How to break in new gears? (1 Viewer)

[Malahki]

I just installed new Nitro 4.56 gears and ARB Lockers front and rear on my BJ74 and am wondering about proper break in procedure. The Nitro brochure that came with the gears says to do a 15 minute run and then let cool down, and then change the oil after 500km's. I have now done 3 short runs.

My question is regarding the front. I wonder how to break in the front diff properly. My original thought was to just lock in the hubs while driving in 2Hi. After a little thought it seems that while driving on the highway this would only be breaking in the coast side of the gears as the front axle would be getting pushed. Driving around town though would work both side of the gears with speeding up and slowing down but would this be enough to break in the gears?

With dry roads I didn't really want to run in 4hi, but should I just get it out on a straight highway and run 4hi at 80kmh for the 15 minutes and then allow for cool down?

 

[JLHEEPETR]

I know the Yukon literature says about the same...run it for 15 minutes and allow them to cool. They also suggest not exceeding 50 or 60 mph in the first 500 miles I believe, and to keep changing speeds. Given that I would lock in the hubs for a day or two around town. I am in the same position as you with two new gear sets so I'm curious to see what others have to say.

 

[Malahki]

Good point on varying the speed, thanks

 

[Tapage]

almost 8 years back .. I jackup my front axle and let 'em run .. with a little drag ( barrely touching the terrain )

 

[JLHEEPETR]

Checked with the Yukon book again for "New Gear Break-In".
-Avoid heavy acceleration for the first 100 miles
-Drive the vehicle lightly for the first 15 to 20 miles and stop. Let the differential cool before proceeding.
-Drive at least 500 mile before towing
-When towing for the first time drive less than 15 miles with full load and stop. Let diff cool 20 minutes. Repeat twice more for total 45 miles.
-Change gear oil after first 500 miles to remove metal particles and phoshporic coating.

 

[liljlandon]

I would find a dirt road, lock them in and go. If you cant do that, the jack stands work well. I have also been told not to worry about the front as it sees very little high speed use and rarely works itself hot...

But, the local shop told me to change the oil at 500 miles and then every 30,000 after that in "those 'light' weight toyotas."

 

[PPFJ60]

Here is one method of breaking in new R&P. This was not a successful break in.

The R&P had less than 100 miles on it when punched the skinny peddle to get up this rock. The front tires came off the ground, the RPM's went up, the front tires came down and the pinion snapped off due to axle wrap.

 

[GLTHFJ60]

Here is one method of breaking in new R&P. This was not a successful break in.

The R&P had less than 100 miles on it when punched the skinny peddle to get up this rock. The front tires came off the ground, the RPM's went up, the front tires came down and the pinion snapped off due to axle wrap.

 

[rusty_tlc]

Who ever said this never drained the oil out of the diff on a truck that had been crawling over rocks all day.

"I have also been told not to worry about the front as it sees very little high speed use and rarely works itself hot... "

 

[liljlandon]

Who ever said this never drained the oil out of the diff on a truck that had been crawling over rocks all day.

Just passing on what i have been told... Personally I did the dirt road method.

 

[rusty_tlc]

Just passing on what i have been told... Personally I did the dirt road method.

Having opened a front diff on the trail I can tell you from first hand experience the oil was plenty hot.

The dirt road method is perfect, I never pass up a chance to drive on dirt roads.