I just intallled a new Eaton posi unit in the 12 bolt in my 67, What is the best type grease to use with these? My father in law is a royal purple dealer and I can get some of their grease from him, but I am not sure about using synthetic in a rearend. Any help appreciated. I did a search on the subject but couldnt find much. Seems like I read on here once that the really slick oils like the synthetics defeat the purpose of a posi unit. Thanks for any replies. graemlins/beers.gif

I just put an Eaton in my 10 bolt. I was told that synthetic lube is too slippery and the posi won't work correctly. Use a good quality petroleum based lube of the weight recommended by Eaton (mine was 80W 90), and add a 4 oz. bottle of friction modifier, such as GM Posi-Lube, part #1052358. This will keep the posi from "chattering" as you go around corners.

Ok guys B.S. alert here. A good synthetic lube is your BEST bet for those Eaton posi's

Amsoils series 2000 gear lube already has the posi ingredient built into the lube and it works GREAT.
I just had an Eaton 3.08 posi installed last summer and its purring like a kitten.
A synthetic that is not built for posi might need the additive you speak of from GM.
The syns will not negatively affect the slip, so go ahead and use it. There are many others in here that also use the syns in their posi's with great results.
If you use the 'search' function again, type in the name Big Gear Head for user name and you will get a long list of threads dealing with lubes in Eatons.
He is a dealer for Eaton and also for Amsoil as I
am too.
Hope this clears things up.

smile.gif

Here is the scoop, straight from Eaton. This card was in the box with my posi unit.

"The Eaton Posi LSD you have purchased should be installed using a Mineral based gear oil 80 W 90 (GM#1052271). As an extra precaution for heavy usage applications it is also recommended to use 4 oz. of GM Limited Slip Axle Lubricant additive #1052358. The Eaton Posi LSD is NOT recommended to be used in synthetic oils because of the naturally higher temperatures created by the friction discs." (Emphasis not mine)

If you consider this to be "BS", then good for you... you must know more than the engineers who designed it. I have chosen to operate mine as recommended by the manufacturer.

I had the same tag in my Eaton box when it arrived and I promptly threw it out. The tech people at Amsoil have talked with Eaton about this and Eaton is concerned about some lesser quality syn's on the market that are not up to the challenge. Having heard this direct from Amsoil and the fact that their product warranty covers its use in Eatons, I have and will continue to recommend its use. Big Gear Head who sells and installs Eatons, (from this site) also uses Amsoil in his Eaton installs for years now as well.
Obviously, it would be in Eatons best interest to revise their little carton tag but until they do, folks have to do their research, talk to people knowledgable in the field of lubes and act accordingly.
I respect a persons fear of that tag and have offered the rationale that the lube 'engineering' experts have passed along.

The right products work great. smile.gif

[Obviously, it would be in Eatons best interest to revise their little carton tag but until they do, folks have to do their research, talk to people knowledgable in the field of lubes and act accordingly.]

Actually, I think it would be in Amsoil dealers' best interests for Eaton to revise their little carton tag.

What you say may be true...but until I hear it from Eaton, I'm stickin' with dinosaurs!

Cheers.

Its a catch 22 really. Amsoil says to use their product with the protection of their warranty to back it up. They asked Eaton to change the tag but Eaton says other products out there still wont do the job, so they want to opt out of their problem with those by using the tag. To exempt Amsoil or others from their tag would then endorse that oil over others and around and around it goes.
Ive used Amsoil since 1975 and never had a problem and as long as they back their product with warranty and make the recommendation to use it, a consumer is safe, either way.
But you do what you feel is right, no fault in that. I just know my posi will run over 20 degrees cooler and that translates to reduced friction and longer life.
Thanks for the word swaps graemlins/beers.gif

I'm NOT trying to start a fight or be nasty...honest. And I'll listen to and respect your answer...but I don't think "reduced friction" is necessarily what you want in a posi. There has to be a certain amount of friction for a posi to do what it is designed to do...to provide traction to both wheels in the straight ahead mode, yet slip enough while going around corners to provide differential. If you were after "reduced friction" you'd also put whimpy springs in them.

