do our cars have a vent for the rear diff like most other rear diff's do?
reason i ask is this,,
on my build i am doing a mod to the rear cover.
the rear cover will integrate a drain plug and a fill plug.
i wanted to know if i can get away with a rubber "pop in" plug to serve as the fill.
reasons for this are obvious to anyone who's done rear diff oil changes before.
you have more clearance to "add" oil from the rear of the diff tipping a bottle of gear oil in,, and why not have a drain plug as well.
is the rear diff under pressure from heat and such? I assume yes but not like its a lot.,,, since i see no vent at all anywhere... nothing mentioned about a vent in the shop drive train manuals either.
Look on top of the axle tubes. The 7.5" rear shows it on the passenger side.
The rear does have heat in it, but there shouldn't really be any pressure. It users splashing to lube up tye gear. Everything else is lubed up by the oil in the axle tubes.
I seem to recall a little vent cap thingy in the axle tube, top side.
They use the vent to bolt the rubber line from the body to the axle. My ol 92 dakota has a pop in rubber plug on the diff cover on the mopar 8.25 and I will say the rear definitely needs vented or after a long trip you'll pop a pinion seal or axle end seal.
looked at the vent on the axle tube,, seems to integrate a axle vent as mentioned along with a brass block to split one brake line into 2 ....
so yes thats where the vent is.
The vent on my 8.8 is on the passenger side top towards the wheel. I replaced my differential cover a while back used a B&M cover I found on ebay. Only problem I had was getting stupid. The cover has a drain and fill plug but I forgot about the fill plug on the drivers side front of the differential. Filled the rear end using the fill plug on the cover as a gauge. Took the car for a drive and was smelling gear oil. Parked it and I had gear oil all over the gas tank cover. Then I remembered the fill plug on the differential which is quite a bit lower than the one on the new cover. Drained about a half quart been good since. Felt like an idiot.
Yup. Same place on the 7.5 as well. Looks like this: https://lmr.com/item/LRS-4022A/86-04-Mustang-88-Rear-Axle-Housing-Vent