Do I need new bolts for crossbeams?

[wagon-r]

Hopefully these are easy, quick questions. I am going to pull the front crossbeam (below the radiator), so that I can install my Bisi header with the two pieces hammered together (fit isn't very good).

The service manual says that the bolts must be replaced, at about $9 each. Is this necessary?

Also, do I need to worry about supporting anything when I pull the front crossbeam?

[Fleetw00d]

I have dropped one end of the cross beam (I was having trouble getting the engine to drop enough during a timing belt change) and I replaced the cross member on another of my Accords after an accident released battery acid all over it. I reused the bolts and torqued to spec. You might use some Loctite blue to prevent them from backing out. No problem so far.

[illinois_erik]

Hopefully these are easy, quick questions. I am going to pull the front crossbeam (below the radiator), so that I can install my Bisi header with the two pieces hammered together (fit isn't very good).

The service manual says that the bolts must be replaced, at about $9 each. Is this necessary?

Also, do I need to worry about supporting anything when I pull the front crossbeam?

surprisingly a lot of the bolts in the engine bay say they need to be replaced after removal, I think youll be fine reusing, Ive reused plenty with no ill effects. The ones that say to be replaced have a little hole at the end in the threads with a dab of nylon in it, kind of a built in threadlock. Anyway like mentioned youll be fine using blue locktite and torque to spec.
Do you think if the front end is jacked up high enough you can sneak the header in up thru the bottom? Your alignment may change a little since the radius rods are connected to the cross beam and knuckles and are responsible for caster, thats where I would disconnect them from is at the knuckles. The beam is pretty light so dont worry about it being very heavy. Once the radius rods are disconnected and the 4 bolts are out of the beam it should all come out without any fuss....unless you have ABS. Then itll be a headache. Other than caster and front frame rigidity it serves no other purpose. good luck.

[lucifer1]

Those bolts are locks bolts with plastic in the threads to keep them from vibrating loose. They are considered one time use. I have reused them without a problem but they need to be torqued to spec.

I have had them come back loose on my integra when I tightened them without torquing them. They were plenty tight but probably not all the same tightness. After torquing them to spec, no problems.

[wagon-r]

Do you think if the front end is jacked up high enough you can sneak the header in up thru the bottom?

Actually, I hope that with the crossbeam and the radiator removed and the AC moved out of the way that I can either drop it down from the top or bring it up from the bottom.

Once the radius rods are disconnected and the 4 bolts are out of the beam it should all come out without any fuss....unless you have ABS. Then itll be a headache.

I do have ABS. What is the extra headache?

[wagon-r]

Those bolts are locks bolts with plastic in the threads to keep them from vibrating loose. They are considered one time use. I have reused them without a problem but they need to be torqued to spec.

I have had them come back loose on my integra when I tightened them without torquing them. They were plenty tight but probably not all the same tightness. After torquing them to spec, no problems.

I'm a bit obsessive when it comes to torque specs - everything gets torqued as best I can - so it sounds like I shouldn't have any problems reusing the bolts.

[wagon-r]

Your alignment may change a little since the radius rods are connected to the cross beam and knuckles and are responsible for caster, thats where I would disconnect them from is at the knuckles.

I'm dropping the vehicle an inch, so I was intending to have an alignment done when I am done anyway. That will at least tell me if I screwed up the caster.

[illinois_erik]

Actually, I hope that with the crossbeam and the radiator removed and the AC moved out of the way that I can either drop it down from the top or bring it up from the bottom.


I do have ABS. What is the extra headache?

The ABS modulator is mounted to the beam with a few hardlines from the braking system and electrical connections attached to it. Mine were very corroded. You might not have the same issue, but being as old as it is you may run into problems. Then theres the added fun of bleeding the ABS circuit if you do crack the lines, and be careful if you do because some of the lines will have brake fluid under very high pressure

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I meant sneaking the header up thru the bottom without removing anything at all, might be something to test before fully committing.

Anyway get you a bottle of blue locktite and TTS you should be good, the radius rod bolts to the knuckle I believe are one time use too

[cb7 calling]

Not related but I recommend using rtv copper where the header may leak. Not the spray the silicone. It's good to like 600 or 700 degrees which should be enough to prevent leaks. I dunno why everyone doesn't use it on their leaky race headers.

[wildBill83]

When you go to have an alignment done find a place that is willing to tweak your subframe. You will not be able to get it back on in the same spot. This affects suspension geometry.

[wagon-r]

Not related but I recommend using rtv copper where the header may leak. Not the spray the silicone. It's good to like 600 or 700 degrees which should be enough to prevent leaks. I dunno why everyone doesn't use it on their leaky race headers.

My understanding is that exhaust header temperatures can exceed 1000F. Will the rtv copper silicone hold up?

[wagon-r]

The ABS modulator is mounted to the beam with a few hardlines from the braking system and electrical connections attached to it. Mine were very corroded. You might not have the same issue, but being as old as it is you may run into problems. Then theres the added fun of bleeding the ABS circuit if you do crack the lines, and be careful if you do because some of the lines will have brake fluid under very high pressure

----
I meant sneaking the header up thru the bottom without removing anything at all, might be something to test before fully committing.

Anyway get you a bottle of blue locktite and TTS you should be good, the radius rod bolts to the knuckle I believe are one time use too

Thanks for the good advice.

And I'll make sure the alignment is proper when I am done.

[illinois_erik]

Thanks for the good advice.

And I'll make sure the alignment is proper when I am done.

Youre welcome, good luck, hope it goes easy for you

[Tishock]

Not related but I recommend using rtv copper where the header may leak. Not the spray the silicone. It's good to like 600 or 700 degrees which should be enough to prevent leaks. I dunno why everyone doesn't use it on their leaky race headers.

Copper RTV is only a temporary fix. It eventually dries up and breaks off. That portion of the header where both pieces merge moves around a little. Which in turn hastens the RTV deterioration.

I'm reminded of your earlier post where you showed us the f'ed up slip joints on your Bisi header. Resulting in it being very difficult to merge the slip joints. I forgot to mention that maybe you should try using a Pipe Expander to correct the out of round flaw in those header slip joints.

[johnl]

As already mentioned the only reason Honda considers these to be 'one-use' bolts is because of the nylon 'locking' insert / plug, which loses effectiveness each time the bolt is used (worn away by rotation against the threads, the same as with Nyloc nuts). In reality these inserts don't prevent the bolt from becoming loose, but do help prevent the bolt vibrating out if they do lose tension.

I've re-used them with no problem, just make sure they are tight enough and use a thread lube on the threads and under the bolt head. Lubricating the bolt reduces friction and allows the bolt to be in greater tension for X tightening torque. The goal is for the bolt to elastically stretch slightly (but not permanently stretch), which is what really keeps the bolt tight.

If you feel it become easier (as opposed to harder) for the bolt to turn further as it's tightened, or the bolt continues to turn with no increase in the force needed to turn it, then this is a sign that the bolts' elastic limit has been exceeded (or the threads are starting to strip) and the bolt has permanently stretched, in which case the bolt should be replaced.