Dip Stick Tube snapped :-(

[Stephen Masefield]

I can' be the first person to have had this happen to them ....

The Dip Stick has felt kinda loose for weeks and then this weekend when I pulled it up, it came up with a portion of the guide tube still on it - snapped at the point where it enters the engine case.
Now what ....?

A friend had an old case where a rod had smashed the case - ie scrap metal ! so investigated how the tube fitted - it seems to be press fit but wouldn't budge ? So cut I it out witha grinder and hammer... and this one was bent to boot where it leaves the engine case ... I think they should be straight ? Maybe it got bent with the engine case lying around for so long in his scrap metal area...

So - my engine has to come out anyway for a ring and valve guide job... How the H*** do I get the broken stub out ? And then fit a new tube...This can't be a first !!! Ideas please ! (And a source of new guide tube ?)

[David Jones]

Steve, I think you will find the tube is the same diameter as the fuel line, 7.5mm or 5/16" same as domestic fuel line. It is a very tight press fit and I would think if once the case is apart if you should crimp the end with vice grips and leave them attached you should be able to drive it through into the case as it will stretch thinner as you knock it in.
I fixed a loose one by smearing it with JB weld and pressing it in to the correct pre measured depth. It has not moved in two years.

[Wes Bender]

Tube probably got bent during an engine removal or installation. I always remove the dipstick prior for that reason.

[Vic Skirmants]

There is a very small step in the tube at the case. In other words, it is actually two diameters.
Yes, it is a very tight fit. Although one time when my race engine hit 300(!) degrees oil temp, when I pulled into post-race impound, I pulled the dipstick to see what the oil looked like; immediately dropped it; it was HOT! It also had the tube attached! Shoved it back in; when it cooled the tube was tight again.

[Dick Weiss]

If the end of the tube exists, you can use a 7 x 1 metric fine tap to thread it's end but keep it aligned to its ID for aro0und 1/4"-3/8" deep,
add a nut to be able to pull it straight out--you could use a propane torch to heat the surrounding area, too.

[Harold Singh]

I use the temp gauge stick and it’s much shorter. Clears and engine drop easily.

[Phil Planck]

Root cause of the break? As I recall, one of mine tubes was getting cut where it passes through the shrouding. Not sure if there is supposed to be a grommet there or not. Otherwise, try to get it centered in the shrouding hole.

[Vic Skirmants]

No grommet at the shroud. Should be centered with no contact.

[Alex Mestas]

Stephen:

About 6 years ago while checking my oil on a club drive my oil dip stick stem came off with the dipstick. It apparently had been broken at the stem at some point put back in with a JB Weld product. I stuffed a piece of rag and nursed it home. I was fortunate to find a used oil stem piece but had the same challenge "What now?".

In Southern California we are very fortunate to have several Master 356 Porsche mechanics among them Jack Staggs in San Clemente.

He machined a steel rod the same diameter as the filler stem, gently taped in the broken end into the oil pan. When he drained the oil the piece came out. So I got the new stem installed and the oil changed as the same time. It was ingenuity at its best.

[Stephen Masefield]

Seems I have two approaches-
1. tap it m7x1 insert bolt and try to (gently) slide hammer it up and out it - using heat on the case at the same time...I have just ordered a brand new tap to make sure it is sharp and fresh.
2. Or Jacks approach - tap it in through - with some heat as well I guess, to ease it through with some expansion ....

Will post solution as when I do it - engine out first anyway.

Thanks one and all, and still open to any other ideas of course

Steve

[Stephen Masefield]

Opps I never did post the solution ...
I made a drift as per Alex above...
Heated and tapped broken end down into the case and retrieved it by removing the drain plate.
I sourced another (real) tube from a case that past restoring.(I couldn't find a tube of right diameter as its an interference fit)
I measured the dip stick length to make sure I didn't drive it too far and marked the tube where it was to be at the top of the case hole.
Froze the tube in family freezer and heated the case gently - it went in very easily and when tube and case were at temperature it was gripped and held tight.

.

[Mike Wilson]

Mike

[Patrick Ross]

I also had a problem dipstick tube on a 912 engine I am building (with much help from Rick Woltz) for my C coupe project. We were a little far down the road when I noticed the tube was bent, and we started mulling our options.

After email communication with Steve, we abandoned the internal thread idea and made a steel drift and welded a coupling nut on top for the slide hammer to attach.
We held the top of the donor tube tight against the drift with vise grips and hammered up while heating the case with a hand held mapp torch. That worked, giving us proof of concept.
Next we did the same with the ‘ready to break’ problem tube, and got it out about 8mm before it broke. Then we tacked the drift to the stub and out it came.

Of note, neither the donor tube nor the ‘problem tube’ had a ‘shoulder’ as described earlier in this thread. Both are from 912 cases.

Many thanks to Steve and all the contributors to this thread, and those who make this forum possible.

Pat