PML Sand-Cast Aluminum Differential Cover

Installation

For the 5.7 HEMI RAM

By Mark Simonds (MrHemi) Editor

Virginia Beach, Virginia

As you can see in the first picture showing the stock cover, it was definitely time to replace it.  There was rust starting to develop on the face, and I was concerned with the fact that there was not a magnet on the cover to collect metal fragments.  I understand the fact that you should expect to have some metal particles in the differential housing, but the amount I saw in the drain pan was too much for my taste.  And without a magnet of some sort to grab those pieces… well, you get my point.  The truck had only 8K miles on it, so I hope I caught the problem in time. 

The installation obviously starts with removal of the stock cover.  If you have the luxury of a vehicle lift, raise the truck so you can comfortably work without reaching up. Since I did not have a vehicle lift (just a driveway), I lifted the rear end with a 3-ton hydraulic jack and set the rear axle on jack stands (always remember to chock the front tires).  Place a drain pan underneath the differential and loosen all twelve bolts that secure the cover (be prepared for tight bolts – the factory torques the crap out of these bolts).  Remove all bolts except for one at the top, and then carefully pry the bottom of the cover from the differential.  Be sure not to scrape or gouge the surface of the differential.  Once the majority of the fluid is drained, remove the last bolt and take off the cover.  In my install, 95% of the factory gasket (RTV) came off with the cover.  The remaining RTV was scraped off with a sharp putty knife.  Clean and dry the mounting surface with a lint-free cloth.  Test fit the PML cover, and be prepared… if you have a 20” spare tire, there’s not a lot off room to work with.  Of course you can remove the spare, but I didn’t want to mess with it.

Now you’re ready for the actual installation…squeeze a 1/8” to ¼” bead of Permatex 26B High Temp RTV (or MOPAR equivalent) on the differential, making sure to have a continuous bead of RTV, and to go on the inside of the bolt holes (see picture of proper bead instructions at http://www.yourcovers.com/diff_cover_install3.pdf).  Make sure all twelve of your new bolts (included with the cover) have the washers on, line up the cover with the bolt holes, and secure the bolts finger-tight.  In a criss-cross pattern, torque all bolts to 15 ftlbs.  The head of the bolts have an Allen wrench type design, and I was lucky to have a T-45 Allen socket attachment which fitted on my torque wrench.  If all you have is an Allen wrench, then tighten as hard as you can by hand, then use a pipe extension to turn the bolt another 1/4 rotation.  Torque the magnetic drain plug to 25 ftlbs, and when ready, the filler plug to 25 ftlbs as well.

The RTV will dry in one hour and fully cure in 24 hours.  I waited two hours before re-filling the pumpkin with fresh MOPAR synthetic gear lube, 75W-140 (I have the trailer package) and the limited-slip additive.  The stock capacity was 2.25 quarts… with the PML upgrade you can pour three full quarts with the increased size (depth) of the cover. 

Check for leaks, and then take a spin down the road to the nearest parking lot.  This step is crucial… do at least four or five tight “figure eights” in the parking lot to ensure the gear lube makes it to the outer areas of the axle.  Check for leaks once again, and you’re good to go!!

This was a very easy installation and the look of the PML cover is outstanding.  It was a perfect match, was made with high-quality materials, is much stronger than the original, and the look is great.  I would highly recommend the PML differential cover to any RAM owner.

You guys really need to take a look at your stock differential… whether you replace the stock cover with an aftermarket one or not – check out your gear lube for metal shavings.  It could impact the life of your drive train.  There’s nothing worse than to have pieces of metal in your rear-end! 

Excerpts from www.yourcovers.com:

PML Differential Covers feature stiff aluminum construction with .160" thick wall and .350" thick precision-machined gasket flange provides uniform clamping force on the gasket. Much less prone to leak than stock covers which are typically made of .035" stamped steel.

Differential Cover Features

PML Transmission Pans and Differential Covers feature 2 to 4 quarts of increased lubricant capacity. This extra oil provides substantial additional cooling for the transmission and differential under stressful conditions. Heat buildup, the chief nemesis of a transmission, causes the oil to lose its lubricating properties. Break down of the oil leads to increased wear on the clutches, bands, and seals. The end result is costly premature rebuilds and lost time. Our covers and pans feature raised cooling fins in addition to the increased fluid capacity to reduce oil temperatures by 20 to 30 degrees. Drain plugs are included on all covers and pans to make oil changes easy.

PML designed our new line of automotive products using state of the art CAD/CAM technology to ensure that the parts are an exact fit for the intended automobile, truck, or SUV. All designs are cast in 356 aluminum and heat-treated to T6 standards. The result is a finished part that actually increases the torsional strength of the transmission case or differential housing and a gasket surface that remains flat far better than stock parts. PML valve covers, differential covers, and transmission pans are thoroughly tested to ensure form, fit, and function before they go into production. We have pans and covers for many models and makes and more under development all the time.

Read about and see pictures of an installation of PML's differential cover and transmission pan in Truckin's SUV magazine. See the August 2002 issue, page 54, Tech Side article "Well Covered" or click here for a PDF file of the article.

Final tid-bits…

Purchase date:  October 2003

Install date:  October 2003

Install time:  1.5 hours

Tools required:  Standard socket/wrench set, Allen wrench, gasket scraper, pan to collect old lube (see picture).

Other items required:  MOPAR gear lube (75W 140 – 3 quarts… 75W 90 w/o trailer package), limited-slip additive, RTV (see picture).

Difficulty level (1-5): 1

Horsepower/Torque gains (rear wheel):  N/A

Purchase link: www.YourCovers.com

Purchase price:  Visit PML website for current prices, www.YourCovers.com

Additional costs:  $103.00 (3 quarts MOPAR Synthetic gear lube, additive, and RTV from local Dodge parts).

Purchase vendor:  PML, Inc.  201 West Beach Avenue, Inglewood, CA 90302 (310) 671-4345

Application:  Dodge 9.25 RG, 12 Bolt (Part # 9518).

Miscellaneous information:  Fits Durango, some Dakota, RAM 1500, some 2500 series trucks.

Volume:  0.7 qt. over stock.  Shown on www.hemitruckclub.com in as-cast finish… actual RAM 1500 cover is black with aluminum polished heat fins.  Click here for dimensions of the cover.