Bolt snapped inside camshaft

Sykonica · Post by **Sykonica** » 22 Dec 2021, 16:01

I was working on my 01 XC70 today. When trying to replace some cam seals, I was installing the locking tool, and after gently tightening the (cheap) bolt, it snapped inside the camshaft on the intake side. After trying to back it out with several extractors, it’s still stuck. The plan is to drill out the bolt and see if I need to re-tap the threads to install the locking tool. I’m hoping someone here can answer some of the following questions:

Is my camshaft f****ed?

Is drilling out and (if needed) re-tapping my best option here?

Has anyone else ever experienced this? I can’t really find anything about it on any forums anywhere.

Thanks in advance for your help!

Post by **firstv70volvo** » 22 Dec 2021, 17:35

Sykonica wrote: ↑22 Dec 2021, 16:01 I was working on my 01 XC70 today. When trying to replace some cam seals, I was installing the locking tool, and after gently tightening the (cheap) bolt, it snapped inside the camshaft on the intake side. After trying to back it out with several extractors, it’s still stuck. The plan is to drill out the bolt and see if I need to re-tap the threads to install the locking tool. I’m hoping someone here can answer some of the following questions:

Is my camshaft f****ed?

Is drilling out and (if needed) re-tapping my best option here?

Has anyone else ever experienced this? I can’t really find anything about it on any forums anywhere.

Thanks in advance for your help!

It's been my experience you have to be very careful with hardened extractors and drill bits, you don't want to break off anything hardened in the bolt drill hole.

If you decide to drill into the broken off bolt try using left handed drill bits because if the bolt isn't bottomed out and tightened too tight you can get lucky sometimes and just drilling with these type of bits will back out the broken bolt out. Sometimes it helps to use flat headed punch smaller than the diameter of the bolt and give a rap or two before trying to extract it. All this assumes the bolt is broken off inside the threaded camshaft hole, which means you need to careful with any of the expose threads in the camshaft. If you get the broken bolt to turn you don't want any damaged threads working against on the way out. Good luck

https://www.amazon.com/Neiko-01925A-Ext ... 6046&psc=1

Post by **firstv70volvo** » 22 Dec 2021, 17:40

firstv70volvo wrote: ↑22 Dec 2021, 17:35
Sykonica wrote: ↑22 Dec 2021, 16:01 I was working on my 01 XC70 today. When trying to replace some cam seals, I was installing the locking tool, and after gently tightening the (cheap) bolt, it snapped inside the camshaft on the intake side. After trying to back it out with several extractors, it’s still stuck. The plan is to drill out the bolt and see if I need to re-tap the threads to install the locking tool. I’m hoping someone here can answer some of the following questions:

Is my camshaft f****ed?

Is drilling out and (if needed) re-tapping my best option here?

Has anyone else ever experienced this? I can’t really find anything about it on any forums anywhere.

Thanks in advance for your help!
It's been my experience you have to be very careful with hardened extractors and drill bits, you don't want to break off anything hardened in the bolt drill hole.

If you decide to drill into the broken off bolt try using left handed drill bits because if the bolt isn't bottomed out and tightened too tight you can get lucky sometimes and just drilling with these type of bits will back out the broken bolt out. Sometimes it helps to use flat headed punch smaller than the diameter of the bolt and give a rap or two before trying to extract it. All this assumes the bolt is broken off inside the threaded camshaft hole, which means you need to careful with any of the expose threads in the camshaft. If you get the broken bolt to turn you don't want any damaged threads working against on the way out. Use a drill bit as large as possible with enough room not to drill outside the diameter of the broken bolt and into the threads of the camshaft and keep in mind you it's difficult to get it perfectly centered and drill perfectly straight. Good luck

https://www.amazon.com/Neiko-01925A-Ext ... 6046&psc=1

Post by **jonesg** » 23 Dec 2021, 03:31

It would be very simple and cheap if you remove the cam shaft and give it to a machine shop.
used cams are fairly cheap and not hard to source. ebay, erie volvo etc.

Post by **abscate** » 23 Dec 2021, 04:48

If it’s flush you can use the cam tool without the bolt if you carefully keep pressure on the intake cam dog and just get the seals done that way.

It’s an intake cam with no VVT on the XC70 in 2001 isn’t it?

Sykonica · Post by **Sykonica** » 23 Dec 2021, 06:41

abscate wrote: ↑23 Dec 2021, 04:48 It’s an intake cam with no VVT on the XC70 in 2001 isn’t it?

That’s correct.

What I’m most concerned about is having that debris in the camshaft over time. I don’t think that the threaded end serves any purpose other than the locking tool.

Given that the camshaft spins at high speed for long periods, is there any danger of having it be slightly out of manufacturer tolerance (either from part of the bolt living in there permanently or accidentally cutting out some of the threaded portion upon extraction)?

Post by **BlackBart** » 23 Dec 2021, 08:39

Sykonica wrote: ↑22 Dec 2021, 16:01 I was installing the locking tool, and after gently tightening the (cheap) bolt, it snapped inside the camshaft on the intake side. After trying to back it out with several extractors, it’s still stuck. The plan is to drill out the bolt and see if I need to re-tap the threads to install the locking tool.

Has anyone else ever experienced this? I can’t really find anything about it on any forums anywhere.

I did this EXACT thing the same way you did. I tried reverse bit, extractors, drill with a 90 degree angle fitting.

I eventually got off center and ruined the threads. Got a used exhaust cam from the Volvo parts guy in Atlanta (good service).

Redid the head with new seals, learned how to set the VVT on both cams, glued it all together, and it’s been running smoothly ever since.

I bought better grade steel 7mm bolts for the holding tool, and DID NOT crank them tight - it just has to engage.

My thread is probably somewhere with a search.

Post by **volvolugnut** » 23 Dec 2021, 11:52

Probably a good upgrade for any of the cheapest tools - replace the fasteners with known high quality.
volvolugnut

Post by **jonesg** » 28 Dec 2021, 04:05

you can actually leave the broken bolt where it is, drill and tap for a smaller dia bolt.
It would only take 1/4 inch of threads into the cam to clamp the tool in place.

Post by **abscate** » 28 Dec 2021, 05:37

Given that the camshaft spins at high speed for long periods, is there any danger of having it be slightly out of manufacturer tolerance (either from part of the bolt living in there permanently or accidentally cutting out some of the threaded portion upon extraction)?

No, there is a higher chance a charging rhinoceros will ruin it.