So this just happened ...!

You can replace the pump with an OEM one (I have one in stock) or the internal rotor with an aftermarket one.

 

I have not once seen one of those broken. That includes working at the dealer who sold more BBis' than any other and being in the largest volume dealer during the TR years.

How do people do that? Use 60 weight oil or something? I am genuinely curious.

 

Having that vacuum pump shaft break at that location has been reported here many times (and mine did, too). See this thread:

https://www.ferrarichat.com/forum/threads/vacuum-pump-on-tr.386800/#post-141830176

especially post #14 (and the thread in that post) that shows how one member made an aftermarket part with a much improved design without a sharp radius where the diameters change for a fatigue crack to form at that location. Don't know if he still makes them for sale.

If you do an internet search on "170956 Ferrari", and looks at the images, you'll see others also make a reproduction vacuum pump shaft (but more identical to the original design).

 

What are your thoughts on the necked down area of the OEM part as a shear point to save the splines in the cam?

 

Aren't the female splines in a separate coupling piece that mounts into the end of the cam? Maybe having the smallest diameter there is a good idea, but Kerry's part still has that (so would have the same shear strength there) -- Kerry's just doesn't have a super sharp internal corner to promote a fatigue crack forming. My guess would be that the (maybe not well-controlled) heat-treating of the part might be another contributing factor to this failure -- maybe making it needlessly over-brittle.

 

Wasn't Kerry making new shafts for these pumps? I had one break too...in fact I still have that broken pump around here somewhere.

 

Its not part of the cam but you would need to remove the engine and cam to replace that insert assuming of course you can get one still. Im just speculating and sometimes I dont like reinventing a part only to find Ferrari did something for a reason. I cant tell you how many times during a restoration I find something I question but realize they actually put thought into it and their way is the best way. Then of course there are things they did that are just plain stupid.

 

How do they get broken?

speculation... if the pump is not installed in the correct orientation, the drain hole is not at the bottom. Perhaps these pumps are hitting a hydrolock from too much incompressible oil in the pump’s cavity(?)

Never tried to mis-install it. Can it be installed without the correct orientation?

 

If you took the locating dowels out you could have it on wrong but otherwise no.

 

have a look here:
https://www.ferrarichat.com/forum/threads/vacuum-pump-on-tr.386800/
in post 3 you see how I solved the problem.
originally installed the oil drain hole is not at the buttom. it is 90 ° turned and so the oil inside the pump never may drain complete. when you then start the engine the rest of the oil is still inside the pump and can not drain fast enough but the oilpump delivers more oil what can not be compresse like air and then the shaft will break.

 

Fyi gt car parts is where I think I bought my replacement? Cuz the party from Ferrari was $1k, there's was a"reasonable" $450 if I remember correctly. It's an easy replacement.

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I’ve been rolling with mine broken for 15,000 miles.

 

I have seem more of these broken then not.

 

and this all without you recognized it. but how you know then that you have been driving those 15.000?

 

When I did my engine out I pulled it off and cleaned it up. De burred it. Sealed it back up. It’s just for low RPM braking.

 

And like I said I have worked on them daily since long before the TR came out in a couple of the biggest dealers on the planet, shop foreman in the biggest overseeing all the jobs and own one of these and never seen it happen.

 

I had a friend with 250,000 miles on his TR and never broke one.

Not so sure I'd call it a faulty design.

 

You get real close to one of my suspicions. Installation. How many have trouble getting the splines to align and get a heavy tool to assist?
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Say it ain’t so!

 

could it be cold weather related? Heavy weight oil in the freezing cold could be like sludge in the first second and if you run up the RPM after giving it throttle, maybe it could stick. The designers maybe put that small radius in there to be a circuit breaker instead of breaking the camshaft.

 

Or a timing belt. I have considered that but broken shafts do not seem to be limited to cold climates.

My car and my clients get 0-40 or 5-40 oil. I know of many that still like putting syrup in their engines.

 

1990? If you don't mind, whats the VIN?