There is a hole in the case at about the 7 o'clock position next to the seal retaining screw, and a stock adapter has a channel cut out between the hole and the screw. What is the purpose of the hole, and is the channel really needed? I ask because I am working with Speed Gems on creating a Cad 331 to LaSalle/Olds adapter plate, and need to determine if the channel is needed, or if the hole can simply be covered over. Hopefully the attached pictures can illustrate what I am referring to!
That is the oil return hole, the front bearing is not shielded and there is no front seal on those transmissions so the excess bearing lube oil is controlled by the threaded slinger on the input shaft and is returned to the main case through that return hole. So yes you need it, without it the trans oil will run out the front of the bearing retainer and oil down the clutch and flywheel.
Curious here too about a front seal. Couldn't a guy use a shielded bearing (front only) to help control oil? It would save a lot of gear lube!
I must be missing something here by your description. A 49 to 53 Cadillac 331 standard shift bell housing fits exactly/ perfectly to a 37 up LaS or 1950 Olds transmission. If you mean the later non-extended bell 331 engine from 1954 up, there was once an aftermarket aluminum adapter bell that kind of looks like the Ford flathead trans to Chevy engine shallow bell adapter. It extends the back of the later 331 engine to be able to use the stock early Cadillac 49-53 bell housing. I know because I had one, but I don't recall a name or part number. But anyways, I can't understand why you said plate adapter. I can't see how a plate can do what? Unless you are trying to use a plate to adapt to a different aftermarket bell that Speed Gems has in stock? That's what it seems like to me One more important thing to add to what was already answered... I think it was hamb member 5-Quart from NJ that said the LaSalle front bearing retainer that is also the throw out bearing guide tube, that the 37 only input shaft is smaller diameter than 38 up LaS side shift input shaft as well as the 1950 Olds input shaft . Meaning that the bore ID in the later bearing retainer is a larger bore ID to fit over the larger 38 up shaft OD diameter. So, if a person still has the stock 37 input shaft but used a 38 up bearing retainer/ TOB guide tube, then it will leak oil out past those spirals on the input, because it doesn't fit close enough to let the spirals move the oil backwards to the drain. I just don't understand what you are building. You have to use something for a TOB to ride on, and like was said, you need to design the parts to move the oil to return like the factory design did. Some miscellaneous Adapters over many brands used a aftermarket bell with a bolt on guide tube that fits inside the bell, I'm not talking LaS only conversions, could be other transmissions. I forgot where I saw that type.
Follow up question - is the cutout at the 12 o'clock position needed? Does that serve the same purpose?
Speed Gems makes a 'generic' bell housing for the early extended-bell Cadillac 331 engines, and then they also make different adapter plates that bolt to their bell to allow different transmissions to be used with the 331. So right now that is what we are working towards. And you are correct, this particular setup will be for the '38 and up LaSalle/Olds transmission, using the stock candlestick.
The notch at the 12'oclock position is to locate the front bearing retainer/throw out bearing sleeve and keep it from rotating as it does not bolt to the front of the transmission. The sleeve drops into place and is held there when the transmission is bolted to the bellhousing.
I'm talking about the 'arched' channel at the top, that sort of matches the oil channel at the bottom. Is that also for oil return somehow?
Peter, the channel at the top is the register for the candlestick. No oil there. Oil hole as mentioned is at the bottom.
OK, so here's picture of the candlestick in the adapter, we are saying the arched channel at the top has no purpose, correct?
Don't know but could there be a shift rail that would need that clearance to go into for first or third gear?
Peter, sorry for the late reply on the candle stick but the top of the candle stick should have an index tang that fits in the top space of the bell. It keeps the candlestick from rotating and blocking off the oil drain in the lower part of the bell. You can see that tang in this video if you look closely at his video. I have seen them worn off to the point that the retainer will spin. di Falco Fabrications | Bearing retainer and throw out collar for Cad-la Salle transmission adapter. #cadlasalle #hotrod #hopup #roddersjournal | Instagram
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