 My exhaust stud bolts keep coming loose. WTF! |
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| alpha434 |
 Aug 28 2007, 12:41 AM
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#1
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My member number is no coincidence.  Group: Members Posts: 3,154 Joined: 16-December 05 From: Denver, CO Member No.: 5,280 Region Association: Rocky Mountains  |
Title says it all. They just keep coming loose. Are they supposed to have lock washers?
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| Twystd1 |
Aug 28 2007, 01:39 AM
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#2
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You don't want to know... really..... Group: Members Posts: 2,514 Joined: 12-September 04 From: Newport Beach, California Member No.: 2,743 |
QUOTE(alpha434 @ Aug 27 2007, 11:41 PM)  Title says it all. They just keep coming loose. Are they supposed to have lock washers? Do you mean exhaust stud NUTS..????? Or are your STUDS backing out...??? CCC |
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| Toast |
Aug 28 2007, 01:48 AM
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#3
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Not bad for carrying sway bars. Group: Members Posts: 3,377 Joined: 20-January 04 From: Las Vegas Member No.: 1,580 Region Association: Southwest Region |
Yea, I thought they were suppose to too. (IMG:style_emoticons/default/WTF.gif)
Ron found loose bolts on mine this weekend as well. (IMG:style_emoticons/default/blink.gif) |
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| alpha434 |
Aug 28 2007, 01:50 AM
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#4
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My member number is no coincidence. Group: Members Posts: 3,154 Joined: 16-December 05 From: Denver, CO Member No.: 5,280 Region Association: Rocky Mountains |
One stud backs out. On all the others, the nuts keep falling off.
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| akellym |
Aug 28 2007, 06:45 AM
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#5
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Eyes Of The Deep Battle Group: Members Posts: 597 Joined: 25-July 04 From: Annandale, MN Member No.: 2,395 Region Association: Northstar Region |
Loctight! I used the red on the studs and blue the removable type on the nuts, haven't had that problem again.
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| Bartlett 914 |
Aug 28 2007, 07:38 AM
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#6
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Advanced Member Group: Members Posts: 2,216 Joined: 30-August 05 From: South Elgin IL Member No.: 4,707 Region Association: Upper MidWest |
QUOTE(akellym @ Aug 28 2007, 04:45 AM) Loctight! I used the red on the studs and blue the removable type on the nuts, haven't had that problem again. I have read many times where people us loctite on the studs. I find it hard to believe this can help. This stuff breaks down at temperatures well below the heat in the heads. If the studs are working out, then the fit must be too loose. There are special copper plated nuts that should be used. These are one time only. If removed, they should be replaced with new ones. For that matter, if removed then the copper exhaust gaskets should also be replaced. |
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| akellym |
Aug 28 2007, 07:57 AM
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#7
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Eyes Of The Deep Battle Group: Members Posts: 597 Joined: 25-July 04 From: Annandale, MN Member No.: 2,395 Region Association: Northstar Region |
QUOTE(Bartlett 914 @ Aug 28 2007, 08:38 AM) QUOTE(akellym @ Aug 28 2007, 04:45 AM) Loctight! I used the red on the studs and blue the removable type on the nuts, haven't had that problem again. I have read many times where people us loctite on the studs. I find it hard to believe this can help. This stuff breaks down at temperatures well below the heat in the heads. If the studs are working out, then the fit must be too loose. There are special copper plated nuts that should be used. These are one time only. If removed, they should be replaced with new ones. For that matter, if removed then the copper exhaust gaskets should also be replaced. QUOTE OEM specified as 271 High temperature, high strength for heavy duty applications Designed for larger fasteners 3/8" to 1" (9.5mm to 25mm) Locks studs, bushings and large fasteners against vibration loosening Strengthens slip and light press fits Removable with heat and hand tools This is from the Loctite web site. All I know is my studs have never come loose since I used this and the blue seems to hold up very well in high heat.... |
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| Bartlett 914 |
Aug 28 2007, 08:25 AM
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#8
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Advanced Member Group: Members Posts: 2,216 Joined: 30-August 05 From: South Elgin IL Member No.: 4,707 Region Association: Upper MidWest |
QUOTE(akellym @ Aug 28 2007, 05:57 AM) QUOTE(Bartlett 914 @ Aug 28 2007, 08:38 AM) QUOTE(akellym @ Aug 28 2007, 04:45 AM) Loctight! I used the red on the studs and blue the removable type on the nuts, haven't had that problem again. I have read many times where people us loctite on the studs. I find it hard to believe this can help. This stuff breaks down at temperatures well below the heat in the heads. If the studs are working out, then the fit must be too loose. There are special copper plated nuts that should be used. These are one time only. If removed, they should be replaced with new ones. For that matter, if removed then the copper exhaust gaskets should also be replaced. QUOTE OEM specified as 271 High temperature, high strength for heavy duty applications Designed for larger fasteners 3/8" to 1" (9.5mm to 25mm) Locks studs, bushings and large fasteners against vibration loosening Strengthens slip and light press fits Removable with heat and hand tools This is from the Loctite web site. All I know is my studs have never come loose since I used this and the blue seems to hold up very well in high heat.... Hi Kelly I think you are putting the heat exchangers on properly and all is fitting as it should. With or without the loctite. The last line on the specs you listed "removable with heat and hand tools" is the problem. The material is thermoplastic and not thermosetting. |
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| davep |
Aug 28 2007, 08:35 AM
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#9
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914 Historian Group: Benefactors Posts: 5,143 Joined: 13-October 03 From: Burford, ON, N0E 1A0 Member No.: 1,244 Region Association: Canada  |
You are not supposed to use ordinary nuts. There are special purpose nuts for this application that are self locking. I think most are the copper plated varieties as noted. Some are a bit pinched so that the hex is not perfect, and the threaded hole is ovaled. Others have a domed top that is 3/4 sliced underneath. If you use the correct nuts you won't have any issues most of the time.
http://www.pelicanparts.com/catalog/shopca...p_pg1.htm#item3 |
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| Jake Raby |
Aug 28 2007, 09:08 AM
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#10
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
Check the tune up... Continually loose exhaust nuts are a symptom of extreme exhaust gas temps...
