Rearend break in

[62440]

When l had my reared rebuilt the mechanic told me to make sure to break in the gears for the usual 500 miles..l got to thinking, l don't think anyone breaks in a new car so is it really nessary to break in a new gear set. What are your thoughts ?

 

[Mopar Hunter]

Yes, I wouldn’t go over 300 miles before you change the rear end oil too.

 

[5.7 hemi]

I never do that, break in gears. If it’s set up properly, drive it like it’s a rental. That doesn’t mean go out and do 5k clutch dump, but drive it. After a few heat cycles, check the color of the fluid, still honey color?, drive on.

 

[R413]

What kind of ring and pinion gears and what ratio? These are deciding factors to break it in right or go for it without a care.

 

[62440]

It's a 8.75" 742 housing with a Dyna Power-lol suregrip and 4:10 gears. I put about 100 miles as instructed and l couldn't resist it anymore and l got on it hard about 60 mph a half dozen times. I hope l didn't harm it

What kind of ring and pinion gears and what ratio? These are deciding factors to break it in right or go for it without a care.

 

[62440]

 

[62440]

 

[CHARGERSTEVEN]

Getting on it at 60 mph wont hurt anything as the car is in full forward motion n ever thing is allready engaged,hope it kept a good straight line when you nailed it.You would know in the first 20 miles if something was wrong,you would hear it or smell it burning up.

 

[moparedtn]

Gorgeous car by the way.
(Geez, lookit that fuel line!)

 

[493 Mike]

View attachment 996428

Removing the hood latch really cleans up the front area!
Mike

 

[Ron H]

Old school - I'm still one preferring a break-in period as all the parts mating get to know each other and hopefully become best friends. Kinda like it's not advised to ask for sex on a 1st date...

 

[493 Mike]

Rear gears are broken in on a lapping machine. That is what determines the pinion depth and backlash dimensions. None the less, no machine should be beaten upon fresh out of the box. I have a lot of respect for engineering and machining!
Mike

 

[62440]

Thanks guys, Hopefully l got that silliness out of me the other day. I'll try to finish the break in as suggested and keep my fingers crossed there is no damage done.
493Mike, the car still has the stock hood latch, it's just hard to see.

 

[493 Mike]

Thanks guys, Hopefully l got that silliness out of me the other day. I'll try to finish the break in as suggested and keep my fingers crossed there is no damage done.
493Mike, the car still has the stock hood latch, it's just hard to see.

Ahh! I am used to later, early Bs. Still looks clean.
Mike

 

[khryslerkid]

l don't think anyone breaks in a new car so is it really nessary to break in a new gear set.

New vehicle gears are broken in at the factory on a machine before they are installed. That's why you can just jump in the car and drive it.

A new ring and pinion that you buy to install into your rear housing isn't broken in. That's why any ring and pinion manufacturer will tell you to drive your newly installed set normally for the first 500 miles. They want you to drive for about fifteen miles normally then stop and let the rear cool down. Then repeat this several times. This will not allow the gears to overheat or fry the rear end lube.

Different manufacturers have different surface textures on their gears. Some are a bit smoother in texture and will wear in easier than others with a rougher surface. After the first 500 miles it is recommended to change the lube. Just like breaking in a engine there will be unwanted contaminates.

Look up your specific brand of ring and pinion and see what they recommend for break in.

 

[493 Mike]

New vehicle gears are broken in at the factory on a machine before they are installed. That's why you can just jump in the car and drive it.

A new ring and pinion that you buy to install into your rear housing isn't broken in. That's why any ring and pinion manufacturer will tell you to drive your newly installed set normally for the first 500 miles. They want you to drive for about fifteen miles normally then stop and let the rear cool down. Then repeat this several times. This will not allow the gears to overheat or fry the rear end lube.

Different manufacturers have different surface textures on their gears. Some are a bit smoother in texture and will wear in easier than others with a rougher surface. After the first 500 miles it is recommended to change the lube. Just like breaking in a engine there will be unwanted contaminates.

Look up your specific brand of ring and pinion and see what they recommend for break in.

This heat issue is more prevalent with 9" Ford axles. The pinion is mounted lower on the ring (greater angle) and is not as efficient as our 8 3/4" design, although stronger.
Mike

 

[5.7 hemi]

Stronger eh? It use 3 bearings on the pinion, because it’s sit lower on the ring gear. Of all the rear axles between the big 3, Mopar had the strongest...Dana 60!

 

[62440]

I can't remember the brand for sure but there is a "US Gears" decal on my tool box ,,, I've put a few more miles on it and everything seems good.

Different manufacturers have different surface textures on their gears. Some are a bit smoother in texture and will wear in easier than others with a rougher surface. After the first 500 miles it is recommended to change the lube. Just like breaking in a engine there will be unwanted contaminates.

Look up your specific brand of ring and pinion and see what they recommend for break in.

 

[khryslerkid]

If you have a hundred miles on it and it's quite you'll be good to go. Just do the lube change at 500.

That's a great looking '62 you have there

 

[62440]

When you change the oil do you just suck it out or pull the Diff and give it a wipe ?