broken cam bearing bolts

7252 Views 21 Replies 14 Participants Last post by idahotuner, Apr 4, 2008

REDSENTRASE-L

Discussion Starter · Feb 7, 2004

anybody elso broke the cam bearing bolts? these are the bolts that are on the caps that hold the cams down. i broke a total of 3. bummer.

1 - 20 of 22 Posts

honkeybizkit

· #2 · Feb 8, 2004

were you cranking in the correct order, torque and had the cam seated properly with the bearing caps in the correct direction and original position?

i havent had problems but if you accidentally put them in the wrong place, over torque, or flip the bearings the wrong direction, you can mess up the bearings cam and bolts.

hope you didnt sheer them off below the surface, then u must extract them, had to do that on 2 motor mount bolts on my old car, wasnt bad tho.

good luck, just be extra careful on those cam installs.

james vick

· #3 · Feb 8, 2004

The torque spec for those is only 6.7-8.7 ft-lb. That ain't much. The ones by the distributer are 13-19 ft-lb still not much.

JDM_2ner

· #4 · Feb 8, 2004

use a center punch and a hammer/mallot. Punch a "divit" into a flat surface towards the center of the bolt that is broken. Then use reverse tungsten drill bits. Start off with as small of a bit as possible( the bolts are hardened steel). Then use an extractor with lots of oil. Good luck. If it is sticking up above the head, use a vicegrips.

1FastP11

· #5 · Feb 8, 2004

REDSENTRASE-L said:
anybody elso broke the cam bearing bolts? these are the bolts that are on the caps that hold the cams down. i broke a total of 3. bummer.

I broke one a couple of years ago doing a cam install. The broken stud was beneath the surface of the hole, so drilling or doing something not extremely careful resulted in thread damage.
To my luck a guy who worked on a machine shop also worked extracting broken studs. His method consisted of arc welding a lil' pinch on top of the broken stud, one pinch at a time until the the weld reached above the hole, then he grabbed the protrutding weld with locking pliers and started unbolting. He took 30 seconds on the whole process.

Good luck
Back then I was freaked out like hell

praedet

· #6 · Mar 28, 2005

Sorry to revive an old thread, but has anyone broken one off recently?

I had one shear off this past Saturday and this is my daily driver. The bolt sheared off after all the other bolts were tight, so there are 5 caps on tightly, but one of the caps is only held on by one torqued down bolt.

I have some extractors that I have used pretty effectively in the past, but do I dare risk it, or just take it to a machine shop?

Based on discussions with the other guys present during the install, I am keeping it under 4K rpm and only driving it when I have to...

Please help, this is really pretty scary

Ted

bigtoe

· #7 · Mar 28, 2005

Done that and repaired it just fine.
Your saving grace is the fact that the broken piece, "dutchman", did not bottom out in the hole, the thread therefore is not loaded on the flanks.

Make a little BRASS dowell that will fall into the hole above the dutchman. The center of the brass piece has to have a hole about 1/8 inch or say 2mm drilled through it.
The idea is to use the brass piece as a guide for a drill (1/8 or 2mm) bit to not damage the threads in the hole.
Drill a hole in the dutchman about 1/4in deep. Then use a Tool Steel Extractor and wind it out. Piece of cake and a rag with a good helping of grease to catch the drillings save you from having to wash the head out.

I have done this, ONCE, now I just hate those bolts. Been looking for a Stud Kit for that very reason.
The fix is easy, the cure is the stud kit. Interested peoples, we need to find this and make it available.

cortrim1

· #8 · Mar 28, 2005

I broke one installing my rocker arm stoppers. I would not recomend trying to drill them out. you can use a scribe to turn the bolt back out of the hole. You can also super glue the bolts back together and remove them. These bolts have zero torque load on them when they are broken so the glue trick works well but make sure not to get any on the sides of the hole.

praedet

· #9 · Mar 28, 2005

bigtoe said:
Done that and repaired it just fine.
Your saving grace is the fact that the broken piece, "dutchman", did not bottom out in the hole, the thread therefore is not loaded on the flanks.

