MagHytech Rear Diff Cover Lube Level

[seafish]

I am coming due for a rear diff lube on my 2005 4x4 with AAM axle and I was just able to buy a lightly used MagHytech rear diff cover at a great used price.
I KNOW that it is a high quality, well built product, but I am quite confused over the increase in lube capacity.

Everything that I have read about it indicates that almost all of the increase in fill capacity comes from OVER filling the differential to a level OVER the axles, far past the oem level--
I am concerned that this will lead to foaming and/or axle venting and the subsequent improper lubrication of the differential due to the foaming.

SOOOO....Are you guys who run the MagHytech rear diff cover filling to the top of the dipstick fill line (almost 8 quarts) or only to the bottom 1/4" of the dipstick (approx 5.5 qts, ie the oem fill level)??

Have ANY of you seen or experienced problems with the overfill, or is it always a good thing??


For those of you who are NOT running the cover, but ARE interested in the details, here are a couple threads (for your reading pleasure...lol) that details the same concerns--


http://www.dieseltruckresource.com/dev/06-mag-hytec-rear-end-diff-oil-t132044.html

https://www.turbodieselregister.com...2123-mag-hytec-rear-end-cover-amp-fluid-level

All informed opinions welcomed!!

 

[Joseph Donnelly]

Mag Hytec's dipstick allows for filling to a level that keeps some lube in the tubes for better lubrication of the outer bearings. You can fill anywhere from stock level to 8 qt. I use 6 quarts.

 

[seafish]

Thanks Joe, just what I wanted to know.

One more question, does your answer imply a concern with filling even higher??

 

[Joseph Donnelly]

Not really a concern, but there might be more chance of a seal leak if the tubes are full.

 

[Bob4x4]

Way............. back when talking to the owner/and origional designer of the covers he told me the hi mark was the level recommended by the machinest hand book.

 

[seafish]

Way............. back when talking to the owner/and origional designer of the covers he told me the hi mark was the level recommended by the machinest hand book.

...what machinest handbook???

 

[Bob4x4]

The way he made it sound it was a classic that had been around for years.A quick Google search came back with a ton of hits for one first published 30 years before me.The theory had to do with the correct oil level to operate any pinion gear iirc

 

[seafish]

The theory had to do with the correct oil level to operate any pinion gear iirc

OK, thanks for clarifying...still will probably go with only a 6 to 7 quart fill once I take some measurements on the inside of the pumpkin myself, then correlate to the MagHytech dipstick for future reference.

Anyone else want to chime in??

 

[Larry Willard]

I always filled mine to the high mark. Never had a problem on the other trucks, but haven't added one to the new truck yet.
Larry

 

[Jim W]

...what machinest handbook???

I believe it might be one similar to this one. http://www.amazon.com/Machinerys-Handbook-29th-Erik-Oberg/dp/083112900X

Great handbook to have.

Jim W.

 

[mfurrh55]

I've been running one for 80,000 miles at the high mark, well 1/4" below high mark and have not had any problems towing or leaking, Monte

 

[seafish]

Thanks for all the info guys...I might have to pick up a paperback version of that machinery handbook.

 

[drag racer]

I have always filled to the mark on the dipstick - 8 qt. Recently, I had to work on the rear hubs (first time they have ever been off), and there was a reasonable, but not excessive by any stretch amount of oil that makes its way to the hub bearings. After seeing that, I would not run any less.