Clutch not disengaging

Could be a Tillton Engineering flywheel. Could a picture of the back side of this flywheel be posted?

Tilton engineering flywheels have steel friction faces held in place using aircraft structural screws with flanged lock nuts on the back.

After some discussion with Tilton, I got them to offer Aluminum flywheels for the Fiat SOHC engine with the dowel pin holes, it was based on a sample flywheel sent to them many years ago. Adding the dowel pin holes was a fix for the ability of this Fiat engine to shear off all six M10x1.25 thread, grade 12.9 flywheel bolts under race conditions. After their first one they made and worked out well, Tilton incorporated the dowel pin holes into their standard offering for Fiat.

If this is a Tilton flywheel, know this is a high quality part that is no longer made and rather special.


Bernice



mblommel said:
Unknown. I posted an image of the stamped mark on it in this post:
http://www.xwebforums.com/forum/index.php?threads/18618

No amount of searching on the interwebs has helped me find out who made it so far.
Click to expand...
 
Rupunzell said:
Could be a Tillton Engineering flywheel. Could a picture of the back side of this flywheel be posted?

Tilton engineering flywheels have steel friction faces held in place using aircraft structural screws with flanged lock nuts on the back.

After some discussion with Tilton, I got them to offer Aluminum flywheels for the Fiat SOHC engine with the dowel pin holes, it was based on a sample flywheel sent to them many years ago. Adding the dowel pin holes was a fix for the ability of this Fiat engine to shear off all six M10x1.25 thread, grade 12.9 flywheel bolts under race conditions. After their first one they made and worked out well, Tilton incorporated the dowel pin holes into their standard offering for Fiat.

If this is a Tilton flywheel, know this is a high quality part that is no longer made and rather special.


Bernice
Click to expand...

Thanks for that information Bernice. Unfortunately I do not have a photo of the backside. However I do remember that the friction surface was retained with countersunk bolt heads on the front side and nylock style locking nuts on the back. Since it looks like I'm going to have to pull the gearbox anyway I will make sure to snap a few more photos.

I had always thought that flywheel as something a bit special. It goes with the rest of the items on the car, PBS dual DCNF manifold, Revolution wheels, etc.
 
The TIlton aluminum flywheel was patterned using a 1300cc flywheel to keep the weight as low as possible.

The Phillips head aircraft structural screws are # 10-32 with all metal lock nuts that look like this:

http://www.aircraftspruce.com/catalog/hapages/MS21043.php

Nylocks cannot be used to secure steel face clutch linings due to the amount of heat involved. Nylocks are rated to 250 degrees F, All steel lock nuts are rated to 450 degrees F, A286 stainless steel lock nuts are rated for 900 degrees F.

Very possible these TIlton flywheels are made of 2024 series Aluminum alloy which retains higher strength over the very common and lower cost 6061 series aluminum alloy commonly used for aluminum flywheels (really not the right stuff).

If the flywheel comes off the car again, check the torque on these # 10-32 nuts to making sure they are tight.

Make sure to use the stock flywheel plate with six bolt holes to prevent the flywheel bolts from digging into the aluminum flywheel. Do consider installing ARP flywheel bolts as a problem preventive measure.

It is very possible this is a TIlton flywheel.. a rather rare part for this engine.


Bernice


mblommel said:
Thanks for that information Bernice. Unfortunately I do not have a photo of the backside. However I do remember that the friction surface was retained with countersunk bolt heads on the front side and nylock style locking nuts on the back. Since it looks like I'm going to have to pull the gearbox anyway I will make sure to snap a few more photos.

I had always thought that flywheel as something a bit special. It goes with the rest of the items on the car, PBS dual DCNF manifold, Revolution wheels, etc.
Click to expand...
 
Gearbox coming out

Well, the boroscope I borrowed from work didn't show much in the bellhousing, but when I removed the return spring from the clutch arm I could very easily move the arm back and forth with no resistance. Obviously something is very wrong. So, the transmission is coming out. :sad:

Bernice: I will take photos of the back side of the flywheel and inspect the hardware holding the friction surface in place in an attempt to identify the flywheel.

Thanks to all for their advice.
 
Gearbox is out

I pulled the X transmission today and took some photos.

First a few things I found:
  • TO bearing fork is properly attached to the actuating arm
  • Pressure plate fingers seem very "flat"
  • bolts holding the friction surface of the flywheel seem to be as described by Bernice

Here's the PP:
15187172239_e2d99204fb_z.jpg


Shouldn't the arms be angled more outward, ready to be pressed in by the TO bearing?
15187173269_ea9a5747c0_z.jpg


TO bearing in the "OUT" Position:
15187234610_63391d7aa0_z.jpg


TO bearing all the way "IN":
15370761431_707db9b4ec_z.jpg


Back side of the flywheel with all metal locking nuts for friction surface for Bernice's inspection:
15373913105_2975cf85a6_z.jpg


So, I'm wondering if possibly I have either:

  1. wrong pressure plate
  2. friction disk on backwards

But I'm not sure. I seem to remember the disk only going one way. Anybody have an idea of where I went wrong?


Thanks!
 
