Going insane here, dino better than syn?!?!?!?!

[CrazyMike]

Got a real interesting debate for you guys here........


I run 37's and bigger with a stroker, D44 rear end grenades 3 times in one summer, this summer in fact. I have a high pinion hi clearance Currie Iron Rock Jock D60 in the back now, goodby to rear end issues!!!!! At least I thought....


I've been an absolute believer of synthetics since grade 11 mechanics, and have seen time and time again the benefits of good quality synthetics over mineral. I run Amsoil exclusively, nothing against Mobil, or Red Line, Amsoil is readily available in my small town, other synthetic lines are not.

So what's the point Mike? Currie says they'll void warranty if I run synthetic gear lube!!!!

They recommend 85/140 mineral gear oil, I have that available but it's getting stupid cold here so I got their approval to run 80/90 mineral gear oil, Chevron is the brand, as is the 85/140.

The reasoning why Currie doesn't approve of synthetics? The explanation I was given is that they have had component failure in 9" axles they build which they beleive was a direct result of the synthetic oils used did not, or COULD not, deal with "excessive shear, pressure", and for reasons unknown they believe mineral-based 85/140 offers much better protection.

One guy I talked to earlier this summer, he siad stick with mineral for break in, and I can run my choice of oil, which would be Amsoil severe duty 75/140. Once we began install I talked with another gent that stated all warranty will be void if I did not run approved oil.


So, what do you guy think I should do here. I have no probem running mineral through the warranty if they want that, but even then I'm not sure of the grade. I can use 85/140, but it is getting cold, and that oil is thick.

Should I stick with 80/90 Chevron, or can I switch to 85/10 where it gets -40c/-40f. Keep in mind my Jeep is parked in a heated garage in the winter, and when it's out, it's being driven so it won't be outside for prolonged periods, but it will be parked here and there for 2-3 hour at a time. Will 85/140 hold up to this?

Regarding the synthetic question, most shops building axles use synthetics, why can't I?!?!?

Thanks for the time, discuss!!!!

 

[Lonnie]

If you want the warranty you should follow their reqt's.

 

[CrazyMike]

Please excuse my garbage spelling, and I forgot the vehicle

2004 Rubicon, 4.6L I-6 stroker, 37's, all sorts of goodies!

 

[INDYMAC]

That looks like a nice, fun ride!
If you have your heart and mind set on synthetics, maybe AMSOIL will pick up your warranty issue and run with it. In fact, maybe they will offer free products for your trouble when you explain your situation...just to prove the builder wrong!
Good luck, and enjoy the winter.

 

[Pablo]

Quote:

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The explanation I was given is that they have had component failure in 9" axles they build which they beleive was a direct result of the synthetic oils used did not, or COULD not, deal with "excessive shear, pressure", and for reasons unknown they believe mineral-based 85/140 offers much better protection.

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Did they put this is writing? What exactly does the warranty say in writing?

 

[gomes512]

You can try the Amsoil thing or just use what they recommend.

I only have a 35c rearend and a locked 30 front. Both will run 85-140 dino year round without any problems. I ran 75-90 once in the summer and managed to chew up the bearings. Keep in mind also that a quick start to a higher speed (say 25mph) after a period of non-use will increase axle life. Allowing the oil to get whipped up to the upper portion of the axle faster providing more immediate lubrication.

The only gear oil I've had problems with was Wally world's Super Tech blue bottle dino, guess the batch I got didn't come with anti-foam adds.

 

[c502cid]

I've run with Curries stuff in the past. If it's under warranty, I'd run with what they say.

 

[Titan]

My guess is contamination issues. They'd rather put a non-synthetic in and have people change it regularly to remove the contaminates from ingress of water/mud/dirt. Just a guess...

 

[INDYMAC]

Currie is not the first that I've heard recommend dino over synthetic for differential gears, especially high offset. I think Bob of BITOG fame was the first I heard to proclaim this preference. He said that they would have a better propensity to climb gears than synthetics. I use LE 607 SAE 90 GL5 (mineral based with -11F PP) in my Tundra rear diff and my S2000 rear diff (high offset). But I use Valvoline syn 75W90 in the transfer case and front diff.
I say use the Currie recommendation with warranty. It sounds like a no hassle arrangement.

