The mini-starter on my bbc will bind about every third time I start it. Today it wouldn't disengage from the flex plate. I loosened both bolts and got it to retract. The flex plate is tight. There are only two bolt holes in the starter. It was tight. I've tried shimming the inside, then the outside bolt, then both bolts with no improvement. Looking at the flex plate the very edge of the teeth facing the starter are wearing off. The starter and flexplate do not appear to be mounted parallel to each other. I've never noticed that before, maybe it was just the angle I was at. I've hopefully attached some pics. Appreciate any thoughts.
starter engagement
Paul J
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The mini-starter on my bbc will bind about every third time I start it. Today it wouldn't disengage from the flex plate. I loosened both bolts and got it to retract. The flex plate is tight. There are only two bolt holes in the starter. It was tight. I've tried shimming the inside, then the outside bolt, then both bolts with no improvement. Looking at the flex plate the very edge of the teeth facing the starter are wearing off. The starter and flexplate do not appear to be mounted parallel to each other. I've never noticed that before, maybe it was just the angle I was at. I've hopefully attached some pics. Appreciate any thoughts.
Attachments
Might be that the Flexplate isn't 100% flat and gets way too close to the starter pinion gear somewhere causing it to bind up or not engage properly. Could be tweaked more than can be easily shimmed for. If you want to continue using a small starter, my suggestion is get a more powerful better designed starter and shim it. This starter worked for me when I had a similar problem with a mini starter with that same pinion gear yours appears to have.
That starter Steve linked is a good part.
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Mark the flexplate every 90 degrees then spin the engine from the front with a big ratchet (cold engine,make sure the ignition is off and the throttle is wide open so it cranks easier) then look for where the flexplate is bent.If it's bent you'll need to replace it.Don't trust your eyes you'll need something to measure it.
If the starter gear doesn't disengage, there a few possibilities.
- faulty one way clutch in starter.
- out of round f/plate [ unlikely ].
- the ring gear has seen better days, looking at the pic. Possibly some of the damaged teeth have 'burred' over, resulting in the pinion gear getting stuck.
I would try a shim under the inner bolt only.
- faulty one way clutch in starter.
- out of round f/plate [ unlikely ].
- the ring gear has seen better days, looking at the pic. Possibly some of the damaged teeth have 'burred' over, resulting in the pinion gear getting stuck.
I would try a shim under the inner bolt only.
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Are you using knurled bolts? Is the starter drive coming out far enough? Have you followed the instructions for setting clearances? If the starter drive is not disengaging when operated electrically it needs to be shimmed, if your manually engaging without power, its normal. The engine has to turn for it to pull back.
Sometimes with aftermarket starters and aftermarket "knurled" bolts the two do not match up in hole and bolt diameter. Additionally, I've encountered low grade bolts that bend at the knurl after a few months of frequent starter use on a 10:1 compression BBC and high torque mini starter.
These issues create mis-alignment of starter gear to flywheel/flexplate - enuff to damage one or both.
I've read that shim sleeves are available to correct the bolt to hole mismatch.
That flex plate is done. You will never get it to mesh right anymore. You should always grab the pinion gear and pull it out to mesh them by hand to see the alignment and depth. You can remove the solenoid to easily move the pinion on original style starters. Mini starters are a little tougher but it still needs done.
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This is absolutely true. the knurled portion of the bolt should be a close fit in the starter where the starter meets the block. Many aftermarket mini starters require this bolt. I spent $15 on some shiny ARP bolts only to find they had the smaller diameter knurl so they now are shelf ornaments!
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There are 3 lengths for knurled bolts, make sure you get the right ones.
Pretty sure! What does that mean?
I would also be looking for a crack or cracks up towards the center
of the flexplate while your there.
I agree the flex plate is toast and probably cracked.
Bolt dont look correct from what I can see.
How long has it been acting up and or sounding crappy
while cranking?
I would also be looking for a crack or cracks up towards the center
of the flexplate while your there.
I agree the flex plate is toast and probably cracked.
Bolt dont look correct from what I can see.
How long has it been acting up and or sounding crappy
while cranking?
I for sure would put in a new flex plate; looks rough to me.
