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MWC fab 9 break in

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Old May 29, 2011 | 07:24 PM
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Default MWC fab 9 break in

Anybody no the break in for MWC Fab 9 with Yukon alum center and wavetrac?
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Old May 29, 2011 | 07:34 PM
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in drive on jack stands for 15 mins, in reserve on jack stands for 15 mins. Drive for 15 mins, let it cool down for an hour then repeat 4 times, for a total of five 15 minute drives with an hour cool down in between. Then regular driving for the first 500 miles, no prolonged highway driving or any amount of time spent at a constant RPM. Change the oil at 500 miles and drive the **** out of it!
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Old May 29, 2011 | 08:03 PM
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Thanks just about got mine done and ready to start the break in!
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Old May 29, 2011 | 08:32 PM
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NP, I got mine installed last weekend, but unfortunately I'm already down again, My stupid exhaust was banging on the rear end and no amount of adjusting the exhaust would fix it. Shitty TSP y-pipe and welded on I-pipe! True duals coming soon!
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Old May 29, 2011 | 09:55 PM
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Had the same problem so just running on open headers
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Old May 29, 2011 | 10:22 PM
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Originally Posted by schuz_GXP
Had the same problem so just running on open headers
careful with that, you need at least 30" of pipe of each header, otherwise your o2 sensors will get a false lean reading.
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Old May 30, 2011 | 08:10 AM
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Speed density tune no o2's
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Old May 30, 2011 | 09:40 PM
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Originally Posted by TransWS6Am
in drive on jack stands for 15 mins, in reserve on jack stands for 15 mins. Drive for 15 mins, let it cool down for an hour then repeat 4 times, for a total of five 15 minute drives with an hour cool down in between. Then regular driving for the first 500 miles, no prolonged highway driving or any amount of time spent at a constant RPM. Change the oil at 500 miles and drive the **** out of it!
What's the effect of prolonged highway driving? Hopefully my rear end is here soon. I have a 300 mile round trip to Dayton for the Trans Am Nationals in August. Not sure if I'll have the time to log in 500 miles of city driving before the show.
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Old May 31, 2011 | 08:31 AM
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The biggest issue is overheating the gear too quickly. All gears come heat treated from the factory, but the breask-in process is to actually "surface temper" the gears, while establishing a wear pattern. Surface tempering makes the very top surface of the metal extremely hard, moreso than the other metal in the component.

A 9" gear builds alot of heat by it's design nature, thus making the break-in procedure that much more important with this style rearend. If you talk to the gear manufacturers, they will tell you that 95% of all the returned gears are from improper break-in. They will actually cut the gears apart and check the hardness depth to verify the situation.

The absolute worst thing anyone can do is go out and immediately beat on the car with a new gear installed... no matter what rearend is in it. The point here is to bring the gears up to operating temp slowly, and then let them cool slowly... several times. Any clutch dumps, burnouts, excessive highway mileage, etc.before the surface tempering is done will do nothing but damage your new investment.
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Old Jun 27, 2011 | 11:34 AM
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Originally Posted by TransWS6Am
in drive on jack stands for 15 mins, in reserve on jack stands for 15 mins. Drive for 15 mins, let it cool down for an hour then repeat 4 times, for a total of five 15 minute drives with an hour cool down in between. Then regular driving for the first 500 miles, no prolonged highway driving or any amount of time spent at a constant RPM. Change the oil at 500 miles and drive the **** out of it!
Do you run it in reverse for 15 mins directly after running it in forward or do I need to let it cool down for an hour?

Do the 5 15 minute drives with an hour cool down in between have to be run in succession or can I do a couple a day? 30 mph tops correct?

I'm scheduled to have a dyno tune on the 11th; is this ok to do since it won't require hard launching?

One more question.. how many quarts of 80w90 will I need?

Hope to have it installed tonight

Thanks...

Last edited by 97ss497; Jun 27, 2011 at 11:43 AM.
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Old Jun 27, 2011 | 12:05 PM
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Originally Posted by 97ss497
Do you run it in reverse for 15 mins directly after running it in forward or do I need to let it cool down for an hour?

Do the 5 15 minute drives with an hour cool down in between have to be run in succession or can I do a couple a day? 30 mph tops correct?

I'm scheduled to have a dyno tune on the 11th; is this ok to do since it won't require hard launching?

One more question.. how many quarts of 80w90 will I need?

