3 on the tree to sm465 conversion questions
- Thread starter Jamesz
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Jamesz
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One more question. What size bolts do I need for the sm465 to go to the bellhousing? I have been reading different answers. Would you or any others have information/pictures or such to share? Thank you guys so much for the help!
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Just off memory, they are 1/2" x13 bolts, maybe 1.25 or 1.5 inch long. I can go out and check to be sure in the AM, if I remember.
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I finally remembered to double check. The bolts are 1.5" long. Course thread, 1/2".
Jamesz
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Thanks man! So do I would assume I would need nuts for the bottom two? The bellhousing I got has threads on the top mount holes but none on the bottom. I don't know if I got the wrong one or not.
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All four holes should be threaded.
Jamesz
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That's weird. I was thinking about it today when I got to the shop so I grabbed some pictures. Do you think I should look into maybe threading these holes?
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That bell housing with open bottom has room to put nuts inside. Older style, will probably only fit the 11" clutch. Advantage is you can use stover style lock nuts. Will not vibrate out.
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Welp. I had ASSumed that you had the typical aluminum bellhousing that was used in the squarebody trucks. My bad, lol. I'm guessing you will need longer bolts for those bottom holes then, maybe 2". I've never had one of those older bellhousings.
Jamesz
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I thought I did too lol. I've never worked on much gm stuff mainly toyota and motorcycles. So I'm not familiar with all the different styles yet. So far so good though! These trucks are super simple.
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You want to measure your bellhousing. Newer style is 6.29" trans flange to engine flange. For many years engines had a single engine mount in the front and used a mount on each side of the trans bell. This is how the many 6 cylinder engines were mounted. Your bell has those mounts.
As more V8s were installed the mounts were switched to 1 mount on the back of the trans and 2 mounts on each side of the engine. You can use that bell as long as the front to back measurement is correct, also the diameter of the rear hole needs match the trans. I think you need 5 1/8" hole.
Squares came with this style bellhousing:
This will fit a 12" clutch.
As more V8s were installed the mounts were switched to 1 mount on the back of the trans and 2 mounts on each side of the engine. You can use that bell as long as the front to back measurement is correct, also the diameter of the rear hole needs match the trans. I think you need 5 1/8" hole.
Squares came with this style bellhousing:
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This will fit a 12" clutch.
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Do you think my spare bellhousing is this one?
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I believe there are different diameter trans holes, i.e. the little 3 speed is smaller.
Think about that cast iron bell. You could call it a quick change clutch. Unbolt and slide the trans back. Bar the engine around and remove the pressure plate bolts, it and the disc slide out the bottom. Reach in and slide on the new throw out bearing. Slide the new plate an disc in and install 2 lower bolts loose. Don't need a pilot tool, use the trans. Move it in and push the disc up with 1 or 2 screw drivers and hook it on the trans input shaft. You use that shaft because you can.
Most vehicles 1950 and older vehicles had stick shift trans. Clutch disc was a common wearable item. Maybe the engineers were thinking about the mechanics or were former mechanics. Zoom ahead, engines got more powerful, need for a larger clutch.
