Strange square holes in case...

[JamesMilk]

Ok, so I have discovered what looks to be a blown out case. The hole leads to the 3rd/reverse drum. It's up under the shift gear for an automatic trans. I just need to know it is can be repaired(tig weld) or has to be replaced, can't find anyone else with this problem online. But I'm guessing this is why my th350 has no 3rd gear shift. Give me your opinions please. It isn't holding the transfluid under heavy load, But reverse works with no load.

 

[Matt69olds]

That’s just a drain hole. They are cast that way. I have a th350 torn apart on my bench, I’ll take a pic when I get home from work.

 

[JamesMilk]

So I should continue with the rebuild?

 

[Blue Ox]

@Matt69olds would be the expert on these things, but judging by the casting flash I'd say that's how they're made.

Once you get the case clean I would deburr those. Obviously it's not too critical if it made it this far, but all that sharp, thin metal sticking out would drive me nutz.

 

[JamesMilk]

Yeah, was wondering if I was losing fluid to push the truck into 3rd or not

 

[Matt69olds]

Crap, I forgot to take the picture. If that’s the only concern, then go head with the overhaul.

Lots of cases have holes cast into them that look just like what you are seeing. Aluminum is expensive, they don’t put any more into the case than is absolutely needed.

 

[Matt69olds]

Here is a brand new case cast by ATI for drag racing. You can see the hole in the same place.

 

[Matt69olds]

And another case for sale on EBay.

Do you have a service manual? Once you get the pump and forward/direct drums back together it’s easy to air check your work.

Stack the direct drum with bearing onto the forward clutch housing. Set the pump with the bearing or thrust washer in place onto the input shaft. Turn the entire assembly over, with the shaft dropped thru a hole in the workbench. You can apply air thru the holes in the pump and look for the clutch to apply.

 

[JamesMilk]

Thanks for the knowledge, I'm about ready to pull it from the truck, just a few more bolts to loosen. Was just making sure I didn't waste money on my rebuild kit. I will send pics of when she finally is free.

 

[JamesMilk]

Ok here is the clutches and case body. My clutches were completely burnt up, except for 1st gear. And my accumulator spring was broke into 3 pieces.... time for the bushing removal and clean the everything up.

 

[JamesMilk]

1 more pic

 

[bucket]

So what is the trick to getting that accumulator retainer clip out of the groove? Or is there no trick, you just have to struggle?

 

[JamesMilk]

So what is the trick to getting that accumulator retainer clip out of the groove? Or is there no trick, you just have to struggle?

I used a small flat head screwdriver, there's a small hole that you can use to push the retainer clip out with a few taps of the hammer.

 

[Matt69olds]

I used a small flat head screwdriver, there's a small hole that you can use to push the retainer clip out with a few taps of the hammer.

This^

Use a small punch thru the hole to push the snap ring out of the groove, then use a small screwdriver or pick to pull it out.

 

[bucket]

Awesome, thanks fellas! I never realized there was a hole there. Looks like I need to do some more cleaning on the Chevelle so I can find it.