just wondering

[us111]

HI all,never posted here but read all the time and was hoping maybe someone could help..I have a 76 k-10 4x4 pickup,on the front and rear pumpkin someone took a plug out of the top of them and installed a piece of rubber hose on each one,on the end of the front one it looks like some sort of plastic breather cap shoved in end of hose,the rear is just open up against the bed floor,,is it for heat or something?? thanks all

[CUSTOM/10]

Those are vents for the differentials. Heat build up will cause pressure to build and then a vacuum when it cools down. With a vacuum water and other debris could get suck in to the housing. There should be a plastic vent on the end of each tube. ( These are from the factory )

Gary

[CyberRanger]

Most factory 4x4s & trucks have breathers @ the top of the axles' standard transmissions & transfer cases to allow for expansion & contraction due to changes in temperature of the fluids & air in the units. Some even had the breather extended up to the frame. If you four wheel much it is inevitable you'll go through water deeper than the top of these breathers & it is easy to then get water inside the gear housing. To say the least, this isn't good for the gears or lubricants.

My truck has had the breathers removed & pipe threaded nipples put in place & rubber hoses run up to the top of the firewall to a filtered breather for both axles, the tranny & the transfer case. Water would have to get seriously deep to be an issue, although its still possible for water to get into the gear housings other ways--just a lot harder.

[us111]

thanks guy's..just what i needed to know..

[Americanrider]

It's a good idea to check them every 6 months or so to make sure the are not plugged up with gunk. When they plug up it will cause the internal pressure to push oil out through one of your axle seals.