How long should torque converter bolts be? [Archive] - Team Camaro Tech

: How long should torque converter bolts be?


1968camaro123
Mar 29th, 03, 03:16 AM
Guys,
I just bought a TH350 with some brand of high stall converter. The flange on the converter where it bolts to the flywheel is around 3/4 of an inch thick? Usually it's only around maybe an 1/8 or so. Should I just buy longer bolts?
Thanks,
Donnie
P.S> The converter is kind of a bright blue if that makes a difference in knowing what brand it is.

Oldani Motorsports
Mar 29th, 03, 08:25 AM
Get some good grade 8 fine thread bolts and nuts that are long enough to go through the converter mount pads. I like to use bolts with a slight shoulder, good surface ground flat washers under the bolts and nuts, and blue Loctite on the threads. And, check your flexplate before you install the converter and tranny. Many aftermarket converters use a bigger 7/16" bolt size, and you often need to enlarge the bolt holes in the flexplate. Finding this out after you have the trans bolted to the motor is not a good time to discover this! smile.gif

Vintage 68
Mar 29th, 03, 09:24 AM
Is this a "flange" that is 3/4" thick or a Block that is welded to the converter and tapped for a bolt to go into?
Some 'H.D.' GM over the counter converters were painted a bright 'Chevy blue' color. They had a threaded block welded to them for the flexplate bolts.

BPOS
Mar 29th, 03, 10:32 AM
Some converters use a bolt with a nut, and others have a threaded mount. Don't rule out the fact that your converter could have metric threads. I think most aftermarket converters were originally factory units with new internals. I had a B&M Holeshot 2400 for a T350 and it had metric threads.

Measure the depth of the threads, add the thickness of the flexplate, and get grade 8 bolts that are slightly shorter so they won't bottom out.

[ 03-29-2003, 02:48 PM: Message edited by: BPOS ]