Valve Cover screw insert stripped

[Dan Marucci]

All,

Did a search and couldn't find anything, so here I go:

Got a 2009 Hexhead R1200 RT-P. The left side upper valve cover screw wouldn't reach torque spec after I checked my valve gaps. Pull the whole thing back off, and find a little metal shaving around the hole. There is a steel insert in the aluminum head. Has anyone ever successfully replaced one of those inserts on the bike, or do I just drill it and install a heli-coil?

Anybody? Bueller? Bueller?

 

Thanks for your time,

Dan____

 

Edited August 5, 2019 by Dan Marucci
misspelling

[LBump]

Some Reading

 

Additional Reading

 

More Additional Reading

 

Good luck with the repair. 

[lkraus]

I'd strongly suggest you stop using a torque wrench on those bolts.  The spec is only 10 Nm (7.4 ftlb), which is at the low end for a clicker type 3/8" drive torque wrench, and out of the midrange where it is accurate.  A 1/4" drive wrench measuring in-lb is appropriate (88 inlbs), but unnecessary.

 

Use a short 1/4" ratchet or screwdriver torx, tighten until you feel the bolt's shoulder touch the head, and immediately STOP tightening. The gaskets are then compressed enough to prevent leaks and maintain sufficient tension on the bolt to prevent loosening. The goal in using a very short ratchet or a Torx screwdriver is to reduce the leverage of the tool, and increase your sensitivity to the instant when the step on the bolt makes contact with the head. Usually, I have my thumb on the head of the ratchet and apply pressure with my index finger only about an inch down the handle. Once the step makes contact, the gaskets can not be compressed any more, and that is enough to prevent leaks. Tightening any further only increases stress on the threads, without doing anything at all to the gasket sealing pressure. 

 

I generally agree with using a torque wrench wherever possible, but in this particular application I think it is unnecessary and prone to user error. Even an 1/4" drive inch-lb torque wrench is typically over a foot in length and reduces sensitivity to the step contact. I think the large heads and washers on the bolts lead us to think they need a lot of torque, but the threaded portion is actually pretty slender.

[lkchris]

7 hours ago, lkraus said:

I'd strongly suggest you stop using a torque wrench on those bolts.  The spec is only 10 Nm (7.4 ftlb), which is at the low end for a clicker type 3/8" drive torque wrench, and out the midrange where it is accurate.  A 1/4" drive wrench measuring in-lb is appropriate (88 inlbs), but unnecessary.

 

Plus, given that these screws bottom in the hole, that's the time to stop turning the screw.  The torque spec given is a "courtesy" figure only.

 

This has been the case since the introduction of the Oilheads.  You may note that when Camheads arrived, the number of screws has halved, i.e., from 4 to 2.  Still no leaks just bottoming the screws.

[Ponch]

On 8/5/2019 at 6:50 AM, lkraus said:

I'd strongly suggest you stop using a torque wrench on those bolts.  The spec is only 10 Nm (7.4 ftlb), which is at the low end for a clicker type 3/8" drive torque wrench, and out of the midrange where it is accurate.  A 1/4" drive wrench measuring in-lb is appropriate (88 inlbs), but unnecessary.

 

Use a short 1/4" ratchet or screwdriver torx, tighten until you feel the bolt's shoulder touch the head, and immediately STOP tightening. The gaskets are then compressed enough to prevent leaks and maintain sufficient tension on the bolt to prevent loosening. The goal in using a very short ratchet or a Torx screwdriver is to reduce the leverage of the tool, and increase your sensitivity to the instant when the step on the bolt makes contact with the head. Usually, I have my thumb on the head of the ratchet and apply pressure with my index finger only about an inch down the handle. Once the step makes contact, the gaskets can not be compressed any more, and that is enough to prevent leaks. Tightening any further only increases stress on the threads, without doing anything at all to the gasket sealing pressure. 

 

I generally agree with using a torque wrench wherever possible, but in this particular application I think it is unnecessary and prone to user error. Even an 1/4" drive inch-lb torque wrench is typically over a foot in length and reduces sensitivity to the step contact. I think the large heads and washers on the bolts lead us to think they need a lot of torque, but the threaded portion is actually pretty slender.

 

I use one of these. I have good feel with it. 

[Ponch]

On 8/4/2019 at 9:56 PM, Dan Marucci said:

All,

Did a search and couldn't find anything, so here I go:

Got a 2009 Hexhead R1200 RT-P. The left side upper valve cover screw wouldn't reach torque spec after I checked my valve gaps. Pull the whole thing back off, and find a little metal shaving around the hole. There is a steel insert in the aluminum head. Has anyone ever successfully replaced one of those inserts on the bike, or do I just drill it and install a heli-coil?

Anybody? Bueller? Bueller?

 

Thanks for your time,

Dan____

 

 

You might want to look at Timesert. Better than helicoil. 

[dirtrider]

1 hour ago, Ponch said:

 

You might want to look at Timesert. Better than helicoil. 

 

 

Afternoon Ponch

 

In a lot of cases the  Time-Sert is a better choice (especially on an application where the fastener gets removed/repalced a lot), in my estimation the Time-Sert is not the best choice on the BMW 1200RT though.

 

If you look a the 1200RT cylinder head the bosses that valve cover bolts screw into are very small diameter & stand alone unsupported. To install the larger diameter Time-Sert you need to drill a fairly large hole, then thread it to be even larger. That doesn't leave much alloy remaining around the Time-Sert so the boss could easily crack or split.  

[Ponch]

2 hours ago, dirtrider said:

 

 

Afternoon Ponch

 

In a lot of cases the  Time-Sert is a better choice (especially on an application where the fastener gets removed/repalced a lot), in my estimation the Time-Sert is not the best choice on the BMW 1200RT though.

 

If you look a the 1200RT cylinder head the bosses that valve cover bolts screw into are very small diameter & stand alone unsupported. To install the larger diameter Time-Sert you need to drill a fairly large hole, then thread it to be even larger. That doesn't leave much alloy remaining around the Time-Sert so the boss could easily crack or split.  

And valves should be checked every 6k. I’ve seen helicoils come out. I just wouldn’t feel confident they’d last. 

[dirtrider]

4 minutes ago, Ponch said:

And valves should be checked every 6k. I’ve seen helicoils come out. I just wouldn’t feel confident they’d last. 

 

Afternoon Ponch

 

Yes, if installed incorrectly they can come out on the fastener, if installed correctly they usually stay put.  But even if one were to come out then a new one is easily re-installed.

 

On the other hand with a Time-Sert,  if it cracks or weakens that small diameter  boss then you REALLY have problems & need to remove the cylinder head & do some precision welding & machining.