[035]

I just finished installing a new Ring & Pinion (with Detroit Locker) in my Dana 60 rear axle. It's pretty cold outside (@ freezing) and i used 90W to lubricate things during assembly and it was as thick as glue. Now i'm concerned with breaking-in the new gears, i've have heard that synthetic is a no-no for this.
So, what brand and weight gear oil do you all think i should use?
thanks for any help, i'm almost ready to roll/wwwthreads_images/icons/smile.gif

3/4tonYJ
My Jeep Page

 

[Guest]

Never thought of this, synthetic shouldn't be used to break in gears!? Ummm, ok, why, and are the semi-synthetic's ok, or do I need to find some real stuff... problem is, where do I get it? we have three choices of gear oil here, el-cheapo, semi senthetic or full synthetic... I didn't want to put the budget stuff I always use in my brand new gear set... ok, now I'm rambling. - HELP /wwwthreads_images/icons/smile.gif

Florida Mud CJ-5
'77 RB304, t-150 D20 4" 35" swampers

 

[GeeAea]

Yes.......I'm curious as well. It's recommended that you don't use synthetics for engine break in... heck, they even print it on the bottle .......but this is the first that I've heard of not using it for gear break in.

Feed me YJ.......feed me!

BTW- Mobil 1 sythetic gear oil (I just ordered a case @5.25/qt.) only comes in 75-90 weight and meets the GL5 specs.

GeeAea


Figures don't lie ....... but liars sure do figure.

 

[035]

I can't remember who told me or where i first heard it./wwwthreads_images/icons/smile.gif so i called "Randy's Ring & Pinion" (who i believe are experts) and asked them. They said that "you what your gears to heat up for proper break-in and synthetics run cooler" (we also talked about some metalogical/wwwthreads_images/icons/frown.gif stuff about "heating and cooling" that went over my head) so they don't recommend synthetics during break-in for this reason (but after 500 miles, put it in)

I've also heard that some "Circle Track" racers have burned up "new" ring & pinions that they didn't break-in before going to synthetics. (i doubt that this always happens?)

for the record i do like synthetics, while in the military it's all that we used in our aircraft, (engines, gearboxes, rotor and prop systems etc...) we sometimes abused some of that equipment and the oil/fluid just never broke down/wwwthreads_images/icons/smile.gif

3/4tonYJ
My Jeep Page