Cavity in lower gear case of pre alpha?

[1970 Chieftain V]

Can anyone tell me what this cavity is on the front side of the lower gear case of a pre alpha unit? It is in front of the the boss for the lower shift shaft. I think it might be a passage for the little witness hole. When i took the lower gear case off this cavity was filled with a gritty mess.

Thanks for any answers.

Jason

 

[Haut Medoc]

Re: Cavity in lower gear case of pre alpha?

The shift shaft cavity......
It does have water in it when the drive is immersed & does connect to the exhaust cavity...​

 

[achris]

Re: Cavity in lower gear case of pre alpha?

It's just a casting cavity. Make sure it's cleaned out properly, one of the common problems with those drives is that the cavity fills up with dirt and water and starts corroding, eventually breaking through. The small hole at the bottom is a drain for that cavity. Make sure it's clear and draining each time you flush the engine after use.

Chris.........

 

[Bondo]

Re: Cavity in lower gear case of pre alpha?

It's just a casting cavity. Make sure it's cleaned out properly, one of the common problems with those drives is that the cavity fills up with dirt and water and starts corroding, eventually breaking through. The small hole at the bottom is a drain for that cavity. Make sure it's clear and draining each time you flush the engine after use.

Chris.........

Ayuh,.........

Unless you live in a Freezing Climate,.........

Then the trapped water just Splits the case Wide Open..............

 

[ziggy]

Re: Cavity in lower gear case of pre alpha?

Ayuh,.........

Unless you live in a Freezing Climate,.........

Then the trapped water just Splits the case Wide Open..............

hum, man, i guess i done got away sinful. both old 1 drives i've had have had that area packed full of sand and crap. both only barely weeped out the drain hole. both i'm sure i let sit over the winter prior to cleaning them out.....wish i'd a read that sooner and i'd a been ontoit it sooner too. cleanin the crap out that is. anyways, yers looks mighty nice and clean....cool........ maybe ya got some new lower shift shaft parts too. nice and clean looking.......right on.....

 

[1970 Chieftain V]

Re: Cavity in lower gear case of pre alpha?

... anyways, yers looks mighty nice and clean....cool........ maybe ya got some new lower shift shaft parts too. nice and clean looking.......right on.....

When I first took it apart it was packed to the top of the shift shaft with sand, dirt and crap. What you see in the picture is after 1.5 hours of work and it still doesn't let water out of the hole.



Thanks everyone for the answers.

Jason

 

[ziggy]

Re: Cavity in lower gear case of pre alpha?

When I first took it apart it was packed to the top of the shift shaft with sand, dirt and crap. What you see in the picture is after 1.5 hours of work

yep, that's the way mine were too... as for still not gettin water out the hole after cleaning, i don't know....? exhust restriction? both of mine started pissin liberaly after cleaning.....

 

[achris]

Re: Cavity in lower gear case of pre alpha?

Try opening the hole up slightly with a drill, or blowing compressed air up it.

 

[1970 Chieftain V]

Re: Cavity in lower gear case of pre alpha?

Try opening the hole up slightly with a drill, or blowing compressed air up it.

I am not sure what path the hole takes to get to the cavity? I would hate to drill into the oil cavity where the gears are.


Jason

 

[Bondo]

Re: Cavity in lower gear case of pre alpha?

Ayuh,...........
Picking at the hole with a Stiff piece of wire will give to the direction of the hole......

 

[ziggy]

Re: Cavity in lower gear case of pre alpha?

not sure what path the hole takes to get to the cavity

i tried to take a pic for ya but couldn't get the flash down the hole. sorry it didn't work out. that hole best i can tell is perpendicular to the drive. it goes straight in and comes out at the very bottom of the cavity. i reamed on mine for a while useing a piece of spring steel wire.....ya should be able to punch thru from the outside to the inside with that idea. if not. the drill bit idea. maybe don't put it on a drill motor....just hand ream it with the bit...might make ya feel better that ya won't drill thru it......

 

[1970 Chieftain V]

Re: Cavity in lower gear case of pre alpha?

Ayuh,...........
Picking at the hole with a Stiff piece of wire will give to the direction of the hole......

This is what I did. I used a coat hanger and WD40 and kept poking and prodding from the inside until the plug finally came out. Flows nice now. The hole on the outside pretty much goes straight in until it is under the cavity and then a hole is drilled from the cavity to link the two.

Jason