Thanks Grant
the car was running with that grim looking dizzy until about 8 weeks ago!
I will read your instructions for removing the dizzy and hopefully i can get to that # plug
looking forward to another adventure on monday!
Bob

 

ok Grant
so i just read your excellent instructions, but i think i am already in timing trouble as my rotor has been freewheeling !
when i removed the plug wires i have labelled them, so if i remove the dizzy base what is the procedure for replacing without the rotor to dizzy body referencing notch?
things appear already bleak !
can i rotate the engine to achieve TDC and a reference point? if so do i do this before removing the dizzy or is it now academic?
Thanks in advance

 

Bob,

I understand the free wheeling rotor and shaft.

The placing of the engine at TDC Compression Stroke of #1A is just an industry thing, so that when the repairs are done, the engine is ready to accept, You just need to get the rotor pointing at the related spark plug terminal in the cap, #1A in this case. The V12 cap has a #1 cast in the cap adjacent to that post, easier.

#1 is used by me from habit, but it matters not as far as the engine is concerned.
EXAMPLE: Using #3A (easy plug to get to), set the engine at TDC for that cylinder, then when returning the distributor, ensure the rotor is pointing AT #3A cap terminal.

If this is not done prior to removal, NO PANIC, simply time the engine before refitting, and all is sweet.

My 1st V12, I took the distributor out, OOPS, coz all the 6 cyl engines are a "tang drive" and only return one way. I had no idea the V12 was gear drive, BUGGA. 3 days later, running, many, many beers, and NO books, Forums, or the like, just a shady tree a Jag, and BEER.

 

Haha, Grant. An original “shade tree mechanic”
Thought it was just my father and grandfather that did that stuff.......or told such stories.

 

When I get to the car tomorrow the temp is likely to be negative 5 so once I ve established if the shaft etc is rotating on cranking I will probably be getting very cold hands.....so may well take the easy route of just removing the dizzy rather than trying to find a TDC reference, I hope i am not going to make the refit a very difficult job to re-time
Thanks for your help so far....no shady trees this time of year, and i'm trying dry january!

 

I encountered the loose rotor twice in my auto life.

1. I was rushing from class at college to my after school job at a full service station. My 41 Studebaker just quit about a half a block away. I coasted in. worked all afternoon. then came a quiet evening. My boss let me work on it Dizzy rotor turned freely!! Pulled it., All seemed well. Timing gear!!!! Not hard to get to it. amazing! toothless fiberoid thing. Dad came and got me. OK to use the Dodge for class and work, for a time. Got a new one. Put it together. Wow! It ran again!!!!

2. Circa 54. Northern Germany., circa Lutjenburg. army service. My Belgian assembled 50 Chevrolet 6 quit. Lucky in a small town in front of a small mechanic shop. Same issue. free style rotor!!! Made a deal with shop to fic. They had an ancint 30's vintge Chevrolet truck Similar engine. So, they were familiar. Got it back runnning sweetly. reasonable price. guys pleased to get the work

3. My forst endeavour with a Chev v8. Tang for the pump helical gear for the cam! Set just off and let it twirk in to the correct alignment. took a few stabs to get it..

 

Bob,

Remove that distributor, too bloody cold for messing at the moment.

The engine can be set up for refit later.

I have a PDF on it somewhere, and will send it when cyber space returns it.

SIMPLE, so worry not.

 

soooooo, removed the distributor this morning with no issues, I have dismantled it as far as the main body and centrifugal weights, how do I get that drive gear off the bottom end, it has a knurled looking pin through it....should it just tap out?

Thanks

 

Thats the theory.

I have never driven one out, they be super tight in that gear, and I was always afraid of smashing that gear. Hence the soaking in Diesel for the ones that had a stiff lower section.

 

Bob
Put us out of our misery! Have you found out why the dizzy is turning freely?

 

hey Greg sorry to keep you dangling!
from what I can see the top half of the main spindle (the part with the weights on appears to be turning independently from the lower part that goes down to the jackshaft. I can see what appears to be the point where the two parts of this shaft join just below the centrifugal weights and assume that whatever normally locks these two parts together has failed, is is a slot and groove? I have been unable to move the pin holding the drive gear on the shaft so this is as far as I can get right now, the top has a clip that secures the top end but this is recessed and so far inaccessible.....would be nice to be able to see the broken part.....in any case looks like I m looking for a new dizzy and then some timing work!
Any suggestions on further dismantling gratefully accepted!
thanks for your input everyone

 

Grant explained to me that the dizzy shaft is in two parts, the bottom including the pinned drive gear part which is machined down at a given point to a tallish spindle, onto which spindle is a fitted quite finely an outer hollow top shaft that fits over the spindle, and carries the rotor. The outer hollow top shaft can rotate a bit on the bottom part's spindle, in order that the timing advance and retard can move the rotor relative to the geared part. But the top part can only rotate so far before hitting a stop device, which I think, I am not sure, is part of the balance weight and springs parts.
I reckon you have somehow either managed either to sheer off the spindle part, or break the device that prevents the top shaft rotating more than so much. As you say, a replacement dizzy is your best bet. But check that there is not something that can be easily fixed with a spot of weld or similar.
good luck, and a pic or two would be interesting when you get it all apart. FWIW, I do not think it is necessary to remove the gear pinned to the bottom shaft at all.

 

Once I have completed my household chores to managements satisfaction, I will dig out my spare dizzy, dismantle it, and do an explain.

DO NOT hold your breath, may be 24 hours before management gives me the "nod".

 

OK, I escaped. Phone rang, she will be hours, HA.

Here ya go. If its confusing, ask, I will sort it.

 

Absolutely brilliant explanation and snaps Grant. I have learnt something, again. Many thanks

 

Soooo here's the photo of the area where the two parts of the shaft have decided to rotate independently of each other

Yesterday I sourced a replacement distributor from a 1990 vanden plas parts car, (bargain 75$ CAD) cleared the snow of it and removed before my fingers froze! The replacement is in far better condition than the one seen above, pickup resistance in spec, even rotor and cap look in serviceable condition, planning to fit as soon as temperatures rise a bit hopefully next week......I will let you all know how this goes.....so Mr Grant please forward instructions on how i can reset the ignition timing as everything is now out of whack!
This forum is awesome, thanks to everyone for sharing their experiences

 

OK!!!

Much better a good part.

Getting there, step by step...

Carl

 

SOOOOO
yesterday I braved the cold and along with my very patient wife ( training was not an easy process) we found TDC on 1A dropped in the distributor according to Grants excellent instructions and she fired up first turn of the key......depression and black clouds cleared! not only that she ran better than ever and thats before the final timing is done (Grant can you help here please!) That sad looking distributor swapped and replacing the injector rail hoses has completely changed the sound and feel of the motor. So to anyone else contemplating a distributor service do not be afraid follow the instructions and it really is relatively simple once you take a breath and a slug of your favourite motivational juice, look past the spaghetti of wires and hoses and it all makes sense
thanks again guys

 

Well done, great work. Grant will be along once the sun comes up in Oz to give you his drive-timing (patent G Francis) info.

The big thing in future is to be sure to use the oilcan to place a few drops of synthetic down the rotor shaft having removed the rotor every so often, thus ensuring the thing never jams on you again.

 

Here you go Bob.

SIMPLE cars these Jags, and especially the Double Six versions.