need to break in gears

[crawlin91]

I got new 4.56s front and rear. can I just leave the front hubs engaged but 4x4 off to give the front diff some nice even wear before I wheel the piss out of it?

 

[metalmacguyver]

Front gears dont get broken in. Even from the factory they dont get broken in. Driving around with the hubs engaged will only wear the gears on the coast side, not the drive side which is kind of pointless.

For the rear gears, drive really easy on them for the firs 100 miles, then change the fluid and you will be good.

This info is from my gear installer who has done 600+ installs with out any comebacks. It worked out well for me.

 

[Explorin94]

For the rear gears you can also jack it up and run them dry for 10-20 minutes. With the truck idling and in low gear. Once that is done recheck backlash adjust if needed and you're done.

 

[MAKG]

DRY????

No way.

Jack it up WITH FULL LUBRICANT and run it in 1st gear with the throttle at idle for a few minutes, very first thing. Then drive it lightly for 100 miles. Then change the gear oil.

For the front, you can "break it in" like you suggest, just backwards. Leave the hubs open and put it in 4WD. It's not really necessary but won't hurt anything.

 

[crawlin91]

yeah ive been babying the rear for about a week now. will change the fluids soon probably just hit a nice easy trail and test out the 4x4

 

[Explorin94]

DRY????

No way.

Jack it up WITH FULL LUBRICANT and run it in 1st gear with the throttle at idle for a few minutes, very first thing. Then drive it lightly for 100 miles. Then change the gear oil.

For the front, you can "break it in" like you suggest, just backwards. Leave the hubs open and put it in 4WD. It's not really necessary but won't hurt anything.

I have done it for years and have not had one fail yet.

 

[4x4junkie]

I would NEVER suggest the running of dry gears either.

To break in gears (polish the tooth surfaces) you MUST have a load on them. Running around in any form of 2WD (4WD with hubs unlocked, 2WD, locked hubs, etc) does nothing more than possibly break in the bearings. It needs to actually be in 4WD transferring power to the front wheels.

I will say however front gear break-in is not near as critical as for the rear.
Go find yourself a graded dirt road somewhere, put it in 4WD and drive for a good 20-30 miles and you can consider it broken in then.

 

[Bent Bolt]

For the rear gears you can also jack it up and run them dry for 10-20 minutes. With the truck idling and in low gear. Once that is done recheck backlash adjust if needed and you're done.

You'll need to adjust more than backlash if you run them dry. Do you run your engine dry too ??

 

[Explorin94]

You'll need to adjust more than backlash if you run them dry. Do you run your engine dry too ??

Why? Should I