Amsoil might be just perfect for these things. And I certainly am not saying that it will cause harm. I just think that if you want the posi to grab tight when it should, more friction, not less is the answer.

I always use Amsoil 75W90 Series 2000 in all of the posi rear ends that I build, unless the customer goes against my advice and uses something different. It has always worked without any additive, except for Auburn limited slip differentials, which don't work well with any kind of oil. You can take my advice which comes from 21l years of experience building rear ends and 6 years of experience with Amsoil, or you can use something different.

"Amsoil says to use their product with the protection of their warranty to back it up."

Does this mean if the posi fails (due to lube)- Amsoil will pay for the repairs/replacement?

I'm very curious as I will be ordering a new Eaton in the next 15 days. I always wondered because the first thing the magazines do is put in high quality syn and the brag about how great it is. My next door neighbor installed an auburn last month and went with old technology because he had a similar card in his box and was scared of warranty issues, much like Calebs67rs.

Yes thats right. A warranty is a warranty. If you have failure in mechanically sound application, after using according to their recommendations, with lab tests on the used product to confirm its condition, their warranty stands.
The reduced friction that comes from using the syns is primarily where the teeth meet not just the turning radius friction. Petro lubes loose out under high pressure and the teeth can meet for micro seconds where the metals touch. That is where the heat comes from as well as the sheer as the lubes are squeezed between metal.
Maybe Big Gear Head and I can make another ovature to Eaton to reconsider their box tag again. This issue keeps coming up and never ends.

Thanks a lot for the replies, I have decided to go ahead with the synthetic oil.

Just as a follow-up - I called the shop where my ring and pinion was set up. He has been doing these for 30 years, mainly for off-road vehicles, and is not an Amsoil dealer. His reply - don't use synthetic.

BPOS out.

The reason that most people are afraid of synthetic oil is because they heard about someone who knows someone who may have had a problem with something that was actually not even related to the oil, but the oil was the first thing that got blamed. People who are afraid of good synthetic oil listen too much to myths and not the facts. The fact is that no petrolium oil is as good as a good synthetic oil. There are some junk synthetic oils, but there are a few that are really good. I'm not trying to **** anyone off, but it does get frustrating when people fight what they don't understand. Ok, I'm done venting.

Big Gear Head and Click: Please don't be frustrated or P.O.'d...that was never my intent. You have even mostly convinced me, a 45 year old skeptic, who is set in his ways, that Amsoil will work just fine with the Eaton posi. But please understand where I am coming from. The people who design and build these things recommend against synthetic lubes for them, and so far, the only people I have heard who recommend synthetic lube for them are you two, who sell and profit from its use.

I consider myself to be a reasonably savvy consumer. When I pay good money for a product, and they specifically recommend against using synthetic oil in it, I'm going to heed their advice. This doesn't mean you guys are wrong. But, skeptic that I am, I need to hear it from Eaton.

I guess what really torqued me off was the fact that my opinion, which is based on the best advice from the manufacturer, was considerd by one of you to be "BS". I would suggest that you give people a little credit as far as being able to read the directions before discrediting them.

Ok BPOS graemlins/beers.gif Now let me clarify something you misread. My B.S. alert was aimed at the statement, (not you personally) that syns are to slippery for a posi, which is not true at all. The tag has no mention of 'slippery' on it. It deals with temperatures, again syns can take a wider range of temps than any petro oil.
I never attack a person in here, it benefits nobody. I only take issue with information I believe is not totally correct. I will try to be more clear in the future.
I know from experience over the last 25 years of using Syns, (not making a profit from them), that every new customer will have questions because syns go against the grain of the 'good old boys' in the petro business and what they have recommended for years. They have the public brain washed that only changing oil every 3,000 miles is in their best interest when they turn around and market partial syns with extended drain intervals.
That being said, I dont take your information as making me mad or PO'd at all. Its been an interesting debate in my mind here.
I enjoy education people about something I firmly believe in. I will defend the products against old school theory that was put to rest decades ago but for some reason wont die off.
I will guarantee you that many of the NASCAR and other high powered cars are running syns in their rear ends, trannys and of course engines too. Same with the Monster Trucks.
Old time mechanics are the hardest ones to convert to syns for some reason, so the myths will stay alive as long as they do, or until they think out of the box.
I will be following up with Amsoil again on the Eaton issue and report back when I hear on how we can deal with that stupid tag in the box. As I stated earlier, I can fully understand a person being skepticle after reading that and if they so choose they can put their old dinasaur in and be happy. I just know they will be 'happier' with the syn in there.
Keep em revving

