Thread: TTY head bolts won't budge

I've never used any of the freezing products for removal of fasteners, but I'm a big fan of my MAP gas torch. I've used it both to heat the material containing the stuck fastener, or to selectively and aggressively heat the fastener before leaving it to cool a while. Repeated cycles work well doing this especially if you have reason to suspect that there's been an issue with corrosion bonding the threads.

I also like using an old fashioned, hammer operated impact driver and impact sockets. It actively drives but is relatively kind to the head, delivers a safe shock in a useful direction and can be used with a fair bit of sensitivity to the situation.

Just thumping the end of a ring spanner is a no-no. I reckon it's one of the best ways to damage the head making removal harder. There's so much spring in the spanner too, that the percussive force is damped and doesn't work as well. Loss of control is easy, meaning the spanner can walk and trash the head.

Another "trick" passed on to me by an old race motorcycle mechanic who used to make good pocket money extracting damaged fasteners at race meets is to give some low momentum but very high velocity knocks on the flats of the head before using any rotational force. Think little hammer like a tack hammer and a hardened punch. This light but sharp blow at right angles to the thread works to break the corrosion weld between fastener and thread. It's saved me many times with small diameter flange-head bolts threaded into alloy, where the bond between the flange and the face of the alloy assembly is stronger than the 8mm or 10mm head.

Guys
Its a no no to use an impact gun on an LR V8 engine.
Unofficial factory advisory, and if you see how much "meat" is surrounding the bolt pocket in the block you will know why!

I use a long Snap On breaker bar and a quality double depth 5/8 socket--quality is the word for the socket!
I have never needed to heat the bolt, but I suppose in an extreme rare case it might help.

I have had the occasional bolt head round off due to someone previously using the wrong socket and then I have had to weaken the bolt head with a die grinder to sheer it. Not an easy task in the backs of the heads.

Dennis
zedcars

Originally Posted by Hoges

4.6 V8, 10 bolt head. I can undo the TTY bolts (16mm head) normally under the rocker cover - they make a "cracking" sound but can feel them begin to "de-tension" but can't move the external ones...even with repeated impacts with a 250ft lb 12V electric rattle gun. When I use the 6pt impact socket and a long breaker bar I can feel the beginnings of a 'rounded' head -so I've not proceeded...

I've sprayed liberally with the Freeze Release and given the bolt head a few medium 'taps' by placing a ring spanner over it and hitting the other end of the spanner with a hammer to try and break down any adhesion between bolt head and aluminium surface ...to no avail.

would appreciate advice on how "experts" break the seal.

I understand there are some special sockets which clamp onto rounded heads...where do you get them and do they work?

thanks

Sounds like your 6 sided socket needs to be upgraded to a quality tool socket, if your rounding off the bolt heads it is because the socket is opening up, a quality socket will not open up, try again with a good socket, it also pays to undo the bolts in the opposite sequence to which they were done up, Regards Frank.

where in brisbane? I have a couple of runs to do in the near future and may be able to come round to whip them out for you.

PM sent

Originally Posted by zedcars

Guys
Its a no no to use an impact gun on an LR V8 engine.
Unofficial factory advisory, and if you see how much "meat" is surrounding the bolt pocket in the block you will know why!

I use a long Snap On breaker bar and a quality double depth 5/8 socket--quality is the word for the socket!
I have never needed to heat the bolt, but I suppose in an extreme rare case it might help.

I have had the occasional bolt head round off due to someone previously using the wrong socket and then I have had to weaken the bolt head with a die grinder to sheer it. Not an easy task in the backs of the heads.

Dennis
zedcars

what is a double depth socket?

I think you will find Macman was referring to a manually operated impact driver, NOT a impact gun (air or electric)

I was, but the OP was talking about an impact gun.

Message to Blknight.aus: "Dave You ARE the MAN!" big thanks for detouring well out of your way on a busy Friday evening and swiftly removing said headbolts! Deeply appreciated!