Cavalier seats

The message from Peter Twydell contains these words:

The seat belt is mounted to the seat and the seat then mounted to the floor. I suppose they're worried that it may be weakened in some way if you reuse the bolts.

As to whether it's really necessary - no idea.

Don't the new ones come with threadlock on them?

The message from DuncanWood contains these words:

If that's the only reason for using new bolts then I'd just put new threadlock on 'em!

That's the 64000 dollar question.

Wouldn't that be like buying a ready meal? Even main dealer mechanics know how to put Loctite on a bolt (don't they?).

I do know that some engine rebuilds require new bolts, but I've never been 100% sure why that is either, unless it's something to do with their being softish and the threads getting worn when they're extracted?

The message from Peter Twydell contains these words:

Some bolts are "stretch" bolts which elongate during the tightening process and this is allowed for in the tightening specifications. I suspect that if you were cunning you could devise another tightening spec which worked with old bolts.

However, I've re-used bolts on various engines which allegedly need jew bolts and not come unstuck yet.

Guy King ( snipped-for-privacy@zetnet.co.uk) gurgled happily, sounding much like they were saying :

Friends of mine have, and have. Including one guy who snapped a set of flywheel bolts while I was in the car. I've also needed to replace a 15,000 mile head gasket where the reused stretch bolts were barely finger tight when dismantled.

In article , Guy King writes

OK, stretching makes sense if there's a nut on the exposed far end, doing the pulling and clamping parts together. ISTR seeing a TV programme years ago that showed the then-new K Series engine using this technique. What's the process if there's no tensile force on the bolt, though? How can a "standard" cylinder head bolt stretch when going into a blind hole??

The message from Peter Twydell contains these words:

The bit between where the thread ends and the head of the bolt stretches.

There's always tensile force on tight bolts. Otherwise they wouldn't be tight, and up to a point, all tight bolts are stretched. Blind hole or nut, the same applies. Same with cyl head bolts, they stretch because the torque required to twist and break them, is greater than the resistance given by the thread. Stretch bolts are designed to stretch to a point from which they don't recover when removed. Restretching, weakens them. Therefore they shouldn't be reused. Mike. Mike.

The new bolts are pre-coated with a locking compund which is not as effective if the old bolt is put back in. You could also clean up and re-apply some new compund and re-use the old bolt. They are not one-use stretch bolts. Tightening torque is 15lb ft / 20 Nm

As a side note, make sure that you install the locking clips to the seat belt tensioner before you remove the seat to prevent it from going off accidentally. The clips are red and hooked onto one end of the tensioner. There is a sticker on the side to show where it should be installed.

HTH

Anthony Remove eight from email to reply

In article , Mike G writes

OK, I get it now. I was forgetting the effect of the torque on the threaded portion and considering only the head. Am I right in thinking that what you're saying is that once the head is in contact with the surface, the rest of the bolt is forced to turn in the thread when the head is turned further, thereby moving down the thread and stretching ? (Not elegantly expressed, but it's late and I'm still working)

In article , Anthony Britt writes

Thanks for the tips. Talking of locking compounds, is the type important? I know there are several flavours of Loctite, for example, but have no idea what the differences are.

The different varieties offer different locking strengths - for example screwlock is a low to medium strength compound for use where a fastner is to be undone at some point in the future. Studlock is of higher strength where a fastener is not expected to removed. A standard screwlock variety will suit your needs - usually the blue coloured type sold in car accessory shops.

HTH

Anthony Remove eight from email to reply.

The message from Peter Twydell contains these words:

Yes.

The message from Peter Twydell contains these words:

There are sorts that are intended to allow for later disassembly and some that most certainly don't!

It's also worth noting that mild threadlock has a secondary advantage - it stops nuts corroding to bolts, making them easier to remove years later.

Do you have to be so verbose? Mike.

The message from "Mike G" contains these words:

No.

In article , Mike G writes

Would you please tell me why that's verbose?

If you can explain it better and just as accurately, why didn't you?

The message from Peter Twydell contains these words:

He was taking the mickey out of my one word answer. Don't worry, those of us behind this glass screen in front of you like to play sometimes.