Can I use Redline 75w90?
- Thread starter Sputter
- Start date
I’ve been using the non limited slip version of that weight for some time without issue.
OP
Thanks Jerry. I just noticed it had LSD additives. Is that ok for my diffs?
That’s perfect. I didn’t want it in mine due to my truetracs which work better without the lsd additives.
Yes, the additive is compatible with all differential types. That's why it's contained in most GL-5 gear lubes.
I personally prefer valvoline conventional 75w-90. It is cheaper and supposedly keeps the gears cooler. However, you already had the Redline laying around so why buy something else.
KennethS
TJ Enthusiast
Dunno where you got that information. Everything I have ever read says synthetic oil is slipperier (less friction), which would mean lower operating temperatures.
The only times conventional is recommended over synthetic is during break in when you actually need increased friction so the moving parts wear together properly.
Actually the synthetic acts as a heat sink and traps the heat in the gears. @Jerry Bransford explained it very well recently that Currie was having to do a lot of warrenty work on new axles and did tests on a differential that showed with synthetic the cover would show a cooler temperature compared to Conventional but the actual gears themselves were getting to hot during the initial break in period and causing the gears to fail. Conventional would actually pull the heat out whereas synthetic trapped it in. They put an actual probe in the pumpkin and compared the Temps between the two.
This lead to Currie mandating that only conventional gear oil be used during the initial break-in period or the warranty would be void. I would have to assume that even after the break-in the gears would still be getting hotter with synthetic.
This lead to Currie mandating that only conventional gear oil be used during the initial break-in period or the warranty would be void. I would have to assume that even after the break-in the gears would still be getting hotter with synthetic.
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KennethS
TJ Enthusiast
I think some of what you posted defies the laws of physics.
A heat sink is something that conducts heat away from the source that is generating the heat.
I am in agreement that conventional oil should be used for break in. After that, synthetic provides superior lubrication. That is well documented.
A heat sink is something that conducts heat away from the source that is generating the heat.
I am in agreement that conventional oil should be used for break in. After that, synthetic provides superior lubrication. That is well documented.
https://wranglertjforum.com/threads/dana-30-gear-oil.1291/#post-1298173
Posts 20 and 25 specifically.
https://wranglertjforum.com/threads/recommended-gear-oil.9968/page-2
And post 21 here.
Perhaps thermal blanket would be better wording than heat sink. I'm sure that synthetic lubricates and will work just fine. Just saying that it will run hotter than conventional. I wouldn't run synthetic if I planned on doing much towing or serious off reading
Posts 20 and 25 specifically.
https://wranglertjforum.com/threads/recommended-gear-oil.9968/page-2
And post 21 here.
Perhaps thermal blanket would be better wording than heat sink. I'm sure that synthetic lubricates and will work just fine. Just saying that it will run hotter than conventional. I wouldn't run synthetic if I planned on doing much towing or serious off reading
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KennethS
TJ Enthusiast
I’m not an expert on this by any stretch of the imagination but that defies the laws of physics that I learned in school. Maybe I’m missing some important details. Friction generates heat, so better lubrication means less friction, which means less heat.
I think that’s why experimentation, trial and error become the mother of ingenuity rather than physics books in most scenarios. Something else or a complex of something else’s could be going on that would not violate physics.
KennethS
TJ Enthusiast
Yeah, I agree. To my knowledge physics has yet to be proved wrong, there’s just factors that haven’t been identified and entered into the equation.
OP
Looks like my TJ came with the LSD option so this oil is probably a great option all the way around. Thanks everybody!