graemlins/thumbsup.gif

BPOS,
I was not venting at you, but at the drive train shops that are giving synthetic oils a bad name. Randy's Ring & Pinion is the only shop that I have come across that actually has given it a real chance, and Randy likes it. Eaton is probably just trying to protect themselves from the bad synthetic oils. I had a Amsoil rep contact them and they treated it like the other drive train shops, not even a chance. It is a long, hard process to change the thinking of the public. graemlins/clonk.gif

Any reason why people use the term "grease" for gear lube? I saw another post a while back something about "correct grease for a muncie".

Usually I think of grease as thick pasty slippery stuff for lubing ball joints or pie pans.

Maybe it's southern slang? :confused: Just curious.

Originally posted by BPOS:
Just as a follow-up - I called the shop where my ring and pinion was set up. He has been doing these for 30 years, mainly for off-road vehicles, and is not an Amsoil dealer. His reply - don't use synthetic.

BPOS out. I got your back. Unless you frequenty change your differential oil, I wouldnt recommend synthetics either. There is really nothing to gain from its use in a differential in a street car . I couldnt even tell you a ratio of oil related brake downs between synthetics and everything else. If I could give you a number, it would be more than 100+:1 in favor of 'everything' else.......and that one was related to "StayLube"...... I have tried every consumer available synthetic and have even formulated some different ones to gain a MPH or three in Land speed record cars.....and some are better than others. BUT, I will say that synthetics are not for everyone. If you have an opinion, share it, dont try to shove a product that YOU are a dealer for down someones throat.......

Being in the niche automotive consortium that I am, and being a dealer for just about every oil you can purchase for under and over $25.00 a quart, I still have found nothing better than a parafin based 140wt gear oil for the differential. Now you want to start talking race cars, my opinion changes......but only slightly.

In the Trophy trucks (SCORE), I still use a parafin based oil but go to an ISO9000 250wt. In the land speed record cars and Indy/Cart chassis is about the only place I would really consider the use of a fully synthetic gear oil in a differential because of the materials and tolerences used on the mechanical load surfaces. Christ for that matter, there are still applications using 'peanut' oil.......where even the "best" synthetics fail.

Until most of the people on this site start instrumenting the differential and transmissions with thermocouples and retrieving actual temperature data, like some of us do and have done , the replies on temperature specifics are speculation. The 'hear say' proves nothing to the real world. I use different type oil lubricants in different devices, for different reasons. There is NO one company that makes the best lube for every device .....period. I use a mixture of RedLine MTL and LE 'Monolec' in the transmission and I use Schaffer ISO9000 140wt in the differential. But this is me.....I have my opinion from various worlds of automotive racing and private industry service/installation/fabrication. I dont have oil related break downs.......and niether do my customers. There is NO real snake oil, there are only real technicians.....engineering or otherwise.

Originally posted by big gear head:
I'm not trying to **** anyone off, but it does get frustrating when people fight what they don't understand. I couldnt agree with you more.

[ 02-24-2003, 01:30 PM: Message edited by: chicane67 ]

So what you're saying is, unless the car/truck is driven as hard as possible all the time, or is strictly a race prepped vehicle that punishes it's differential constantly, synthetics are overkill? That's what I'm getting from your post Chicane.
That would lead me to believe that a synthetic needs to be under intense abuse in order to perform or have longevity, so in a street driven environment, a synthetic fails?

