[F ROCK]

The crankshaft on my project engine is from an automatic car and is not drilled for a bearing. there is a hole, almost the size of the bearing, and then it steps down to a much smaller size.
my engine shop says they'd have to send it out for that.
what should I expect to pay for this service?

the 400 in my car wasn't drilled either. I found that out as I was doing the conversion. I cleaned up the hole with a dremel, and then cut the bushing down until it just fit snug in there. It's been in there 3 years without any issues; but i'd like to do it the right way this time.

I found one Manual trans 400 crank somewhat local to me but it was pricey and covered with rust.

[tom s]

I have read where guys have had the converter snout turned to fit unbored cranks?Tom

[STEELCITYFIREBIRD]

.......... I'm going to have to go check mine on the stand,........I hope it is drilled all the way.

[tom s]

OK so you need a pilot bearing or bushing?I know guys have turned down bushings to fit the auto cranks.Tom

[F ROCK]

I have turned down a bushing for my driver and it worked fine but on my new engine, I want a bearing that will require machining of the crank.

[Tom Vaught]

Your Deal, your engine.
I have a crank that will take a Pilot Bearing.

I personally do not like Pilot Bearings. I like Bushings.

So I bought 5 bushings (all turned to the proper size for my Manual Trans Crank) and I have a lifetime supply. So do what you want to do.
Bushings are basically a no brainer to install. If your shop cuts the crank and the outer race for the pilot bearing is not correct for 3 or 4 extra parts, what are you going to do then? Mod the crank again? How long do you plan on keeping the car/engine?
I am on year 53 of my deal.

I would buy 3 or 4 of the pilot bearings that all checked out basically the same outer diameter then cut the crank to that dimension.

Tom V.

[F ROCK]

Originally Posted by Tom Vaught

Your Deal, your engine.
I have a crank that will take a Pilot Bearing.

I personally do not like Pilot Bearings. I like Bushings.

So I bought 5 bushings (all turned to the proper size for my Manual Trans Crank) and I have a lifetime supply. So do what you want to do.
Bushings are basically a no brainer to install. If your shop cuts the crank and the outer race for the pilot bearing is not correct for 3 or 4 extra parts, what are you going to do then? Mod the crank again? How long do you plan on keeping the car/engine?
I am on year 53 of my deal.

I would buy 3 or 4 of the pilot bearings that all checked out basically the same outer diameter then cut the crank to that dimension.

Tom V.

Thanks Tom.
My crank isn't really machined for either, it's a YS400 and it only has a rough, stepped hole.
As I have mentioned, on my driver, I cleaned up the hole and turned a bushing and that was fine.
I just thought it would more true if I had it machined instead of dremeled.
I think a quality bearing installed properly will outlast a bushing.
I see your point about buying a few, true pieces; bearing or bushing.

[TedRamAirII]

Originally Posted by Tom Vaught

Your Deal, your engine.
I have a crank that will take a Pilot Bearing.

I personally do not like Pilot Bearings. I like Bushings.

So I bought 5 bushings (all turned to the proper size for my Manual Trans Crank) and I have a lifetime supply. So do what you want to do.
Bushings are basically a no brainer to install. If your shop cuts the crank and the outer race for the pilot bearing is not correct for 3 or 4 extra parts, what are you going to do then? Mod the crank again? How long do you plan on keeping the car/engine?
I am on year 53 of my deal.

I would buy 3 or 4 of the pilot bearings that all checked out basically the same outer diameter then cut the crank to that dimension.

Tom V.

X2. Much better with a bushing. No bearing to go bad, no galling up the end of the input shaft if the bearing locks up. I've never had it done.

[F ROCK]

Wow.
Every time I used a bushing on my work truck I felt like I was cutting corners.
pilot bearings wear out that often?
thank you for your advise I will rethink and have another look. it certainly is cheaper and easier with a bushing.
I do have to turn it down some to fit it in there tho.

ALSO- what do you use to lube the bushing? I soaked mine overnight in oil. is that enough? I think I greased the end of the shaft a bit as well.

[Tom Vaught]

Good Bushings (Bronze alloy (I believe, do not hold me to that), seem to have very good life even when powershifting the crap out of the trans.)

I destroyed a bearing in 4 months and it was a new piece, hurt the input bearing on the trans too.

Whatever you do plan on having some spare parts in the drawer.

Tom V.

[Schurkey]

Bearings are susceptible to failure from forces involved in installing the trans. If you don't get the shaft perfectly aligned with the bearing, you're adding side-loads the bearing wasn't designed to accept. You won't know about the bearing damage for a little while, though.

I'll never use a bearing if I can get by with a bushing.

[STEELCITYFIREBIRD]

As far as lube, a pilot bushings is impregnated with lube, so nothing extra should be used.

[JLMounce]

Do all auto cranks across the years have this issue? Always kind of wondered about it as I decide between an auto or manual with over drive.

[glhs#116]

Since I'm looking at an auto to manual swap in my future I'm interested. I believe factory cranks on auto cars are a crap shoot. Some machined for pilot bearing some not. I believe I should be OK since my crank broke and I have a cast Eagle crank in there now. Is the same true for newer six speed OD transmissions as for the classic ones? Bushing rather than bearing?

