Wheel lug torque
03-22-2007, 03:59 PM
#16
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Now, wait jest a cotton pickin' minute...
Tech Bulletin 8507 says:
"...lubricate thread and shoulders of aluminum nuts with Optimoly HT..."
(Thanks to Dave A. for the reference.)
Page 40-14 in Volume IV of the Factory Workshop Manual says:
"Optimoly HT (copper-colored)
For steel-steel threaded connections and contact surfaces of assembly parts. Never use Optimoly HT on contact surfaces of steel to light alloy, as moisture will produce corrosion. When applied to threads, this lubricant has no effect on tightening
torques.
Optimoly TA (aluminum color)
For all connections with aluminum or with magnesium, for corrosion protection. When applied to threads, this lubricant has a slight effect on tightening torques."
(Thanks to Dave A. for the reference.)
Which are we supposed to believe?
Tech Bulletin 8507 says:
"...lubricate thread and shoulders of aluminum nuts with Optimoly HT..."
(Thanks to Dave A. for the reference.)
Page 40-14 in Volume IV of the Factory Workshop Manual says:
"Optimoly HT (copper-colored)
For steel-steel threaded connections and contact surfaces of assembly parts. Never use Optimoly HT on contact surfaces of steel to light alloy, as moisture will produce corrosion. When applied to threads, this lubricant has no effect on tightening
torques.
Optimoly TA (aluminum color)
For all connections with aluminum or with magnesium, for corrosion protection. When applied to threads, this lubricant has a slight effect on tightening torques."
(Thanks to Dave A. for the reference.)
Which are we supposed to believe?
03-22-2007, 04:21 PM
#18
Chronic Tool Dropper
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OK--
The only reason I even started using anti-seize on the lugnuts was after reading notes from folks asking how to remove stuck lugnuts. Looked at the Al -> Al mating between the nuts and the wheel, and could see how there might be a galling issue there, but only if the nuts are overtightened (friction caused by too much pressure during the actual tightening) or undertightened (wheel 'walks around' under the nuts). Being the religious torque wrench user, I considerd that I should be immune from these problems anyway.
But then the tech bulletins... Are they in reaction to [dealer] problems, where owners are miffed about (same as 'reluctant to pay for'...) damage to their expensive aluminum wheels?
In general, I'm not a fan of using anti-seize in this service, only because the failure result for lugs that don't stay tight is potentially much worse than any failure that might require a stripped nut to be removed with a hole saw. I'm not aware of any other car manufacturer that suggests anti-seize on lug nuts. I will suggest that it really is a good idea on the tractor wheels on the snowblower, and it might be important in other corrosive environments like the boat trailer wheels that go into the salt water. In each of those cases, for me anyway, the service is under very regular scrutiny.
My 928 wheels come off several times a year for various reasons, so electrolytic corrosion is just not an issue. They get a little new anti-seize maybe once a year, just enough to keep a little color on the faces. I don't coat the threads only because the stiff too easily transfers to clothes, hands, etc. It might be the wrong thing per the factory but there is a reason.
YMMV, of course.
The only reason I even started using anti-seize on the lugnuts was after reading notes from folks asking how to remove stuck lugnuts. Looked at the Al -> Al mating between the nuts and the wheel, and could see how there might be a galling issue there, but only if the nuts are overtightened (friction caused by too much pressure during the actual tightening) or undertightened (wheel 'walks around' under the nuts). Being the religious torque wrench user, I considerd that I should be immune from these problems anyway.
But then the tech bulletins... Are they in reaction to [dealer] problems, where owners are miffed about (same as 'reluctant to pay for'...) damage to their expensive aluminum wheels?
In general, I'm not a fan of using anti-seize in this service, only because the failure result for lugs that don't stay tight is potentially much worse than any failure that might require a stripped nut to be removed with a hole saw. I'm not aware of any other car manufacturer that suggests anti-seize on lug nuts. I will suggest that it really is a good idea on the tractor wheels on the snowblower, and it might be important in other corrosive environments like the boat trailer wheels that go into the salt water. In each of those cases, for me anyway, the service is under very regular scrutiny.
