[70f400]

I received a replacement MSD RR dist curtesy of Summit customer service. Glad they stand behind there products.

The new distributor with the steel gear has little to no endplay. When I installed the BOP polymer gear there was .025-.030 endplay. How much endplay should there be .002-.007?

I measured the edge of the hole to end of gear and found approximately .02 difference with calipers. I have a .02 shim I placed on it and now there is no endplay but the shaft spins free. Should this work.

[70pontiaction]

I think I used to shim them at around .012 - .015" but it's been a few years since I blueprinted a distributor.

[Sun Tuned]

Nah you don't want to shim it too tight.
BOP says they want .010 or something very close to that if I remember correctly. See your instruction sheet for exact numbers.

I disagree with their numbers. I think that's too tight on an aluminum stock dist. I realize yours is not stock aluminum housing.

My personal opinion... .025 is fine, unless it's iron housing, I don't like any of em tighter than .015 period. Now there will be those that differ with this and that's fine too. I've never had an issue at all with my end play numbers and like anything else...
Your results may vary.

Glad they stepped up for you.

[Schurkey]

Originally Posted by 70f400

there is no endplay but the shaft spins free. Should this work.

Steel shaft. Aluminum housing. Aluminum expands more than steel. What happens when the housing expands from heat? You had better have enough free-play so that when the distributor housing is as hot as it can possibly get in service...there's still some free-play. It is ENTIRELY possible for oil temperature to get to 300F; sometimes higher depending on throttle position and length of time.

Shimming distributors is way over-emphasized. Downright counter-productive, in the case of Oldsmobiles, where not enough free-play will destroy the block surface that the distributor gear rides against. The oil pump drag will cause the distributor shaft to thrust upward or downward depending on the angle of the helical gears. Unless you lose oil pressure, the thrust is going to be quite reliable.

[Cliff R]

I NEVER shim them tighter than .012" for any reason. I shoot for around .020", it can be a little more and I don't get nervous. I've pulled out many a factory HEI that was up over .080" and still going strong.

For Oldsmobile's I just leave them wherever they are at as Schurkey mentioned they thrust down into the block and rest against an insert of some sort.

Learned that deal the hard way when I got blamed for a distributor we set up taking out the cam bearings in an Oldsmobile build......FWIW......Cliff

[Schurkey]

Originally Posted by 70f400

I received a replacement MSD RR dist curtesy of Summit customer service. Glad they stand behind there products.

The new distributor with the steel gear has little to no endplay.

How does MSD get by with this?

Are the Ready-To-Die distributors made in China now? I didn't think so, but...

[Sun Tuned]

Well you know how this game is played by now...

Throw crap at the wall and see what sticks.

They like a lot of other companies might seem to think it's cheaper to just replace only the stuff that flys apart than to correct the issue at hand in the first place. That's becoming more and more the norm instead of the exception these days.

Maybe it was just a fluke anyhow. Or maybe he has something going on. Hard to tell over computer.

But whatever it is that's not looking right.
I figured he'd had to eat it....

[Sun Tuned]

Looking again at where that bushing is worn, if that dist was installed in the engine what I call anatomically correct(in other words was the vac advance on the driver side like it would have been if Pontiac installed it)...
I think I'd dry seriously be checking cam end play just for a precautionary measure.

That looks really suspect to me. I'd look into it.

[GOAT WHORE]

I have over 16,000 miles on my MSD rtr and no issues.