Cariboocreek

Cariboocreek

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Changed diff fluid today. Made a bit of a mess as the fill plug just wanted to cross thread and the fluid was leaking out the fill hole onto my arms and everywhere else.

Question is now I seem to have a leak. I don't think its possible to overfill if the car is level. Or am I wrong? I filled until it was coming out the hole and then it still took me 15 minutes to get the plug in. I am hoping it’s just fluid trapped in the crossmember from the mess with the fill plug.
 
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OL Yeller

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Hopefully it's just the spilled fluid making its way out. Is there a crush washer on the fill plug? If so, you should replace it each time you change the fluid.

Good luck
 
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turbozig

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Changed diff fluid today. Made a bit of a mess as the fill plug just wanted to cross thread and the fluid was leaking out the fill hole onto my arms and everywhere else.

Question is now I seem to have a leak. I don't think its possible to overfill if the car is level. Or am I wrong? I filled until it was coming out the hole and then it still took me 15 minutes to get the plug in. I am hoping it’s just fluid trapped in the crossmember from the mess with the fill plug.
I use a form a funnel to channel the oil away from the frame crossmember and differential cooler. This way oil does not get all over everything and get trapped in the frame and cooler fins. Hopefully you didn't strip the plug threads either. I have been using this process for over a dozen C7'S now with no issues, except the convertible Z51 is a pain.
 
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Cariboocreek

Cariboocreek

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Thanks. I think the threads are good. I don't force stuff. Just kept backing it out until it sorted itself out. I cleaned up the leak fluid on the floor last night and there is less this morning. I think its the mess of the fluid that went everywhere that is causing the fluid on the floor.
 
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I did this post a while back:


GM does not sell the factory rubber washer that is on the fill/drain plugs for the rear axle you have to buy the whole plug assy. I just did my 3rd rear axle fluid swap and did use the rubber O rings that I got @ Walmart online but my endgame is to use instead an alum. crush washer so I am working toward that (have not had time to open up the metal washers that I have for them to fit the GM diff plugs. There is also the possibly that a rear axle crush washer on the GF's Mazda CX-3 could also be the right size to just slip right on so I need to go to a Mazda dealer and check that with the GM plug.

To get better access to the fill plug I have found out that if you use a 1/4" drive 3" extension and either use a 1/4" U-joint with a 1/4" drive ratchet or 3/8" to 1/4" adapter on your 3/8" drive ratchet end and on the diff end use a 1/4" to 3/8" drive adapter that fits perfectly up there for you to snap the 1/4" to 3/8" adapter to the diff plug and you have room to attach your ratchet on the other end and loosen/tighten the diff plug. I'll take a picture(s) later so you can see what I mean if the description above is too complicated to comprehend.
 
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Black 03 Z06

Black 03 Z06

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The C5 uses a crush washer for the diff drain plug and the last time I purchased one you could buy them separately. Can't see them being much different in size from 5 to 7 but it is GM. Mine was originally replaced under warranty because of a leak. The mechanic used the same washer, it was bent into a heart shape and continued to leak. Fixed it myself with a new one. I also found that heating the gear lube in a bowl of very hot water made the transfer much easier when pumping it in.
 
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Do you have a picture of the C5 diff drain plug? I wonder if it's the same plug as for C7, if it is and there is an alum crush washer for the C5 plug then the washer should fit the C7 plug.
 
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Tony unfortunately I don't have a pic of the crush washer but I do have a spare plug I can measure tomorrow. I can probably get a picture of the plug for you.
 

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