Tranny (shifter) bokerforked (Found: star cam broke off the shift drum!)

[lnewlf]

was welded on originally, was it not ? someone should be able to reweld it. I know a guy who welded a tooth on a flex plate thru the inspection hole...meebee a chamfer around the shaft to make room for the bead and put the heat on the shaft...not much too loose

 

[wfooshee]

No room for a countersunk head, thought about it but the center of the star cam is too thin. Welding, maybe, but whoever welds it has to come here....

That's how the part was originally attached, with a weld, but what I know about welding will fill.... a VERY small space. Would have to see if it can be welded in situ as opposed to a part on a bench.

I drilled for a 1-24 bolt, because that's pretty close to the size the original dimple let me get to, and I have US drill bits. Turns out I need a tap, too. Guess which tap in my set, out of the 17 SAE sizes, is worn and won't cut?

 

[TownsendsFJR1300]

Well, I got the shifter down into first gear using a pair of channel-lock pliers to turn the drum. I ran it back up as far as third, then back down to first, turning the shift drum with the pliers while turning the tranny shaft with my other hand. So it looks like the actual gearbox and shift drum are OK.
I successfully drilled the shift drum shaft, intending to try bolting the star cam back into place. The shaft had a little dimple which got me started on center very easily. Turns out the shaft opens up after about a quarter of an inch into the interior of the shift drum. Unfortunately, my plan hit a snag there, as there's no way I can turn a tap that deep inside the tranny housing; no room for the tool. Maybe there's an extension available for the purpose, I don't know.

The star cam does fit on the drum in exactly one place, so the break faces mate very nicely. I don't know if it could be welded,.

if the "star" still threads on and stops where it should, it wouldn't be difficult at all to put a plug weld (MIG) right down the middle (flush). Of course all the oil reidue would have to cleaned up. As posted, theres really not a lot of stress on that part, just old age and fatigue is likely why it failed (or poor weld). If it was shifting fine before, I have to doubt there was anything wrong with the gear box itself to have the end break off. Being there's not a lot of stress there, I don't think the weld would affect the harness of the drum..

Wouldn't take long to weld up but I would unplug majot electrical componants before hand (ECU, Battery, etc)

Should you decide to replace the part, once the engine is pulled and flipped upside down, the biggest part would be just removng the lower case. The head can stay on, half the gear box comes out the side, the other shaft, straight up, then the broken drum

 

[wfooshee]

It doesn't thread on, it just sits on the shaft. Looking at the part, it appears the thing broke just under the existing weld. There is a collar in the center, which may have had an alignment notch or peg to assemble it for welding originally.

Oh, yeah, this should be fun: Everybody sees how many notches the cam has, right????

 

[Donal]

Looking at your lower picture, I would be inclined to find a good machinist (any model engineers in your area?) and get him/her to to clean off the 'front' face of the cam and then machine up a clamping washer to fix to the shaft........

 

[TownsendsFJR1300]

It doesn't thread on, it just sits on the shaft. Looking at the part, it appears the thing broke just under the existing weld. There is a collar in the center, which may have had an alignment notch or peg to assemble it for welding originally.

Oh, yeah, this should be fun: Everybody sees how many notches the cam has, right????

Six notches, one for neutral too. The deep grooves are where the "roller" (from the shifter sits in and holds the drum.

Good pic with the weld. Grinding the old weld away isn't difficult at all. The key would be

getting the transmission in neutral and the "star" in neutral, (of course sitting flat on the drum).

That's a simple MIG weld run around both tha failed.

Should you go the welding route, make sure the ground is to the "Star" or you'll likely, once ground is established, put a small welded arc in that spot. With all the oil inbetween everything, the best ground would be the star itself..

If that "star could be pinned, just before the welder ran a bead would be the best to ascertain the absolute, perfect position. The pin could be removed once welded.

Part #3, the roller, sets in those grooves and holds the drum from moving once in gear:

 

[Fred W]

It doesn't thread on, it just sits on the shaft. Looking at the part, it appears the thing broke just under the existing weld. There is a collar in the center, which may have had an alignment notch or peg to assemble it for welding originally.
[img=[URL="https://lh6.googleusercontent.com/-sJWcxuGagBs/U7jXO9wmqiI/AAAAAAAAN10/toKmEnURYsE/s800/star%20cam%201.jpg%5D"]https://lh6.googleusercontent.com/-sJWcxuGagBs/U7jXO9wmqiI/AAAAAAAAN10/toKmEnURYsE/s800/star%20cam%201.jpg][/URL]

[img=[URL="https://lh5.googleusercontent.com/-246QZkVsYYg/U7jXOxcVupI/AAAAAAAAN1w/0stZj5WcAdI/s800/star%20cam%202.jpg%5D"]https://lh5.googleusercontent.com/-246QZkVsYYg/U7jXOxcVupI/AAAAAAAAN1w/0stZj5WcAdI/s800/star%20cam%202.jpg][/URL]

Oh, yeah, this should be fun: Everybody sees how many notches the cam has, right????

Looks to me like the original weld was faulty. The bead on the back of the star plate looks to have all been applied to that plate and not bridged to the shaft it was being welded to. That would also point out the difficulty of welding the thing from the end. It might be done, I'm not a welder so couldn't say for certain, but it wouldn't be as strong as a good original weld if done right.

 

[TownsendsFJR1300]

Actually, the blueish tint on the back side of the star is from the original weld, heat soaking thru. The weld
was likely done by machine and on the outside appears good. That bluish tint, verifies it WASN'T heat treated afterwards, the drum itself, likely heat treated before hand.