Hope to have it installed tonight

Thanks...
The first step is really just making sure you are coating everything. As far as the five break in periods you can do it how ever works best for you and yes you do not want to go over 30mph. As far as the dyno that is your call, we set up this break in period to help the customer out, if you chose to do other wise that is up to you. Launching a car is not the only thing that causes gear noise issues, improper break in does how ever.

It takes a little over 3qts.
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Old Jun 27, 2011 | 03:09 PM
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Thanks for the info Jason.

I was able to push my dyno tune out 2 weeks so I should be able to get some break in miles on it before the tune.
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Old Jun 28, 2011 | 12:05 PM
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The gear *must* be completely finished with the break-in process before any chassis dyno time. If it is not done chances are you will ruin the gear set.
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Old Jun 28, 2011 | 12:16 PM
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Originally Posted by ssvert99
The gear *must* be completely finished with the break-in process before any chassis dyno time. If it is not done chances are you will ruin the gear set.
This 10X. It takes some time to do this properly.
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Old Sep 13, 2011 | 10:23 PM
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Originally Posted by 97ss497
Do you run it in reverse for 15 mins directly after running it in forward or do I need to let it cool down for an hour?

Do the 5 15 minute drives with an hour cool down in between have to be run in succession or can I do a couple a day? 30 mph tops correct?

One more question.. how many quarts of 80w90 will I need?
Originally Posted by MidwestChassis
The first step is really just making sure you are coating everything. As far as the five break in periods you can do it how ever works best for you and yes you do not want to go over 30mph. As far as the dyno that is your call, we set up this break in period to help the customer out, if you chose to do other wise that is up to you. Launching a car is not the only thing that causes gear noise issues, improper break in does how ever.

It takes a little over 3qts.
So I'm getting ready to install mine next week and have a question. The 15 min in drive, 15 min in reverse, then 15 min drive not going over 30 MPH followed by an hour cooldown thing, is the 15+15+15 min all consecutive then an hour cool or 15 foward on stands, hour cooldown, 15 in reverse, hour cooldown, 15 drive then cooldown?

And also, what fluid do you guys recommend? I know non-synthetic, but any particular brand over another? Anything that Autozone, O'reillys or Advanced Auto carries? Thanks!
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Old Sep 13, 2011 | 10:28 PM
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Also what, in miles, would you consider excessive highway driving? Is 50 miles one way too much?
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Old Sep 14, 2011 | 09:36 AM
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The part on the stands is nothing more than to coat the gears and make sure everything is OK, by the time you get it off the stands you can start your break in procedure. You do five fifteen minute heat cycles, you drive for 15 minutes at 15MPH and let it cool for an hour. You do that five times.

As for Excessive there is no correct right or wrong with this, we just suggest not trying to do all 500 miles in one driving secession. After the first 15 minute cycles take the car for a cruise around town and give it time to cool off. Do that a few times and you will be up on your 500 miles in no time. While cruising just do not hop on the expressway and hold a certain speed for long periods of time until you are finished with the break in procedure.

As for fluids we have no recommendations, we suggest to our customers to use what they feel comfortable with.
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Old Sep 18, 2011 | 03:03 PM
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were are you going to drive for 15mins at 15mph? 5 times?
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Old Sep 18, 2011 | 03:15 PM
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Originally Posted by studderin
were are you going to drive for 15mins at 15mph? 5 times?
That's what I was thinking. I'm doing the install at the shop where I had the rear end shipped to. I could prolly make it home in 15 mins at 15 MPH since it's not that far, but I'll have to throw my hazards on and creep home. The other drives I'll just stay in my neighborhood and basically creep around the block.
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Old Sep 18, 2011 | 04:02 PM
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Ok so just to make damn sure about this. This is the procedure to use when breaking in a MWC fab 9" rear end:

***Five total heat cycles all done while lifted on jackstands off the ground at 15mph***

(1): 15 mins in drive as 1st cycle with an hour cool down after

(2): 15 mins in reverse as the 2nd cycle with an hour cool down after

(3): 15 mins in drive as 3rd cycle with an hour cool down after

(4): 15 mins in reverse as 4th cycle with an hour cool down after

(5): 15 mins in drive as 5th cycle with an hour cool down after to finish it off

Once jackstand session is complete, regular driving for the first 500 miles, no prolonged highway driving, or any amount of time spent at a constant RPM.
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