AMC 20 Differential Cover with a Drain Plug

[jdcaples]

I'm thinking about changing out my Corp 20 diff cover with one that has a drain plug.

If you have replaced yours with one sporting a drain plug, which one did you choose?

Do you (still) like it?

Is this just a bad idea?

I don't need a rock-proof cover. I just want to drain rear axle fluid w/o resealing the diff cover plate to the housing, or trying to suck the fluid out the fill hole.

Thanks

-Jon

 

[HackFabrication]

I haven't done this yet, but the one I'm looking at is: https://www.amazon.com/Nitro-NPCOVE...115&sr=8-2&keywords=amc+20+differential+cover

 

[Hedgehog]

It does seem odd that there is no drain hole in most differentials we work with. I asked about this to a long time jeep guy. He has seen where jeepers have drilled and tapped their differential housing for a drain plug. Seems like a good idea to me.

 

[jdcaples]

Just an update:

I've considered several products and have yet to make a commitment.

1) Hack mentioned Nitro (NPCOVER-M20) Xtreme Aluminum Differential Cover for AMC Model 20 - one reviewer indicated "A little tight between gas tank cover and rear.Rubs just slightly even with a 3in lift," but the reviewer didn't mention which model on which he installed the product.

2) American Rebel, Outlaw Differential Cover - AR-AMC20-XJS

and

3) OX Locker Heavy-Duty Differential Cover for AMC20
OX Locker Heavy-Duty Differential Cover for AMC 20 - OX-AMC16P

Looking at the picture, I didn't see a drain valve. I wrote to the OX locker people on Saturday - asking if the drain was at 3 o'clock or 6 o'clock and I was surprised to receive a response the same day. "The drain is at 6 o'clock."

So I looked again. It's almost indiscernible, but there is a drain point at the 6 o'clock position.

At this point, OX is winning, but I'm still researching...

-Jon

 

[Torxhead]

I always like to install a magnetic drain plug just to help get some of the loose metal out of harms way anyplace where there is fluid. Some of the older Willys did have that bottom drain.

 

[Lumpy Grits]

That 6 o'clock drain will get beat to death in the rocks etc.
When I drain my Ford 9". I do it by siphon method through the fill hole, and let it go all night.
LG

 

[jdcaples]

For me, rocks aren't a great concern, but for what it's worth, all the plates I'm looking at have recessed drain plugs.

-Jon

 

[Lumpy Grits]

Any object can mash that opening to the point you can't remove the plug. I've seen this happen many times.
We're talking about alum here-NOT cast iron.
LG

 

[jdcaples]

The OX Locker cover plate is cast iron....

-Jon

 

[WHATROAD]

I've been looking at covers for the better part of six months. I have decided on the OX as well. Hoping Santa drops one down my chimney. I don't think anything else comes close. And you can weld to it!

 

[Belizean]

If I was going to hazard a guess at this as to why there is no drain plug, it is probably because most people would never removed the cover and there would be a build up of water,crud and shavings that would never be removed. This way it does maybe get removed and a serious cleaning. Just a thought

 

[jdcaples]

Found another aluminium cover, this one with a .5 quart capacity over stock...

YourCovers.com AMC Dana Spicer Model 20 Differential Cover, For Jeep CJ5 and CJ7, Cherokee Truck and Wagoneer

The Ox Locker's still in the lead for me.

-Jon

 

[HackFabrication]

Although the last aluminum you posted has a larger capacity, it doesn't appear to have recessed holes for the bolts. Fine for street applications.

There used to be another manufacturer making the iron/steel cover, but for the life of me, I can't seem to find one other than the OX.

 

[jdcaples]

I purchased the OX locker. It came today.

I'm under the weather right now with non-contagious medical challenges so

I'm not sure when I'll get around to installing it.

My observations thus far:

I asked on the Morris4x4 site if it changed the volume of fluid required.

Answer: No.

It didn't come with a gasket.

It came with twelve grade 5 bolts with 1/2" standard wrench-able heads.

The drain and fill plugs are Allen driven, but I don't know what size at the moment.

At the bolt holes it's at least .33 inches thick.

I set it on my bathroom scale: 15.0 lbs.

If it bolts up as advertised, I'll call it a nice product.

-Jon

 

[Hedgehog]

Oil quantity? Fill it until oil dribbles out of the fill hole. ......

 

[jdcaples]

Oil quantity? Fill it until oil dribbles out of the fill hole. ......

FSM says 3 pints, but I'll take your advice.

Someone did fill the diff on my old van like that - until it dribbled out the fill hole - and I blew out the rear seals on an off ramp. Exciting moment.

Given that, I thought the FSM was the way to go.

Thank you, kindly sir!

-Jon

 

[hole]

My current stock 20 cover rubs slightly on my over sized 21 gal fuel tank mounts under full work out conditions. My buddies 7 did the same thing. Most of the aftermarket covers seem bulkier/thicker to me, and would only make this problem worse. My friend with the 7 is a fabricator and made his own cover, with a drain, that no longer rubs the tank. He's been running his for almost 2 years now with no issues, so this winter I'm going to pester him to make one for me (unless I pick up a 44 that I've got my eyes on at the moment). The OX cover does look nice though

 

[Lumpy Grits]

FSM says 3 pints, but I'll take your advice.

Someone did fill the diff on my old van like that - until it dribbled out the fill hole - and I blew out the rear seals on an off ramp. Exciting moment.

Given that, I thought the FSM was the way to go.

Thank you, kindly sir!

-Jon

Have the Jeep sit'n on level ground and fill till the oil runs out the fill hole is the best way to fill both axles, tranny and t'case.
LG

 

[Hedgehog]

The fill until it dribbles out the fill hole is pretty much standard fair for differentials. Basically because you don't necessarily know what is in the differential. Different lockers are different sizes, even ring and pinion gears vary substantially in size. Filling to the filler hole is the safest way to know you have enough oil in the differential. If your oil level blew the seals on your van you had a different problem, if pressure played a roll it's likely to have been a plugged breather port.

My stock Dana 44 cover barely clears my 21 gallon gas tank as well. You can put a drain plug in your stock cover.

 

[Lumpy Grits]

The stock model 20 cover, is a somewhat thin sheet metal stamping and not a good candidate to install a drain bung.

LG