A20 Rear End Fluid

[Nor'Easter]

Replacing oil in Timken 5800 rear end.  Around 7 qts. through breather got me to the 1" fill plug on the forward housing, passenger side.  This level is no where near the axle centerline, and I'm concerned about getting oil up and out to the hubs during operation.  

 

Is it standard to also fill the hubs from the outside before setting the outer bearing?

[j hancock]

Not familiar with that axle but I would look for an additional fill plug.  Dual reduction?  I would think the capacity should be more in the 14 qt range.

[Nor'Easter]

Yes it's a two speed.  7qts might reach the lower 1/4 of the ring gear.  I can fill it through the breather port, just hate to pour more in without knowing what the actual fill is.

[41chevy]

What truck is this rear in?  And are you sure it doesn't have the Rockwell Timkin Posi Lube grease fittings for the axle bearings.

[Nor'Easter]

Have not found a reasonably located plug.  One is well below the axle centerline on passenger side, which took 7qts.  The next is on top of pinion bearing housing (near U joint flange) which would fill well above axle centerline.

ID tag states Timken Detroit Axle Co, and only gives fluid spec, not capacity.  I am not against just using grease, but there are proper opening to allow center section to overflow into tubes and then into hubs, but it would take a lot of fluid.  Each tube itself could hold 2qts. Sorry about photos, you can thank Steve Jobs for his upside down photo algorithms.

 

 

 

Edited April 19, 2019 by Nor'Easter

[JoeH]

Square headed plug on the passenger side looks right to me.... Fill to that, put a floor jack under right hub to flood the left hub, then put the jack under the left to flood the right hub, then fill the center again.

[Nor'Easter]

Note that the picture of the square plug on passenger side is upside down.  It is currently filled to that level, and is atleast 2-3" below axle centerline.  It took 7 quarts +/-.

[41chevy]

15 to 16 pints plus and additional 1.5 if axles were pulled and re installed. Same rear as LN8000, and big GMs in the 70's/ 80's

[Nor'Easter]

I pulled the outer bearings and filled the hubs, and put another 1-1/2 in the center through the vent.  Should be 8-1/2 qts now.  

[JoeH]

It doesn't need to be filled to the axle center line, just barely above the bottom of the axle tubes so oil will flow to the wheel bearings. Also, as the ring gear spins it should swirl the oil outwards, helping to circulate the oil to the wheel bearings. As you make turns and go over uneven terrain oil should flow back and forth from the wheel bearings.