Differential covers 101
PU Truck mag That answered a lot of my questions about these covers. Extra large ones may not make a lot of sense because they disturb the oil flow in the housing.
Forum Discussion
None of mine has a drain plug...maybe a newer truck some day...
You can deal with draining and cleaning a diff cover that has no drain plug...
After the first time using the old and VERY messy process...in reassembling the diff cover...clean the diff casting flange area REALLY good...down to the bare metal
Then apply non-silicone gasket glue/sealant/etc to the cast iron flange and gasket side touching it...maybe the new synthetic lube is more stable, but IIRC, synthetic diff lube reacts with silicone based RTV to leak...
Let place the diff cover on and hand tighten the bolts, but DO NOT torque it down. Let the gasket sealant set before torquing the diff cover bolts
Fill and forget about it till the next diff fluid change. I change mine out about ever 2 years
Then to drain the diff fluid...loosen all of the diff bolts about half way out and place your diff lube fluid catch pan underneath the diff
Then wack the center of the diff cover with a rubber mallet and the diff cover will pop off, but stay on the diff
The fluid will drain into your catch pan
Then remove the diff cover bolts after the fluid stops draining
Inspect and clean the diff innards
Replace the cover and tighten the bolts to spec. I've done this for years and years without ever having to buy another diff cover gasket
You can deal with draining and cleaning a diff cover that has no drain plug...
After the first time using the old and VERY messy process...in reassembling the diff cover...clean the diff casting flange area REALLY good...down to the bare metal
Then apply non-silicone gasket glue/sealant/etc to the cast iron flange and gasket side touching it...maybe the new synthetic lube is more stable, but IIRC, synthetic diff lube reacts with silicone based RTV to leak...
Let place the diff cover on and hand tighten the bolts, but DO NOT torque it down. Let the gasket sealant set before torquing the diff cover bolts
Fill and forget about it till the next diff fluid change. I change mine out about ever 2 years
Then to drain the diff fluid...loosen all of the diff bolts about half way out and place your diff lube fluid catch pan underneath the diff
Then wack the center of the diff cover with a rubber mallet and the diff cover will pop off, but stay on the diff
The fluid will drain into your catch pan
Then remove the diff cover bolts after the fluid stops draining
Inspect and clean the diff innards
Replace the cover and tighten the bolts to spec. I've done this for years and years without ever having to buy another diff cover gasket
