Correct Lube Amount/Level for Mag-Hytec

[John Berger]

Ok, let's get this settled once and for all. According to the product review on the TDR, the correct amount of fluid to install in a Mag-Hytec cover for a Dana 80 differential is 62/3 quarts. I have had to put in right around 7-1/4 quarts to get it above the minimum fill line. Roy at Mag-Hytec says 8 quarts for a Dana 80 axle. My dealer thinks, not saying so authoritatively, but thinks that the fluid level may be the culprit in my ongoing leaky pinion seal problem. Why the discrepancy over the amount of fluid? The Mag-Hytec instructions say to fill to at least the minimum fill line which is more than 7 quarts. I am interested in any and all opinions, but an authoritative answer would be the ideal situation, not just for me, but for all other Mag-Hytec owners out there. TIA

 

[drag racer]

I add 8 quarts to my Dana 80, and the oil level is just a hair under the "full" mark on the disptick. Never had any problems.

 

[DAWG-1]

I did my new Mag Hytec cover a couple of weeks ago. I added 8 quarts of Royal Purple synthetic and it works just fine, no L. S. modifier needed.

 

[Pete Peterson]

Just another one to add to the count, I put 7 1/2 quarts in mine (80) series and came to the middle of the two marks. Used Amsoilseries 2000 75-140 with no modifier and no chatter... ... ... Pete

 

[John Berger]

I installed the cover in the summer of 1999. Miles on truck 13K. The factory pinion seal first leaked the following spring sometime while I was on vacation. Fixed under warranty. Mileage - 31K. That seal started leaking at 49K miles. Replaced once, leaked from the install. Dealer denies warranty coverage. The differential had between 7-1/4 and 7-1/2 qts in it. Changed fluid from Amsoil Series 2000 75W-90 to Series 2000 75W-140. Put in 8 quarts. The new seal I had put in by another dealer started leaking in 10 days. The dealer and I agreed to drop the lube down to the sight nut. Replace the seal, it leaked for about 75 miles and then stopped. I know what the Mag-Hytec instructions say and also what Roy says, but the only common denominator to my leaks is enough fluid in the pumpkin to give that pinion seal a constant lube, even while sitting. These pinion seals are only supposed to be splash lubed. If this seal leaks, I'm going to a high quality non-synthetic and trying that. I should not be having these kind of seal leaks and I'm getting really tired of running the truck and getting a leak every 6-8 months. By the way, the dealer said the pinion and gears look and feel tight. The truck rides good, but I'd love to have another truck like mine to drive just to compare rides. I would think that if the drive shaft was out of balance, I would have bearing failures by now. Sorry for the long post.



Running with a dry rear-end..... for now

 

[John]

John, the mark nearest the bottom of the Mag-Hytec dipstick is equal to the bottom of the axle tube, the upper mark on the dipstick is equal to the bottom of the axle. You should fill your differential to somewhere between these two marks... with the truck on level ground (front to back AND side to side). Also note that the level is checked with the dipstick seated (tightened) against the diff. cover.