Itinerant Air-Cooled

'77 fuel injected bus. While taking off the fan shroud the left lower stud just pulled right out. Hardly holding at all. So, I'm thinking of either try to cement it in or is this a case for one of those heliarc thingies and drill and tap a new set of threads? What think you guys?

Thanks

Joseph

mentalQtip wrote:'77 fuel injected bus. While taking off the fan shroud the left lower stud just pulled right out. Hardly holding at all. So, I'm thinking of either try to cement it in or is this a case for one of those heliarc thingies and drill and tap a new set of threads? What think you guys?

Thanks

Joseph

Go straight to a step stud without using a helicoil. Drill the hole and tap unless the hole is gouged out just perfectly enough that you can straight on thread in the next size up. You can try a 9X8 or a 10X8 step stud used on exhaust ports most usually.
Because the fan housing is supporting the rapidly spinning alternator and exhaust system over there on the left side, you want this done right.
Colin

I went with a 10/8 because no place I went said they had an 9/8 stepstud. However it worked great and the shroud is firmly secure.

Thanks

Joseph

mentalQtip wrote:I went with a 10/8 because no place I went said they had an 9/8 stepstud. However it worked great and the shroud is firmly secure.

Glad you got it; I've never heard of a 9/8 step stud, but most good* hardware stores stock a range of 10/8 studs.

Robbie

*not Home Depot or Lowes.

asiab3 wrote:

mentalQtip wrote:I went with a 10/8 because no place I went said they had an 9/8 stepstud. However it worked great and the shroud is firmly secure.

Glad you got it; I've never heard of a 9/8 step stud, but most good* hardware stores stock a range of 10/8 studs.

Robbie

*not Home Depot or Lowes.

Some Type 4 engines had "first repair step" 9 X 8 exhaust studs, they are completely impossible to obtain, I have been told.
German Supply has the 10 x 8 repair studs.
Colin

Amskeptic wrote: Some Type 4 engines had "first repair step" 9 X 8 exhaust studs, they are completely impossible to obtain, I have been told.

I have put them on my list, joining the largest size T4 flywheel shims.

With trepidation I drilled and tapped and threaded the 8/10 step stud in and damn, it holds securely. The shroud is mounted and the engine is installed. Yay!

Thanks

Joseph

Congrats! Now in a hundred years when the internet is connected to human brains, people will be politely discussing why the "factory" might have used an eight-ten stepped stud.

Robbie