There likely would have been a machined lip on the "star" to keep it its precise position before welding
(possible a jig), but more likely a snug fit, then welded as the part while being rotated..

We used to weld shortened rear wheel drive drive shafts on the lathe with a MIG welder. Get it true in the
lathe, both ends synced. Ground the welder to the lathe then slowly turn the lathe by hand holding the MIG
handle exactly where you wanted the weld. Always came out as if a machine welded it, no balancing needed as it was dead on..

 

[08FJR4ME]

No room for a countersunk head, thought about it but the center of the star cam is too thin. Welding, maybe, but whoever welds it has to come here....
That's how the part was originally attached, with a weld, but what I know about welding will fill.... a VERY small space. Would have to see if it can be welded in situ as opposed to a part on a bench.

I drilled for a 1-24 bolt, because that's pretty close to the size the original dimple let me get to, and I have US drill bits. Turns out I need a tap, too. Guess which tap in my set, out of the 17 SAE sizes, is worn and won't cut?

My guess is you mean a 10-24. If welded previously then it should be able to do again. I would hold off on tapping if that's the route to take. You won't need a massive welder for this job. The small portable units you carry with on hand are pretty amazing today. So I don't think getting someone there would be a problem. The biggest problem would be finding the wright welder. I have a guy that works for me who is phenomenal. Sadly that doesn't do you any good. You might want to call some of the welding supply houses. They may be able to recommend someone.

Dave

 

[TownsendsFJR1300]

Even if you could put in a threaded screw, that's NOT going to stop the star from rotating on the drum. Unless you drilled and pinned it and even that, I wouldn't trust.

The old weld needs to be ground down and the star re-welded on (pretty much from scratch as the factory did it).

A 110 volt, 135 amp welder set on high would take care of it, (preferably with gas for less weld splatter).

 

[wfooshee]

In my bolt-on plan I was going to epoxy it as well to avoid rotation under the bolt, but getting the oil off the surfaces worried me. Looks like finding a welder is the way to go, as long as he understand how important the alignment is. And yes, the 1-24 was a typo, dropped the zero.....

 

[majicmaker]

Glad you cleared that up. Never heard of a 1-24 thread pitch. I can sleep now. That would have kept me up all night.

 

[TownsendsFJR1300]

Any updates?

 

[wfooshee]

Still working on getting RH's motor picked up. I haven't made the trip because a coworker was going to Orlando for AN ENTIRE WEEK, and then he never got up with him. I think he just couldn't be bothered. (Coworker, not RadioHowie.) Another guy from here is headed down sometime soon, and he claims to actually have a cousin in RH's town!

I've passed on the welding idea on the advice of a couple of guys here that I trust. One wanted the part in his hand to weld it, and hell, if I could get the part into his hand I'd be using the one from Patriot's motor, assuming hppants still has the shift drum from that.

Putting my cylinder head onto Howie's motor is the path I've decided on, but getting the motor here hasn't happened yet. My coworkers' assistance hasn't been what I'd hoped.....

 

[RadioHowie]

Still working on getting RH's motor picked up. I haven't made the trip because a coworker was going to Orlando for AN ENTIRE WEEK, and then he never got up with him. I think he just couldn't be bothered. (Coworker, not RadioHowie.) Another guy from here is headed down sometime soon, and he claims to actually have a cousin in RH's town!

I'll make SURE my phone stay's on the charger when it's not on my belt, AND keep an eye on the call-log.

Putting my cylinder head onto Howie's motor is the path I've decided on, but getting the motor here hasn't happened yet. My coworkers' assistance hasn't been what I'd hoped.....

Sounds like the best plan. Now if we can just get it up there!

 

[wfooshee]

Well, yeah, since it gets the POS out of your hair......

 

[RadioHowie]

Well, yeah, since it gets the POS out of your hair......

......and start a little weekend project of your own???

 

[Dutch]

If it was me - - -

Clean the weld off the "star"

Locate it on the shaft.

Drill a two .156 (5/32) holes 180 degrees apart, straight in from the end, between the shaft and the star - the drill will follow the seam.

Tap those holes with 10/24 thread - insert set screws flush with red Loctite.

(30 years tool/die maker)

 

[wfooshee]

I like the thinking, and it's similar to but better than my original idea of a center bolt into the shaft. But see, the whole issue, just as with having it re-welded, is that I have NO position reference without the scar on the inside of that weld face.

Right now I can set the thing on the shaft, turn it a bit this way and that, and it practically clicks into place.

I could try marking its position somehow, but ANY error is going to ^$@* up my shifting permanently by putting the cam in the wrong position relative to the shift drum. If the cam settles any amount not dead on, the gear dogs will be slightly removed from the right position, not fully and completely engaged.

 

[TownsendsFJR1300]

Rotate that drum to neutral Using your threaded hole (and nut).

Clean down the old weld on the "star".

Bolt that star to the drum and use the shifter roller (that holds the drum in place) to ALIGN THE TWO (you don't even need to use the spring, as long as the roller falls into its appropriate indent). The trans is now in neutral, the shifter is now confirmed in neutral with the roller/arm.

Tack weld (2 or 3 tacks, on the heavy side) the star in that exact position. Remove bolt if it'll later be in the way. Run a bead around the star.

Make sure the supporting bearing is covered with a wet rag (not to catch fire) and use that star (use a small clamp to it) as your ground.

IMO, I'd get another opionion from another welder if you can get the above two lined up as such.