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Labrador Retrievers rule!
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Discussion Starter · #1 ·

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Labrador Retrievers rule!
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Discussion Starter · #2 ·
Just finished measuring the volume (in water) of the Rockcrusher AAM 10.5 rear cover.

I got 3 quarts. +/- an ounce to slight spillage. That's 96oz. total, US measure.

This volume is just for comparative purposes to stock cover and other possible brands.
 

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Labrador Retrievers rule!
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Discussion Starter · #4 ·
MFR gripes....

Things I don't like about Rockcrusher so far... And I havn't even installed mine yet:

A)The Fill Plug is a 14mm Hex, not the 3/8 SQ. drive of the Factory plug.
Who has a 14mm allen wrench/socket handy?

B)The Hole is not tapped properly. Should be a tapered pipe thread, so it bottoms out before falling into the housing.
Mine is loose, and Two layers of teflon pipe tape was insufficient to prevent water leakage during the "volume test".

C)The Bolts should be 5mm longer than factory ones to have the same ammount of thread depth... (According to Coder's pic below: )
I would use the factory ones over the ones they provide.
 

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Labrador Retrievers rule!
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Discussion Starter · #5 ·
Dammit............
My rear pinion seal is leaking. :tdwn:
 

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Dammit............
My rear pinion seal is leaking. :tdwn:
Could it be because you have to much fluid, you should only put in 2.65 quarts, the Rockcrushers fill-hole is not the way to measure fluid level with those covers, you must go by volume.

You have almost 1/2 a quart to much oil? It still should be sealed and not leak I would think, but I am a little puzzled why the pinion seal would leak.
 

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Labrador Retrievers rule!
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Discussion Starter · #7 ·
I have not installed my Rockcrushers yet.
I'm still stock.
 

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Things I don't like about Rockcrusher so far... And I havn't even installed mine yet:

A)The Fill Plug is a 14mm Hex, not the 3/8 SQ. drive of the Factory plug.
Who has a 14mm allen wrench/socket handy?

B)The Hole is not tapped properly. Should be a tapered pipe thread, so it bottoms out before falling into the housing.
Mine is loose, and Two layers of teflon pipe tape was insufficient to prevent water leakage during the "volume test".

C)The Bolts should be 5mm longer than factory ones to have the same ammount of thread depth... (According to Coder's pic below: )
I would use the factory ones over the ones they provide.
You need H-14 Hex Bit for the fill hole plug:
 

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Labrador Retrievers rule!
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Discussion Starter · #9 ·
Thanks for the info you posted over at the original thread:
"The fill-hole is higher on the new covers because there is a rib where the hole would normally be, but the volume of fluid is the same. The fluid simply ends up being further down from the fill hole than one the OEM covers."
 

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Labrador Retrievers rule!
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Discussion Starter · #10 ·
I just happend to have an SAE allen key that I ground down to 14mm to fit the
fork caps on my Yamaha.
 

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Labrador Retrievers rule!
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Discussion Starter · #11 ·
Just finished measuring the volume (in water) of the Rockcrusher AAM 9.25 Front cover.

I got 2quarts + 2 ounces. That's 66oz. total.
 

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Moab Tested
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I just measured my Rockcrusher covers.
Front was 72 fl. oz.
Rear was 102 fl. oz.
I'll measure the stock ones tomorrow when I take them off.

My fill plug takes a 9/16" allen. I ran a 3/4" NPT pipe tap in the fill holes to clean up the treads. I do this this on everything. Habit from work. I had 2 layers on the plug when I did the volume test with parts cleaner with no problems. One thing that I did notice. Is that on the rear cover. The plug screws pretty far down the hole before it stops. On the front cover. The plug sticks out about 2 threads with it stops.
 

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Labrador Retrievers rule!
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Discussion Starter · #13 ·
So checking fluid level by the fill hole is now a no-no.
You would need to make sure the "service" department at Dealer or a Quickee Lube
understands this fact.

If I have my Dealer service my leaky pinion and axle seals, I'm gonna wait to install my Rockcrushers.
 

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Labrador Retrievers rule!
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Discussion Starter · #14 ·
How did we get such different volumes?
I agree about the front plug was better than the rear cover.
 

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Labrador Retrievers rule!
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Discussion Starter · #15 ·
I filled it full, the laddelled it into a 16oz (2cup) measuring cup.
Each time I poured out the cup, I marked it down on paper.
 

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Moab Tested
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I used a ratio rite cup. Fill it up to the 18 oz line each time and dumped it in. The front took 4 cups, and the rear took 5 cups and 12 oz. I was using parts cleaner for the liquid. This gave me the chance to clean the insides too. :D
 

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Labrador Retrievers rule!
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Discussion Starter · #17 ·
As long as you do it the same way on the stock covers RustyPW08, it should be a good comparason.

I am seriously concerned about if Rockcrusher did increase the volume, we have absolutely no
way of knowing how much additional fluid to add to reach the proper level.
 

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Labrador Retrievers rule!
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Discussion Starter · #18 ·
My hunch is that there is no difference in volume compared to stock.

If there is... I have two Rockcrusher covers for sale...:bawl:
 

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Here is the product details from the manufacturer, it says nothing about an increased fluid capacity. Other aftermarket diff covers that I have purchased in the past usually say "the cover increases fluid capacity .6 quarts" or some similar, but Rockcrusher does not so I assume it is still the same.

From:

http://www.quadratec.com/products/p...it=Go!&h=t&cn=RockCrusher+Differential+Covers

"The strength and durability of these Rockcrusher diff covers (diff hats in Australian) are absolutely the strongest and most durable units on the market to date. Rockcrusher covers are .250” thick with reinforcement ribs. The larger diameter oil fill hole is located higher on the cover to aid in filling rotated housings. Includes mounting bolts, fill plug, and easy to follow installation instructions."

or email Rockcrusher and ask them at:

[email protected]
 

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Labrador Retrievers rule!
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Discussion Starter · #20 ·
I was aware of their lack of information on fluid capacity.
I hate to assume.

It would be the easiest way to make a casting mold, to just copy a stock cover.
This way you don't increase capacity, and don't have to worry about how the fluid
flows in a rotating assembly. No engineering required.
 
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