Not an expensive repair and you don't even need to take the trans out. You just need to separate the trans from the engine. Take the drive shaft out and the cross member bolts. Back out the bolts
between the engine and trans, but don't take them all the way out. Disconnect the plate from the torque converter and pull the trans back. Get a wrench up there and take the fly wheel out. Done it probably a half dozen times. If you
take your time its not a bad job. If I'm not mistaken there is a trick to getting the flex plate bolts disconnected. You put one wrench on the bolt, then you use another wrench at the bottom of that wrench as a kind of leverage to loosen/tighten the bolts.
Double, Triple check your wiring.
Also, go over that flex plate and look at all the teeth. They make a tool so you can turn it, the tool is not expensive.
Forgot to add this; bolts don't look correct to me either, but if that is what came with it then so be.
The site has been terribly slow for me that I can barely type although all my other PC applications work fine. I'm using an editor and then copying and pasting into the web site. Too many advertisements?
Not an expensive repair and you don't even need to take the trans out. You just need to separate the trans from the engine. Take the drive shaft out and the cross member bolts. Back out the bolts
between the engine and trans, but don't take them all the way out. Disconnect the plate from the torque converter and pull the trans back. Get a wrench up there and take the fly wheel out. Done it probably a half dozen times. If you
take your time its not a bad job. If I'm not mistaken there is a trick to getting the flex plate bolts disconnected. You put one wrench on the bolt, then you use another wrench at the bottom of that wrench as a kind of leverage to loosen/tighten the bolts.
Double, Triple check your wiring.
Also, go over that flex plate and look at all the teeth. They make a tool so you can turn it, the tool is not expensive.
Forgot to add this; bolts don't look correct to me either, but if that is what came with it then so be.
The site has been terribly slow for me that I can barely type although all my other PC applications work fine. I'm using an editor and then copying and pasting into the web site. Too many advertisements?
not sure on a mini starter, but on a regular starter you need 1/8 inch between the outside of the ring gear and the axle of the starter gear. I would check that every 90*.
last few remanutlfactured starters I've bought for a automatic, I had to shim them quite a bit to get the proper space. I think they are made in China nose cones on the reman starters. jim
last few remanutlfactured starters I've bought for a automatic, I had to shim them quite a bit to get the proper space. I think they are made in China nose cones on the reman starters. jim
hello i agree with everyone the flex plate is toast, make sure your start circuit is working good good charged battery is what you need, so when your ready to set up the new ring to starter gear clearance get a the big paper clip undo till its straight just bend it so you can handle it , slide it between the starter gear and flex ring with the starter gear fully engaged slides in the clip a little drag good to go, dont forget there is a tooth amount difference between automatic flex plate and stick, im sure you know this any way keep us posted on your progress.
hey be safe and happy motoring
hey be safe and happy motoring
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THe bolts that David Bates posted from Summit are the bolts to use just measure your starter,s length the bolts shank should be about a 1/2 an inch longer than the starter.Don't use just any bolt it is that important.You're on the edge of having to replace that flexplate order the bolts before you cause any more damage.
Put the bolts in an electric drill with protective cardboard around the threads. Drill running, use some emery paper to take the edge of the knurling.
Some claim the knurling is to 'centre' the bolts. I do not believe this. I have measured the knurling on a few bolts, it is about 0.004" larger in diameter than the bolt shank. When you think of the variables involved in starter mounting: concentricity of the bolt threads, how these threads centre when the bolts are torqued, difference in expansion rate of a 14" flywheel/f'plate compared to the block, I don't see a 0.002" radial difference as being significant to starter mounting.
I believe the knurling is purely to identify the bolts as starter bolts.
Some claim the knurling is to 'centre' the bolts. I do not believe this. I have measured the knurling on a few bolts, it is about 0.004" larger in diameter than the bolt shank. When you think of the variables involved in starter mounting: concentricity of the bolt threads, how these threads centre when the bolts are torqued, difference in expansion rate of a 14" flywheel/f'plate compared to the block, I don't see a 0.002" radial difference as being significant to starter mounting.
I believe the knurling is purely to identify the bolts as starter bolts.
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Oh, but it is. There are two different knurl diameters I have seen on GM 3/8"-16x4.33" long starter bolts (0.398" & 0.381", thats 0.017" difference) and you need the correct ones for your starter. The fact that the bolts the OP bought at O'Reilly's did not fit points to the fact they were the larger knurl bolts which many of the later GM and aftermarket mini starters use. I'm not saying that the correct bolt is a cure-all for starter engagement issues but it is a good place to start.
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