Aluminum Threads

[Wild Will]

don't take well to steel bolts tightened too much; the threads rip right out. Why oh why didn't BMW include steel threaded inserts for the valve cover bolts in the heads? Steel case studs run into aluminum threads was the primary reason for so many air cooled VW engine failures; no tight heads = no compression. Anyway, NAPA Auto to the rescue. They sell the correct heliocoil set for $20. Pretty easy job. It's far too easy to overtighten the valve cover bolts into the tiny little 6mm aluminum threaded holes, and rip the threads right out of the head. So, take care if you do your own service when running a bolt (steel) into aluminum threads. Use a quality torque wrench (my 3/8 drive Snap On was only $300) OR tighten with your "off" hand - if you're right handed, use your left to tighten. Some long forgotten German-trained 'wrench' who was usually drunk well before lunch break taught me that one back in the late 60's, when I was still learning. Guess what? I'm still learning.

[Acacia]

You stripped the thread with your $300 Snap-on? Or, was that before you got it?

Or, was it that you have only now learned what the half drunk German wrench taught you years ago?

Is this a case of delayed reactions? :104: Some of us are dyslexic, others are ...?

Or, is it a case of, "...too soon old, too late smart?"

Who has not been there? Nice to read others do this kind if thing too!

[Wild Will]

has its challenges. Some ham fisted Cro Magnon mechanic had stripped 2 of the threads and I didn't discover it until I did the next service. I left it for awhile and it didn't leak, but decided to while away the wet winter hours seeking moto perfection while I played Bloomfield/Kooper far too loud, sipping a 33 degree Heineken in my shop, where the sign out front states:
"There's Nothing Here Worth Your Life". So far so good, but it's only been 30 years...
p.s., I don't use a torque wrench on valve cover 6mm bolts; I use my "off" (left) hand.

[jamming]

WW...I use a 1/4 inch snap-on palm ratchet, with a allen socket on mine!
I torque using my fingers only. Never had one leak.
I've easy outed more than my share of bolts from the last mechanic to work on something that I don't want to be that mechanic.
Oh, and a good copper based anti-seize on everything I take apart, except the ones that call for no lube upon assembly.
Roger

[DarthRider]

I like to work with 1/4" drive sockets & a short ratchet. It makes it much easier to "modulate" how hard you're twisting. One hand only but I use my predominant side hand, sometimes 4 fingers, sometimes 2.
I worked for 6 months at the local BMW shop once and learned that from master tech Hugh Malloy, he used 1/4" drive unless he needed something larger, like for a spindle nut, and he used long extensions...often l-o-n-g extensions. That was a revelation and a great time saver.

Dave

[Ed K]

Gee WW, it must be 20 years or so since I had to put a heli-coil in... bummer!

Then again...the only service that I have personally done on my RR is an oil change...

[Acacia]

For those applying anti-sieze - make sure you are also adjusting the torque down as most given torque specs are for dry threads!

[BobFV1]

Will -

Sage advice.

Like you, the ham-fisted mechanic at a BMW dealership stripped one of mine and it developed a pretty good leak. I had the service done just before a ride to Vegas, and by the time I got to Vegas my pant leg was all oily and the darn thing had a pretty steady drip-type leak. Heli-coil saved the day.

I agree 100 percent with Roger for two reasons - I happen to know he is a qualified aircraft mechanic, and I use the same method he uses, which is the same one my dad, a master car mechanic (until he passed on 30 years ago) taught me when I was a kid. If there is no real requirement to have a lot of pressure on the threads, just make em snug and check them every now and then to see if they back out at all (they shouldn't). If it doesn't leak, you've hit it just right. So I use a 1/4 inch palm ratchet I bought from Ace Hardware for 14.00 (with metric sockets - I had to buy the allen heads and hex heads at Sears) and I just snug them down until I have a little resistance and I sense that the gasket is compressed but not pulverized to bits.

Frankly, the key to this whole puzzle should be a factory torque setting of 8 - to me that means "just snug with a little ratchet".

____________________________

Oh - I like the "wrong-handed" trick. When I was going through the firearms course at the Federal Law Enforcement Training Center for the first time in 1984, we had to run a drill simulating a disabled shooting hand and we had to deliver six rounds from our service revolvers "weak-handed" - it was tough to even provide the little amount of force necessary to pull the 5 pound trigger-pull with my weak hand! Never forgot that. Never had to shoot anybody with my weak hand either - but I could!

[Mymindsok]

I'm glad that someone else has discovered the 1/4" drive trick! I've been doing that for the las 20 years and thought that I invented it!

If you're not careful, you can still strip those valve cover, cam tip and oil filter bolts but not as quickly as with a 1/8th drive!

The 1/4" drive stuff also takes up less space and weighs less if you want to take some tools along on a long ride. Remember: If you take the tools and some spares, you'll gurantee the fact that you'll never need em unless someone else breaks down. Thats a fact!

[geechie]

Ed K wrote...

Gee WW, it must be 20 years or so since I had to put a heli-coil in... bummer!

Twenty years heck! It's been thirty plus since I've listened to Bloomfield/Kooper. Man! That was some good shit!

George

[Arby]

I just did a top end job on the Buell. It really didn't need it at 40,000 mi, but I got a deal I couldn't refuse on E Bay.
The Buell has lots of steel 1/4 20 bolts's in to aluminum on the rocker boxs , valve covers, etc.

1/4 in is real close to 6mm, the correct torque for both is measured in inch lbs, not ft lbs.,which means it doesn't take much to over torque.

Even though I feel comfortable with my "feel" for proper torque on bolts, I still used an inch lb torque wrench.
Prevent stripped threads, plus nice even application of pressure to the gasket surfaces to prevent oil leaks.

A decent inch lb torque wrench, with conversion to metric scale is probably 80 dollars or less from Craftsman or a good parts store like NAPA.

It's a nice addition to the tool box.

Bob

[Wild Will]

Twenty years heck! It's been thirty plus since I've listened to Bloomfield/Kooper. Man! That was some good shit!

I'll bet that you'd be blown away if you listened at this point. They did a double album I got in Italy 30+ years back. If you're serious, I'll shoot you a CD. Another Kooper piece that is still awesome is the first Blood, Sweat and Tears album, not the one with David Clayton Thomas. There are two blues cuts on that album that will stand your hair (or in my case, scalp) on edge. Timeless delights! Back to the shop now, to primer all the metal I've prepped where the farking worthless powder coat has failed. Like PIAA lamp shells and Touratech "Hard Parts". Just turn up the volume and pop a Heineken again. Why not, it's not a riding day - many of the roads are closed due to flooding and mudslides. A poor 72 year old gentleman was buried today just N. of San Fran when cleaning his gutters - 12 foor deep mudslide. Geez! Them mudslides are like deer!

[Jomarti]

Occasionally I find corrosion in aluminum threads on disassembly of engine covers as on my 2000 Triumph Sprint. If this happens to you, find a bolt with the same diameter and thread pitch, use a Dremel to add slots along the bolt length, usually 3-4, then use this to run in and out of the corroded and/or dirty threads. This works better than using a tap, which for some unknown reason sometimes removes aluminum.

Second item- I usually use anti-seize when running steel capscrews into aluminum but have always been a little uncertain how much to reduce torque numbers when doing so. Anyone have authoritative info on this?

[Acacia]

Jomarti,

My source is lost in antiquity, but since then I have use a 10% reduction in torque for 'lubricant' covered threads - and had no stripping, warping issues.