judge it, relative to objective criteria and not guesses and hunches! What I'm stating is that if you want to compare/contrast two or more products, then what measurement criteria are you going to use?

Results are what matter most, not inputs. Hence, I recommend UOAs. So to fairly and accurately judge this, you're going to need to know a few things:
1) what are the universal averages for your diff in terms of wear metals, exposure, etc?
2) what are the statistical deviation nodes for "normal" variance?
3) what are you going to use as a baseline?
You need to hold as many conditions constant as possible, so that the variant (fluid) is the majority actor in any changes noticed, if any at all.

Read my "normalcy" article; you need to understand how to delineate normal from abnormal, and apply logical conclusions rather than just hypothetical hunches.

 

[pjc360]

When you compare the synpower to the amsoil on the spec sheet they look really similiar to each other. I still need to buy some paint, to paint this axle, and I need to pay to have the brake drums turned. So I think I'm going to run the synpower just because I can get it on sale for 9.99 a quart right now and that would save me 20 dollars to put towards paint and getting the drums turned.

 

[zrxkawboy]

Originally Posted By: pjc360
So I think I'm going to run the synpower just because I can get it on sale for 9.99 a quart right now and that would save me 20 dollars to put towards paint and getting the drums turned.


I would do the same. You really can't go wrong either way.

 

[BrianF]

I just re-read this thread. I must say that I agree heavily with dnewton. Is amsoil better than the other lubes?? Maybe.... maybe not. In this application is it better? Maybe, maybe not.

If one can get an oil that meets an excellent spec (J-2360) at half the price of a competing oil than have at it. I must agree, why would I pay more for a fluid X when a less expensive fluid Y will do as good.

Again I look at the application. Is this diff going to be taxed very heavily? Is a more expensive fluid even needed? What it also comes down to with me is this: You have a sealed unit with a finite level of fluid, no filter and it can only have so much capacity for wear particles and other [censored] that goes with it. Can fluid X deal with the wear material any better or hold any more than fluid Y?

Perhaps a real world test is required. two identical vehicles, one using X and one using Y, see what one makes it to a million miles or more. I bet the vehicle would rust away long before anyone would give a [censored].

I use amsoil, a big factor was that a brother got it for cheap and literally gave it to me for free. To save shipping and outrageous prices I went locally and found great fluids at good prices.

The synthetic 80w140 and 75w90 oils meet J-2360 and a whole host of other OTR trucking specs and I get it for 9 bucks a liter. If I spent upwards of 24 bucks a quart of RP for similar oils would I tell a difference? Probably not. My trucks will long be dead before any difference is found.

So I took the difference in cost and used the money to take the kids to the water park.