Tach Drive Dizzy Shafts

[big2bird]

I have, for the most part, always used Paragon Repo shafts in my rebuilds. The gears seem to mesh better, and the Mid America shaft has no chamfer on the oil pump end. (Aids in insertion). Now, while you can use a Mid America shaft, and either chamfer it with a grinder, or just struggle a little longer to get it in the engine.
So today, I am finishing assembly on a dizzy for a VM member, and since the car is going down the road, and I am out of Paragon shafts, I decide to use a Mid America shaft. WRONG.:tth:
Look at the following pictures, and see if you spot the problem. The Mid America shaft has the squared end, and is the top shaft as viewed..




Lars will pick up on this right away.

 

[TimAT]

Looks to me like it'd be a bear to get into the oil pump drive.

 

[big_G]

I see the weight/rotor platform on the M-A piece is out of phase with the original unit, although I don't know if that will be a problem.

 

[big2bird]

I see the weight/rotor platform on the M-A piece is out of phase with the original unit, although I don't know if that will be a problem.

Bingo. No way to align the rotor with the dimple on the gear.POS
If I have time someday, I'll try it on the Sun machine using a clear cap, meanwhile, I'm glad I caught it.
I NEVER have issues with the Paragon stuff, and hope they continue in business with their good qualtiy control.:thumbs:

 

[mrvette]

Eh the most to be off is if the thing was on there backwards, probably split the diffy since off 90*.....

not so awful evil.....smoke a doobie and expand your mind, you old hippy....

:clobbered::bounce:

 

[big2bird]

Oh. Before the ration of e-mails and phone calls asking, this is the first time I tried to use one of these. All you guys have gotten the proper shaft(ing).

 

[lars]

I have pointed this problem out to Mid-America on 4 different occasions, including a personal phone call to the owner, written correspondance, and e-mails. Due to my complaints, they are sending me correctly clocked shafts when I order and specify (I typically have to send back 2 shafts before they send me a correct one), but they are not purging their inventory because "most people don't care about the clocking."About 2/3 of their shafts are clocked wrong, and you have to request a "correct" shaft to get one that's right. Although the "wrong" shafts will still allow you to install the distrubutor and time the car, you cannot "clock" the distrubutor correctly in the block with the incorrect shafts, and you cannot install the distributor shielding on C2's once the engine is timed correctly due to the incorrect clocking. Pretty crappy attitude on the behalf of Mid-America when they are knowingly selling bad parts.

(Someone please feel free to forward this to Mid America)

Lars

 

[redvetracr]

I realize it`s not the point but you should be able to correct that by re-brazing the weight plate if you want to seeing how your going to "spin" it and adjust the curve anyway.
BTW, have you tried the spray weld technique to repair a grooved factory mainshaft?

 

[big2bird]

I realize it`s not the point but you should be able to correct that by re-brazing the weight plate if you want to seeing how your going to "spin" it and adjust the curve anyway.If it had to be saved, sure.
BTW, have you tried the spray weld technique to repair a grooved factory mainshaft?

Metal Spray? I haven't used that in 30 years. For $60 for a new one, I don't know as metal spray and re-machining is worth it.

 

[redvetracr]

probably not but there is something to be said for genuine GM...

 

[big2bird]

I have pointed this problem out to Mid-America on 4 different occasions, including a personal phone call to the owner, written correspondance, and e-mails. Due to my complaints, they are sending me correctly clocked shafts when I order and specify (I typically have to send back 2 shafts before they send me a correct one), but they are not purging their inventory because "most people don't care about the clocking."About 2/3 of their shafts are clocked wrong, and you have to request a "correct" shaft to get one that's right. Although the "wrong" shafts will still allow you to install the distrubutor and time the car, you cannot "clock" the distrubutor correctly in the block with the incorrect shafts, and you cannot install the distributor shielding on C2's once the engine is timed correctly due to the incorrect clocking. Pretty crappy attitude on the behalf of Mid-America when they are knowingly selling bad parts.

