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Mag-Hytec Differential Covers

Mag-Hytec Differential Covers

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Mag-Hytec Differential Covers (14-bolt 10.5)
After swapping the 1/2 ton axles out of our test Blazer in favor of a Corporate 14-bolt full-float and Dana 44, it was time to put the finishing touches on the project. A considerable amount of time and expense, including an ARB air locker up front and a rear Detroit locker made it mandatory for some form of protection for our latest investment. Added fluid capacity, aluminum construction for better cooling and the ability to handle off-road abuse made the short list of features while shopping for a differential cover.

Mag-Hytec differential covers not only accounted for the items on my short list, they offered a drain plug to change gear oil without pulling the cover and a dipstick for monitoring fluid levels. Because our Blazer weighs between 5,000 and 6,000 pounds with 36" tires and sees quite a bit of extreme trail use as well as mountain driving, Mag-Hytec provided a logical fit. The first thing I noticed when I took the 14-bolt cover out of the box was the weight and depth of the unit, the mounting flange thickness is 1/2-inch and the cover is 1/4 to 3/8-inch thick.


Increased Lubricant and Cooling Capacity


Magnetic Dipstick and O-ring Seal
As well as offering increased lubricant and cooling capacity (up to 45 degrees cooler), Mag-Hytec covers set your vehicle apart in both aesthetics and function - cast in A356-T6 aluminum and textured powdercoated black with machined cooling fins. Magnetic drain plugs trap worn gear material promoting fluid integrity. Each unit is fitted with ARP 568 O-rings for superior sealing. All hardware is 303 stainless steel for years of trouble free operation.

Installation is a snap because the covers come with all the hardware that you need, including the proper size allen wrenches and very detailed instructions. When installing the cover on a 14-bolt axle, the brake line bracket that attaches to the cover via a cover bolt will have to be modified. Simply remove the brake bracket and round the corners off with a grinder until it fits into the cover bolt indentation.


Before Bracket Modification


After Bracket Modification


Easily Check Fluid Level


Beefy Mag-Hytec cover
After installing the cover simply remove the magnetic dipstick and fill with the proper fluid, I took Mag-Hytec's advice and went with LE (Lubrication Engineers) 607 Almasol, SAE 90 / ISO VG 220 to protect my differential gears and new locker. After dumping 5 quarts into the rear of the Blazer I took it for a test drive around the block and drove it back into the garage for a final inspection, no leaks and no problems at all. The cover adds an aggressive look to the Blazer, makes it easy to check and change the gear oil and offers the ability to check for excessive mechanical wear without removing the cover.


Mag-Hytec Differential Covers (Dana 44)
When installing a Dana 44 cover on the front of a Blazer or truck the tie rod will be fairly close to the cover due to its size, but don't worry it will fit, just position the cover sideways and finagle it in between the gears and the tie rod until it drops down into position. Under full lock (wheels turned all the way in one direction) the tie rod is very close to the cover but does not come in contact with it.


Everything You Need


Dana 44 / 14-Bolt


Prepare to Drain


Clean Gasket Surface


Stock Oil Reference Plug


Tie Rod Clearance
As with the rear cover, I was very impressed with the quality and workmanship of these Mag-Hytec products, I needed functionality and they delivered, they also look great and should provide years of trouble free service.

Mag-Hytec Installation Recommendations

The following tools will be needed to install the Mag-Hytec 14-bolt cover:
9/16 socket wrench and driver (for removing the old cover)
1/4 allen bit with a 3/8 ratchet drive (1/4 allen key may be used)
5/16 allen bit with a 3/8 ratchet drive
3/8 drive torque wrench
Gasket scraper
Wire brush
Smooth flat file
Oil drain pan (minimum 5 Qt. capacity)
New gear lube API Spec. GL-5, MT-1 (Amsoil synthetic is recommended.)
Amsoil is available by calling SD Enterprises at (310) 322-8532
Friction modifier (for limited slip equipped differentials only)

This kit should include the following parts. If any of the parts listed below are missing, e-mail
Number Quantity Item
1 1 Mag-Hytec Differential cover with O-ring
2 12 3/8-16 stainless allen cap screws
3 12 3/8 stainless washers
4 1 Drain plug assembly with magnet and O-ring (installed)
5 1 Dipstick assembly with magnet and O-ring (installed)
6 1 Stainless steel oil level reference plug with O-ring (installed)
7 1 1/8 pipe plug (for optional temperature sender not included)

A word of caution to the installer / vehicle owner:
The Mag-Hytec cover is designed to fit the factory Dana axles as supplied as original
equipment. However, in some applications, or because of the use of certain factory
options and/ or after market equipment, there may be clearance problems between
your Mag-Hytec cover and other vehicle systems (specifically some rear sway bars). It may be necessary to install spacers or shims to lower the sway bar. It is the responsibility of the vehicle owner/cover installer to ensure that no other vehicle component comes in contact with the Mag-Hytec cover. Contact with any vehicle component, or the making of any modification to the Mag-Hytec cover, automatically voids the warranty. Mag-Hytec assumes no liability, expressed or implied, for damage or injury to persons or property.

Note: For some installations, removing the spare tire may provide better access to the work area. However it is not necessary in every case. The installer should determine if there is adequate work space prior to starting the installation.