This is the kind of posts that I really enjoy. Not only do I learn something, I get to hear it from people who are passionate about their views. Not just "I heard it from this one guy". Click, Gearhead, and Chicane are all committed to their opinions and will never be swayed by the conflicting viewpoints. We all get to read the posts and form our own opinions based on who drives the point accross best. We could all move to Iraq if we want just one answer. Thanks alot guys, keep up the good work.
Scott

If I tried to push too hard then I apologise. I could tell about the tests that Amsoil did compairing the operating temperatures of different oils and I could tell about the independant lab tests conducted with Amsoil and other oils, but I'm sure that there would be one or more people who would come back and say that those tests were biased. I have done some tests of my own, but I can't give actual numbers because I didn't get too technical with them. I do know that the Series 2000 Amsoil has cured some problems with some of the differentials that have come through my shop. I have seen some differential failures due to over heated oil. Amsoil and some of the other good synthetic oils can withstand almost twice the temperature of petrolium oils. GM, Ford and Chrysler have gone to synthetic oil in all new truck differentials. Chicane, I respect your opinion and it appears that you have done some serious testing, but even if I never sold another quart of oil I would still feel that a good synthetic oil is better in any differential than petrolium oil. I hope no one gets offended by my comments, this is just my opinion.

What I should of added is that most of what I have stated is specifically realated to "load".

In a high performance, high HP/torque or towing application specifically concerning differentials and transmissions, the most important characteristic of the lubricant in use is film pressure strength. Secondly would be of its ability to carry heat without breakdown (seperation of chemical additives, normally heat related).

In a differential there are numerous mechanisims that all use the same oil. The different mechanisims all have a loading principal and they are not all the same. In specific consideration for differentials, the bearings 'see' a different load than that of the hypoid gear set. This now is where the film pressure strength comes into the senario.

Dealing with a radial bearing, like that of an engine bearing or a differential bearing ball or tapered roller makes it compliant to 'its' mechanical principal. It incurs its heat from point loading and resistance but not mainly from impact loading. The heat created has to be transfered, absorbed and dissipated. This type of mechanical device works better with the influence of an oil with specific characteristics.

A hypoid gear set incurs its heat from impact loading and surface friction. This type of mechanical device works better with that of a oil with different characteristics.

But, this is not all realitive...... The component properties have ALOT to do with the viscosity. It is their ability to stay homogenized that makes or breaks the questioned oil formula. The mixtures overall composition makes its film pressure strength, its ability to carry heat and if it will stay homogenized.

What works best for a radial bearing, doesnt mean that it works best for anything else, even a hypoid gearset.

The carrier, axle and pinion bearings load differently than that of the ring and pinion gears. The pressure and temperature created at the load points are also different. In a high performance application I would believe that you are more worried about impact loading and bearing speed. As for a towing/RV I would believe load capacity is the main concern. So in a high temperature environment (high speed, high loading) where shock loading isnt repeatitive a synthetic would most likely reign supreme. As would a lower speed higher viscosity oil in a differentail going through the gears (moderate speed, impact loading).

The oil related failures that I have seen are more present at the ring and pinion, more than that of the bearings. As for the oil in these related failures, it was from a temperature breakdown. I dont want to say the names of the manufacturers of those oils, but I will say this. I WAS COMPLETELY SURPRIZED . It was from companies that I do hold in high reguard and after a lively chat with some of their chemical engineers there were things brought to my attention that I was unaware of.

Scott I want to say thank you and to also add that I too value what we have here at Team Camaro. I do hold many participants, specifically in this thread and in numerous others, in the highest reguard. BGH and Click are very thought provoking and I am glad to maybe be the same way for someone else.

BGH , you know as well as I do that in the business that every company has to do its marketing and make it sound better than the next guy, and I too have seen the numerous independant testing and have actaully been apart of one here and there. But all companies have their "independant testing" and make the same claims.....it goes back to my 'Snake Oil' comment...... I didnt really want to 'seem' like I was pointing a finger at you guys because of your support for a specific company. I just dont want everybody to get the impression of any-old synthetic being the "Right" one for the job.

Most products that the 'Big Three' use in the factory are still designed around "average" use. Please define "average"......and on top of that, the recommended service intervals......

If anyone were to consider the use of synthetics, I will back the claims of my fellow Team Camaro members. In a differential, Amsoil, Lubericant Engineers "Mono-Lec", and Schaffer's "209" would be excellent choises. As for the weights of these oils, I would use a strait 140wt in a rear differential and a strait 90wt in a front end.

