I am in the middle of putting a new engine in my 74 and this is my first time doing a full clutch and trans.

2 questions.

First, when installing the new pressure plate, prior to tightening it down it sits a little over 1/4 inch off the flywheel. It tightens down fine against the clutch disk and I just want to make sure that is normal. I am assuming it has to be pulled in tight because it is new compared to the old one which had little flex left in it.

Second, my old engine had an 1/8 inch flat plate that sat against the block and then the bell house bolted to it. It seems to be just more of a spacer, so I am not sure if I really need it. The old flywheel is 1 1/8 inch thick and the new one is 1 1/4. I attached a picture.

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As usual, thanks for all the help!

 

When installing a pressure plate to the flywheel...and using a line-up tool. It IS NORMAL that the pressure plate is AWAY form the flywheel. THUS...you have to be careful when tightening it down to the flywheel. You want to bring it down slowly and EVENLY to the flywheel...instead of just tightening one bolt down all the way and then the next bolt, etc. THAT WAY IS INCORRECT.

Pulling the pressure plate down evenly takes any chance of damaging it. Make sure you use the tightening sequence for 6 bolts. There is a specific way to do it so it will pull it down evenly...and I usually tighten each bolt down 1/4 to 1/2 turn MAX and then go to the next bolt in the sequence...until it has seated...then I torque them. Take your time...no need in being in a hurry here.

That plate that you posted a photo of is the block saver plate due to you must have an explosion-proof bellhousing. I would re-install it.

AS for the thickness of your new flywheel....You might need to check and possibly adjust the pivot stud....due to the thickness is now 1/8" thicker. This can effect the action of the clutch fork...and if the block saver plate is used...you HAVE TO CHECK the depth of your pivot stud where the clutch fork is attached.

You might want to check the bore concentricity of the bell housing and make sure it is correct. Because if you just bolt it on this new engine...if the bore concentricity is off enough....you can have clutch failure prematurely. This is NOT my opinion...but a FACT that most clutch companies what you to check and adjust with the correct off-set dowels out on the market.

Then you need to check the parallelism of the flywheel also. ONCE AGAIN...not an opinion...but a FACT.

I DO ALL clutch replacements this way. And you would be shocked on how many were off...ESPECIALLY when an explosion proof bellhousing is being installed.

Depending on the transmission...your pilot bushing may also needs to be replaced to the new style needle bearing type. If you use the solid bronze type...just make sure it is NOT METALLIC...and a magnet will not stick to it. The original oil impregnated bronze bushing were NOT magnetic....and I will NOT install a magnetic bronze bushing ...even if it came in the clutch kit a customer brings by.

Make sure the pilot bushing slides on the end of the input shaft and does not bind...if it does bind up...your clutch will not engage when the engine is running....SO...this is why it is SO VERY,VERY, VERY IMPORTANT that when you are attaching the transmission...you do not force the transmission in place and get it to seat against the bellhousing by tightening the bolts to pull it up to the bellhousing and it is hard to do so. IF you force it to go in... and it is off just a little bit...or you let the transmission hang on the clutch disc ( BIG MISTAKE!!!)...you can cause damage to the pilot bushing and the clutch disc. A damaged or binding pilot bushing can cause the input shaft not be released when the clutch is engaged and it will not allow you to shift into gear with the engine running.

When the engine is off...the transmission will be able to shift through all gears...but this is due to the input shaft is NOT turning with the crankshaft ...because it is stuck to it due to a burr or something went wrong when the transmission was being installed into the clutch disc and pilot bushing.

For what it is worth...I use ONLY SPEC clutches and flywheels...but to each his/her own.

DUB

 

Perfect! You answered everything and I appreciate it.
I am thinking of just replacing the bell housing as somewhere in the car's history, the old one got banged up a bit on the bottom. If not I will use the shield also.
Last question, and I am asking just to confirm what I have read, once I have the clutch fork in and everything reinstalled, the throwing bearing should sit approximately 1/8 inch off the pressure plate with no contact? And this would be accomplished by the pivot stud to move the fork back more?
Thanks for the help.

 

1/8" is fine but the pivot stud alone does not do it. The purpose of the pivot stud is to create a pivot point...obviously.

I believe Centerforce ( in their clutch packet information) have a measurement of the end of the pivot stud to the flat machined surface of the bellhousing where it contacts the engine block being 4.75" (if my memory serves me correctly)

What this measurement does is so with the correct LENGTH throw-out bearing. When the clutch fork is manually moved so the throw-out bearing contacts the pressure plate...the arm of the clutch fork is in the center of the square cut-out in the bellhousing where the rubber seal is normally installed so crap does not enter the clutch area.

Having the pivot stud out of adjustment too much changes the pivoting angles and can cause for the ratio of "throw" to change. Which can make the clutch fork be past the center of travel "so-to-speak" and be on the backside of center...which can cause the clutch fork to be at an angle that is not correct due to the limited amount of swivel the throw-out bearing has when engaged into the clutch fork. Also..if off too much...it can cause the clutch fork to hit the floorpan/transmission tunnel area...depending on year model.

You linkage pieces need to be fresh and NO WEAR on them. Any wear on the shafts can cause for free-play ...which can thus cause for excessive adjustments to compensate for these linkage parts being worn. The ONLY spot that has "free-play" in it is where the rod that gets attached to your clutch fork is slotted longer than the diameter of the clevis pin to secure it to the clutch fork. Other than that. making sure you use the CORRECT "G" clips to secure the two rods to the "Z" bar that is going from the frame to your engine block is HIGHLY ADVISED. Using cotter pins on these parts that attach to the "Z" bar do not apply the tension on them as they were designed.

Using the anti-rattle spring is also advised.

Also if you have to use the off-set dowels..I like the MOROSO type where you have to drill a hole in the side engine block and tap it so a small set screw is used to hold the position of the dowels when correct concentricity has been achieved. I do not like the Lakewood type where you can not turn them and keep checking because they are designed to be knocked in place.

DUB