What the heck????

[DennisG01]

I just found air being expelled from a place I wasn't expecting - before any of you hooligans read too far into that, it's on the truck!

The underside of the transmission bell housing (nearest the oil pan) has two female threads built-in. On the passenger side, some sort of support rod is attached. But, on the driver's side, the thread hole is open. Well, I just found out that with the engine running, air comes out of that hole! It's not under pressure (light finger pressure over the hole will stop it), but what the heck is causing that? Is that normal?

[ronniejoe]

The spinning converter will centrifugally pump a little air. Don't worry about it.

[DmaxMaverick]

Easy there. No need to panic. The air is from the TC/flex plate rotation. Sounds like one of your supports is missing, leaving the hole open into the TC (bell) housing. Replace it at your soonest convenience if you are heavy loading or off roading. If you are only commuting, no hurry.

[DennisG01]

Thanks, guys. It was just something I was really surprised to see (feel), you know?

Regarding the missing support: I have seen the open thread hole before (always with the engine off, though) and wondered why there was no support rod there. But I always blew it off thinking "I can't be missing a support rod, cause how the heck would one of those things just disappear - that hole must just be for something that GM never got around to doing.

Anyways, I was looking up there, but couldn't figure out where the other end of the rod would connect to. Is the other end of the rod attachment point easy to get to?

[More Power]

On the 80's 6.2L diesel equipped 4x4 trucks, both trans support rods were used. The driver's side rod bolted onto a plate sandwiched between the driver's side motor mount & cyl block.

Some newer vehicles don't use that rod/mount, which leaves an empty hole on the bottom of the trans.... :)

Jim

[Robyn]

All the 4X4's with the IFS only use the right side support bar.
The older trucks used both and also many used another rod that bolted to the right side of the T case and bolted to the right side of the bell housing in the second bolt up. All this Iron is to keep the bell housing from cracking when you get rough with the truck off road.
They will go down the road fine without it but its a good idea to keep it on the truck.
Same goes for the little front bracket on the starter. Many folks leave them off but sooner or later the starter main bolt, housing or even the block can crack and or break.

Cheers
Robyn