The correct GM flywheel bolt bolt number is 14100556 whicg should be a M10- 1.0 Pitch x 23MM long. I was told by my local GM dealership they are out of stock and no longer made. I ended up using ARP P/N 254-2801 which is for a 4.6 - 5.4 Liter V-8.
Caution: The ARP bolts are 25 MM long and must be reduced to 23MM or they will bottom out and not seat the flywheel to the crankshaft flange. Care should be taken to not overheat the steel while grinding to reduce length.
Are we talking two different bolts ?
Flywheel to crank shaft.
Clutch pressure plate to flyheel
I think tommy is looking for #2.
Yeah, I think the PP bolts are 8mm thread. I have been wrong before... ya know, there's really no reason you couldn't use a bolt with a shank a bit too long, then cut threads as far as you need and then cut the bolt to length with a whizz wheel. That's where McMaster or similar would come in.
I'm looking for both, and pirate delivered! Im going to order those arp bolts, then he'll be receiving $5.
Pirate, could you email me your PayPal address? TomS@grassrootsmotorsports.com
Bolts with a body are used to locate the pressure plate rather than dowel pins. Using a bolt without such a body will not accurately locate the pressure plate. Size/pitch of the thread is not the issue.
I understand that now, that's why I'm ordering the correct ARP hardware. I was hoping the response here would be "nahh, you don't need a shank, you'll be fine."
You thought special bolts might be just a mistake?
Tom, No need for any payment just glad I could pass on some information.
I would like to comment about cutting additional threads on bolts though. Most specilized bolts use rolled threads rather then cut treads. The rolled thread has a small radius at the bottom of the thread rather then a sharp V shape. Rolled threads also have a tighter tolerance and tighter class fit then standard die cut threads. Cutting addition threads can cause stress risers and lead to bolt failure. For instance just about all bolts for aircraft applications use rolled threads. Not trying to lecture but just wanted to bring that up for everyone's safety! Also, it is extremely inportant to use a torque wrench so you don't surpass the yield strength of the bolt and weaken it.
Chas_H wrote: You thought special bolts might be just a mistake?
No, I thought bolts without a shank might do an equal job at locating the pressure plate on the flywheel.
I really started this thread to see if anyone knew what the correct bolts were, though, as I had no clue. Remember, I've never seen the proper bolts, as I'm converting from an automatic.
Bolts with a shank? If it looks like this, it's called a shoulder bolt.
I think you have it.
Hot dog! 914 is the weiner!
Oh, sorry. I'd always heard it called a shank, but that makes more sense.
Nope, Martha Stewart says this is a shank.
A shoulder bolt has a larger-diameter unthreaded area; on a regular bolt with an unthreaded area it is called the shank.
So now we have the correct nomenclature.
Ok, I've got the new bolts, they fit, as far as I can tell. :D
For the pressure plate, should I use the flat washers that came with the arp hardware, or the lock washers that came with the last set of bolts I bought?
I'd go with the washers that came with the bolts you are planning to use.
Proper stretch is more critical for proper clamping pressure and properly stretched bolts won't loosen.
For most lock washers to work they need to bite into the metal, and a hardened bolt won't allow for the washer to bite into it.
914Driver wrote: Bolts with a shank? If it looks like this, it's called a shoulder bolt.
Where the 'shoulder' is a precision ground surface with specified diameter, and the end where it transitions to the threads is also ground flat, such that distance 'Lg.' in the picture is a specified length.
Carter
The 'shank bolt' is not exactly the same as a 'shoulder bolt'. A shoulder bolt generally is used in a high precision application, such as mounting a bearing to a flat surface, you don't want the bearing to be able to shift on the bolt. A shank bolt merely keeps threads out of an area subject to shear forces. An AN bolt is a good example of a shank bolt; the grip length is figured by measuring everything to be clamped, add 1/16" or so, then use AN flat washers to keep the nut from bottoming out before everything is torqued properly.
Blue Loctite.
I got it figured out, and the transmission is in! The bolts fit perfectly, and the pressure plate was centered perfectly.
I used 60 ft-lbs. of torque and blue loctite.
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