cunningwolf09jk

I know there are some threads out there about this but im at work and cant spend time searching. Im getting ready to have gears install and just have some general questions.

Question 1 - How long is the new gear break in period and what does it mean.

Question 2 - The shop that is doing my gears said i should use mopar diff fuild is that right or is there something better?

Question 3 - Is there anything i have to do after the break in period?

Thanks for the help

redrockin7

1) I've heard 500 miles break-in. I've heard not to let them get too hot by taking one 500 mile trip; do more short trips that allow them to heat and cool between trips.

2) Mt Zion told you to use Mopar Diff Fluid? Maybe the Mopar stuff is non-synthetic? Which (i'm not sure on this one) you might need to use for break-in... they put Amsoil synthetic in mine I believe, but mine were already broken in (I bought the axles already geared and they had ~500 miles on them).

3) You mean other than changing the diff fluid again and make sure everything looks good in there? I haven't done anything special to mine since I've got it (after the breakin and diff fluid change to amsoil), so I don't think so. I drive mine like I drove it before the new axles/gears.

serveapurpose

1) I've heard 500 miles break-in. I've heard not to let them get too hot by taking one 500 mile trip; do more short trips that allow them to heat and cool between trips.

Agreed!

TEEJ

Yeah - 500 miles, but with initial short hops, and feeling to see if its getting too hot.

Any dino juice is ok for break in, you're going to dump it after 500 - 1,000 miles anyway to get the little break in shards/particles out anyway.

The idea of break in to to let the teeth eat whatever need trimming for it all to mesh smoothly.

This is why initially, its SUPPOSED to get hot, from the friction of this initial wear to get things seated, meshed, etc....

..and why you DO those short trips, let it cool, then continue, etc...as if you keep breaking it in on a long trip, it can OVER heat, and damage your guts.

BlackNorthernJK

wut he said

mkjeep

I "heat treated" mine by doin 75mph , 200 miles in a couple days. A year and a half later , all is still well.

mpkelley20

Total newbie to gears question but why the break in period when replacing gears but not when you get a new Jeep? Are the stock gears somehow already broken in?? Again, sorry for the newbie question!

guinnessisgood

No one told me to at the dealer, but I still drove my brand new jeep as if it was in a break in period.

Rhino64

Drove mine home from the dealer (160 miles) between 80 & 90 mph none stop. Figured if it's going to break let it be on there dime. Runs great today almost 9K hard miles.

spinlock

The factory gears are already temperature cycled to reduce warranty liabilities. Cost of the process negates its from being offered in aftermarket products.