Rearend break in

[493 Mike]

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

Just suck it out. Or do what I have done on my 65. Drill and tap for a 1/8" pipe plug at the bottom next to the seam on the housing. The exiting gear lube will flush any shavings out.
Mike

 

[BSB67]

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

Why the lube change after 500 miles? Is it to remove any metal contaminants either left behind from the rebuild or break-in?

 

[moparedtn]

Why the lube change after 500 miles? Is it to remove any metal contaminants either left behind from the rebuild or break-in?

Yup.

 

[5.7 hemi]

Funny thing is when the cars were new, they didn’t have a break in period. Trucks might have, but I haven’t seen documentation for on cars.

 

[khryslerkid]

Funny thing is when the cars were new, they didn’t have a break in period. Trucks might have, but I haven’t seen documentation for on cars.

Post #12 and #15

 

[Ron H]

If doing a search about mechanical break-in, most inform to follow a period of 500-1000 miles. Have heard this as long as I can remember from a bunch of mechanics and my elder brother (mechanic at one time having done many motor rebuilds/hot rodding) was a stickler for allowing break-in. It's not ahh...that much of an intrusion to wait for redlining and always followed the advice. When rebuilding my motor after a number of additions to improve HP, I noticed the engine ran at appreciably higher temperatures for the first few hundred miles. Some header mfg's will say not to install them on an engine before break-in due to extra heat a new motor generates.

 

[5.7 hemi]

I said cars back then, meaning 62-75, I also said I wasn’t sure on trucks. Does anybody have original owners manual from that time period?

 

[khryslerkid]

I said cars back then, meaning 62-75, I also said I wasn’t sure on trucks. Does anybody have original owners manual from that time period?

 

[Ron H]

Kinda compelling - the defense rests your honor...send the jury home for supper.

 

[5.7 hemi]

Does it say ANYTHING about the rear end? I’m not seeing it. Bring the jurors back in. Lol!!

 

[moparmarks]

So how do you break in the gears on a race car? Keep your foot out of it for the first 2000 passes?

 

[BSB67]

What do all the race guys do with their new gear sets?

How do they do the 500 mile break in on new car rear differentials? Do they run them in for 8 hours? Something just doesnt seem right there.

 

[BSB67]

Oooops, looks like you beat me too it.

 

[khryslerkid]

So how do you break in the gears on a race car? Keep your foot out of it for the first 2000 passes?

A quarter mile pass really doesn't build up much heat. Running them long enough to build up too much heat can cook the lube then ruin the gear set. The heating and cooling cycles the manufacturer recommends will probably help to temper the gear set a bit also.

I've see guys at the track running their rears while on jack stands to put some heat in the gears before a pass. But I'm sure it's not an excessive heat like driving them under a load for many miles at a time. (Just spitballing here)

 

[62440]

That's a great idea. Did you need to build up the housing with something like a thick washer or something with JB Weld

Just suck it out. Or do what I have done on my 65. Drill and tap for a 1/8" pipe plug at the bottom next to the seam on the housing. The exiting gear lube will flush any shavings out.
Mike

 

[69 R/T]

I had my 69 Dana 60 gears upgraded to 4.10 by a rear end shop. The shop had explicit break in instructions to follow. No sustained long duration driving, cool down periods, no harsh activity, and an oil change at 500 miles. I bought a Dana/Spicer gear set for less noise and reliability. No instructions were in the box about breaking in the gear set.

 

[Bob McClure]

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 ?

 

[Bob McClure]

Ring and pinion manufacturers recommend 500 miles of normal driving with no trailer pulling and then change the gear lube. Personally this is a lot of work and a lot of money so I would only drive the car for 20 minutes at a time until you get to the 500 miles with no high-speed driving. This prevents the gear oil and the gears from getting too hot. I would also strongly recommend a magnetic drain plug if it has one and a magnetic fill plug.

 

[Ron H]

Thought I'd get more 'traction', nice pun intended in my #11 post, about break-in and asking for sex on a first date. Just isn't a good idea to try to go banging da gears on the first date. Well I thought I came up with a funny line on this anyway...lol. Fond memories dating back when. I did have one gal I had known for a few years being in classes together, who actually wanted all out on our 1st date at the outdoor theater in the backseat of my GTO! Man was I sore the next day with a load of hickeys! She had no stun adjust...all kill...we eventually broke up that might a saved my life. Da good old days...did I say a break-in period is good advice?

 

[toddc72]

Installation manual I had handy

Yukon Gear Manual:
Break-In:
All new gear sets require a break in period to prevent damage from overheating. After driving the first 15 mile or 20 miles it is best to let the differential cool before proceeding. I recommend at least 500 miles before towing. I also recommend towing for very short distances (less than 15 miles) and letting the differential cool before continuing during the first 45 towing miles. This may seem unnecessary but I have seen many differentials damaged from being loaded before the gear set was broken in. I also recommend changing the gear oil after the first 500 miles. This will remove ant metal particles or phosphorus coating that has come from the new gear set.