Dialing in the clutch/trans and bellhousing indexing?

[5.0calypso93lx]

After trying to research to see if I have the right clutch fork, I came to a few good threads on corral about drivetrain alignment and proper clutch install and alignment. I had nothing but problems since day 1 with my old combo and I'd like to make sure that doesn't happen again.

I started by researching to see if I had the correct clutch fork. I have a lakewood piece that I believe is the extended version. I'm pretty sure it's the correct one as the hole in the bellhousing for the clutch cable is nearly perfectly aligned with where the cable end will sit in the fork. Are there any clearance issues I need to check for the fork or any alignment issues I can check for?

The next issue I'd like to address is indexing the bellhousing. I found this link:

http://www.circletrack.com/drivetraintech/ctrp_0404_bellhousing_alignment/index.html

It seems to be pretty clear, but starting on picture 7, how is the dial indicator resting or mounted on the flywheel? And what do the authors mean by "zeroing out" the dial indicator?

The instructions on page 2 of that link say to "Rotate the flywheel and read the gauge." How far do you rotate the flywheel? I don't understand what they mean by that?? I think maybe once I understand that, I'll get the rest.

My last question is on clutch install and alignment. With the clutch pressed in, how far away should the clutch disc be away from the flywheel? Is there anything else to measure or check?

[5.0calypso93lx]

Sounds like you can get a dial indicator that is magnetic and that's how it will attach to the flywheel. I also now understand zero'ing the dial indicator.

I guess what I'm not understanding, is that when you rotate the crank and the dial indicator rotates around the inside of the bellhousing hole and the pin of the indicator moves in and out, what should you be writing down? The maxes and mins? How does that tell you that you are centered or not?

This actually all may not even be applicable to me, because I have a quicktime bell. It came with these rings that go around the tob retainer on the trans and that then slides inside the hole of the bellhousing. If that ring is correctly machined, that will take up all the "slack" and highs and lows of what would normally be on the inner hole of the bellhousing. Am I correct in assuming this?

[KenB]

Sounds like you can get a dial indicator that is magnetic and that's how it will attach to the flywheel. I also now understand zero'ing the dial indicator.

I guess what I'm not understanding, is that when you rotate the crank and the dial indicator rotates around the inside of the bellhousing hole and the pin of the indicator moves in and out, what should you be writing down? The maxes and mins? How does that tell you that you are centered or not?

Best thing to do is write down the numbers each 90* and that will tell you which way its off if it is.


This actually all may not even be applicable to me, because I have a quicktime bell. It came with these rings that go around the tob retainer on the trans and that then slides inside the hole of the bellhousing. If that ring is correctly machined, that will take up all the "slack" and highs and lows of what would normally be on the inner hole of the bellhousing. Am I correct in assuming this?

No, it's always applicable. There should never be any slack in that hole for any bellhousing. What that ring is for is so you can use it with different transmissions by just changing the ring. What you are measuring is if the entire bellhousing is properly aligned with the engine/crank. If it's off, you can correct this with different dowels on the block.

[5.0calypso93lx]

Best thing to do is write down the numbers each 90* and that will tell you which way its off if it is.


No, it's always applicable. There should never be any slack in that hole for any bellhousing. What that ring is for is so you can use it with different transmissions by just changing the ring. What you are measuring is if the entire bellhousing is properly aligned with the engine/crank. If it's off, you can correct this with different dowels on the block.

That makes sense. Probably not a bad idea to do it at 12, 3, 6, and 9 so you can tell exactly which direction it needs to go. Looks like I'll do this either way then just to be sure. Thanks for the info, that really helps.

[redfirepearlgt]

Sorry if this is elementary - Don't know your level of expertise with precieion measuring devices. please don't take offense.

