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Topic: after market Dizzy FYI *** IMPORTANT READ (Read 929 times) previous topic - next topic

after market Dizzy FYI *** IMPORTANT READ

my son is dealing with a lot of dizzy problems like others who have decided to use the box stores and lifetime warranty and so forth.  A few years ago his 88bird dizzy when bad and he did a core for a new one.  For unknown reasons he seems to end up going through one about every 10 to 14 months.  with a reciept its a simple swap at the parts store.

one of the key indicators your after market dizzy is giving you heads up its about to go bad is every so often your car feels like it just missed spark ,, engine may buck once or twice then the issue is gone.  This is what mason is seeing happen.  On my 1990 Bronco,, since i really dont do many mile per year on it,, i have had an after market dizzy in there and its just now starting to have a minor misfire as well.

getting back on topic.
Recenty mason dropped in another dizzy.  it went in like normal and all is well but within a 20 or 30 mile test hit, something did not seem right.  He got back home and pulled the dizzy.  The bottom of the dizzy gear was warn off (the size that faces the engine block "Pad" so to speak where you can see the oil pump drive shaft.  Also the gear on the dizzy was jacked up.  He is a steel on steel setup due to a new"er" explorer build i did for him a few years ago. 

He inspected his cam and it looked like it survived. He mentioned that he seems to recall that when he installed this dizzy, it seemed like the hold down clamp felt different as he tightened it down.  It was like the hold down clamp was "pushing the dizzy down into the engine as he turned the bolt.  He ordered up a dizzy and dropped it in and all is well to date.
He brought this faulty dizzy back home over christmas and i looked at it to confirm my idea was correct. 

SO.... here is the meat of it....

CHECK your new dizzy for one particularly important measurement.  I had suspected that the only way this could have happened is if the roll pin holding the dizzy gear on the shaft is located futher down the shaft.
i compared an oem dizzy to this faulty one and found that his faulty dizzy gear roll pin was about 3/32'' lower than its supposed to be.  The damage it caused was the bottom of the dizzy gear ate away at the engine block ear where the dizzy shaft drops into and as well the bottom of the dizzy gear and as a result the dizzy gear teeth themselves.

This caused us to look up specs on an oem 5.0L dizzy and to our surpise there is a huge amount of information on this topic as well as clearnces.

Hope this helps someone


Re: after market Dizzy FYI *** IMPORTANT READ

Reply #1
But the length on the distributor housing AND the shaft is identical to the old one, no?

There's a place here that rebuilds distributors, on the popular units...surely they'd do a 5.0 Ford....I'll nose around. I'd rather have a rebuilt OEM part than a chinese POS that (as you've discovered) has piss poor tolerance and QA issues....

You can change the gear, too, if need be..
'84 Mustang
'98 Explorer 5.0
'03 Focus, dropped a valve seat. yay. freakin' split port engines...
'06 Explorer EB 4.6

Re: after market Dizzy FYI *** IMPORTANT READ

Reply #2
everything about the dizzy itself appears to be correct.
 the only difference is the hole that was drilled for the dizzy gear roll pin.  that hole is further down the shaft.

this problem dizzy is already back into the autozone system as an exchange for a new one.

this issue is going to be really hard to detect and i guess the only way you will know is when you drop it in the hole and notice that you have an ever so slight gap between the engine block and the dizzy base. 

Re: after market Dizzy FYI *** IMPORTANT READ

Reply #3
The location of the gear is very important and it's a good idea to check side by side dizzy's before exchanging on the location.  If you have the chance to get one from the local yard whether good or bad electronically, it may be a good idea to grab it as a visual check.

Although the spring pin hole may offer a quick check, the location of the teeth is what matters.  The location of the spring pin hole for the gear and distributor shaft may differ but the teeth location must be the same.

Thanks JC for the heads up!
1988 Thunderbird TC, 5spd
Stinger 3" single exhaust, Cone Filter, Adjustable Cam Pulley, Schneider roller cam, Walbro 255 lph, AEM Wideband O2
'93 Mustang Cobra replica wheels on 235/50R17

'21 F150 Powerboost
'17 Husqvarna TX300

Re: after market Dizzy FYI *** IMPORTANT READ

Reply #4
The Cardone remanufactured units are really good as far as I know.  The one that comes with the TFI chip is P/N 842892MA.  They do not have lifetime warranties but I would bet the quality is a lot better than the AutoZone house brand.

83 351W TKO'd T-Bird on the bottle

93 331 Mustang Coupe - 368 rwhp