Fluid Questions

I’m just about done with the rebuild of my drivetrain and I have a question on what types of fluid to use.

Here’s a list of what I’m running:

Dana 25 with Powerlock
Dana 44 with Powerlock
T90, Dana 18, Warn OD
1970 Jeepster Manual Saginaw Box

I usually run synthetics in most of my vehicles. But I fear synthetics in my differentials will make the Powerlocks slip more and be less effective than if I used a conventional oil. What do you recommend for the above listed components? Synthetic or Conventional? What weight? Any brands in particular I should use? Thanks for your input.

 

linc, I use 80w-90 non-Synthetic Castrol for the axle gears, tranny and t-case. The steering box I use a lithium base chassis lubricant.

 

Linckeil,

Remember you'll need to add a friction modifier to the whatever you choose to put in those pumpkins.

 

I used Lucas gear oil in my dana 30 and 44 along with the trans and transfercase. I have Aussie lockers so I don't need the friction modifier.

 

everything but front knuckles gets 85w90, they get 140w.

 

actually the PROPER synthetic is better for your LSD than conventional. Redline 75w-90 does not need a friction modifier. http://www.redlineoil.com/products_gearlubricants.asp

take a look there for yourself. I have the trac lock 9 or whatever jeep is calling it now) dana 35 in my xj that is notorious for wearing out but i have 160K on it and it is just as tight as ever with redline. I run all my gears in redline.. it makes a huuuuge difference in transmissions with regard to shifting..


BUBBA

 

Lucas and Pennzoil claim this.....but they haven't worked for me.
After driving for 100-200 miles on freeway, come to a stop and turn off freeway, rear axle would clunk loudly. Had to add the l/s additive to make it go away.
If you don't drive your Jeep long distances, you might not have a problem or notice it.

 

As Bubba said, when I bought the Wrangler, I couldn't get it into reverse. A friend said to try the Red Line and after about 2 weeks it was very smooth and never had that rough shifting problem again.

I read where most of the top syn. gear oils are supposed to have the "additive" for ltd slip, Red Line, Mobil 1, Purple, but you can buy it separate and add it yourself.

 

Yeah if you read through the redline site it tells you exactly what you need adn I have always been very impressed with their products.. they do exactly what they say they do.. My LSD's acted better, my tranny's were amazing.. it's $$$ but hell for something you change every 50K or more I can handle it..

BUBBA

 

Ok, so I read up on Redline on their site as well as independent claims. Looks to be good stuff. I'll run the synthetic 75/90 in my trans, transfer case, and OD. I'll also run it in my differentials and if the Powerlocks chatter or act funny, I'll add a little bit of friction modifier if necesary. I am a bit concerned that synthetic oil in a limited slip will make things a bit too slipperly, thus making the clutches in the Powerlocks less effective. But from what I'm being told, it shouldn't be a problem. How much of this stuff am I going to need to fill up these components and where's a good place to buy?

Also, any other input on what to use in my manual saginaw box?

 

I used to be a REDLINE distributor. Since I sold my company I have used AMSOIL just because it is easier to get. Prices are about the same.

 

Gotta use grease in the steering box. The manual calls for lithium-based chassis grease.

 

Linc,

I've used www.synlubes.com . Al Smith sells both Amsoil and Red Line. His service is pretty quick.

 

summit racing also has redline.. that's where i get mine...


BUBBA

 

Ready to refill my rear axle and transfer case of my 62 CJ5. Being a AMSOIL dealer I have all I need in stock. My mechanic recommended regular gear oil & GL4 for TC. Seems a lot of folks here are using synthetic with no problems. Don’t want to shop with this virus going around. Advice ??

 

Who is using synthetic in a transfer case? You understand that the transmission and transfer case share oil? The yellow metal parts in the transmission need GL4, according to many posts here. I presume the axles will be fine with what you have on-hand.

Amazon: https://www.amazon.com/CRC-Sta-Lube...1&keywords=gl4+gear+oil&qid=1586442474&sr=8-4

 

I was thinking of using the Amsoil manual transmission and transaxle gear lube which is GL-4 rated

 

I have yet to see or experience a synthetic lube not cause issues with the older transmissions requiring GL-4. Every one of my customers that ignored my advice (and void their warranty) that used synthetic had shifting/grinding issues regardless what brand they used. Comparing a YJ, XJ, or other late model vehicle is apples and oranges. The materials, clearances, etc. are miles apart.
I bet a limited slip lasts much longer with synthetic. If the clutches cannot lock up or the friction is less then of course the clutches will last longer. They won’t be as aggressive as intended however. Basic physics.
My recommendation is to use GL-4 I the transmission/transfer case if they share lube then use GL-5 with friction modifier in the diffs with Powerlocks. I’ve seen the Powerlock clutches destroyed in 100 miles by using the wrong lube and no friction modifier.
Transmissions, transfer cases, and differentials are very expensive to rebuild or repair. Why experiment unless you have the time and deep pockets?

 

I respect your comments and will follow your recommendations. Thanks