Firewall/Chassis splice bolt

[Rick Fischer]

Hiyas

All ready to separate the fiewall from the chassis. Inner rail bolts are out but cannot shift the two long tie bolts. Nuts off easy enough but looks like the bolts have grown into the firewall and the chassis anti-compression tubes.

Big tommy bar threatens to shear the bolt heads.

Lots of torque while 2lb hammering not playing either; even resists 6lb sledge.

Big heat - a la cutting torch flame - did try on the hollow fire wall half but all that did was increase the probability of shearing the through bolt head

Am looking at cutting through with a slitting saw and then drilling out :(

Before I get that drastic, have I missed anything?

Previous experiences?

Cheers

RF

[JDNSW]

Your experience is typical - I don't think you have missed anything. I would expect a minimum of a month soaking in penetrating oil would be needed, then heat, repeat - as often as necessary.

John

[wrinklearthur]

RF, I share your pain as I have a firewall / chassis to separate as well.

If mine has gone past the point of being unable to remove the bolt ( there is a high probability of this ), I am going to sacrifice the rusted up crush tubes and weld new ones in.

To do this, I am going to cut the tube with the bolt inside, then grind the tube flush up to the flat of the firewall pillar and repeat this for both sides of the pillar.

With the firewall clear, in the middle of the cutoff bolt drill a pilot hole that is the centre to the outside diameter of the crush tube.
Use that pilot hole to centralise a metal cutting hole saw with the outside of the crush tube, cutting the tube end past the weld, do this on both sides and the old tube should then punch through easily.

Slowly does it with the hole cutting saw and use plenty of cutting oil to keep the tips of the saw cool.
.

[Rick Fischer]

Thanks guys

Seeing I'm not about to hang about for a month keeping soaked, will run a slitting saw between the two and then drill or punch out; ulitmately will be like Arthur's I would guess. Bugga! :( Oh Well! Don't reckon it will be the last "drastic action"

Cheers

RF

[123rover50]

Once you cut through with a really thin slitting blade in the angle grinder at the join between the two you will get them apart then the two pieces may drive out as less friction etc.
Make up the missing bit with a suitable washer as packing when re-assembling.

Keith

[wrinklearthur]

Once you cut through with a really thin slitting blade in the angle grinder at the join between the two you will get them apart then the two pieces may drive out as less friction etc.
Make up the missing bit with a suitable washer as packing when re-assembling.

Keith

I have a reciprocating blade saw with a metal blade that I use for cutting on small jobs.
Using one of those or a thin blade in the angle grinder like Keith said would be worth a try first.
When cutting metal with a reciprocating blade saw, use some oil to keep the blade cool.
.

[Aaron IIA]

I had to replace a firewall chassis outrigger on my SI. My donor chassis had the bolt stuck in the crush tube, either snapped or cut off flush at each end. To get it out, I heated the bolt and crush tube using two oxy cutting torches, one from each end. You need a lot of heat to get the entire length of the bolt and crush tube red hot, including the middle section. I then drove the bolt out using a large hammer. The outrigger and crush tube were suitably supported to prevent distortion.

You may have to cut through the bolt using a 1mm grinder blade to get the firewall off initially, but this thickness can be made up with a suitable washer.
Aaron

[Rick Fischer]

Hi guys

Yep, all off. Had to wait to get a larger dia angle grinder from a neighbor. Once they were slit at the join the bolt remains came out (with a bit of difficulty) :)

Cheers

RF