Itinerant Air-Cooled

It looks like at some point someone built it up with very bubbly welding, and then ground it flat. Why?
Also, what's the purpose of that little weepy hole at top center, a little ESE of the bolt hole?

Very difficult to weld magnesium. might it be a poor casting?

whc03grady wrote:

IF the bearing support in your nosecone was actually welded, I suspect that it was an attempt at reducing input shaft bearing movement, similar to how Colin installed a Long Enterprises bearing retainer plate here:

http://itinerant-air-cooled.com/viewtop ... 34#p202534

See how the bearing-retaining magnesium is worn down and would allow the bearing to "walk" fore and aft? We don't want that, so it looks like yours was repaired by building up the material instead of using a plate. The third option for a repair, is to mill the entire nosecone a few thousandths, so the bearing (and outer sealing edge) has new flat material to work with. I think this third option is only for slightly worn bearing supports, as too much material off could skew the lineup of parts.

Colin's less-verbose and more thorough explanation:




Is the "weep" hole through to the exterior? I read somewhere that there should be a "breathing" hole in transaxle cases, possibly to account for expansion and contraction of materials and air due to heat.

Robbie

Well, shit.
Not realizing the nosecone and gear carrier were such delicate snowflakes, I flatly scraped a razor blade across the mating surfaces of both, to get rid of Rancho's residual silcone. What doom hath I wrought?
And, I didn't have that metal plate. I went gear carrier-Permatex Aviation-paper gasket-Permatex aviation-nose cone. Again, am I due a redo?

whc03grady wrote: ... am I due a redo?

Well sure, eventually. That mainshaft bearing/nosecone juncture seems to be a real weakness of the design. Pretty much all hi-mileage xmissions
have ate-up nosecones. The bearing in my '71 was spinning in its bore back in '97, making noise, and it's still spinning today, making even more
noise. The repair/reinforcement plates are steel, and I can't imagine the bearing wearing a groove in it as in the photo above.

The Permatex goop would presumably handle any little gouges or scratches that may have made their way onto your mating surfaces.

Installing a Long Enterprises steel plate in my '78's trans and putting in a new steel hockey stick ball was one of the first jobs I tackled with Colin. What a transformation in the shifting! No more struggling, it glides easily into all gears. Definitely a worthwhile project. However, Long Enterprises has just closed shop. Colin was going to attempt a purchase of some of the steel plates, since he knows them, but I'm not certain where that sits right now. They would be easy to fabricate in any metal shop with a laser cutter.

whc03grady wrote:Well, shit.
Not realizing the nosecone and gear carrier were such delicate snowflakes, I flatly scraped a razor blade across the mating surfaces of both, to get rid of Rancho's residual silcone. What doom hath I wrought?

Possibly nothing. Did you "rake" the razor blade? Or did you gouge any metal chunks off? The gasket and Permatex should be able to seal up any inconsistencies just as good as the RTV did in this case.*

And, I didn't have that metal plate. I went gear carrier-Permatex Aviation-paper gasket-Permatex aviation-nose cone. Again, am I due a redo?

No! No redo!

You are on the right path. If you spent as much energy assembling your car as you do second guessing, you'd be driving right now. I mean that in mostly jest; your work is fine, no metal plate required. And it is better to overthink than under-think.

Robbie

*Want to know a secret? One time I ripped a nosecone off and accidentally shredded the gasket. On a deadline, I gooped up some Permatex Aviation and reinstalled the thing with all the shredded gasket pieces in their general approximate positions. Some hung out, and I'm sure some were submerged in gear oil. The damn thing wouldn't leak.

asiab3 wrote:Possibly nothing. Did you "rake" the razor blade? Or did you gouge any metal chunks off? The gasket and Permatex should be able to seal up any inconsistencies just as good as the RTV did in this case.

I pulled it flat across the surfaces thus /-------->

asiab3 wrote:If you spent as much energy assembling your car as you do second guessing, you'd be driving right now.

Tell me about it. (And there's more second- and third-guessing on the way.)

kreemoweet wrote:

whc03grady wrote: ... am I due a redo?

The Permatex goop would presumably handle any little gouges or scratches that may have made their way onto your mating surfaces.

I'm guessing there are multiple solutions for sealing products that will work just fine, but when I installed my retainer plate I asked Rick his opinion and he recommended using the Permatex Ultra Blue.

THall wrote:

kreemoweet wrote:

whc03grady wrote: ... am I due a redo?

The Permatex goop would presumably handle any little gouges or scratches that may have made their way onto your mating surfaces.

I'm guessing there are multiple solutions for sealing products that will work just fine, but when I installed my retainer plate I asked Rick his opinion and he recommended using the Permatex Ultra Blue.

UltraBlue clashes terribly with the grounding strap copper hue and the green paint of the BobD's undercarriage, so I used Permatex Aviation.
Colin

Luckily for me, the Permatex Ultra Copper exhaust paste blends well with my Ultra Copper Honda Paint.

Robbie

Colin wrote:UltraBlue clashes...

Robbie wrote:Ultra Copper ... blends ...

Ultra Black goes with anything.