 

[bruce381]

"""The reasoning why Currie doesn't approve of synthetics? The explanation I was given is that they have had component failure in 9" axles they build which they beleive was a direct result of the synthetic oils used did not, or COULD not, deal with "excessive shear, pressure", and for reasons unknown they believe mineral-based 85/140 offers much better protection.""

Cause they are right SOME syn gear oils have BAD shear stability and will shear baddly and NOT offer the gear protection needed, Who is bad?? I can not say BUT that is there concern I think.

so using a 85/140 mineral with NO VII or shear problems that is there call.
bruce

 

[Jim]

I have had good luck with Red Line shock proof gear oil in my motorcycle. Very little wear metal on the magnet after 20,000 miles. And this stuff sure climbs gears!

 

[BuickGN]

I've had better luck with dino oil than synthetic in my Buick. When I switched to synthetic I noticed much more cylinder wall scuffing and piston pins wanting to seize. Switched back to dino and have yet to have the problem again. I change oil every 500-1,000 miles anyway.

 

[INDYMAC]

Quote:

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I've had better luck with dino oil than synthetic in my Buick. When I switched to synthetic I noticed much more cylinder wall scuffing and piston pins wanting to seize. Switched back to dino and have yet to have the problem again. I change oil every 500-1,000 miles anyway.

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And I thought I changed my differential oil often at once a year!

 

[MolaKule]

Try Amsoil 75W110 or Schaeffer's 267. Both are very shear resistant oils.

 

[unDummy]

Simple rumours. Too bad companies still don't understand what synthetic is. It was no different with motor oil, ATF, PSF......

I hate it when a company forces a fluid but can't give a REAL reason why.

And, since they did originally require a 140wt, I would just use the synthetic version of a 140wt. I wouldn't step down a grade.

If you got their approval to use a mineral 90wt, I don't see why you couldn't use a synth 140wt. Could a 140wt synth shear below a 90wt mineral gear oil? Wheres the common sense to a mineral 90wt approval and not a 140wt synth?

It would be more honest if the company said they occasionally shipped a crapend and simply looking for something else to blame.

 

[Pablo]

Quote:

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Simple rumours. Too bad companies still don't understand what synthetic is. It was no different with motor oil, ATF, PSF......

I hate it when a company forces a fluid but can't give a REAL reason why.

And, since they did originally require a 140wt, I would just use the synthetic version of a 140wt. I wouldn't step down a grade.

If you got their approval to use a mineral 90wt, I don't see why you couldn't use a synth 140wt. Could a 140wt synth shear below a 90wt mineral gear oil? Wheres the common sense to a mineral 90wt approval and not a 140wt synth?

It would be more honest if the company said they occasionally shipped a crapend and simply looking for something else to blame.

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Stop making sense.

 

[BuickGN]

Quote:

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Quote:

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I've had better luck with dino oil than synthetic in my Buick. When I switched to synthetic I noticed much more cylinder wall scuffing and piston pins wanting to seize. Switched back to dino and have yet to have the problem again. I change oil every 500-1,000 miles anyway.

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And I thought I changed my differential oil often at once a year!

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That is once a year give or take a month. Didn't realize you guys were talking about diffs.

 

[Steve S]

Quote:

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I've had better luck with dino oil than synthetic in my Buick. When I switched to synthetic I noticed much more cylinder wall scuffing and piston pins wanting to seize. Switched back to dino and have yet to have the problem again. I change oil every 500-1,000 miles anyway.

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How did you notice all that stuff? How do piston pins want to seize? what about cylinder wall scuffing?

 

[flatlandtacoma]

Definately run the 85w140, especially since you have a heated garage.

 

[CrazyMike]

I will stick with a mineral based through the warranty, I'll switch over to a 85/140 Chevron within the week. I get the feeling "It doesn't realy matter what you run as long as it's not synthetic, ANY synthetic" is the train of thought, I just don't agree with that one. I'm sure I could find a synthetic 75/140 that has great sheering properties and will climb ring gear effectively, but how do I find that out..........

I'll see if the local parts store will get me one of those Lucas Oil displays maybe, the one with a crank and a series of sprockets showing the oil's properties of how it climbs up top, you guys know what I'm talking about eh?

Thanks for the insight everyone, 85/140 for now, heated garage will help keep the oil fluid enough I won't worry about starving a bearing. Then we see which synthetis wil work the best with a HP........