Cam Bolts Broken After Replacement

[sapote]

We are going to use the lang racing bolts and 243 loctite this time. Is 9 ftlbs the recommended torque?

9 ft-lbs. clean the oil off the threaded holes and the surface at the end of the cams where the sleeves mate on. Metal to metal and no oil here.

[Sid_E46]

9 ft-lbs. clean the oil off the threaded holes and the surface at the end of the cams where the sleeves mate on. Metal to metal and no oil here.

I believe I may have done 12 ftlbs but would that be enough to cause damage.

[maupineda]

I believe I may have done 12 ftlbs but would that be enough to cause damage.

Well, an M6 takes 12NM which is 9 ft lb, you gave them more than 30% so not ideal. I believe these are 8.8 class, if they are higher grade then you were fine, but I am almost sure the OE bolts are 8.8 class

for sure some one will correct me if I am wrong

[Sid_E46]

Well, an M6 takes 12NM which is 9 ft lb, you gave them more than 30% so not ideal. I believe these are 8.8 class, if they are higher grade then you were fine, but I am almost sure the OE bolts are 8.8 class

for sure some one will correct me if I am wrong

Yep, oe is 8.8 grade.

[terra]

I believe I may have done 12 ftlbs but would that be enough to cause damage.

For the OE bolts, yes. Especially since they're already kinda lubricated with oil +/- loctite when you're installing them.

Technically the OE bolts are upto the task if an appropriate thread locker is used. But it's very easy to overtighten. Stronger bolts gives you more wiggle room in that regard.

[Sid_E46]

For the OE bolts, yes. Especially since they're already kinda lubricated with oil +/- loctite when you're installing them.

Technically the OE bolts are upto the task if an appropriate thread locker is used. But it's very easy to overtighten. Stronger bolts gives you more wiggle room in that regard.

This is making me paranoid to check my own car now.

This wasn't as much of an issue in the 01-04 cars though correct?

[jet_dogg]

Well, an M6 takes 12NM which is 9 ft lb, you gave them more than 30% so not ideal. I believe these are 8.8 class, if they are higher grade then you were fine, but I am almost sure the OE bolts are 8.8 class

for sure some one will correct me if I am wrong

I was going to post this.

The smaller the bolts the more critical slight torque variances become.

[Cubieman]

Remember the Langs are grade 12.9 vs OE 8.8, I went about 12ft lbs if I recall correctly and used red oil resistant loctite.
Total overkill, wish I would have used the BMW torx bolts w/ blue 243 loctite. I may not be able to get those out down the road easily using the red.

[Slideways]

Remember the Langs are grade 12.9 vs OE 8.8, I went about 12ft lbs if I recall correctly and used red oil resistant loctite.
Total overkill, wish I would have used the BMW torx bolts w/ blue 243 loctite. I may not be able to get those out down the road easily using the red.

Not without a blowtorch


Changing cams is going to be extra fun

[jet_dogg]

LOL!!!!

[sapote]

It's interesting to see the notches on the bolts cut by the splined sleeve. Obviously the sleeve only hammering the bolts in one direction -- CW I think. But in order to hammer the bolts, the sleeve must be running behind (slower than) the cam sometime, and then accelerated faster and hammered the bolts. The exact hammering effect was happing on the vanos disk holes by the EX hub tabs with the disk original larger holes. The modified smaller holes reduced the hammering significantly.

[Cubieman]

Not without a blowtorch


Changing cams is going to be extra fun

Yea, I dread the day I have to loosen those bolts.

My hopes are if they won't come out in situ I could fully remove the TC tensioner and hopefully have enough slack to slip the sprockets off the hubs and then pull the cams with sleeves still installed so the bolts can be drilled out more easily.

[bigjae46]

Loctite no workie if there is oil present. Not matter what kind of loctite you use.

[Cubieman]

Yea, I'll bet I spent 10mins+ on each hole using various chemicals/cleaning tools to make sure the female threads were clean. That takes a while to do it correctly, you can't simply roll a q-tip around for a sec and call it good.

I found Locitie 768 cleaning solution and MEK along with some very tightly wound conical cotton q-tip like things for cleaning guns helpful. Also a dental pick was nice to get out the big pieces of old locite I had on mine as someone had already been in there.

https://www.amazon.com/Tapered-Regular-Type-III-Cleaning-American/dp/B008CPU4JW/ref=pd_aw_fbt_img_1/132-0523072-3019750?pd_rd_w=i5fEO&pf_rd_p=0ac31943-e5c4-4aef-ab7b-6ab45d3ad9aa&pf_rd_r=XTTSTCQ7CXPGT94GNREW&pd_rd_r=88ebc6e3-26e0-4a5d-b4d8-f932b32cc705&pd_rd_wg=NJAe6&pd_rd_i=B008CPU4JW&psc=1

[bigjae46]

Yea, I'll bet I spent 10mins+ on each hole using various chemicals/cleaning tools to make sure the female threads were clean. That takes a while to do it correctly, you can't simply roll a q-tip around for a sec and call it good.

I found Locitie 768 cleaning solution and MEK along with some very tightly wound conical cotton q-tip like things for cleaning guns helpful. Also a dental pick was nice to get out the big pieces of old locite I had on mine as someone had already been in there.

https://www.amazon.com/Tapered-Regul...08CPU4JW&psc=1

I have a spare set of those parts so I had mine hot tanked. That is overkill but you can pull those parts off and properly clean them


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