You might be lean or need some extra ignition advance.. Heads and oil can be cool and EGT can be elevated- |
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| Chris Pincetich |
Aug 28 2007, 10:34 AM
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#11
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B-) Group: Members Posts: 2,082 Joined: 3-October 05 From: Point Reyes Station, CA Member No.: 4,907 Region Association: Northern California |
If they back out then you are ready to replace the stud with a new, non-corroded one and torque it to spec (IMG:style_emoticons/default/beerchug.gif)
If you are too cheap to get new nuts every time, whick shouldn't be too often, you can double nut the stud (not much room, but enough) which when tightened properly should not loosen. Exhaust leaks smell, are loud, and could damage your heads I think (IMG:style_emoticons/default/sad.gif) |
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| Cap'n Krusty |
Aug 28 2007, 10:38 AM
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#12
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Cap'n Krusty Group: Members Posts: 10,794 Joined: 24-June 04 From: Santa Maria, CA Member No.: 2,246 Region Association: Central California |
Just some thoughts on the subject. NEVER use lockwashers on exhaust components. They get hot, lose their tension, and it's as if they were never there, only looser. Loctite is a debatable question, and I won't weight in here. As for locking nuts, the factory never used them. The original nuts were standard nuts with helicoiled threads. 2 litre cats used thick nuts with a thick flange, 1.7s and 1.8s used conventional size nuts with a washer. If you're having a problem, I'd look to the integrity of the pipes and the rear support bracket. The flanges need to be intact and as parallel as possible, and the bracket MUST be there. The studs need to fit properly in the threads in the heads. The Cap'n
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| Jake Raby |
Aug 28 2007, 10:56 AM
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#13
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
I prefer high grade stainless nuts double locked against each other (two per stud) with milk of magnesia for anti seize..
I do this when doing exhaust system testing to ensure that studs won't strip and to ensure we won't encounter problems during system swaps in the dyno cell. I make exhaust systems gglow cherry red for hours and the locking nuts will weld themselves to the studs, I never use them. Keep in mind that at the port exit the temperatures can exceed 1100F on cars that are driven hard. |
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| alpha434 |
Aug 28 2007, 05:24 PM
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#14
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My member number is no coincidence. Group: Members Posts: 3,154 Joined: 16-December 05 From: Denver, CO Member No.: 5,280 Region Association: Rocky Mountains |
Thanks for the insight. I was worried about the lock washers anealing. I think I may go with Jake's stainless plan. I WAS using the flange nuts with the helicoiled threads. All of them on one side have fallen out at one point or another. The copper seems ok. But I can probably get some 12mm nuts with the right thread pitch from work in SS. And I'd prefer the 12mm. What a PITA to get a 13 mm socket in there!
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| SLITS |
Aug 28 2007, 05:30 PM
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#15
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"This Utah shit is HARSH!" Group: Benefactors Posts: 13,602 Joined: 22-February 04 From: SoCal Mountains ... Member No.: 1,696 Region Association: None |
Copper "crushed nutz" loosen too!
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| rhodyguy |
Aug 28 2007, 06:34 PM
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#16
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Chimp Sanctuary NW. Check it out. Group: Members Posts: 22,080 Joined: 2-March 03 From: Orion's Bell. The BELL! Member No.: 378 Region Association: Galt's Gulch |
use a 12mm 1/4" drive socket. the thinner walls help.
k |
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| GWN7 |
Aug 28 2007, 07:34 PM
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#17
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King of Road Trips Group: Members Posts: 6,280 Joined: 31-December 02 From: Winnipeg, MB, Canada Member No.: 56 Region Association: Northstar Region |
I think someone is screwing with you and loosing them up at night when your sleeping soundly........
Next thing people will be following you around and complaining your car is too loud to the police (IMG:style_emoticons/default/blink.gif) (IMG:style_emoticons/default/beerchug.gif) |
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| alpha434 |
Aug 28 2007, 09:50 PM
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#18
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My member number is no coincidence. Group: Members Posts: 3,154 Joined: 16-December 05 From: Denver, CO Member No.: 5,280 Region Association: Rocky Mountains |
Not true, you dirty SOB.
I already set up a a camera and I've been monitoring it for a week. |
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| GWN7 |
Aug 28 2007, 10:36 PM
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#19
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King of Road Trips Group: Members Posts: 6,280 Joined: 31-December 02 From: Winnipeg, MB, Canada Member No.: 56 Region Association: Northstar Region |
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| brant |
Aug 28 2007, 10:51 PM
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#20
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914 Wizard Group: Members Posts: 11,623 Joined: 30-December 02 From: Colorado Member No.: 47 Region Association: Rocky Mountains 
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QUOTE(alpha434 @ Aug 28 2007, 12:41 AM) Title says it all. They just keep coming loose. Are they supposed to have lock washers? I'm with Bruce on this one. my guess is that its the work of underwear gnomes! brant |
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