MSD Distributor

Mark m. · Aug 16, 2013

Any one ever have this happen with a MSD distributor? This thing was brand new maybe a hour of run time. Looks like the roll pin broke. Pretty much ate my cam and oil pump gear up. After looking around on the web this seems to happen a bunch.
Waiting to hear back from MSD but when I talked to them yesterday they said they would replace my dizy and I said what about the **** it ****ed up in my engine and was told not there problem.

**** YOU MSD

zukkev · Aug 16, 2013

That's ****ed up...
Likely cause for the broken shaft at the roll pin is the shaft seized in the housing due to too tight of tolerances, not allowing oil flow through the dist bushings...

Harvester of Sorrow · Aug 16, 2013

This in the Duster or the Chevelle?

Mark m. · Aug 16, 2013

Harvester of Sorrow said:
This in the Duster or the Chevelle?

Duster:booo:The car was running at a idol with 70 PSI oil pressure when it broke.
Oh well time to tare down the engine. At least I'll know what I got now. This engine was a bit of a mystery anyway since the car came from a storage auction.

CHOP SHOP · Aug 16, 2013

Damn MSD, seems they have alot of probs these days.

Binder · Aug 16, 2013

Mark m. said:
Looks like the roll pin broke. Pretty much ate my cam and oil pump gear up. After looking around on the web this seems to happen a bunch.

Sure you don't have that backwards?.... Yes this does happen a bunch. Typically what happens is the oil pump jambs which stops the distributor and shears the roll pin. It's highly unlikely that the distributor pieces tore up the gears as when the distributor broke the engine also stopped turning...... Yes what you said is possible but usually happens the other way around.

Binder · Aug 16, 2013

Mark m. said:
Duster:booo:

What engine?.... Why does the distributor shaft have a roll pin when the gear is on the oil pump shaft? Are you sure it wasn't just a hole with no pin installed in it?

CHOP SHOP · Aug 16, 2013

Im with binder on this one.

Even the common problem cant be what happened. In most cases the pump locks up and the gear connects the pump to the cam and the dist so the dist roll pin shears to let the engine spin but not the dist and the eng dies. and repairs are needed.

On the mopar (im no expert on mopars) I think the cam and pump are one connection and the dist just sits in the gear with a tab. Even if the pump locked up and chewed the gear, I dont think the dist has enough momentum/inertia to shear off the shaft just from the weight of the rotor and advance mech spinning.

At 800 rpm that shaft should be able to take a dead stop with out busting like that.

I would look at the side of that Oring seal for a HARD impression of contact to see if the manifold hole is off and putting a side load on that dist shaft.

Ive had old manifolds with sloppy holes that dont like todays machined fit dist. Ive also seen the mounting pad be crooked to the lip on the dist making crooked pressure when clamped down.

Just some things to check.

Mark m. · Aug 16, 2013

Its a 440 mopar. Cam is still turning everything moves free still. I guess when I tear it down I'll know more about what happen and yes most everything I read said that usually a broken oil pump or timming chain can cause this.
The shaft on the dizy is two piece and from what I remember it looked like it had a roll pin in it.

Binder · Aug 16, 2013

CHOP SHOP said:
Even if the pump locked up and chewed the gear, I dont think the dist has enough momentum/inertia to shear off the shaft just from the weight of the rotor and advance mech spinning.

At 800 rpm that shaft should be able to take a dead stop with out busting like that.

Good point. The pump stopping couldn't have sheared the dist shaft.

Mark m. · Aug 16, 2013

Well i'm sending it back to MSD for them to look at. May not be there problem but everything I'm reading about MSD say there quality has went to hell. Maybe thats just the web.
My buddy just bought a brand new one for his chevelle also and when he took it out of the box a tooth was broke off the gear. Now thats some nice quality control.

Harvester of Sorrow · Aug 18, 2013

Mark m. said:
Duster:booo:The car was running at a idol with 70 PSI oil pressure when it broke.
Oh well time to tare down the engine. At least I'll know what I got now. This engine was a bit of a mystery anyway since the car came from a storage auction.

Well that sucks. Now you can sell me the car.