2017 GMC Sierra 1500 - Diff Oil Change

Things used to be so simple…
Ordered the rear cover gasket (Delco) from Amazon.
It was shipped in a plastic bag like a clothing item.
I’m sure y’all can imagine what has happened to it during shipping…
Twisted etc.
I’m hearing that these can be used over again but I’m old and don’t like to reuse gaskets.
A trip to the dealer is next. Hopefully they price match but I don’t hold out much hope.
 
FWIW I'm like you and don't like to reuse existing gaskets. I bought new gaskets for my last 3 Chevy truck differential changes ('97 C2500HD twice and '13 K1500, both limited slip). Have yet to use one. Existing gaskets were still perfect and I would have just made extra work for myself changing them out for no gain. No leaks whatsoever.
The 2500 required a very early first change (5000 miles?) that I missed and caught about 5 or 10k late. Lot of metal in the fluid and some pretty big chunks of metal shavings (threads, etc.) in the bottom from break in. Subsequent change fluid looked good and no metal bits.
The fluid from the 1500 looked new when it came out at 50k.
 
FWIW I'm like you and don't like to reuse existing gaskets. I bought new gaskets for my last 3 Chevy truck differential changes ('97 C2500HD twice and '13 K1500, both limited slip). Have yet to use one. Existing gaskets were still perfect and I would have just made extra work for myself changing them out for no gain. No leaks whatsoever.
The 2500 required a very early first change (5000 miles?) that I missed and caught about 5 or 10k late. Lot of metal in the fluid and some pretty big chunks of metal shavings (threads, etc.) in the bottom from break in. Subsequent change fluid looked good and no metal bits.
The fluid from the 1500 looked new when it came out at 50k.
Never say never. I probably would be fine reusing it but not willing to gamble. A reused selector shaft seal (Turbo 350) cost me a “come back” back in the dealership days. Seals, o rings, and gaskets are all replaced every since then.
 
Well… today I crawled under the truck to remove the diff cover and change the grease. Every bolt felt like it was bringing the threads with it on every turn. I aborted the attempt. Backed only one bolt all the way out just to see what could be causing the max effort. There is what looks like a near permanent thread lock goop on every bolt. I’m thinking that this sure enough may cause a broken bolt and/or damaged threads. Does the service manual have any info regarding a one time use bolt? Seems odd that this would be assembled with the intent of a “lifetime” gear lube. Any thoughts or am I just chicken shift?
 
Thanks stevejones. Nice video. Those bolts buzzed right out. The fellow did mention locktite. I’ll give it another try. What’s the worst that could happen?? Maybe drilling and tapping some broken bolts!
 
FWIW I changed the diff fluid on my 2012 Silverado with the G80 locker at about 25,000 miles and it was really nasty looking. The second time I replaced it at 42,000 miles a couple of months ago it looked a lot better. I use non synthetic 80W-90 gear lube from the NAPA (their brand).
 
FWIW I changed the diff fluid on my 2012 Silverado with the G80 locker at about 25,000 miles and it was really nasty looking. The second time I replaced it at 42,000 miles a couple of months ago it looked a lot better. I use non synthetic 80W-90 gear lube from the NAPA (their brand).
Smart man. I do that once a year with my older Silverado's G80 rear diff, sometimes every other year. It apparently needs that OCI every time, and I do NOT abuse the truck whatsoever. Perhaps it's the severe environment I live in these days.
 
Smart man. I do that once a year with my older Silverado's G80 rear diff, sometimes every other year. It apparently needs that OCI every time, and I do NOT abuse the truck whatsoever. Perhaps it's the severe environment I live in these days.
Yes, it looked almost black the first time I drained it. I figure if I'm doing frequent changes there's no reason to use syn.
 
So like this then. 2013 Silverado 1500 2WD. 250K
 

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Just changed my front and rear diff fluid on my 2017 GMC Sierra 1500.
Truck has 66,500 miles on factory fill. 9.5" rear end with limited slip.
Fluid looked like new when changed. Went with Amsoil Severe Gear 75/90
Wish this truck had a drain plug like my 1999.
 
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