Transmission tech

Dual Mass Flywheel and clutch

    Ever since I got the truck it had a rough idle along with a boat load of rattling at idle.  After checking everything on the engine side I decided to pull the tranny and check the dreaded dual mass flywheel.  It is reffered to as a dual mass due to the 2 part design of the flywheel.  If you have ever seen a standard clutch dics you might have noticed the little springs around the hub.  These are there to soak up engine harmonics witch cause a growling noise under light loads.  Diesels by nature create allot of harmonics therefore, in the 90's the technology wasn't there to make a clutch disc that could handle the task.  So, ford decided to make a 2 piece flywheel in which the clutch surface and the part that bolts to the motor (flywheel) are acctually 2 seperate pieces allowing for larger springs located in the flywheel rather than in the clutch dics.  The problem with that is that after about 200,000 miles they tend to wear causeing the aforementioned rattle and even a rough idle (like it's running on 7 cyliders).

So now that we covered the technical side, lets see what I found when I pulled the trans.

YouTube Video


    You can see in the video the center of the flywheel staying stationary and the clutch surface moving and you can also hear the nasty little rattle that was driving me nuts.  So I pulled the flywheel and seperated the two pieces by removing the ring of bolts just outside the crankshaft bolts and this is what I saw.



    You can see the springs and retainers are trashed.  So now for the fix, I could have replaced the whole mess with OE parts to the tune of about $1,500.  Well since my money tree had not blossomed yet I went the cheaper and more durable route.  I bought a south bend clutch and solid flywheel.  After the install I noticed a much stiffer pedal feel and let me tell you, the boys and South Bend can build one beefy clutch.  I did however notice that at idle in 1st or 2nd gear I do get a little bit of a growl from the harmonics but it isn't anything harsh or annoying so for a clutch 10 times better than OE, I will live with it.

Clutch pedal bushing

    Well guys and gals, after the clutch install I noticed allot of play in the clutch pedal.  99% of the time this is caused by a worn clutch pedal bushing.  This bushing is located on the end of the clutch master cylinder shaft where it meets the stud on the pedal.  Some dumbass engineer thought that a plastic bushing would work great.  Well to say the least, it's not the best setup in the world and they tend to wear often.  Well, a guy can always just replace the plastic bushing with an OE bushing.....about twice a year.  Or you can go a little better and build the thing to last awhile (are you seeing a pattern here?).  So I removed the master cylider and took a look at what I had.

    As you can see the eye was pretty well worn, might have something to do with the aforementioned beefy South Bend clutch.  So after some careful thought and consideration I decided to replace the whole mess with a heim joint also known as a spherical rod end.  so I cut the eye off the end of the rod and oddly enough I had a small heim joint in my tool box that I used and this is how it all turned out.

    As you can see the heim joint I had was built with a stud out the side rather than the usual hole in the center found in most heim's.  Well since there was a stud on the pedal arm and the bushings in it were also worn I decided to pull the pedal box.  Let me tell you that is not an easy task, took me about 3 hours to get the whole mess out, drill the stud out, replace the bushings, and re-install.

    Well after it was all done I have one small problem.  Like I said before the clutch is rather stiff and there is a spring on the pedal assembly that assists with depressing the clutch.  The problem is that right as this spring breaks over is where the clutch engages.  So if you aint got a strong leg you end up dumping the clutch and roasting the tires.  Haven't decided yet if I will remove the spring completely or try and fab some other fix.  Stay tuned for the rest.
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