Make a little BRASS dowell that will fall into the hole above the dutchman. The center of the brass piece has to have a hole about 1/8 inch or say 2mm drilled through it.
The idea is to use the brass piece as a guide for a drill (1/8 or 2mm) bit to not damage the threads in the hole.
Drill a hole in the dutchman about 1/4in deep. Then use a Tool Steel Extractor and wind it out. Piece of cake and a rag with a good helping of grease to catch the drillings save you from having to wash the head out.

I have done this, ONCE, now I just hate those bolts. Been looking for a Stud Kit for that very reason.
The fix is easy, the cure is the stud kit. Interested peoples, we need to find this and make it available.

So you are saying to make a little "tube" out of brass to slide in the hole, using it as a guide to for the drilling. Once that is done, use my extractor to back it out right? Oh yeah, and put lots of grease down in the hole to catch the shavings?

Sounds good.

What about when I put the new one back in, just torque it to spec, or should I go through the involved order again?

Thanks for the help guys...

Ted

Yahnozha

· #10 · Mar 28, 2005

bigtoe said:
Been looking for a Stud Kit for that very reason.
The fix is easy, the cure is the stud kit. Interested peoples, we need to find this and make it available.

Sourcing metric studs, washers and nuts (or flange nuts *spendy*) is not a problem.

Toolapcfan

· #11 · Mar 28, 2005

I've never broken one but I've felt like they were going to strip out though if I tightenend them to spec.

chriscar

· #12 · Mar 28, 2005

I hope I don't jinx myself here, but I've never had a problem with these. Maybe it's because I'm using an old Snap On *INCH* pound torque wrench. I don't see how you can break one as long as you follow the proper sequence. ****, the final torque spec is 6.7 to 8.7 ft-lb, and there's no way that's going to snap a bolt.

C:\>

praedet

· #13 · Mar 28, 2005

Yeah, we thing the torque wrench might have been to blame, it was set correctly, but never clicked...

chriscar

· #14 · Mar 28, 2005

What's the range on your torque wrench? I don't think most are accurate at that low amount of torque.

C:\>

cortrim1

· #15 · Mar 28, 2005

chriscar said:
What's the range on your torque wrench? I don't think most are accurate at that low amount of torque.

C:\>

torque wrenches are the least accurate in the top and lower 5% of their range. They are also a pain to adjust when they are out of spec.

praedet

· #16 · Mar 28, 2005

this was right in the middle of the range. The guy who wrench it was said that he had suspected a bad wrench before...

Storm88000

· #17 · Mar 29, 2005

The only way you will break one of those is if you're not doing things the way you should be doing. Bottom line, if you don't have a torque wrench, DON'T do a cam install until you have one. Those bolts are way too precious to guess.

praedet

· #18 · Mar 29, 2005

Storm88000 said:
The only way you will break one of those is if you're not doing things the way you should be doing. Bottom line, if you don't have a torque wrench, DON'T do a cam install until you have one. Those bolts are way too precious to guess.

Did you read my post? We used a torque wrench and the specified torque was in the middle of the wrench's range. It just so happened that this wrench appears to be faulty. This was not known until the bolt sheared. Everything was by the FSM til that point...

I agree that the bolt is precious. The TRUE bottom line is, A Bolt Broke and Now I Have to Fix It.

Thanks for everyone else's help, I will be trying to do this on Wednesday hopefully..

Storm88000

· #19 · Mar 29, 2005

praedet said:
Did you read my post? We used a torque wrench and the specified torque was in the middle of the wrench's range. It just so happened that this wrench appears to be faulty. This was not known until the bolt sheared. Everything was by the FSM til that point...

I agree that the bolt is precious. The TRUE bottom line is, A Bolt Broke and Now I Have to Fix It.

Thanks for everyone else's help, I will be trying to do this on Wednesday hopefully..

Sorry, I missed that somehow. Didn't realize the wrench was faulty, mine broke after less than a year. They are little bastards

bigtoe

· #20 · Mar 29, 2005

Yahnozha said:
Sourcing metric studs, washers and nuts (or flange nuts *spendy*) is not a problem.

OK, go get em, sell sell sell. Here is your first order. I'll take two sets.
Trick is that the shank on the stud has to locate the bearing caps like a dowell.

1 - 20 of 22 Posts

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