A mag base is a device used to attach a precision measuring device to a known surface. There are two common types rod style and hydraulic. The author here is using a rod style that appears to be (guessing) made by Starrett. The push dial indicator is the same. He has mounted up the bell housing. Next he attached the mag base to the fly wheel (hence mag base), and adjusts the rods so that the push dial indicator can be mounted as you see. A pre-load is applied to the indicator when setting it up. While attaching the dial indicator to the mag base rod you will allow the plunger to make contact with the inside of the clearance hole of the bell housing you are indicating in. Allow the dial indicator to push in so that it make 1-2 full revolutions. It does not matter what number it is on. DO NOT BOTTOM IT OUT. This means to preload to the point that the indicator has no more travel. Once the preload has been established, and everything is secure, there will be a thumb nut located on the side of the indicator. Loosen it and turn it until the zero lines up with the dial pointer, then snug down. THis is "zeroing out the indicator". Make a mark on the bell housing where the indicator plunger is currently touching. This is your starting point.

Now you are ready to to rotate the flywheel. Do it slowly. DO NOT BUMP THE INDICATOR OR YOU START ALL OVER SETTING IT UP AGAIN. You are likely looking for the high and the low spot,or just the values at 3,6,9,12 o'clock (12 o'clock being your starting point. These numbers will tell you how centered your bell housing is with respectg to the flywheel. You may have enough clearance that you can loosen bolts and slightly adjust until you get the bell housing centered within .001-.002" depending on how well made the bell housing is. Since I have no idea of your tolerance I pulled those numbers out of a hat. Usaully if the dial moves to the left as you rotate the flywheel the hole on the bell housing is getting further away from the center of rotation. The movement to the right just the opposite.

This is not hard once you get the grasp of it. Would be glad to help show you how to do the setup. I have the machinists mag bases and push dial indicator set to do it with if you are close by. Let me know if this helps.

BTW - if you do not have these items there are several wyas to go. Starrett is the platinum level price wise. Harbor freight may be your best bet if this is a one time deal. However, there are MANY great uses for a push dial indicator and mag base setup. They a regreat for many things.

[5.0calypso93lx]

Sorry if this is elementary - Don't know your level of expertise with precieion measuring devices. please don't take offense.

A mag base is a device used to attach a precision measuring device to a known surface. There are two common types rod style and hydraulic. The author here is using a rod style that appears to be (guessing) made by Starrett. The push dial indicator is the same. He has mounted up the bell housing. Next he attached the mag base to the fly wheel (hence mag base), and adjusts the rods so that the push dial indicator can be mounted as you see. A pre-load is applied to the indicator when setting it up. While attaching the dial indicator to the mag base rod you will allow the plunger to make contact with the inside of the clearance hole of the bell housing you are indicating in. Allow the dial indicator to push in so that it make 1-2 full revolutions. It does not matter what number it is on. DO NOT BOTTOM IT OUT. This means to preload to the point that the indicator has no more travel. Once the preload has been established, and everything is secure, there will be a thumb nut located on the side of the indicator. Loosen it and turn it until the zero lines up with the dial pointer, then snug down. THis is "zeroing out the indicator". Make a mark on the bell housing where the indicator plunger is currently touching. This is your starting point.

Now you are ready to to rotate the flywheel. Do it slowly. DO NOT BUMP THE INDICATOR OR YOU START ALL OVER SETTING IT UP AGAIN. You are likely looking for the high and the low spot,or just the values at 3,6,9,12 o'clock (12 o'clock being your starting point. These numbers will tell you how centered your bell housing is with respectg to the flywheel. You may have enough clearance that you can loosen bolts and slightly adjust until you get the bell housing centered within .001-.002" depending on how well made the bell housing is. Since I have no idea of your tolerance I pulled those numbers out of a hat. Usaully if the dial moves to the left as you rotate the flywheel the hole on the bell housing is getting further away from the center of rotation. The movement to the right just the opposite.

This is not hard once you get the grasp of it. Would be glad to help show you how to do the setup. I have the machinists mag bases and push dial indicator set to do it with if you are close by. Let me know if this helps.