Those fingers do look a little slat, but I am by no means an expert. Here is a shot of the fresh flywheel and pressure plate on the 4spd for my 78:

IM002978.jpg


The fingers on mine do look like they have a slight dish outward, but not much. I don't know if mine shifts or not either, since the car is not back together yet.
 
I AM SURE of one thing... that ain't right!

It could be the clutch plate and cover are rusted in the disengaged position or that the plate is in backwards and everything is jammed up.

Pull it apart and turn it over so it looks like the other foto that JimD posted. Also look to see if there was any damage done while it was/or if it was, in there upside down.

I'd be kinda afraid to use this if there is any damage to be seen... as a complete new set could be had for a $130 or so. Not worth the trial and error of installing the trans.

OH... where did you find those clutch cover Allen Bolts... and are they the same or better tensile-strength as the originals? If you don't know, (I don't either...) Page Bernice here and she should be able to help.

Sorry for your trouble here...but DON'T GIVE UP!
 
Last edited:
That looks very much like a Tilton flywheel.

The clutch fingers will flatten when it has been properly seated an torqued on to the flywheel. Do this check:

If the original clutch cover and friction plate is available, measure the distance from the center clutch fingers as is installed on the flywheel to the rear transaxle seating surface of the engine. This will be a bit tricky to do and likely require no less than two scales and a straight edge to assure the measurement is parallel to the rear of the engine relative to the clutch fingers.

*Note this measurement.

Remove the new replacement clutch, install the old clutch pressure plate and wore out friction disc with the correct clutch alignment tool. Repeat this same measurement.