We all have our opinions. I will always have higher respect for those who stand up for what they believe in. Scott is correct, it is the passion that fuels our drive......and some of us are on our way down the nitro methane injected path of knowledge. I hope everyone will also find themselves in the staging lanes.......

Chicane, I applaud your intense background in the mechanical fields that you have experienced. Its obvious they have given you a tremendous insight into many areas alot of us will never see and learn from.
I fully agree with your description of the gears, hypoids, etc that all scream for lubrication but for different reasons and at different times. Unfortunately for us, we can only use one product in our differentials at a time. I also agree in competition or full time use under heavy loads, special attention can be given to using the ideal product for that application that varies from us every day folks.
That being said, for those of us living north of the mason dixon line where temps vary, especially those of us in cold winter climates where a fall cruise can go to 20 overnight, I would never recommend anything heavier than the 80w90 gear oil and of course Id recommend Amsoil. Yes I am an Amsoil dealer since 1975 BUT I make no profit from that dealership, rather I get to buy my oil at dealer cost, smart move I would think.
In addition, I worked for Amsoil Corp. in the late 70's and I was inside the lab, the tech services, dyno room, watching ASTM testing, in the field with dealers and above all, answering thousdand of letters of 'how to do this or that'.
In all that time Ive seen syns explode in sales and product availability as well as syns being slowly phased in by the petro companies as they see consumers wanting them.
I see our collector car market as one with many type of users. Daily cruisers with minimal RPM's, weekend racers with high RPM's, and everything inbetween. Each can benefit from different products that many on this site chat about openly. I dont have a welder, a compressor (yet), no Sun testing machine or a rack of books to refer to. I have a small set of tools and a warm garage. So Im not in a position to help alot of folks yet, unless it has to do with oil and lubes in cars which I know very well and enjoy sharing.
There are glitches (Eaton) that make me roll my eyes when it comes to suggesting lubes but with my contacts and background, I do know that what I recommend is accurate for that person and defendable.
I hope you understand why I would never recommend a 140 weight gear oil for average users, just as I know why you 'would' for situations you might run into. We can agree to disagree on certain points along the way but we can agree fully that there are people we can go to for that special case when it arrives.
If you have non propritary questions about Amsoil, feel free to ask me and if I dont know, I have the right 'ear' to find out, as Ive maintained close contact with my friends there.
Readers of this thread at first blush might think we are having disagreements but in fact we are just sharing, as so many in this board do, and the end user is like a kid in a classroom, listening to teachers, then they go do their homework and make a decision. Their grade is their happiness in the results they see with their trusty Camaro.
I think Ive rambled on enough on this thread but Im glad to see the interest it has raised and if nothing else, TC members that read all this are now smarter for it.
Lets take some coins from petty cash and have a brewski on Al and Dennis graemlins/beers.gif graemlins/beers.gif

I think that about covers it from every angle. I hope Caleb has enough information to make a wise decision regarding the right oil for his new Eaton. Chicane and Click, your knowledge of oil is above mine and I can add nothing else. My brain hurts.

Your brain might hurt but my eyes hurt from reading all this good stuff. smile.gif

The Amsoil Series 2000 is working just fine with my new version 8.2 Eaton posi.

Ok, I think I get it. I'll use a can of my wife's Crisco smile.gif

POWER TO THE PEOPLE!!!!!!!

Hmmmm.............. :cool:

Ok gang, like I promised, a direct response to this issue of Eaton. I think its darn good explanation and reconfirms Amsoil works and is warranted in them.
graemlins/thumbsup.gif
Eaton and Amsoil , synthetics are OK (http://www.brainerd.net/~knudsen/69RS/Eaton%20LSD.doc)

That makes me happy! :D

Are you sure synthetics are OK for eatons? graemlins/boring.gif
Sorry, I went to sleep 2 pages ago.
You guys could write a book, But wait, I think you already have. graemlins/beers.gif

What better use for all this paperwork right?

http://www.brainerd.net/~knudsen/69RS/Gif/wipewithfiles.gif