Cant get dist to seat down all the way.... HELP ASAP

N8Miller

I need NOS....make it 2 of the big ones
Founding Member
Jul 26, 2000
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Kingston, PA, USA
ok, i am swapping dist to see if thats the reason that i have no spark. anyway, pointy end of the oil pump shaft is down, flat end up, dist goes down, but is up about 1/8"...... you can see the O ring.
any tips?

heres a pic--- hopefully it helps
483627_50_full.jpg
 
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Some of the hex ends of the aftermarket pump driveshafts are longer than the stocker.

This means that you need to trim about 1/4" off the bottom of the distributor.
I'm not sure how you can verify this with the timing cover on...
I had my cover off when I mocked mine up...

Could this be the issue?

jason
 
you might try removing the rotor and gently tapping it with a mallet. That's what I had to do and it worked. No problems that I know of. My star washer was just up a little too far preventing it from sliding all of the way on the shaft.
 
ok, explain to me why i have to cut off 1/4" when the other one that came outof it is the exact same size?

rubber mallet theory didnt work. i guess im cutting.

edit: what if i just went to the parts store and got a stock replacement oil pump shaft? should it be shorter and i just use the dist the way it is? i coudlnt get the dist cut till monday at the local machine shop.
 
ok, explain to me why i have to cut off 1/4" when the other one that came outof it is the exact same size?

rubber mallet theory didnt work. i guess im cutting.

edit: what if i just went to the parts store and got a stock replacement oil pump shaft? should it be shorter and i just use the dist the way it is? i coudlnt get the dist cut till monday at the local machine shop.
The distributors are the same, it is the ARP shaft that is different.

The length of the upper Hex section on the shaft is not as long on the ARP rod when compared to a stocker (actually the stocker is hex shaped throughout the entire length).
You could extend the ARP rod Hex section by lengthening the Hex section, but that isn't practical and may weaken the rod.

The easiest solution is to hack a section of the dist off. You will still have plenty of engagement on the shaft.

Give a double check that nothing is hanging up anywhere, then measure off about .200" and break out the hacksaw...

If you want to verify...
Put some paint on the base of the hex on the ARP shaft and install in the motor. Attempt to install the dist; when it bottoms out on the ARP shaft it will rub off some of the paint.


Maybe I should try and get some pics of a mockup of this...
(may be a few days though)


jason
 
jason, i was also using the ARP one BEFORE the new dist install. if the stock one is only a few bucks, im gonna pick up one... i am really only testing to make sure that the dist is bad and thats why i dont have spark.
 
cutting the distributer sounds like a bunch of BS to me...no offense to anyone. I have the ARP oil pump shaft part number ARP-154-7904 from Summit and I didn't cut anything. I'm using the the stock distributer.

Did you install the oil pump shaft yourself? I'll see if I can find a pic, but I don't think I have one. There's a little "star" type washer that goes over the hex end on the top of the driveshaft. I don't remember exactly why it's there, but that was what was holding my distributer up a little and keeping it from seating all the way.

I know you said you've bumped it and malletized it, but I don't really think you should have to cut the distributer. That may solve the problem, but it may not be necessary.

EDIT: Here is a pic of the star washer on the oil pump shaft (the one in the pic is the old shaft - not sure what brand, not my new one):
The start washer was simply up too far on the shaft, so when I tapped the distributer down w/ the mallet, it slid the star washer down the shaft into the appropriate place. If that doesn't work for you, then I don't know.

pic.php
 
look at the shaft in the pic...there's nothing that would keep the distributer from sliding over the shaft except that star washer, which WILL slide down. Cutting the distributer is going to make the distributer slide down in the hole farther because the bottom won't come into contact with the star washer. Will cutting the distributer hurt anything? Maybe not, but I just think he needs to tap a little harder
 
I just had the same problem. I had to cut about 1/8-1/4" off my distributor. I had to do this on my ARP and my FMS hardened shafts. It wont hurt the distributor or the oil pump shaft by doing this. The are hex end and then have round "raised" part after the hex end and wont let the dizzy seat all the way. Unless the motor is out of the car, i wouldnt pull it out to change the oil pump shaft, save yourself the hassle and trim the dizzy to fit, this is a pretty common problem with non-stock shafts.

Anthony
 
Just a general question, as I can't recall the 'correct' answer.

Isn't the star washer supposed to be on the bottom end of the shaft?
I thought the star is supposed to be located on the bottom end, under the lower flange, to prevent the shaft from lifting out of the pump when the distributor is removed.

I think the pic shows the shaft in upside down?


EDIT:
Nevermind, I just found a diagram that shows how it sits.
The pic is correct.