1.Park your vehicle on level ground and apply the parking brake
2.Position a drain pan under the differential to catch the old gear lube.
3.Remove the 10 existing bolts, starting at the bottom.
4.Using a gasket scraper, start at the bottom of the cover and carefully (so as not to gouge the housing metal) insert between the existing cover and gear housing and pry the old cover off.
5.Allow all of the old gear lube to drain.
6.Using a gasket scraper, carefully remove all of the old gasket material (dried silicone) from the housing. A wire brush may be required to aid in cleaning the gasket surface.
7.Use clean lint free rags to wipe down the remaining oil from inside the housing and to clean the housing gasket surface. The surface must be clean and flat for the Mag-Hytec's O-ring to seat.
8.Before installing the new Mag-Hytec cover, check the gasket mating surface on the differential housing for dents, irregularities, or gouges. Should any exist, carefully remove the high spots using a smooth flat file. BE CAREFUL NOT TO ROUND OFF THE FLAT GASKET SURFACE.
9.Using gear lube, apply a light thin layer of oil to the Mag-Hytec cover O-ring.
10.Position the cover by aligning the bolt holes and start one of the new stainless steel allen cap screws and stainless steel washers at the top bolt hole and continue around the bolt pattern until all 10 bolts and washers are installed finger tight.
11.Using a 5/16 hex bit and 3/8 drive torque wrench, torque the stainless allen cap screws to 25-30 ft. lbs. in a cross tight pattern.
12.Check the drain plug, oil reference plug, and 1/8 pipe plug for tightness. If you are
going to install a temperature sender, do so at this time. Remove the 1/8 pipe plug and install the sender in its place. BE SURE TO USE TEFLON THREAD SEAL ON THE SENDER'S PIPE THREADS DO NOT OVER TIGHTEN!
13.Remove the dipstick assembly, and add in the new gear lube. Your new cover will
take approximately 5 1/4quarts for the Dana 70 and 6 2/3quarts for the Dana 80.
There are two marks on your dipstick. The bottom mark represents the minimum fill line and the top mark is the maximum fill line. YOUR OIL LEVEL SHOULD BE BETWEEN THESE LINES. Note: when checking the oil level, remember to thread the dipstick assembly until the assembly is threaded in all the way. Remove the dipstick assembly and check the level. If the oil level is between the two lines, apply a thin film of oil to the dipstick assembly O-ring and reinstall. Tighten snugly (20 ft. lbs.). BE CAREFUL TO NOT OVER TIGHTEN THE ASSEMBLY.

If you have a special application vehicle, or your vehicle has been modified or lifted and the axle has been rotated, you will have to establish the correct oil level for your vehicle as the dipstick marks as supplied by Mag-Hytec will not apply. The correct oil level should be between the bottom of the inside of the axle tube and bottom of the axle shaft. Once you have established the correct level, scribe a reference line on your dipstick for future reference, and fill the differential. 14.If you have a limited slip differential, be sure to add the appropriate amount of friction modifier. We have had excellent results with the Chrysler friction modifier, and it is compatible with Amsoil synthetic gear lubes. (ONE TO TWO 4 OZ. CONTAINERS SHOULD PROVIDE THE DESIRED RESULTS.)

The Mag-Hytec cover is constructed of high quality aircraft aluminum and has a powder-coated finish. The bolts and washers are stainless steel. These components
require no maintenance.

From time to time you may wish to check the oil level and monitor the wear in your
differential. With the Mag-Hytec cover this can easily be accomplished by removing the dipstick assembly using a 1/4allen wrench. You will probably notice some fuzzy metallic particles on the magnetic end of the dipstick: this is normal wear. Wipe the dipstick clean and reinstall (thread all the way in), remove the dipstick and check the oil level. If the level is between the high and low marks on the dipstick, apply a thin film of oil on the dipstick assembly O-ring and reinstall the assembly snugly

(20 ft. lbs.). DO NOT OVER TIGHTEN.
We suggest you follow the manufacturers recommendations for the gear lube drain
intervals. You may change your gear lube without removing the Mag-Hytec cover. Park your vehicle on level ground with the parking brake applied. Position a drain pan under the drain plug located at the bottom of the pan and remove the drain plug assembly. You may notice "fuzzy" metallic particles on the magnetic drain plug. This is normal wear. (If you notice any larger chips of metal on the magnetic portion of the plug, further inspection should be performed. We suggest that this inspection be performed by a professional mechanic who specializes in drive train components.) Remember to clean the drain plug assembly prior to reinstallation. Apply a thin layer of oil to the drain plug O-ring and reinstall (20 ft. lbs.). DO NOT OVER TIGHTEN. Follow the procedure for filling the differential.

Should it become necessary to remove your Mag-Hytec cover for any reason, the Mag-Hytec cover O-ring may be reused. DO NOT USE ANYTHING TO PRY THE COVER FROM THE DIFFERENTIAL HOUSING. THIS WILL DAMAGE THE O-RING. If you have damaged the O-ring, you may obtain a replacement by e-mailing If you need to reinstall the cover and no O-ring is available, you may run a bead of RTV silicone or gasket on the Mag-Hytecs mating surface face and reinstall the cover in the conventional manner.

During your vehicles use, you may come in contact with water above the axle seals or
above the axle breather. You should inspect your gear lubricant at the earliest opportunity. Do so by following the oil level check procedure. If water is detected, follow the drain procedure and refill your differential following the fill procedure.
Mag-Hytec, Inc. Van Nuys, California
14718 Arminta St.
Van Nuys, California 91402
Phone Number
(818) 786-8325
(818) 786-0560 (FAX)
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