Getting a new plate made might be about the same cost as redoing the shaft(s). And way easier. Might be even cheaper too if you can buy the 2" thick plate aluminum at a scrapyard. (or prehaps a machine shop leftover since they usually save big bits) If you machine all the excess off it should not weigh much more, mabe even add holes for lightness. Another thought is you will get extra bolt depth on the five tapped holes that mount the bell.
Another consideration is how well the fellow did the first try- if the interference fit is really tight (as it should be) it will not come apart pretty. If the shafts are true (with little to no runout), it may not come out that well on the next try. Same for the welding, if it looks good. The shaft is the hardest part of the conversion by far, all things considered. If junk shafts were plentiful it would be different, and I would then say redo it.
Am I missing or forgetting anything? I'm getting pretty old so it's possible. I think the thicker plate was mentioned already (way down in the forum) but I don't recall what was said.
--Previous Message--
: Awww NUTS!!! I hadn't even considered
: the reverse chucking complication.
:
: I've got exactly one shot at this, and
: then it's time to settle for the OEM
: 4-Speed (sorry - no offense to all you
: original restoration types).
:
: I "really" want this tranny
: in.
:
: BTW: Dan, I made a mistake. It wasn't
: "your" drawings I would have
: needed, it was those of the guy that
: made the actual input shaft I'm working
: with. I worded that poorly.
:
: Ciao! - Jim
:
: --Previous Message--
: Jim- After some more thought, I can
: see
: if you do get the first try apart it
: will be hard to chuck the toyota end
: back in the lathe to return the pin.
: Since it was chucked from the opposite
: (now cut off) end for the first
: turning, it will have to rechuck from
: the other end. The gear/bearing on
: there will need to be in the chuck this
: time, and might be hard to hold or
: center well. It should work, it just
: won't be as easy as the first time
: around.
:
: --Previous Message--
: Sorry - hit the wrong box-keys above...
:
: Jim- I still haven't found the original
: sketches, but I know they are still
: around here somewhere folded up in a
: book. I never throw anything away,
: hence I can't find anything quick.
:
: But mabe this bit will help you
: understand how I got the length right,
: I remember doing it well-
:
: I started off by measuring how much
: length the stock (triumph) shaft
: extendned past the outer edge of the
: stock triumph bell housing. This would
: be all bolted together, say like you
: just pulled the gearbox from the car
: for repair. Just lay a straight edge
: across the bell housing and see what
: the shaft length protruding is. Today
: on a spare unit I have in the parts
: barn I measure 24 mm (or about 1")
: This is also the section that goes into
: the pilot bushing in the crankshaft.
: You can be off by a couple of mm either
: way measuring and not cause a problem.
: (since the crank pilot hole is recessed
: a bit)
:
: Next step is to have the toyota box,
: adapter plate, and bell housing all
: temporary assembled with the stock
: toyota shaft in there. Use the cut off
: triumph shaft as a guide- laying it
: alongside (or hose clamping to) the
: toyota shaft with the same 24 mm
: protruding past the edge of the bell
: housing. Then you can scribe a line on
: the toyota shaft exactly where you will
: need to make the "step" of
: the pin. (right behind the already cut
: triumph shaft) This is where the
: triumph-toyota shafts butt together,
: with the pin extending out another inch
: or more into the socket. (that is bored
: in the triumph cut off end)
:
: Now you will want to disassemble the
: bell, adapter plate and toyota gearbox
: box to remove the input shaft for
: cutting and turning the pin. (for the
: socket-pin interference fit)
: Decide how long you want the pin to be,
: and add the length with another scribe
: mark. (let's say 1.5" pin length)
: This second scribe mark is where you
: will cut the toyota shaft. The first
: scribe you will use to show where the
: pin step starts, when you chuck it in
: the lathe to grind the pin section. And
: be sure that when you do cut the pin to
: length it is shorter than the socket
: depth. (by 1/8" plus).
:
: If you can get that first try apart and
: not damage the triumph end and socket
: that will be great. If you can
: carefully cut the weld and re-use both
: ends that would be even better. Use a
: small angle grinder and thin as
: possible wheel to cut the weld away.
: The interference fit may pull apart if
: it's not too tight. (some heat may
: help) I'd sure try it since it would
: save so much time and parts. Just the
: toyota shaft would need returning of
: the pin, right? (after cutting the
: extra inch length away?)
:
: I have forgotten which bell housing you
: plan to use- but it does not matter
: really. What matters is the length of
: the shaft protruding from the bell
: face. I know you are painfully aware of
: that bit now.
:
: Let me know if I need to explain it
: some more, in any way.
:
:
: --Previous Message--
:
:
: --Previous Message--
: Hi Dan! How ya doin'?
:
: Best idea I've come up with is to have
: a shop grind off the GT6 shaft you
: installed and then cut and bore out
: another GT6 shaft that I'll give them.
: Without your original drawings, I don't
: think I have any other choice - bummer.
:
: Luckily I have two GT6 gear boxes in
: stock, so I'll still have a fall-back
: no matter what happens. I won't get to
: the project for another month or so;
: I'll get some more news out then
:
: Thanks for checking-up on me!
:
: Ciao - Jim
:
: --Previous Message--
: Jim- Did you try to get to get the
: first one that came out too long apart
: yet? I've been wondering if you had any
: luck with it.
:
: Too bad you are located so far away,
: I'd be glad to help you do the work in
: my shop.
:
: --Previous Message--
: All good stuff. Thanks guys. I'm sure
: the rest will fall into place when I
: actually get to bust the case open.
: Right now I'm just looking at diagrams.
: Doesn't sound too bad though. Finding
: a machinist to do the cutting,
: grinding, boring and interference fit
: on the hybrid shaft will be the
: challenge.
:
: Ciao! - Jim
:
: --Previous Message--
: It has been about 20 years since I
: replaced parts in our GT6 gearbox. I
: remember doing exactly as Carter said
: regarding a temporary short shaft to
: keep the needle bearings in place. I
: was not smart enough to look for
: something at the hardware store and
: instead had the machinist at work make
: me a rod of the correct diameter. The
: pipe is a much easier and better
: solution.
:
: Doug L.
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