Half shafts loose again
Thread Starter
Race Car
Joined: Dec 2006
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From: Tampa Florida
Half shafts loose again
I am replacing a torn boot and found the 1/2 shaft bolts loose. I had this happen on my 82 is this a common issue?
I used blue lock-tight and torqued to 65 is so what is the problem?
I used blue lock-tight and torqued to 65 is so what is the problem?
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Joined: Apr 2007
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Hmm.....don't have the manuals with me, but the torque spec is in the documents. I guess your asking if there is a "better" spec than that in the manuals. Interestingly, mine came loose as well since Devec rebuilt the driveshafts, fortunately discovered in my own drive way. I torqued them...maybe 4k miles ago.
For the everyone else; is there any consensus on why half shaft bolts may come loose? Do lock washers or nuts require replacing? Are the torqued fasteners vibration sensitive?
For the everyone else; is there any consensus on why half shaft bolts may come loose? Do lock washers or nuts require replacing? Are the torqued fasteners vibration sensitive?
Nordschleife Master
Joined: Apr 2003
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From: Abbotsford B.C.
book spec is 62ft lbs.
With harder driving I have them come loose very quickly at this setting once they were initially disturbed.
I safety wire the ones on my track car, and torqued to around 75 ft lbs without anything breaking or stripping. I dont think that they would back out at that level as the last time I went in there the safety wire was exactly where I left it indicating no movement from the bolts.
With harder driving I have them come loose very quickly at this setting once they were initially disturbed.
I safety wire the ones on my track car, and torqued to around 75 ft lbs without anything breaking or stripping. I dont think that they would back out at that level as the last time I went in there the safety wire was exactly where I left it indicating no movement from the bolts.
Nordschleife Master
Joined: Jul 2003
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From: Minneapolis
This is a recurring problem with 928s and 944s.
Make sure to get the bolts and threads very clean as well as the mating surfaces. The grease gets everywhere and will collect sand and road grit. Use blue loctite and torque to spec, rechecking each after all are seated.
It may not be fun to lay under the car and spray brake cleaner above your face (it is my preferred way to spend an afternoon) but ya gotta get it all clean to get good friction and let the loctite do its job.
Make sure to get the bolts and threads very clean as well as the mating surfaces. The grease gets everywhere and will collect sand and road grit. Use blue loctite and torque to spec, rechecking each after all are seated.
It may not be fun to lay under the car and spray brake cleaner above your face (it is my preferred way to spend an afternoon) but ya gotta get it all clean to get good friction and let the loctite do its job.
Man of many SIGs
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From: Florida, USA
If the holes aren't clean the loctite will not hold. You can also use loctite primer to increase the bond. Blue loctite is only good to 300 deg. F Does anyone know the temp of the gearbox? Maybe red loctite is a better solution.
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It's a little more of a PIA, but you have to star pattern when torquing them down. I do 50% first time around, then full tq the second time around. I've never had them come loose, but I don't drive like a madman like some of my 928 brethren...cough...Colin...
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Thread Starter
Race Car
Joined: Dec 2006
Posts: 4,089
Likes: 6
From: Tampa Florida
I cleaned everything real well and torqued a little at a time. The other side is good, seems we should make this like a flex plate, check every oil change. The only thing I can think of was that the person that was helping me did not torque them tight of did not clean them enough. 
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Had this happen once when a workshop replaced the boots. A month later one side is loose on the ground. Got them retightened to the correct spec+, they haven't been loose since (2 years).
why do you own one then 
