[staleg]

When I mounted the used T56 transmission I just used the enclosed flywheel- and pressure plate bolts.
Torqued according to the LT1 instruction manual and used Loctite thread lock.

After that I've been thinking. Should I have used new bolts? A loose flywheel is scary, but on the other hand, if everything is ok, changing the bolts now is a lot of extra work since the transmission is mounted in place.

The motor is a 350 cid L05 rebuilt with carb.

[SSedan64]

I wouldn't worry, they're reused all the time & the Loctite should keep them in place. If it was a Hi HP/TQ engine it's a good idea to upgrade.

[crussell85]

if its together i wouldn't worry about it, it's like a 5 dollar piece of mind is all it is. I would almost worry about the threads in the block failing or the block cracking around the threads before a bolt failure. Even if you replace the bolts the dowel pin for keying the flywheel is probably taking most of the shear load before the bolts join in.

[sqzbox]

Originally Posted by staleg

When I mounted the used T56 transmission I just used the enclosed flywheel- and pressure plate bolts.
Torqued according to the LT1 instruction manual and used Loctite thread lock..

One would think that if you needed new F/W bolt's, they would have included them like they did with the clutch plate.

As far as thinking about it after the fact, I did the same thing after I got married the second time. It's been 30 yrs. today so I guess I did the right thing!

[1ownerT]

Originally Posted by crussell85

if its together i wouldn't worry about it, it's like a 5 dollar piece of mind is all it is. I would almost worry about the threads in the block failing or the block cracking around the threads before a bolt failure. Even if you replace the bolts the dowel pin for keying the flywheel is probably taking most of the shear load before the bolts join in.

A dowel pin in the crank of a SBC?

[1ownerT]

Originally Posted by sqzbox

One would think that if you needed new F/W bolt's, they would have included them like they did with the clutch plate.

As far as thinking about it after the fact, I did the same thing after I got married the second time. It's been 30 yrs. today so I guess I did the right thing!

Congrats!

[staleg]

Originally Posted by 1ownerT

A dowel pin in the crank of a SBC?

I remember it was a dovel pin there, yes.

Thanks for the answers, by the way!

[machine shop tom]

Originally Posted by 1ownerT

A dowel pin in the crank of a SBC?

All one-piece rear main and 400 SBCs have a dowel pin to locate the externally-balanced flywheel. I sometimes use a heavy metal dowel pin to add metal if a small amount is needed in that area when balancing internally balanced SBC cranks.

tom

[kc8oye]

Originally Posted by crussell85

if its together i wouldn't worry about it, it's like a 5 dollar piece of mind is all it is.

I agree! When I swapped transmissions, I had a cracked flexplate, so I decided since I dragrace a lot, to put an SFI approved flexplate in... and since I went that far.. i dropped an extra $8 for ARP's flexplate bolts

[tomslik]

Originally Posted by machine shop tom

All one-piece rear main and 400 SBCs have a dowel pin to locate the externally-balanced flywheel. I sometimes use a heavy metal dowel pin to add metal if a small amount is needed in that area when balancing internally balanced SBC cranks.

tom

some have the dowel, some don't and it AIN'T for locating a externally balanced chevy flywheel...
and i can walk out to the shop and look at a 400 w/o a pin

[crussell85]

Originally Posted by tomslik

some have the dowel, some don't and it AIN'T for locating a externally balanced chevy flywheel...
and i can walk out to the shop and look at a 400 w/o a pin

Is the 400 a one piece rear main though? What would the dowel pin be used for besides indexing the flywheel?

[tomslik]

Originally Posted by crussell85

Is the 400 a one piece rear main though? What would the dowel pin be used for besides indexing the flywheel?

there ARE no 400's with a 1 piece seal and about the only place i ever see the dowel is in 3/4ton and up stuff
i assume it's for somewhat of a drive pin

[crussell85]

i guess i am not sure on the 400 rear mains, But the dowel pin on various crankshafts are there to properly locate the weights on the flywheel to balance the motor, is this that complicated to understand?

[kc8oye]

wouldn't a "pre-used" bolt technically be a 'brand new' bolt?