Recommended gear oil?

[Marcd1975]

FYI for anyone who reads the study - It was commissioned by and paid for by Amsoil.

If anyone thinks that it is coincidence that Amsoil scored highest of the gear oils tested should contact me immediately. I have some swamp land and a bridge that you might want to buy.

You must not know much about amsoil products. Do your research on amsoil, the company and how there oils are made.

 

[Marcd1975]

I would not run a synthetic if you are planning on doing any towing or offroading. Currie did tests a while back after a few warranty claims on their axles and it wasn't until they tested synthetic vs conventional that they realized the conventional is better at heat transfer and the synthetic was causing their issues.

I've been changing out my fluids considerably more often than is needed due to various work. With my numerous water crossings I aim for once a year (in the fall so water won't freeze in them over the winter) which tends to be about every 8k miles. It all depends on what you're doing with them imho some people will be fine at 20k+ I'm sure.



Amsoil tends to be pretty good stuff. Anything that they have formulated to spec I run. You might want to actually look into it before bad mouthing it.

Please do the research on amsoil. They make great stuff. I run it in all my vehicles not one single issue. Amsoil is 100% synthetic which is better than full synthetic. There is a difference between full synthetic and 100% synthetic

 

[toximus]

Please do the research on amsoil. They make great stuff. I run it in all my vehicles not one single issue. Amsoil is 100% synthetic which is better than full synthetic. There is a difference between full synthetic and 100% synthetic

I have, and I'm very aware of the benefits of their oil. I buy several cases of their oil each year. But I don't run it in my Jeep diffs.

 

[Jerry Bransford]

Please do the research on amsoil. They make great stuff. I run it in all my vehicles not one single issue. Amsoil is 100% synthetic which is better than full synthetic. There is a difference between full synthetic and 100% synthetic

Synthetic is ok for a fully broken in axle or new from the Jeep factory but that's not something you'd want to use for new aftermarket gears during the break-in process. Aftermarket gears run much hotter during the break-in process when lubed with a synthetic gear lube. That's why gear manufacturers like Revolution Gear and axle manufacturers like Currie specify conventional gear lubes. It was discovered synthetic acts more like a thermal blanket around the gears and doesn't extract/heat out as well as a conventional gear lube does.

 

[Gilly11277]

I am going to change fluid in a month or so. What do you all recommend for a Dana 44 and Dana 30? Been looking at LubeLocker gaskets but will get some RTV in case the mating surfaces aren't as nice as I expect.

 

[eastbloc]

I am going to change fluid in a month or so. What do you all recommend for a Dana 44 and Dana 30? Been looking at LubeLocker gaskets but will get some RTV in case the mating surfaces aren't as nice as I expect.

Nothing but good things to say about lubelocker, but i would be skeptical to its ability to bond and play well with rtv. If you have some abnormalities for some abnormal reason going on there, just go full rtv.

 

[Jerry Bransford]

I am going to change fluid in a month or so. What do you all recommend for a Dana 44 and Dana 30? Been looking at LubeLocker gaskets but will get some RTV in case the mating surfaces aren't as nice as I expect.

So long as it's a GL-5 Gear Lube it will be fine. A 75W-90 would be fine, the exact viscosity is not critical in an axle. My personal preference is a conventional like from Castrol, Valvoline, or Torco, which is proven to help the gears run cooler than they are with a synthetic gear lube. Yes that is true.

 

[Gilly11277]

Nothing but good things to say about lubelocker, but i would be skeptical to its ability to bond and play well with rtv. If you have some abnormalities for some abnormal reason going on there, just go full rtv.

That has been my understanding after reading up on a few threads regarding LL gaskets. If things won't go as planned I'll just use RTV instead of a gasket. Is there a specific type of RTV I should be using in a gear lube application?

 

[Jerry Bransford]

Is there a specific type of RTV I should be using in a gear lube application?

Permatex Gear Oil RTV or Mopar RTV. Both are resistant to the harsher formulation of gear lubes.

 

[JustDandee]

I think synthetics are ideal for gear boxes- the uniformed molecules give it a higher lubricity and don’t break down as quick but it’s these same attributes that probably don’t make it good for breaking a new gear set. I have had good luck running the Redline brand.

 

[Jerry Bransford]

I think synthetics are ideal for gear boxes- the uniformed molecules give it a higher lubricity and don’t break down as quick but it’s these same attributes that probably don’t make it good for breaking a new gear set. I have had good luck running the Redline brand.

Redline's a very good brand of lubricant, just don't run it to break in new R&P gears.

 

[Rick28]

Your axles are decidedly not fussy about the gear lube they run on so long as it is a GL-5 gear lube which is what 99.999% of them are. If you tow a trailer, a heavier viscosity like an 80W-120 or 85W-140 is perfect. If you don't tow, a 75W-90 or 80W-90 is fine, or you can go with an 80W-120 etc. In other words, the exact viscosity is not important. Just lean towards one of the higher viscosity gear lubes if you tow a trailer like I do, otherwise the exact viscosity doesn't really matter.

And since pretty much all the GL-5 gear lubes you'll find on the store shelves also contain a friction modifier additive required for axles with the Tracloc limited slip differential which your axle may or may not have, you don't also need to add that additive separately if you know you have the Tracloc. If you don't have a Tracloc in your rear axle, it's still ok to run a gear lube with that additive since it is compatible either way.

 

[AdelaideTJ]

Digging up an old thread, but when you say use 75w-90 if you "don't tow" do you mean regular towing daily/several times a week, or literally ever towing? I am going to use a synthetic 80w-90 gear oil by Penrite (Aussie brand). 98% of the time I'll be driving around normally, but I suspect a handful of times a year I'll hitch up a trailer and help friends move the odd cupboard etc. Just trying to understand the extent of towing that would require a higher viscosity gear oil?

 

[Mr. Bills]

75w-90 or 80w-90 will be fine for your application.

 

[JustDandee]

For me I occasionally tow with no concerns. Weight of towing, duration are considerations for using the heavier oil but for me the TJ tow rating I don’t think there is a concern.

 

[Link]

I run a synthetic 75W140 and I don’t tow anything with my TJ. Works quite well. If I only had 75W90 I’d run that.

Don’t over think it. These Jeeps are pretty simple vehicles. Their tolerance is pretty broad.

 

[AdelaideTJ]

I run a synthetic 75W140 and I don’t tow anything with my TJ. Works quite well. If I only had 75W90 I’d run that.

Don’t over think it. These Jeeps are pretty simple vehicles. Their tolerance is pretty broad.

Thanks all, really appreciate the responses. 80w-90 going in tomorrow! Cheers and beers from Down Under