Water pump cover stripped thread

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Biscay 36

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One of the cover screw threads has stripped on the Jabsco raw water pump cover on the 4108.
Drilling out to a larger size and re tapping has been ruled out as too difficult with the pump in place and I don't want to take it off. One suggestion is to epoxy a length of stud in in the hole and use a nut to hold the cover plate on. Anybody know where I might get a length of such stud. It's almost M4 but a coarser thread. Other solutions suggestions welcome.
 
JWBZQK said:
One of the cover screw threads has stripped on the Jabsco raw water pump cover on the 4108.
Drilling out to a larger size and re tapping has been ruled out as too difficult with the pump in place and I don't want to take it off. One suggestion is to epoxy a length of stud in in the hole and use a nut to hold the cover plate on. Anybody know where I might get a length of such stud. It's almost M4 but a coarser thread. Other solutions suggestions welcome.
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Easiest source of stud might be to simply use a long screw with the head cut off.

With luck you may be able to pick up some decent thread deep in the hole but you will have to ID the thread in order to do that. 5/32 W ???? or an American thread
 
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The chance of epoxy holding is remote.Why not try and use a coarser thread on this one screw.You want something like a whitworth thread probably a 3/16th size altho.you will have to measure the screw to get the size.Retap using a "plug" tap last.Thats a tap with a flattened end so that the threads go to end of hole.You should be able to get whitworth taps from a decent tool shop.If your lucky the Whitworth size might be slightly larger than your existing one which is likely to be B.A. type.Whitworth sizes are the outside diameter of the thread.ie 3/16th size is 3/16 outside diameter.If you havent done "tapping " before get someone to do it for you or you might knacker it.
 
If you are replacing the stud the thread is irrelevent, why not a self tapper ? a bodge
but so is everything short of re tapping.
 
It's almost M4 but a coarser thread
Click to expand...

M4 has 2 different pitches, coarse and fine - try a thread gauge on one of the good screws to be more precise. M4 stainless studding is available from Screwfix, amoungst others.
Not being an exact thread match might be an advantage for what you want to do as you can 'jam' the studding in - use 2 nuts locked against each other, and use good quality epoxy such as Araldite slow setting. Degrease the hole and stud thoroughly before applying the glue.

Still, better to drill and retap though! You can get 90 degree adaptors that let you fit a drill in a tighter space...
 
Thanks all, think I'll go for the cut off bolt providing I can get a near thread match and use JB Weld or something similar. But first I'll determine the thread size and try a new screw.
 
If you're considering finding a stud with a thread that will jam into the original thread, then I would suggest cutting a slot along the start of the thread. That will allow it to cut its own thread better. It's still a bodge, though. I don't know the 4108, but is there a good reason for not taking the pump off so as to get it properly sorted on the bench?

Rob
 
Have you asked Jabsco for thier advice???

When I worked thier on the help desk, it is one of the questions I would have loved...

I can not advise, would need all the files, and drawings, that I had to give a proper answer..

Jon
 
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