[dhcarguy]

I got the pilot bushing out and found (I think my vibration problem). The bushing is really beat up and the center hole is worn much wider. Can see in the pictures, I hope.
What would have caused this?? Sure hope it isn't an out of balance engine problem. Engine was in my car when I bought it 19 years ago. Don't know how they balanced it.

[dhcarguy]

you can see the complete center hole of the chevy bushing below

[Tom Vaught]

Is is an optical illusion or are the two pilot holes in the crankshaft on different centers???

Tom V.

[67ramair4]

It appears the flywheel holes are elongated! Were they loose, or is this just the picture?

[dhcarguy]

Tom,
That an optical illusion from camera angle.

Ram air,
No, they were EXTREMELY tight.

Thanks, Dave

[geeteeohguy]

You need to verify that the bellhousing is square and true to the engine. This is done with a dial indicator taking measurements. Shifted dowel pins in the block or a worn or warped bellhousing will cause the transmission input shaft to be out of line with the crankshaft of the engine and cause vibration, worn pilot bushings or pilot bearing failure, and will eat up the mainshaft and bearing on the transmission. On my old Corvette with a scattershield, it was .120 out of line and it took out the transmission main shaft and bearing.

[67Fbird]

Ild say you got your milage out of that one...wow! ^^^ as stated...probably MORE of an alignment issue than balancing.

[dhcarguy]

Originally Posted by geeteeohguy

You need to verify that the bellhousing is square and true to the engine. This is done with a dial indicator taking measurements. Shifted dowel pins in the block or a worn or warped bellhousing will cause the transmission input shaft to be out of line with the crankshaft of the engine and cause vibration, worn pilot bushings or pilot bearing failure, and will eat up the mainshaft and bearing on the transmission. On my old Corvette with a scattershield, it was .120 out of line and it took out the transmission main shaft and bearing.

Thanks Jeff,
I was wondering if that might be one of the reasons. I do not know how to do that and do not have a dial indicator. My car is not able to go to a garage to have it done.
Anyone want to go to Bucks County for a house call.

[67Fbird]

$30 at harbor frieght will get you what you need.

https://www.harborfreight.com/1-in-t...dial+indicator

+ the magnetic base....and you too can accomplish this task. Now if things are OFF....you need correction parts (dowels, shims...) that is still only a few bucks.

[dhcarguy]

OK, I am finally checking Parallel and Concentric with a borrowed dial indicator.

Only got to checking parallel for now. here are my results. What ,if anything should I do with the bell housing. Is it close enough to continue?

I copied onto paper to read easier.
Thanks everyone, Dave

[4dblnkldude]

I would shift that bell over to the pass side .005 then check it again.

[dhcarguy]

Originally Posted by 4dblnkldude

I would shift that bell over to the pass side .005 then check it again.

Thanks Matt,
This isn't for concentric run out, but for just making sure the face of the housing is parallel with the flywheel. I did not check the center runout yet.
Will moving the housing still help with parallel or should I shim behind the bottom passenger side bolt?

Thanks Matt, I'm new at this.
Dave

[chrisp]

Originally Posted by dhcarguy

OK, I am finally checking Parallel and Concentric with a borrowed dial indicator.

Only got to checking parallel for now. here are my results. What ,if anything should I do with the bell housing. Is it close enough to continue?

I copied onto paper to read easier.
Thanks everyone, Dave

Rotate flywheel 1/2 turn & check again.

[4dblnkldude]

Originally Posted by chrisp

Rotate flywheel 1/2 turn & check again.

That'll work too. I've never heard of anyone shimming the bell housing. Is that a thing?

[TB1]

Originally Posted by 4dblnkldude

That'll work too. I've never heard of anyone shimming the bell housing. Is that a thing?

Yes you can shim the bellhousing for parallel run out,I had to do this to install my TKX, But first the radial run out needs to be taken care of either with offset dowel pins or if your lucky the stock ones are correct from the start. Both of these procedures need to be done on the car with the flywheel and bellhousing both torqued to spec.

[chrisp]

Crank run-out should be checked 1st , then flywheel run-out.

[dhcarguy]

I just want to thank everyone for helping out with my issues. I put the old flywheel back on and bell housing. The bell housing to block parallel was out from highest #.032" to lowest # -.05. The center runout starting at 0", then to highest +#(.012). Then 180* which was -.009.

I had to file and shim the bell housing and got it within.006" with the new flywheel. I was able to shift the bell housing up and slightly to the left to get it centered to .005". I could NOT get the dowel pins out. I tried everything I know and read. So I elongated the holes in the housing to get it as close as I could. Now I have to figure a way to fill the very small gap on top of the dowels to keep it from sliding down.

Thanks again, I am SOOOO glad I asked what could have caused my issues. I would not have known to check this stuff.

[geeteeohguy]

Originally Posted by dhcarguy

I just want to thank everyone for helping out with my issues. I put the old flywheel back on and bell housing. The bell housing to block parallel was out from highest #.032" to lowest # -.05. The center runout starting at 0", then to highest +#(.012). Then 180* which was -.009.

I had to file and shim the bell housing and got it within.006" with the new flywheel. I was able to shift the bell housing up and slightly to the left to get it centered to .005". I could NOT get the dowel pins out. I tried everything I know and read. So I elongated the holes in the housing to get it as close as I could. Now I have to figure a way to fill the very small gap on top of the dowels to keep it from sliding down.

Thanks again, I am SOOOO glad I asked what could have caused my issues. I would not have known to check this stuff.

The only real proper way to index the bellhousing is to use the offset dowel pins. I would not be comfortable wallowing out the holes to re-locate it. You say you need to 'fill in' the open areas to keep it from shifting.....a 'field fix' would be to inject epoxy into the void, or to tap in an old feeler guage or some shim stock to take up the void and then inject epoxy or red or green loctite.
Dowel pins often take heat for removal. They can be stubborn.

[wolf]

Originally Posted by geeteeohguy

The only real proper way to index the bellhousing is to use the offset dowel pins.

Somebody (I can't remember who) makes a kit where you do drill out the original bellhousing holes oversize, locate the bellhousing to minimize runout, then weld on new rings that locate on the dowels.