Not kidding you and I was as dubious about the claim as you are. Since I learned this trick, I've never needed a clutch aligning tool for a single plate clutch.

It is a piece of cake to get right and the only quicker way is a cut off input shaft.

Tighten the flywheel bolts finger tight so you can still move the friction plate around with a little effort. With your fingers, put them around the circumference of the friction plate and pressure plate and you can feel the exact position of the flywheel. It's incredibly easy to get right. Once you have it right, tighten the flywheel bolts and bobs your auntie.

Jaysen - mate that sounds like what the problem could be. I'll check later this year when I'm building the kit to force feed the motor. How would I check the gearbox is dead centre though? Bellhousing would be somewhat simpler...

I had a shuddering clutch years ago and when we replaced everything it still happened...so we ripped it all out again and discovered a leaking rear main seal ! Put a new one in and a fresh clutch plate and no more problems.

Wrote this thread I went and got the clutch really hot again by holding it on a hill in fourth gear for about 15-20 seconds till I could smell it.

Went away immediately but now its back and getting worse by the day...

Can't blame the usual problem (the manufacturer) since its a bitsa car.

Is the bearing in the rear of the crank is the correct one?

I had issues with my clutch shuddering and it got worse the warmer the car got. I spoke to a mechanic and he said that the reason could be hotspots on the pressure plate and flywheel.

he explained to me that this happens because the material is cast and not pure metal and inconsistincies occur in the material

Anyways the suddering was driving me crazy so I changed the clutch again only after 20,000 kms and put a new unit in. The flywheel got machined again and all is perfect on the car again. I put all brand new parts while it was out even though I had a lot of life left in the old clutch.

The problem was the hot spots. he kept the parts to show me, and he explained that the flywheel had much larger hot spots than the presure plate.

That means both flywheels I've had are faulty. I'm leaning more to Jaysen's explanation.

as mentioned, hows the rear main? an oily or gummy plate will shudder and it will stop shuddering when riding it like you have been doing up a slight incline. no good for the clutch but heats it up and dries it out for a bit. i'm no mechanic but normally a clutch shudder is from hot spots, flywheel in need of machining or oily clutch plate.

Brand new when I converted it to manual - Its kinda pointless to remove the gearbox on an old motor without replacing a $15 seal. Now I have one of those rare ford 6's that doesn't leak any oil at all.

If I had a scanner I would stick up the docco out of the FR cat, Ill see if I can find it on FRP.com

Here we go, sorry I couldnt copy the pictures, Im a mechanic, and a computer retard at that
TECH TIPS
CLUTCH/TRANSMISSION
INSTALLATION TIPS
1986 and newer V-8 Mustangs
The flywheel to crankshaft bolts must be hand-torqued to 75-85 ft./lb. (302/351W) and 54-64 ft./lb. (4.6L) The 10.5" pressure plate bolts must be torqued to 12-24 ft./lbs. and 11" pressure plate bolts to 33 ft./lbs. + 1/4 turn. Be sure to use the alignment dowels in the flywheels. Pressure plate bolts and alignment dowels
for the 10.5" clutch can be purchased using PN M-6397-A302. Pressure plate bolts N808969-S100 and alignment dowels PN D1FZ-6397-B are for the 11" pressure plate. Evenly tighten bolts in a circular direction
one turn at a time. Bellhousing alignment is crucial for proper clutch and transmission function. Due to production tolerances of engine blocks and bellhousings, it is possible for the transmission centerline and crankshaft centerline to be misaligned. Misalignment can cause transmission gear wear, transmission
jumping out of gear, driveline vibration, clutch pedal vibration, pilot bearing noise, release bearing noise or excessive clutch spin time. It may also damage the pilot bearing, transmission mainshaft bearing and clutch hub. It will also cause harsh shifting. Before installing the bellhousing, check the block mounting surface and bellhousing surfaces for nicks, dents, paint debris, etc. These are some things that could affect the accuracy of your measurements.

HOW TO CHECK BELLHOUSING ALIGNMENT
The first step is to check bellhousing face runout. You are checking for parallelism of the back of the bellhousing to the back of the block. Install the dial indicator (as shown in Fig.1). Rotate the crankshaft and mark down the reading. Be sure to push the crankshaft against the thrust bearing for an accurate reading. Maximum runout is .010. The next step is checking bellhousing bore runout. You are checking to see if the bellhousing bore centerline is aligned with crankshaft centerline. Reposition the dial indicator in the bellhousing bore (as shown in Fig. 2). Rotate the crankshaft and mark down the readings. Maximum out of concentricity is .015. If the bore runout is out of spec. install appropriate offset dowels. Offset alignment dowels can be purchased from Lakewood.
.007 PN 15950
.014 PN 15960
.021 PN 15970

Compliments of the Ford Motor Company. This material is NOT my own and has been reproduced for the sole purpose of helping fordmods members with their cluch problems.

Source: Ford Racing Parts Catalog 2006 edition page 130

FINALLY SO I have been doing it the right way all these years as I read this in a ford technical bulletin in 1965 and have found quite a few OUT OF ALIGNMENT bellhousings over the years!

ive got the same problem as the thread starter. Just recently replaced the old 3 bolt flywheel and clutch with a machined 6 bolt flywheel and new heavy duty clutch, with new spigot and thrust bearings, and rear main seal.

Felt perfect for the first couple weeks, now this morning on a cold start, it shudders bad when taking off from first......... tried different ways to minimise it, but the only thing that helps is when you give it 1500rpms and ride the clutch until its got enough momentum before letting it out.

It only doing it when the motor is cold so far, but i assume its not normal and might get worse....

when the clutch was replaced did you put grease in the spigot hole?

if to much or the wrong type of grease is used on the spigot bearing the grease will melt and centrifical force will slowly work it outwards and end up on your clutch plate..
which will make it shudder and eventually destroy the clutch plate..

thanks, will keep an eye on it.

first thing i noticed the clutch is either in or out, in other words, the release point is not very gradual.

I LOL'd at this thread, because of the posts were Bozz mentioned cooking his clutch because it stopped it shuddering.
The reason this is funny, is because I was driving another members car, and was instructed to launch it hard, which I did, and the clutch did not
grip at all, and I kept into it thinking it would grip
Cue acrid clutch smell.
I blame s**t 4L clutches.

Anyway, I get a call from him the next day, saying thanks, because his clutch had stopped shuddering.
It did the same thing as Bozz's though, eventually came back.