My 928 wheels come off several times a year for various reasons, so electrolytic corrosion is just not an issue. They get a little new anti-seize maybe once a year, just enough to keep a little color on the faces. I don't coat the threads only because the stiff too easily transfers to clothes, hands, etc. It might be the wrong thing per the factory but there is a reason.
YMMV, of course.
03-22-2007, 05:22 PM
#20
Chronic Tool Dropper
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Just noticed that I passed a magical '2500 posts' milestone. Then saw that H has more than 5 times that many, with 14 fewer months since joining. I'm not even going to bring the 'quality of posts' factor into this, else I woulld be down even further!
03-22-2007, 05:46 PM
#21
928 Collector
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Dr Bob, the quality of your posts is of the highest. It makes a difference. I joke around a lot, but I do hope my post quality is also high. I try.
03-22-2007, 06:00 PM
#23
Rennlist Member
Originally Posted by WallyP
Now, wait jest a cotton pickin' minute...
Tech Bulletin 8507 says:
"...lubricate thread and shoulders of aluminum nuts with Optimoly HT..."
(Thanks to Dave A. for the reference.)
Page 40-14 in Volume IV of the Factory Workshop Manual says:
"Optimoly HT (copper-colored)
For steel-steel threaded connections and contact surfaces of assembly parts. Never use Optimoly HT on contact surfaces of steel to light alloy, as moisture will produce corrosion. When applied to threads, this lubricant has no effect on tightening
torques.
Optimoly TA (aluminum color)
For all connections with aluminum or with magnesium, for corrosion protection. When applied to threads, this lubricant has a slight effect on tightening torques."
(Thanks to Dave A. for the reference.)
Which are we supposed to believe?
Tech Bulletin 8507 says:
"...lubricate thread and shoulders of aluminum nuts with Optimoly HT..."
(Thanks to Dave A. for the reference.)
Page 40-14 in Volume IV of the Factory Workshop Manual says:
"Optimoly HT (copper-colored)
For steel-steel threaded connections and contact surfaces of assembly parts. Never use Optimoly HT on contact surfaces of steel to light alloy, as moisture will produce corrosion. When applied to threads, this lubricant has no effect on tightening
torques.
Optimoly TA (aluminum color)
For all connections with aluminum or with magnesium, for corrosion protection. When applied to threads, this lubricant has a slight effect on tightening torques."
(Thanks to Dave A. for the reference.)
Which are we supposed to believe?
Seems that not all of the Optimoly users were talking to each other...
03-22-2007, 08:11 PM
#24
Rennlist Member
Dave,
Thats the other thing - I wasn't using Optimoly!
I went with Permatex copper when I was doing my TB/WP on the 84 from a recommendation from someone here in the forum.
After looking into this and reading the pages you stated in the WSM. I had to go to the Porsche dealer anyway so I got some HT and ordered the AT.
The guy at Porsche said that only Optimoly had been tested with stated torgue values by Porsche Engineering. He also indicated that Permatex is a graphite type anti-seize and not the same as the Optimoly products.
Now I just hope I didn't @$&% something up.
Cheers,
Thats the other thing - I wasn't using Optimoly!
I went with Permatex copper when I was doing my TB/WP on the 84 from a recommendation from someone here in the forum.
After looking into this and reading the pages you stated in the WSM. I had to go to the Porsche dealer anyway so I got some HT and ordered the AT.
The guy at Porsche said that only Optimoly had been tested with stated torgue values by Porsche Engineering. He also indicated that Permatex is a graphite type anti-seize and not the same as the Optimoly products.
Now I just hope I didn't @$&% something up.
Cheers,
03-22-2007, 08:50 PM
#25
Chronic Tool Dropper
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Originally Posted by heinrich
Dr Bob, the quality of your posts is of the highest. It makes a difference. I joke around a lot, but I do hope my post quality is also high. I try.
Your's are always good, and frequently entertaining as well.
I do think your post count is skewed high by a lot of emoticon-only posts though.
Hopefully, with mutual support, we'll come through 928 ownership relatively unscathed. Keep up the good work!