[Tom Vaught]

Originally Posted by glhs#116

Since I'm looking at an auto to manual swap in my future I'm interested. I believe factory cranks on auto cars are a crap shoot. Some machined for pilot bearing some not. I believe I should be OK since my crank broke and I have a cast Eagle crank in there now. Is the same true for newer six speed OD transmissions as for the classic ones? Bushing rather than bearing?

Whats behind the input shaft of the trans really is not the issue for some.
If you drive the car like a Car Show Queen, you will typically not have as many issues vs if you are an aggressive driver who shifts at higher rpm, has installed better traction tires and wheels, etc. The Power/torque of the engine vs the loads on the engine from the trans/chassis/tires always go thru the same component The trans input shaft.

As I said before, messing with transmissions is a pain without a Bendpak lift and a trans jack. I like to keep the failures to a minimum.

Tom V.

[STEELCITYFIREBIRD]

The "N" crank I am using was from an auto trans, it had a about an 1/8"thick, rough edged looking "washer" type insert in the back of the crank. Crank from a 1969 Catalina.

Anyone ever come across one of these "washers"?



Pilot bearing/bushing is under the most load when the engine and trans are operating at different speeds, specifically when the clutch is not engaged.

[Tom Vaught]

Originally Posted by STEELCITYFIREBIRD

Pilot bearing/bushing is under the most load when the engine and trans are operating at different speeds, specifically when the clutch is not engaged.

Help me out on this one. Unless you are in 1 to 1 mode on say a Muncie 4 speed trans or Saganaw 3 speed trans, the engine and trans WILL BE at different speeds, always.

Same deal with clutch in, engine will be at what ever the air flow to the cylinders is.

The input shaft on the trans will be running at whatever the clutch disc 'coast down' speed is, the flywheel will be at 'engine' speed, and the transmission output shaft will be at 'driveshaft' speed. So the clutch disc/ input shaft (when the clutch is not engaged) sees what load again?

Tom V.

["QUICK-SILVER"]

Originally Posted by STEELCITYFIREBIRD

Pilot bearing/bushing is under the most load when the engine and trans are operating at different speeds, specifically when the clutch is not engaged.

Originally Posted by Tom Vaught

Help me out on this one. Unless you are in 1 to 1 mode on say a Muncie 4 speed trans or Saganaw 3 speed trans, the engine and trans WILL BE at different speeds, always.

Same deal with clutch in, engine will be at what ever the air flow to the cylinders is.

The input shaft on the trans will be running at whatever the clutch disc 'coast down' speed is, the flywheel will be at 'engine' speed, and the transmission output shaft will be at 'driveshaft' speed. So the clutch disc/ input shaft (when the clutch is not engaged) sees what load again?

Tom V.

Sitting still waiting on the light to change, transmission is in low gear and you have your foot on the clutch, engine is at ??? RPM and the pilot shaft and clutch disc aren't turning at all. Think about a high RPM launch...Pilot bearing/bushing is getting spun hard till you drop the clutch.
Once clutch is 'engaged' (assuming it holds) it doesn't matter what gear you're in...Pilot shaft and clutch disc will be the same as engine RPM. During that, the pilot bearing/bushing isn't seeing any work at all.
So what SCF was saying, stand still taking off and gear changes is when the pilot shaft spins at different RPM's than the engine. Pretty much the only time the pilot bearing/bushing sees any work. Trans in gear and clutch 'dis-engaged'.

Clay

[TedRamAirII]

The pilot bushing is "in use" whenever your clutch is disengaged.

[Tom Vaught]

Originally Posted by "QUICK-SILVER"

Sitting still waiting on the light to change, transmission is in low gear and you have your foot on the clutch, engine is at ??? RPM and the pilot shaft and clutch disc aren't turning at all. Think about a high RPM launch...Pilot bearing/bushing is getting spun hard till you drop the clutch.
Once clutch is 'engaged' (assuming it holds) it doesn't matter what gear you're in...Pilot shaft and clutch disc will be the same as engine RPM. During that, the pilot bearing/bushing isn't seeing any work at all.
So what SCF was saying, stand still taking off and gear changes is when the pilot shaft spins at different RPM's than the engine. Pretty much the only time the pilot bearing/bushing sees any work. Trans in gear and clutch 'dis-engaged'.

Clay

Had to read the posts a couple of more times to get the words right for me.
This is my understanding of how things work, correct me if I am still confused.

I agree with the above post. Confusion (for me) comes in with calling the pressure plate the clutch. Maybe would have been less confusion on my part with using proper names, clutch disc, pressure plate, input shaft, throw-out bearing, flywheel, and the pilot bearing.

When the pressure plate is energized, (clutch disc is not touching the flywheel) the throw-out bearing is located on the transmission throw-out bearing support so the load is on the
transmission throw-out bearing support. The clutch disc does not see a load or does the
trans input bearing and the throw-out bearing/bushing.

When the pressure plate is released, the clutch disc tries to find its center "mesh" with the flywheels center. this is when you have the load on the trans input bearing and the throw-out bearing/bushing.

Tom V.