Correct D44 drain plug location

old_man · Jul 7, 2009

I have D44's front and rear on my rig. My question has to do with the correct drain plug location. Is it just above the axle line or just below the axle line.

The covers are different for a front HP vs a rear LP.

tomcat · Jul 7, 2009

old_man said:
I have D44's front and rear on my rig. My question has to do with the correct drain plug location. Is it just above the axle line or just below the axle line.

The covers are different for a front HP vs a rear LP.

above the center line.

old_man · Jul 7, 2009

This is a LP axle. All the pix I find show it just below. How did you come up with just above?

MoparManiac · Jul 7, 2009

HP = just above
LP = just below

That's just from my observations. Usually all aftermarket diff covers mount them all above.

Wayne Sihler · Jul 7, 2009

The cover I have is from a front D44 from a ford truck.The bottom of the fill hole is above the cast seam in the housing.just a little higher than the center line of the axles.Rear axle is from an 87 XJ.

Wayne

tomcat · Jul 7, 2009

old_man said:
This is a LP axle. All the pix I find show it just below. How did you come up with just above?

you want the gear oil to lubricate the bearings as well as your ring/pinion. on rear axles, this means making its way all the way out the tubes to the outer wheel bearings.

i can't think of how you are supposed to fill the axle to the correct capacity without having the fill plug above that level.

also, the fill plug is not a "fill to here" measurement tool. many times, a quarter inch or more below the fill plug is where the axle is supposed to fill to.

fill plug as high as possible, fill to SPEC, not to spilling out of the hole

MoparManiac · Jul 7, 2009

tomcat said:
you want the gear oil to lubricate the bearings as well as your ring/pinion. on rear axles, this means making its way all the way out the tubes to the outer wheel bearings.

i can't think of how you are supposed to fill the axle to the correct capacity without having the fill plug above that level.

also, the fill plug is not a "fill to here" measurement tool. many times, a quarter inch or more below the fill plug is where the axle is supposed to fill to.

fill plug as high as possible, fill to SPEC, not to spilling out of the hole

If it is a LP FRONT axle, then there are no outer wheel bearings the gear oil needs to lubricate. These axles I have seen with a fill plug below centerline.

If we are talking about a LP REAR axle, then I'd agree with you. I've seen these with fill plugs just about even with the axle centerline.

Also, I've never had a problem filling to the fill hole. With aftermarket diff covers, the volume of oil a differential can hold is increased, which would make for a lower level of oil when filled to spec therefore less oil would be slung. Increase the oil level, increase the amount of oil slung to the bearings.

Again, this may not be the "correct" way of doing it, but I've never toasted a bearing or blown out my seals.

tomcat · Jul 7, 2009

yes, in the front, you are only lubricating inside of the chunk
My rear tends to piss out of the breather when overfilled.

Slip Kid · Jul 7, 2009

On my stock 44 rear, it appears to be slightly below center. The top of the nut looks to be right at center.

old_man · Jul 8, 2009

tomcat said:
My rear tends to piss out of the breather when overfilled.

Something just struck me funny about this

The reason I asked was that I put in a new axle with new seal and bearings about three weeks ago and drove it for two weeks with no issues. I checked the level just before heading to Ouray. I wheeled one day then on the highway the next day the bearing burned up, caused the bearing and retainer to loosen up and the axle, along with brake drum and tire to pass me on a hair pin turn on a mountain pass. When I pulled the plug, the oil was only about a quarter of an inch below the filler hole, but the hole is below the axle.

This was just wierd. Can't find a good reason for the bearing to shell out.

MoparManiac · Jul 8, 2009

Here's a good question.

Do you have an SYE? If yes, then you've probably rotated your pinion up several degrees. When you fill to the fill hole now, you are effectively decreasing the amount of fluid you are putting in.

I try to park facing downhill when filling my rear diff.

veedubshafer · Jul 8, 2009

just go here, look up the original aplication and use the correct amount
http://www.amsoil.com/scripts/runisa.dll?amsoiloaf:index

tomcat · Jul 8, 2009

old_man said:
Something just struck me funny about this

:doh:

fyrfytr1717 · Jul 8, 2009

veedubshafer said:
just go here, look up the original aplication and use the correct amount
http://www.amsoil.com/scripts/runisa.dll?amsoiloaf:index

Doesn't seem to me that would be completely accurate if you have an aftermarket diff cover. I'd imagine most of them increase the volume of your diff. Also, rotating your pinion is going to change the volume as well since the differential housing is more of a cone shape than a sphere.

So long as you're close to the right level, your ring and pinion should get well oiled. This would mean the proper level is really about getting the oil at the right level as it relates to your axle bearings, especially the outers on a rear end. I guess the trick is figuring out how to get it there...:dunno:

Correct D44 drain plug location

old_man

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tomcat

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old_man

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MoparManiac

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Wayne Sihler

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tomcat

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MoparManiac

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tomcat

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Slip Kid

That'll buff right out

old_man

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MoparManiac

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veedubshafer

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tomcat

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fyrfytr1717

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