Transmission Bolts

[Bigdownut]

Hello again I am about to do a spline lube and Chris Harris recommends replacing the Transmission bolts. Do I really need to replace them or can I reuse the old ones?

[Bamboo812]

I always reuse them and the output flange bolts too.

[Bigdownut]

I always reuse them and the output flange bolts too.

Cool thats what I was wanting to hear.

[Kurt in S.A.]

A shop will essentially have to replace them...an insurance thing and probably a prudent thing to do for the customer. The bolts are used (or should be) within the elastic limit of the material as they are tightened. If they are deformed, you shouldn't reuse them. Try manually threading them into the output flange...if they thread easily by fingers, they are not deformed. You should be using the short bolts with no lock washers.

Kurt in S.A.

[bbelk]

This is what you are looking for....

[Texer]

Hi - I was under the impression they are 'stretch' bolts and need replacing after disassembly. Can't remember which of the 4 manuals says so though.

[Duane Ausherman]

I can tell you that the Butler and Smith racing team reused them many times. On our own bikes we reused them and sometimes on customer's bikes. It is a dealer liability issue, as mentioned. I hate replacing perfectly good parts.

[Kurt in S.A.]

Hi - I was under the impression they are 'stretch' bolts and need replacing after disassembly. Can't remember which of the 4 manuals says so though.

They are designed to stretch...that's what creates the tendency for them to not back out...the old lock washers did that but when they broke and fell away, the bolt could easily back out. If you elastically stretch them, they will "spring" back to their nominal shape. If you plastically deform them, but over torqueing them, then new bolts must be used. You can check for elastic deformation by ensuring they thread fine by fingers.

But heck, it's an important joint, the bolts won't break the bank...buy new.

Kurt in S.A.

[Major Softie]

Yeah, actually ALL bolts are "stretch bolts."

I don't know what the actual difference is between those that are called a stretch bolt, and those that aren't, but they all stretch in use. That's what a torque wrench is indirectly measuring: by directly measuring the torque applied to the bolt, it is indirectly measuring the amount the bolt is being stretched.

[Kurt in S.A.]

The service bulletin that came out in June 1983 said to torque to 29 ft-lbs. They stated that "since the bolts are permanently stretched after being tightened, they should be replaced and not reused during reassembly." I suppose if I were to actually figure out how to put exactly that much torque, I might be inclined to buy new bolts. But I used the tool kit wrench with a rag in my hand, and installed dry with a touch of blue Loctite using a good "grunt". I doubt I got the full 29 ft-lbs but I'm sure there was enough (elastic) stretch and coupled with the Loctite, the bolt is not going to back out IMO.

Kurt in S.A.