New Gears..... Update!
I posted here several weeks ago about swapping out the gears in my 2005 GMC Sierra 1500 SLE RWD with 5.3L. I had recently purchased a 21 foot Gulfstream Ameri-Lite that had a listed dry weight of 321...
Forum Discussion
I agree with you, GMW. I've been absolutely pleased with this truck and have no plans of getting rid of it. Guys can't understand why we keep these things on the road. I can't understand why someone would trade up for a few years newer with absolutely no idea of how the vehicle was maintained and what problems could be looming.
I just spoke with Gears Unlimited and they used Lucas 75-140 gear oil. HIs explanation was that many of the rear differential manufacturers are now recommending good old fashioned mineral oil for your gears and claims that there are some noise problems associated with running synthetics in rear ends.
A visit to the Eaton site confirms this:
Q: What kind of oil should I use? Can I use synthetic? Do I need friction additive/modifier?
A: A quality petroleum/mineral based oil works best in the Detroit Locker units. We do not recommend synthetic oil. Friction additive/modifier is not required.
Also, from Popular Mechanics:
Synthetic oil is a confusing topic, and there's a lot of rhetoric, largely because some manufacturers and peddlers of synthetics have made a lot of inaccurate and self-serving claims over the years.
I have no doubt that the synthetic oils have their place in our vehicles but not in every instance. If GM says to use synthetic oil in their rear differentials, it's likely that some synthetic oil manufacturer is paying them to recommend it. It's about the $$$ and it happens in every industry. If people don't think this happens, just watch TV and count the number of Physician Recommended products that are advertised daily.
I just spoke with Gears Unlimited and they used Lucas 75-140 gear oil. HIs explanation was that many of the rear differential manufacturers are now recommending good old fashioned mineral oil for your gears and claims that there are some noise problems associated with running synthetics in rear ends.
A visit to the Eaton site confirms this:
Q: What kind of oil should I use? Can I use synthetic? Do I need friction additive/modifier?
A: A quality petroleum/mineral based oil works best in the Detroit Locker units. We do not recommend synthetic oil. Friction additive/modifier is not required.
Also, from Popular Mechanics:
Synthetic oil is a confusing topic, and there's a lot of rhetoric, largely because some manufacturers and peddlers of synthetics have made a lot of inaccurate and self-serving claims over the years.
I have no doubt that the synthetic oils have their place in our vehicles but not in every instance. If GM says to use synthetic oil in their rear differentials, it's likely that some synthetic oil manufacturer is paying them to recommend it. It's about the $$$ and it happens in every industry. If people don't think this happens, just watch TV and count the number of Physician Recommended products that are advertised daily.
gmw photos wrote:
OP, glad to hear you are happy with the outcome. And again I go back to one of my earlier posts in that it's good to see guys keeping an older, paid for truck on the road, and modding it if they feel the need, for current duty. There is a LOT to be said for a vehicle that we don't have to have a fortune tied up in, that can still do the job, and also make us really enjoy driving it. I feel the same about one of my trucks, a 11 year old vehicle that I love driving every day.
I'm still curious what exactly the gear oil is they installed in your diff. If you know the brand, weight and type, that would be interesting info to share with us.
As a side note, I ran royal purple ( syn ) for a while in the Nissan diff, and sent a sample of it after about 25K miles to blackstone lab. The report was essentially identical to the report I also did earlier with Nissan branded diff oil ( no idea who makes the Nissan oil ). Royal Purple sure is costly !
To those who keep their vehicles a long time, having fluids analyzed at a lab is a fun exercise if you are a vehicle information junkie. I use blackstone-lab. It's fairly costly though if you do it often.