BTW - if you do not have these items there are several wyas to go. Starrett is the platinum level price wise. Harbor freight may be your best bet if this is a one time deal. However, there are MANY great uses for a push dial indicator and mag base setup. They a regreat for many things.

I think I do understand now. I've also found out that there is more than one check you are doing when indexing the bell. First, you're checking to see that the back of the bell is parallel to the back of the block. The 2nd is checking to see that the hole in the bell is centered directly behind the pilot bearing.

When I started this thread, I was only considering checking the alignment of the bellhousing centered behind the pilot bearing. This part I understand about 90% lol. I now get that when you are measuring with the dial indicator, that you want to record the highest and lowest points, which if setup correctly, should be 180 degrees away from each other. Whatever number you get, divide that by two since it is a circle, and if that is within the .005 tolerance you're fine as far as that part of the indexing goes. If not, I'll need those adjustable dowels from Lakewood or whoever.

What I'm still confused about on this step, and maybe I just need to see a dial indicator in person, but is there some type of rod that is on the back of the dial indicator that is centered, so that rod will reach down to the center of the pilot bearing?

[5.0calypso93lx]

This leads me to ask how do you measure the bellhousing so that you know it is parallel behind the block? And what is considered in spec after you do get your measurements? Is this also done via dial indicator?

[dsmawd350]

james im assuing it would be the same way. mount the dial indicator to the flywheel but instead of going up the bellhousing and checking it as you go around it. you would point the dial indicator straight back toward the rear of the car onto a flat surface of the bellhousing that is parallel to the flywheel instead of going perpindicular to the flywheel on the bellhousing. measurement would be taken the same way at 12,3,6,9. use those to see if the bellhousing is more forward or backward top to bottom and side to side

[5.0calypso93lx]

james im assuing it would be the same way. mount the dial indicator to the flywheel but instead of going up the bellhousing and checking it as you go around it. you would point the dial indicator straight back toward the rear of the car onto a flat surface of the bellhousing that is parallel to the flywheel instead of going perpindicular to the flywheel on the bellhousing. measurement would be taken the same way at 12,3,6,9. use those to see if the bellhousing is more forward or backward top to bottom and side to side

Hmm, I see what you're saying, but I'm having trouble picturing it?

[5.0calypso93lx]

I think I do understand now. I've also found out that there is more than one check you are doing when indexing the bell. First, you're checking to see that the back of the bell is parallel to the back of the block. The 2nd is checking to see that the hole in the bell is centered directly behind the pilot bearing.

When I started this thread, I was only considering checking the alignment of the bellhousing centered behind the pilot bearing. This part I understand about 90% lol. I now get that when you are measuring with the dial indicator, that you want to record the highest and lowest points, which if setup correctly, should be 180 degrees away from each other. Whatever number you get, divide that by two since it is a circle, and if that is within the .005 tolerance you're fine as far as that part of the indexing goes. If not, I'll need those adjustable dowels from Lakewood or whoever.

What I'm still confused about on this step, and maybe I just need to see a dial indicator in person, but is there some type of rod that is on the back of the dial indicator that is centered, so that rod will reach down to the center of the pilot bearing?

Scratch that last question. I now see that zero'ing the dial indicator eliminates this problem as long as the dial indicator is flat against the flywheel.

[dsmawd350]

mount the magnetic dial indicator to the flywheel. point the rod straight back off the flywheel to the back parallel surface of the bell and spin the flywheel taking measurements as you go around in a circle. you'd be able to see if say the driver side was sitting forward of the passenger side or the top was set back more than the bottom etc.

[redfirepearlgt]

Scratch that last question. I now see that zero'ing the dial indicator eliminates this problem as long as the dial indicator is flat against the flywheel.

BINGO! Your flywheel is already centered on the crank. This is assuring that, or checking to see how well centered the bell housing is to the pilot bearing which is already centered on the flywheel, etc.,etc. I PM'd you back. Once you see all of this measuring stuff you'll fully get it. Then you'll want to get a set yourself and indicate everything to the 0.001". LOL!!!!