Two 4 bys ago I more or less did the same thing in the front differential. I spotfaced the bottom of the differential housing and drilled and tapped for an 1/8-27 NPT drain plug ("set screw" style). I went with the 1/8-27 as I didn't want to compromise the integrity of the housing anymore than I had to. Besides, warm/hot gear oil would still easily drain out.
I did much the same thing on my Ram however, I purchased a "bare", steel (OE style) front diff. cover and drilled a hole at the lowest possible (realistic) point. I had my VDO pyrometer bung (which isn't used in the Ram application) machined (reduced in length and counterbored to press fit into the drilled hole). The bung was TIG welded on the back side (only) and a powder coat finish was applied. Stainless steel Allen head bolts and washers were used to mount the cover (to match my Mag-Hytec rear diff. cover) and stainless steel hex head plugs were utilized at the drain and fill plug locations.
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John Treibel
'98. 5 2500 QC 4x4 Sport, Glasstite Vision II, 285 BFG A/Ts on M/T Challengers, Warn 4X Boards, Mopar fender flares & tow hooks, NW Custom s/s-rubber mud flaps and accs. , Mag-Hytec diff. cover & DD trans. pan, Edelbrock IAS shocks, Reese Titan V hitch, Jordan Research Ultima 2020 trailer brake controller, SPA gauges (3), Dynamat, '00 Sport grille and headlights/PIAA Super White bulbs, "special" Brite-Box, PIAA Dual Sport 900 aux. lights, BD exh. brake, Amsoil Dual Remote Bypass w. trick billet block adapter and Aeroquip Teflon-s/s hoses, Optima Yellow Tops, DD3s and DD TTPM, Aeroquip AQP s/s fuel hoses, tricked out Cummins valve cover, tricked out Banks High-Ram and 14 cm2 (wastegated) turbine housing, ATS 3-piece exh. man. , Banks 4" dia. s/s exh. sys. , DTT 93% TC, DTT custom tuned VB, BD modified trans. front pump (enhanced by DTT), Air Bulldog induction hood (with NACA ducts), plus MANY other trick modifications
COMING ATTRACTIONS: break out those sun glasses! Plus, BLACKOUT gets a "BIG GULP"
NRA Life (Patron) member