Recently the starter, (mini) on my car started grinding just as the engine fires up.. It engages fine and starts the engine immediately but once in a while it grinds against the flexplate just as the engine fires up. I had a medium thickness shim in place so I added a thick one but it still did it. I then took both of them out but it is still doing the same thing. Anybody ever encounter this? I'm going to try 3 shims tomorrow.

 

Check your crankshaft end play.

 

I can do that but the engine is in terrific condition. I can see though what you are saying and it is certainly possible.

 

Check to make sure the bendix on the starter moves freely and does not hang up on the shaft causing it to grind.

 

Among suggested inspections. Besure teeth on flywheel and starter drive aren't damaged. Many times engine stops in the same place nearly everytime. Sometimes there canbe damaged teeth in different part of the flywheel, where occasionally the engine stops. That would be your concern occurs.

 

Good point,

 

There is scuffing on the flexplate but with the darn thing grinding every once in a while it's bound to have some wear. None of it looks bad enough to cause intereference of movement.

 

Much might depend on what style mini you installed I'd think. Mentioning brand and model might help. Shimming as you attempted only establishes 'depth/backlash' of penetration for mesh and trouble free cranking issues. That needs to be a 'once and done' I'd think. A premium mini such as Tilton will have shimming options that allow adjustment of ring gear 'clearance'. You could very likely use Tilton specifications to measure yours.

This is a very generic Tilton install showing typical desired measurements.

A starter drive/bendix issue I'd think very likely but maybe there's appropriate shimming and clearance checking that wasn't done on the initial install. A cracked flywheel is also a 'maybe'.

http://tiltonracing.com/wp-content/u...er-54-4XXX.pdf

***I do believe you need to consider 'crank-shaft end play' - 'terrific shape' seems to hint an assumed to be correct opinion.

 

When I wrote terrific shape I was just using that as a shorter way of saying I had had the pan off about 2 months ago changing the gasket, at that time I looked everything over and the end play was either .004 or .005 I forget now which it was. Simply trying to keep the post as short and to the point as I could. Since I first posted this question I have rechecked every spec dimension of the starter including the paper clip method of bendix to flexplate clearance. I had put in 3 thin shims and as I write this I can't remember the total thickness of the shims but it was just a bit more than recommended readings. The extra shim all but stopped the problem but not all. Fast forward to last night, I was at a cruise night and the starter started acting like a low battery issue, then all of a sudden it would take of spinning the motor like it should. This happened 3 different times and was thinking bad starter. I got home and was looking things over when I found that I may have a bad ignition switch. I have two buttons on each side of the car mounted on the firewall so I can bump the engine while setting the rockers. I have done this to all my cars for years. If I turn the key on and use those buttons to start the engine it never grinds and it also never drags but I can get in the car and use the key and the problem is there. I am going to change the ignition switch today because apparently it has some sort of contact problem inside the switch. I'll post back after I get the switch replaced and let everybody know the results.

 

My initial thought was something might be wrong with the starter either the solenoid is not pulling back the sliding gear, or the gear itself in the starter is binding. Perhaps there is some wear and tear and under load does not perform normal.

I know much has been said already.

 

Changed the ignition switch today, all problems are gone, no grinding, no drag, just instant fire up like it should be. I'm making an uneducated guess that the switch was somehow activating the drive when I let off the key, the intermittent drag was probably also caused by a problem in the start position/ Thanks to all who responded.

 

Who would have thought but you made a good move in resolving the problem.

In hindsight, I guess you could have monitored the voltage to the starter (S-terminal) and see what was going on but even I did not have the initial thought at that time.

 

Not knowing how the 'bump' starts are actually wired is it possible that the ignition switch failure is maybe related - good that it now cranks as desired but it might be interesting to investigate the whys!

*****BUT - this replacement could/should maybe last for some time. NEXT failure certainly an easier diagnostic effort. SHIM replacements multiple times certainly an effort I'm sure. Shimming as I mentioned should generally be a 'once and done'!

 

Sorry I didn't get back any sooner, been busy getting ready for winter around the house. I totally agree with you about the shims, in fact, I have never had to shim a starter before, just lucky maybe. The mini I have was a swap meet no name special but it is still doing fine. I have no explanation why changing the ignition switch solved the problem but earlier this year I was out of town with the car and the starter would not activate at all with the key so the only place I found that had an ignition switch on a Sunday was Auto Zone. You already know where this is going. I believe the switch I just put in was so much better quality that it was conducting power to the starter so much better that it quit acting up. All I do know is that it took care of the problem.