Thoughts on dino 80w90 vs 75w90 full synth for diffs/TC ?

[TechnoWeenie]

The cost difference is negligible to me.

1. Can I run 75W90 instead of 80W90 in TC and diffs?
2. Will I see any benefit using a synthetic instead of dino?

My experience with passenger vehicle diffs is a LOT different than heavy machinery... The 8.8 in my fords can take 75w90, 80w90, all the way up to 75w140 and doesn't care... but there's a huge difference between a diff that's handling a couple thousand pounds and a diff handling a couple thousand TONS....

I did note the LO says to run 75 straight in colder climates, but didn't know if it'd seriously screw things up running it constantly in warmer (higher than -15F) weather. I think the coldest it got here last year was in the 20s. .heh.

 

[87cr250r]

The rule of thumb when using synthetics in gearboxes is that you can drop a viscosity range without sacrificing protection vs a conventional.

The lower friction and whatever are benefits though they're barely noticeable. I like synthetics because seals last longer with synthetics.

 

[G744]

If it leaks a little bit now, it will leak a lot then.

My experience, at least.

 

[87cr250r]

It is my understanding that synthetic oils don't have the aromatic hydrocarbon content of conventional. Conventional oils cause buna-n rubbers to swell which eventually leads to them hardening and then leak. If your leaks start after switching to synthetics it's because the damage has already been done. Modern engines don't use much buna-n rubber, anyways. It's mostly HNBR, Viton, silicone, and PTFE nowadays. Manual transmissions and differentials may still use buna-n due to lower operating temps.

 

[ericp351]

My 2 cents- The viscosity of the synthetic oil would be A OK, as stated above. YOUR Business, buy why?? The axles, especially should be severely underloaded, relative to capacity and lubrication, for the mass majority of civilian users. If you must overload- you may be better served by 90w-140 in HOT climes. (Any quality GL 5). I worked on a ship where the single reduction gearset was both critical, overloaded, and effectively irreplaceable. Choice was made to go with synthetic oil- dahm the leaks and expense. Your cost so your business. I GUESS your payback time would be beyond my lifespan. Good luck- I'll stick with the Dino Juice and spend the savings on Camo Fuzzy Dice!

 

[TechnoWeenie]

My 2 cents- The viscosity of the synthetic oil would be A OK, as stated above. YOUR Business, buy why?? The axles, especially should be severely underloaded, relative to capacity and lubrication, for the mass majority of civilian users. If you must overload- you may be better served by 90w-140 in HOT climes. (Any quality GL 5). I worked on a ship where the single reduction gearset was both critical, overloaded, and effectively irreplaceable. Choice was made to go with synthetic oil- dahm the leaks and expense. Your cost so your business. I GUESS your payback time would be beyond my lifespan. Good luck- I'll stick with the Dino Juice and spend the savings on Camo Fuzzy Dice!

The difference in this case would be $25 per 5 gallon pail... Which, is why I said cost wasn't a factor. That's negligible.

 

[ericp351]

Great! Sounds like you have a great source of SYN Gear Oil, or a poor source of the Dino stuff! The Synthetic may give you more piece of mind , and a bit less "warn up time" , if heavily loading in sub-zero weather.

 

[BKubu]

If cost isn't an issue, or if I planned to put a lot of miles on my truck, then synthetic would be my choice. However, personally, I always use non-synthetic. I drive all of my trucks a sum total of a few thousand miles a year...so not much per truck. I almost always have to change my oil due to time, not mileage. Things might be different if I sent samples out to be tested, but I don't. My $.02.

 

[TechnoWeenie]

This would be a daily driver.

@BKubu - unrelated - I used to live in Montgomery Village, not much place to park heavy equipment there...

 

[BKubu]

This would be a daily driver.

@BKubu - unrelated - I used to live in Montgomery Village, not much place to park heavy equipment there...

I live in Gaithersburg, but I actually live closer to Damascus. The G'burg zip code stretches a long way from the town of Gaithersburg where you lived. I am in a much more rural area.