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Posted by: dwelle Jan 12 2021, 04:23 PM

i had to pull the oil tank out of my 914 to address a leak, and one of the mounting studs on the tank broke when i went to remove the nut. it broke about a 1/4" off of the tank.

quick google search last night didn't yield any good intel, what am i looking at to replace that stud?...

Posted by: johnhora Jan 12 2021, 04:57 PM

you're talking about this in the drawing below...correct?
if so may need to weld another one on....
how much is left on the tank
take a picture and we can see what to address
I'm sure someone on here has done it on a 6 tank or on a 911 tank

Posted by: dwelle Jan 12 2021, 06:16 PM

yes, the stud on the right hand side of that diagram is the one that broke. there is only 1/4" or so left on the tank.

i can feel the back of the other stud and it feels almost like it's pressed in from the back side...

Posted by: Root_Werks Jan 12 2021, 06:22 PM

If there's enough thread, you might be able to use a stud extender. Might have to put an extra washer or two on the engine bay side. But it would be an easy fix if it's possible.

Posted by: PanelBilly Jan 12 2021, 06:32 PM

Posted by: dwelle Jan 12 2021, 06:46 PM

yeah, there isn't enough of the stud left, and the threads are jacked anyhow.

i'll likely have another welded on?...

Posted by: johnhora Jan 12 2021, 07:35 PM

You could try to cut the old one flush at the base and then drill and tap the hole for a new stud. Being carful not to drill thru into the tank.

Posted by: Mark Henry Jan 13 2021, 08:41 AM

Or carefully weld a new stud on. I've done this before but not on a tank.

Posted by: gereed75 Jan 13 2021, 10:21 AM

Maybe take a bolt with the same tread, grind the head to about .080" thick. Grind the broken stud flat to the tank. Mig the modified bolt/stud to the tank.

That is what I would try. The extra material provided by the ground head would make it easier, less risky to weld. You could push the puddle formed by the hot head metal to flow into the tank wall material for good penetration without burning through the tank wall. The threads would be clean all the way down the stud to the weld, where as when welding a stud to the broken stud you would have to chase the threads down onto the old stud to get a full threaded stud. Possible but a bit risky and a lot of work.

be sure that if you try this to grind off the copper plating that is on the tank. Welding through the copper would ruin the weld.

But that is just my opinion and I am a semi-skilled rank amateur.

Posted by: aturboman Jan 13 2021, 10:54 AM

I've fixed this problem before on 911 tanks. You'll need to carefully grind the broken stud flush to the the tank and clean the area to bare metal.

The only proper way to re-attached a stud to metal this thin is to carefully braze a new stud on and it will be as strong as the original

The tank is too thin for electric welding in my opinion even TIG is a challenge due to the vast differences in material thickness.

Also getting rid of all the oil or rust contamination for a proper electric weld is near impossible, brazing is much more tolerant in that regard.

Posted by: rgalla9146 Jan 13 2021, 01:01 PM

QUOTE(aturboman @ Jan 13 2021, 11:54 AM)

Posted by: dwelle Jan 13 2021, 02:36 PM

ok, thanks. i'm not going to attempt to weld this one myself. time to call in some friends with better skills than i...

Posted by: Cairo94507 Jan 13 2021, 02:46 PM

Personally, I would email @http://www.914world.com/bbs2/index.php?showuser=9892 and explain what happened and send him a picture and see if he could repair it if you shipped it to him. I would want it repaired correctly with a new stud.

Posted by: mepstein Jan 13 2021, 02:50 PM

someone with the right skills will repair it correctly.

Posted by: dwelle Jan 13 2021, 03:58 PM

QUOTE(Cairo94507 @ Jan 13 2021, 12:46 PM)

Personally, I would email @http://www.914world.com/bbs2/index.php?showuser=9892 and explain what happened and send him a picture and see if he could repair it if you shipped it to him. I would want it repaired correctly with a new stud.

Posted by: mb911 Jan 13 2021, 05:49 PM

Thats a tricky spot for sure.. that stud is brazed with a flange from the inside..That will be a tricky repair. A couple ways to go about it.. I think the best way would be to drill and tap then insert a stud and weld or brake in place. That will ensure proper centering.

Posted by: mepstein Jan 13 2021, 06:12 PM

Is there a riv nut type of fitting that can be used.

Posted by: dwelle Jan 13 2021, 08:23 PM

i'm not messing with this. otherwise, the tank is nice, i may just send it to ben...