Engine/Transmission (1998.5 - 2002) Mag Hytec Differental Fluid Level

[kscheffler]

I recently installed a Mag Hytec Dana 80 differental cover for my 2001 4wd. Based on the instructions and subsequent discussions with Mag Hytec tech. represenatives you are suppose to add 8 quarts of gear lube with another 12 oz of the slip additive. All of this fluid results in an oil level that is approximately 1. 5 to 2 inches higher than the stock fill plug level. Mag Hytec acknowledges these high level and says that it better for the bearing seals on the end of the drive shaft due to additional lubrication and the "flushing" of the seals and shaft. I asked why the factory level was so low and I got the old answer the Dodge does not want them to last! THis is all might be true but what about of the problems that I have always heard about overfilling differentals and the excess pressure that results in bearing seal failures. What amounts/levels are other members running there differentals at and has anyone had any problems running at the high levels that Mag Hytec is recommending?

 

[claymike]

This year while on vacation going through Idaho pulling my 5er we were doing the speed limit at 75 mph. It was 103 degrees outside and when we got to camp that night I noticed that my pinion seal had leaked and blown oil back over the rear end. The trip was 5k miles and the seal has not leaked since. Yes I have checked the oil level. I am not saying this is caused by the extra oil. There are many of these applications out there but something is not right.



Mike

 

[kscheffler]

Claymike

Claymike do you remember how much oil you originally installed? I only put in 7 quarts because something does not seem right. So after you lost this oil you did not loose anymore did you replace the oil you lost or just left it at the reduced level? I don't think it is likely that the seal fixed itself once it leaks it might continue to leak?

 

[sbiel]

I thought with this differential cover that the Dana 80 takes 8 quarts in total. If you want to add 12 OZ of differential fluid, it would seem that a little over 7 qts. of gear lube is needed ??



Or am I in error ??

 

[kscheffler]

sbeil

MagHytec says add 8 quarts of gear lube and three 4 oz containers of LSD additive so that equals 8. 3 quarts and then to mark your dip stick. It will likely be over their high level mark. Seems like awful high diff. fluid level?

 

[Oil Man]

Dodge, like every other auto/truck maker, is looking for every oz of fuel savings, even if it shortens the life of a part slightly. Fact, if an oil is running over the bearing it will take more HP to turn it. Fact, if a bearing is not running in oil but just relies on what might drip or splash on the bearing then it takes less HP to turn it. The engineers at Dodge and other Co's are looking for every little bit of help they can get for better mileage. Mag-Hytec knows that the bearing will be better lubed if it runs in the oil (about 1/4 to 1/2 inch).



The same diffs used to be filled to the top of the fill hole. Now they say to fill them 3/4/ inch below the fill hole. The fill hole level did not change. So in my opinion Dodge is looking for less fluid friction at the expense of a little more wear, and Mag-Hytec is looking for less wear.



In the end if you wish to run your gear oil level at the stock level you will still have more lubrication than with the stock cover. I run mine in the middle of the marks on the stick.



I hope this helps.

Sincerely, Kevin D

 

[claymike]

I used 8 quarts and since my truck is a peg leg I did not need the friction stuff. I did not loose that much maybe 1/4 of a quart at the most. I left it where it was. There were some threads on this subject about 1 1/2 years ago. Anyway when I got home from vacation I cleaned off the rear end and since that time no more oil The seal is dry, I am going to be pulling the 5er to the Jamboree in Kellogg ID this coming week so I will let you know what happens.



Mike

 

[drag racer]

I have always used 8 qts with my Mag-Hytec with no problems.

 

[PHaller]

The appropriate oil level within your diff should always be between the bottom of the axle and the bottom of the axle tube. That way, bearings and carrier are addequetly lubricated. My understanding as to why DC put the fill plug low was to prevent seeping axle seals. I heard in another discussion some years ago that DC contrcted with federal Mogul to supply seals but FM rejected the offer because DC was unwilling to pay the amount they wanted. DC went with an overseas supplier which had variable quality control. Thats why we all have rear seal failures at 25,000 miles and another reason DC doesn't fill the diffs to the right level. They KNOW of the high seal failure rate and it's a lot cheaper to just replace seals then seals and brakes too.

-Paul R. Haller-