Stock Differential Covers

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Doppleganger

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Do any of you fellas have the fill holes in the factory diff covers? Mine does not - front or rear. My fill areas look to be in the neck of the diff behind the pinion. I am guessing to fill it til it comes out - which doesn't look to be much in regards to the fluid on the axles themselves.

I have seen aftermarket covers with the fills in them but remember the Bank's videos saying to keep it at stock levels. If there was ever a time they had the fill in the covers (factory) I'd be tempted to get one.

Getting my axles back tomorrow so will be addressing this soon.

Thx.
 

PrairieDrifter

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My 84's 10 bolt front cover has a fill plug on the cover.
 

77 K20

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My '77 K20's D44 stock diff cover has a fill port in it. When I bought an aftermarket Riddler off road protection cover it also had a fill plug- but was probably 2" higher than stock? I took measurements when I installed it and then made sure I didn't over fill it. Kinda sucks, because now to check fluid level I need to take a tie wrap, bend it, then use it as a dipstick and try and measure how far down the gear oil is.

This was my stock cover but with a "chin guard" bolted over the bottom part for some protection.

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The rear axle is a 14 bolt. Both the stock cover and the aftermarket Riddler cover for it do not have fill plugs. Instead it is near the pinion as you said.
 

Cemack

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My 78 did not have the fill
port in the stock cover, it was in the housing itself
 

Raider L

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My fill port is in the right side housing also. @77 K20, You know you could take that cover with the to high hole, off and cut you a new hole in it and weld a little piece of metal over that high hole. Weld a cut down bung over the new hole and there you go! Or call Riddler and ask them what's the deal with that hole being so high. Tell them what you're having to do to check your fluid level. See what they tell you to do.
 

82sbshortbed

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My 82 has it on the right if the pinion gear also. But when I pulled my axles plenty of oil came out. I think it's only supposed to be half full. It gets to the axle bearings and the carrier just splashes it around in the housing lubing the pinion gear and carrier. I think too much oil would cause problems. Just my guess don't know for sure.
 

Dutch Rutter

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My 83 had a fill for the front in the cover and just the normal side of the diff plug for the rear. I swapped covers and added stump protection to them. New covers have fills just like the factory ones.

As for checking the fluid in them. A bent Allen wrench does wonders. Pictures show the front when new and the rear I just took.

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rpcraft

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I seem to recall most 10 bolt rear's don't for some reason. Usually the front does though. I can not speak to 12 bolts to be fair. I don't think a 14 bolt FF or SF has them either but I'm not gonna go look on the axle rack right now to see.
 

78C10BigTen

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I seem to recall most 10 bolt rear's don't for some reason. Usually the front does though. I can not speak to 12 bolts to be fair. I don't think a 14 bolt FF or SF has them either but I'm not gonna go look on the axle rack right now to see.
If i remember correctly my 10 bolt rear is in the housing, bein 2wd i dont have a front...
 

Raider L

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@Dutch Rutter,

Have you looked into the diff covers that have the reinforcement across the middle horizontally, and have bolts at each end of the center reinforcement "rib"? The bolts on each end of the center rib hold up against the bearing housings on each side of the center section to keep everything together in there under extreme load. I'll have to go look but I'm sure B & M makes one, and other high end diff after market people. They have a fill hole in the cover and a drain hole on the cover as well so you don't have to remove the cover for a simple oil change. If you have a Summit catalog laying around you can find a couple.
 

rpcraft

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If i remember correctly my 10 bolt rear is in the housing, bein 2wd i dont have a front...

MY bad, they do have fill ports. I was thinking drain ports, lol...
 

Dutch Rutter

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@Raider L

I saw these which I think is the ones your talking about.
https://www.jegs.com/i/B-M/130/70502/10002/-1

They look good and sturdy and having a drain and fill is a huge plus. I ultimately decided on the purple cranium because I wanted the added protection offroad.

I figure I can always drop a cover or use a hand pump to change fluid and with the SF rear the more I inspect the third member the more peace of mind I have that nothing is going to fall apart while driving. If I were to do it all again, I'd probably swap in a FF rear and go with those B&Ms.

I do highly recommend using lubelocker gaskets if they have your one for your axles.
 

Doppleganger

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I think this was posted awhile ago about another topic....cant remember. But it was this vid I saw that made me more than keep my stock covers.

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Still shocked GM didn't have some sort of a fill bung on all of them. I have had Dana 30's on other vehicles that had 2 'holes'....one to fill halfway or so up and the bottom diff cover bolt was drilled through and would drain if just the bolt at 6:00 was removed. Rule was make sure the top one came out before you touched the bottom one.

Mine are behind the pinion but my axle housing was powder coated so might be interesting getting it out. lol

BTW.....has anyone had to use any type of thread sealant when replacing the plug?
 

rpcraft

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You could get a drill and tap and a 3/4 Iron plug at home depot and make your own. Just get a 3/4 NPT drill and tap kit. They are about 20 bucks as a kit.
 

shiftpro

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Do any of you fellas have the fill holes in the factory diff covers? Mine does not - front or rear. My fill areas look to be in the neck of the diff behind the pinion. I am guessing to fill it til it comes out - which doesn't look to be much in regards to the fluid on the axles themselves.

I have seen aftermarket covers with the fills in them but remember the Bank's videos saying to keep it at stock levels. If there was ever a time they had the fill in the covers (factory) I'd be tempted to get one.

Getting my axles back tomorrow so will be addressing this soon.

Thx.
Don't run the fluid high enough to reach the axles. You can see this in the video you posted.
 

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