(Someone please feel free to forward this to Mid America)

Lars

Really makes you wonder how many of these are out there, and the trouble it has caused. I also bet there are plenty of novices who don't have a clue what is different.

 

[redvetracr]

I have pointed this problem out to Mid-America on 4 different occasions, including a personal phone call to the owner, written correspondance, and e-mails. Due to my complaints, they are sending me correctly clocked shafts when I order and specify (I typically have to send back 2 shafts before they send me a correct one), but they are not purging their inventory because "most people don't care about the clocking."About 2/3 of their shafts are clocked wrong, and you have to request a "correct" shaft to get one that's right. Although the "wrong" shafts will still allow you to install the distrubutor and time the car, you cannot "clock" the distrubutor correctly in the block with the incorrect shafts, and you cannot install the distributor shielding on C2's once the engine is timed correctly due to the incorrect clocking. Pretty crappy attitude on the behalf of Mid-America when they are knowingly selling bad parts.

(Someone please feel free to forward this to Mid America)

Lars

Really makes you wonder how many of these are out there, and the trouble it has caused. I also bet there are plenty of novices who don't have a clue what is different.

"novices" like Mid-America.....actually they aren`t novices but they obviously just don`t give a shit about the crap they sell....

 

[big2bird]

"novices" like Mid-America.....actually they aren`t novices but they obviously just don`t give a shit about the crap they sell....

This what I like about Doc. If it's crap, he won't sell it, even if it's the only source, or it hurts sales.

 

[mrvette]

"novices" like Mid-America.....actually they aren`t novices but they obviously just don`t give a shit about the crap they sell....

This what I like about Doc. If it's crap, he won't sell it, even if it's the only source, or it hurts sales.

Well, Doc is obviously correct, especially with safety related stuffs, like bearing and t-arms, and brakes/suspensions....the rest of it can blow up or OFF and well , so what,.....just irritating, not getting killed over it....

but for a engine/tranny/diffy blowing up....THAT would cause a heart attack....:crap::suicide:

as for this dizzy shaft stuff, I don't remember ever having much issue with them aligning, untill messing with the TPI some years ago, and naturally having the gear on backwards...the dizzy body hit the manifold...so I just 'danced' the wires to pull it back around....but it looked off 1/2 a slot on location, forgot about it....:lol: I have always been more results oriented than pay much attention to the pretty aspects of cars, on account of pretty and a daily driver just don't mix too well for every long....

which is why I hate to paint....

:crap:

 

[big2bird]

Here is a picture of the Paragon shafts. Notice the correct indexing, and the chamfer for easy insertion into the pump drive shaft. MUCH better quality than the Mid America repop.
I have also found the Paragon gears mesh better, and the Mid America bronze coupler can be machined off center, causing the tach gear to mesh incorrectly.
The Paragon shaft is in the middle, GM on left, MA on right.

 

[big2bird]

And of course, the finished product. Rebuilt to spec, curved to the Chevy Powerbook curve, with a fresh B-1 can for the application:

 

[mrvette]

It's ONLY just points, where is the HEI module???

:bump::hissyfit::quote:

 

[lars]

And of course, the finished product. Rebuilt to spec, curved to the Chevy Powerbook curve, with a fresh B-1 can for the application:

Bird -
You might want to reconsider the use of the "B1" vacuum can - it does not have a useful range with a performance engine since it needs up to 18 inches of vacuum to pull all the way in. Few performance engines will idle at 18 inches, so the B1 cannot be used with direct manifold vacuum. A better selection for a performance application is the VC1765. Check vacuum in "drive" if automatic - it must be numerically more than 18" to use the B1 can.
Lars

 

[big2bird]

This is for a bone stock 74, but I'll have him verify the idle vacuum again.

 

[mrvette]

This is for a bone stock 74, but I'll have him verify the idle vacuum again.

LIttle tough to do if you got the dizzy, no???

:bonkers::beer: