Bell Housing Thread Size

[Doppleganger]

What thread is the bell housing bolts? I need to get some bolts to hang the motor on a stand.

3/8-16?

THX

 

[Vbb199]

3/8-16, yes lol.

I just was installing my new 700r4 in my truck earlier lol

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[Frankenchevy]

Yep, 3/8-16. Be careful, for some reason I think I remember the flexplate cover bolts being metric. Just mentioned it if you’re at the tranny stage...

 

[Vbb199]

Yep, 3/8-16. Be careful, for some reason I think I remember the flexplate cover bolts being metric. Just mentioned it if you’re at the tranny stage...

I had the hardest time getting mine off, seemed like a 15mm fit the best.

 

[Frankenchevy]

I had the hardest time getting mine off, seemed like a 15mm fit the best.

Yep, that definitely rings a bell now.

 

[Vbb199]

Yep, that definitely rings a bell now.

5/8 was too big, and 9/16 was too small.

Tried a 16mm, too large.
14 obviously was too small.

So a box end 15mm fit the best.

I had forgotten about the bs involved in a OEM converter

 

[Doppleganger]

Just wondered what the back of the motor threads were - for hanging it on an engine stand. Seemed to me when they dropped off my new motor, it was 3/8-16 where the trans mounts - thought that was kind of small but I guess it works.

How deep is the hole - 3/4 to 1"?

Thanks fellas!

 

[Frankenchevy]

Just wondered what the back of the motor threads were - for hanging it on an engine stand. Seemed to me when they dropped off my new motor, it was 3/8-16 where the trans mounts - thought that was kind of small but I guess it works.

How deep is the hole - 3/4 to 1"?

Thanks fellas!

Something like that. The welds on my cheap harbor freight stand were the weak point. Not the 3/8 bolts...

 

[PrairieDrifter]

I think they're an inch, other than the support rod bolt by the starter, I would recommend getting the trans tight against the motor and take a piece of wire or something and measure the depth of all the dead holes. Then account for a lock washer.

 

[Matt69olds]

I think every GM old school V-8 used 3/8x16 threads for the bellhousing bolts.

However, the transmission stuff gets messy. All the internal stuff is S.A.E, some of the really late model 400 used metric pan bolts. Sometimes the speedometer hardware is metric, and occasionally the old school rebuilt converter to flywheel threads are metric.


I remember some of the old timers at the dealership I worked at telling stories about the bitching when metric stuff first started appearing on American cars/trucks. I seem to recall reading somewhere about some stated putting up speed limit signs with kilometers instead of MPH, and disgruntled motorist shooting them up. Clearly, with the possible exception of the 9mm bullets, Americans did not welcome the metric system.

More useless info:
8mm is almost exactly 5/16

13mm is slightly bigger than 1/2 inch

14mm is slightly smaller than 9/16

16mm is very close to 5/8

 

[Doppleganger]

Something like that. The welds on my cheap harbor freight stand were the weak point. Not the 3/8 bolts...

Terrific. My new motor is sitting on one of their fold-up / mini cherry picker looking things. Would feel better with a cradle. I have an old stand that this original motor is going to sit on.

 

[Doppleganger]

I think every GM old school V-8 used 3/8x16 threads for the bellhousing bolts.

However, the transmission stuff gets messy. All the internal stuff is S.A.E, some of the really late model 400 used metric pan bolts. Sometimes the speedometer hardware is metric, and occasionally the old school rebuilt converter to flywheel threads are metric.


I remember some of the old timers at the dealership I worked at telling stories about the bitching when metric stuff first started appearing on American cars/trucks. I seem to recall reading somewhere about some stated putting up speed limit signs with kilometers instead of MPH, and disgruntled motorist shooting them up. Clearly, with the possible exception of the 9mm bullets, Americans did not welcome the metric system.

More useless info:
8mm is almost exactly 5/16

13mm is slightly bigger than 1/2 inch

14mm is slightly smaller than 9/16

16mm is very close to 5/8

After 30yrs of resto'ing old 4N cars (some with British metric...oh, the joy there), breaking out my old, but almost new SAE stuff is refreshing. Still gets annoying with that stray metric they mixed in.

They needed to just pick one.

 

[bucket]

I think every GM old school V-8 used 3/8x16 threads for the bellhousing bolts.

However, the transmission stuff gets messy. All the internal stuff is S.A.E, some of the really late model 400 used metric pan bolts. Sometimes the speedometer hardware is metric, and occasionally the old school rebuilt converter to flywheel threads are metric.


I remember some of the old timers at the dealership I worked at telling stories about the bitching when metric stuff first started appearing on American cars/trucks. I seem to recall reading somewhere about some stated putting up speed limit signs with kilometers instead of MPH, and disgruntled motorist shooting them up. Clearly, with the possible exception of the 9mm bullets, Americans did not welcome the metric system.

More useless info:
8mm is almost exactly 5/16

13mm is slightly bigger than 1/2 inch

14mm is slightly smaller than 9/16

16mm is very close to 5/8

17mm is very close to 11/16

19mm is very close to 3/4

21mm is very close to 13/16

22mm is very close to 7/8

24mm is very close to 15/16

...just to add a few more.