*Compair this measurement with the previous one. The variation should not be more than about 0.20" or much less. If there is a large difference there is the problem.

~~~~~~~~~~~~

Do compare the new clutch release bearing with the old one be sure they are the same height with the same clutch pressure plate contact diameter. The release bearing as installed look correct.

1960 Series Cap screws have the same strength rating as grade 12.9. The stock M6 bolts are hex head and are likely grade 10.9 which is lower than grade 12.9 or the 1960 series cap screws (1/4" - 20 tpi, black finish).

Move the clutch release arm forward and back. Check to see if the clutch release fork and bearing are moving together with precise slop free movement of the shaft. This is a good time to replace the plastic sleeve bearing that guides this shaft if they have not already been replaced. If there is slop in this shaft, clutch feel will suffer as it the wobble in this shaft will result in excessive clutch pedal movement and less than positive connection to the clutch release bearing to clutch pressure plate.

Make sure that bolt on the release fork is tight and in good condition.
 
tinsel, not just for decoration

Dan Sarandrea (Phila) said:
"Tinsel" ????

You must be from, ahem, Santa Clarita. And just how far is Santa Clarita from Tinsel Town, anyway?
Click to expand...

[ame="http://www.youtube.com/watch?v=befMIl3dRfs"]Tinsel - YouTube[/ame]

Tinsel looks pretty tough in that clip Dan. ;)
 
About 40 miles...

OK... ya got me, I hardly ever use the word and SPELL-CHECK didn't have a problem with it...

I wasn't even thinking about Christmas yet... HA!
 
Clutch is out

I finally had a chance to pull the clutch off the flywheel tonight to take a look at what I've got and try to diagnose my issue.

Here's the assembly as pulled off the flywheel:
15423141542_38115b1b4d_z.jpg


Here you can see the side of the friction disk facing the transmission where you can see the "snout" facing out:
15236935357_5336d7fa9b_z.jpg


Here's the opposite side of the friction disk. This was the side facing the engine. The center section has no snout. It's pretty much flat:
15423483225_dee8063476_z.jpg


Another view of the side of the disk facing the transmission:
15423483545_4336c7c8f0_z.jpg


Here's a view of the the flywheel with the clutch removed:
15400439416_d74818bca8_z.jpg


And another view of the PP just for fun:
15236934057_30c31d6990_z.jpg


At this point I'm kinda lost. Looking back at the photos I have of the older parts the new one's seem correct. The friction disk appears to have been installed in the correct orientation. I'm not sure what else there is. Are there different sorts of TO bearings? Maybe I got the wrong one? Defective PP? :confused::confused::confused::wall:

Any insights would be appreciated. Thanks.
 
Tilton flywheels typically require....

...all of Tilton's other super hoopty stuff, like release bearing, pressure plate assembly, and most importantly the disc which is usually sintered metallic and much thinner than a stock disc.

I've not seen a Tilton flywheel that can accept stock components. That doesn't mean they never existed, I've just not seen them.

I think, from the quick look that I can see in the pix that the steel friction surface is way too tall above the deck of the flywheel (where the plate actually bolts to) to use a stock disc.

The step on a stock flywheel is a mere .020.

This looks more like .120.

That much more material is allowing the disc to sit proud, and the pressure plate fingers are laying against the disc, not allowing any movement or release.

The solutions include:

1. Measure the step height on your Tilton flywheel and do the math to figure the difference between your measurement and stock (.020").

2. Measure the stock disc you have and subtract the difference above to find the optimal cluch disc thickness for use with that flywheel pad.

3. Then Call tilton and ask for either an alternate friction surface pad to give .020 rise in the flywheel you have, or ask for a 17-spline, 180mm diameter sprung hub clutch disc, with a thickness of #2 above.

or

4. Work with a lightened stock flywheel.

-M
 
Hmmmm...

Thanks for your reply Matt.

I made a quick measurement of step between the friction surface and flywheel with the limited tools I have at the house. It's definitely less than .100 inch. Probably more like .080 inch or 2mm. I'll borrow a depth mic from work tomorrow to get an accurate measurement.

I did post some pics of the old PP and disk earlier in the thread. The PP was Sachs and the disk Valeo:

7777289966_d4d636bce3_z.jpg


7777291886_bf2c29df69_z.jpg


They looked a lot like the new pieces I sourced from you (years ago) and appear to be stock pieces. The clutch worked fine with the old components. Perhaps the old parts were the same basic shape/size but with different critical dimensions for a different application?

Man I wished I saved those old parts when I moved.:sad:
 
There have been many varieties made by many manufactures over the years.

Your best option is to obtain a 1300cc flywheel, clutch pressure plate and friction disc then measure the stack height at the clutch fingers with the clutch pressure plate installed and torqued to spec. This should give a base line dimension to allow a point of reference for comparison to the Tilton flywheel. If memory serves correct, the Tilton flywheel should be the same as a stock 1300cc flywheel. That flywheel that was used as the sample is still here with me. It is possible for me to measure stuff from it if needed.

Key here is making sure the stack height from the back of the flywheel to the compressed clutch disc fingers are the same or close. If not, that must be resolved before trying to put it all back together again.

The clutch release bearing could be different, but not that is less likely.


Back then Tilton did all kinds of custom stuff including flywheels, clutches and brakes upon request. They made good stuff, very service oriented and knew what they were doing when engineering performance parts.

One of the items that was quite popular was the 6" multi disc AP racing clutch on a 6" friction surface flywheel. Very light and has enough capability to handle a big block chevy race motor.. well over 500+ lb/ft with a clutch and flywheel that weighed about 6 pounds or so.


Bernice


mblommel said:
They looked a lot like the new pieces I sourced from you (years ago) and appear to be stock pieces. The clutch worked fine with the old components. Perhaps the old parts were the same basic shape/size but with different critical dimensions for a different application?

Man I wished I saved those old parts when I moved.:sad:
Click to expand...
 
Measured the step...

I measured the step from the friction surface to the flywheel surface in 6 places around the exterior with a Mitutoyo depth mic. I get about .0575 inch on all readings.

If the stock flywheel does indeed have approximately a .020 inch lip does this mean a set of .040 inch spacers under the attachment points of the PP to flywheel would put me back in business? It seems like an awfully small difference. But then again I have no idea how much the PP contact surface typically moves axially along the centerline of the transmission input shaft. I was thinking I could have the spacers laser cut to support the entire "foot" of the PP properly. I have a surface grinder at work so I could make all three spacers the exact same height.

I've also been working on identifying the old PP that was used in conjunction with this flywheel. It was only marked with "Sachs TYP MF 180". I'm assuming 180 is the diamter in mm. Some searching on the web turned up this Sachs p/n "01 3082 000 064" but I cannot verify the original application or if it would be the correct part. I'm wondering if anyone out there has connections with Sachs?

Bernice, if you have a stock 1300 flywheel and PP could you possibly assemble it and take the measurements you were describing?

Thanks to all.
 
Give me a day or so to dig up the flywheel, make some measurements and post some images. Don't have a 1300cc pressure plate (cover) or friction disc as the clutches in shop are all of the 1500cc variety.

The spacer m-i-g-h-t solve the problem, what it will do is also raise the seating height of the clutch pressure plate which can result in other problems.

0.060" in the world of clutch friction material is HUGE. That large a step on the flywheel could be causing the pressure plate disc spring fingers to bend inwards far more than they every should.

I'll look in the Fiat factory service manual for flywheel specifications. If there are pages, I'll get then scanned and posted.


Bernice


mblommel said:
I measured the step from the friction surface to the flywheel surface in 6 places around the exterior with a Mitutoyo depth mic. I get about .0575 inch on all readings.

If the stock flywheel does indeed have approximately a .020 inch lip does this mean a set of .040 inch spacers under the attachment points of the PP to flywheel would put me back in business? It seems like an awfully small difference. But then again I have no idea how much the PP contact surface typically moves axially along the centerline of the transmission input shaft. I was thinking I could have the spacers laser cut to support the entire "foot" of the PP properly. I have a surface grinder at work so I could make all three spacers the exact same height.

I've also been working on identifying the old PP that was used in conjunction with this flywheel. It was only marked with "Sachs TYP MF 180". I'm assuming 180 is the diamter in mm. Some searching on the web turned up this Sachs p/n "01 3082 000 064" but I cannot verify the original application or if it would be the correct part. I'm wondering if anyone out there has connections with Sachs?

Bernice, if you have a stock 1300 flywheel and PP could you possibly assemble it and take the measurements you were describing?

Thanks to all.
Click to expand...
 
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