[jamesk527]

About a week ago i had the gear replaced on my MSD distributor at the local speed shop and i went home, exited to put it in. But for some reason it wont fit, i just can't find out why. It is most definitely not the oil pump shaft because my distributor has another inch before its fully set. When i try to put it in i have to turn the rotor to get it to drop in about a half inch then it wont go any farther no matter what i do, and its still sticks out by about an inch. It doesn't even get far enough to hit the cam gear because i cant feel it when i turn the rotor, but the more i push it in the harder the rotor gets to turn. The gear is not upside down, and nothing on the shaft of the distributor looks messed up. I have taken my distributor out many times and it usually just falls right in, but the weirdest part is that i have to practically pry the distributor back off the motor once i try to set it in. Any suggestions? I am hesitant to buy a new one because ill have to send it back to MSD once i get it to have them change the gear to bronze and my car wont be running for 2-3 weeks. I hope its a simple mistake, but i spent 5 hours on it yesterday and i am still stumped. Anybody who could help me i would greatly appreciate it!

[Champion Speed]

I've had similar problems with new distributors...
I would lay the old and new ones out side by side and inspect them, I would also use a set of calipers to measure the OD of the distributor shaft old vs. new ...

[Champion Speed]

I just re-read the post... something is up with that distributor drive gear. I would go back to the shop that did the work. Also, those gears are not to difficult to swap...you may be able to handle it.

[nigel]

Sounds like the shop put on the wrong size gear drive. Did they give you the old one back?

[jamesk527]

Thanks for the quick replies guys. I could try swapping them myself from now on. They did give me the old one back and it seems to be exactly alike (except that the teeth are almost gone on it). But it seemed like it took them an awful long time to do it compared to usual and they said they were having trouble with it but they finally got it done. They also gave me the package and it says 351w.

[KLWorra]

I had a similar problem. The shaft was just a little too large for the hole in the block. I ended up dusting it down about 0.002".

As another suggested, check out dims on the old vs. the new.

[dodgestang]

Have you tried turning the motor by hand (or bumping the starter) when you have the dizzy in as far as you car get it by hand?)

As it engages the cam teeth, the rotor will no longer be able to be turned.

[jamesk527]

Alright i found the problem. I don't know if MSD sent the wrong gear or what, but the teeth are significantly thicker than the ones on my original steel gear. The package the gear came in was the same as the last gear i used so something obviously got mixed up here. The problem was that the gear they took off was so worn down that i couldn't compare them.