When I purchased my 1927 roadster pickup I built up a clutch pack of Turbo 400 disks. As I drive thousands of miles each year and go off roading (I never baby this car) after about ten years of use I bought a set of 8 more disks so as to be ready when the dread day arrives and I need to replace the clutch.
About 3 months ago I lost my clutch whilst driving into town. I finished the ride on low gear and then opened up and turned all three clutch fingers. I noted that there was absolutely no more adjustment left before driving home.
Fast forward 3 months and that clutch has gotten slippy again. As I also need to replace my low band I bit the bullet today are pulled out the engine. My plan was to throw in another disk or maybe an extra metal Ford disk to tighten it up and get some more use on the old clutch. A trip to my parts stash for a metal Ford disk disclosed that bag of 8 Turbo 400 clutch disks. So I took an hour and ground off the extra tabs and got the disks ready to replace those old disks.
I have had the car about 20 years so I ended up bench processing the replacements for 10 years! I also just read a recent post where the poster said he had heard that Turbo 400 clutches are junk: perhaps, I only got 20 years and at least 50,000 miles on mine.
The old disks looked pretty much like the new ones so I mic'ed them to see.
In the interest of full disclosure, that was the first disk I pulled off. I just went out and pulled the rest out. I found that the one I showed was the best of the remaining disks. I had a range of very little wear down to two disks which had NO friction lining left. Two had what looked like rough surfaces but what turned out to be just a film of friction material evenly dispersed on the surface.
So the wear was significant to insignificant and always evenly over the full surface. In addition the material on each disk wore the same amount on the front and rear surfaces.
I have heard that the Watts clutch is 100% fiber with no metal center (I don't know) and that when they wear out the failure mode jams the clutch so you cannot get out of gear.
My experience is that the Turbo 400 wears out slowly and eventually just starts to slip like the Ford metal clutch does. I did not experience any loss of chunks of clutch nor any grabbing or jamming of the clutch.
That's mighty good service from those disks. I'm curious about the clutch spring - stock or ? and have you or can you check the pressure at 2"?
I hope the next set serve you as well.
Walt, I use a stock spring. You were too slow posting as I'm safety wiring the clutch pack back in place now. I cheated and pulled the pressure plate without removing the spring and without pulling the block off the pan. (You can JUST do that by backing off the clutch finger screws so the fingers have play in them) So I can't go back and weigh the spring force without a further tear-down.
The last time I rebuilt the engine I remember having two springs (both stock), I put the stronger one in there.
Terry, The plates look like the very light duty ones. They are paper and are for light duty. I used the heavy duty ones they put in taxi,s and trucks.
Also I see that you are using the stock hub with the removed teeth in the plates. Look at the new plate and your wore out one. You will see that the new plate had teeth that are on an angle. The stock hub has grooves that have straight sides. If you get the hub from Langes it uses all 42 teeth and the angle matches. Its a much better setup. Scott
Scott, a few years ago I built up a 1913 New Zealand Fire Brigade car. I got a new clutch drum for this style clutch. It was really very nice. I would have used one on Rusty this time around except it takes time to order one and they usually want money. For this repair I had the disks and the old drum which doesn't show wear so you know what I did.
As far as light vs. heavy duty clutches, I really don't have any reason to complain about the ones I have as they worked well. I don't abuse my car as badly as in years gone by so I feel that 20-30 years on this go around is a reasonable expectation. In 20 years I'll be 83, when I'm in my 80's or 90's I'm sure I will appreciate having things to do... you can't ask for more fun than pulling your engine and replacing the clutch when you're 90, can you?
Try the HD (heavy duty) 400 clutches that have a cross hatch pattern in the faces. Works well for me.
I agree with Tom and I'm running the green, cross hatch Turbo 400 plates in three of our T's. I had to grind off a few of the multi teeth to make them fit the standard hub. Two cars have been in service for 13 years with no issues. They are smooth shifting into high (without playing around with throttle) just drop it in! Also a very, clean neutral. Reports of the friction material peeling off the metal section is usually the result of water or condensation. I also use the standard (worn / burnt) outer plates and a standard spring.
My local Auto trans shop tells me that in normal vehicle applications the green plates are much harsher in operation than the biscuit coloured ones as they are softer.
In a few days I will prove if another vehicle with the identical set up but has a savage engagement of high was caused by the new outer steel plates from the suppliers. These are blue in appearance and combined with a new spring maybe the cause of the issue. This transmission Also had excessive end float. All automatic transmission plates including Turbo 400 are not designed to slip so the quicker and stronger the engagement the longer they will survive. The Jack Rabbit clutch appears to be the same green material but has a custom steel inner plate the same as the original Ford was.
Just my experience with this set up and look forward to see how the repair mentioned in this post works out.
Alan in Western Australia
You could just use a Ford clutch. They will last another 100 years.
Don't use the smooth lining.
Use the grooved ones. They will last longer, and work smoother, as they are harder, and the grooves feed oil better.
We normally use 2 to 3, O.D. stock disks first, in front of the clutch pack, to get the right spacing for the adjustment screws.
Got good life out of them
I gone back to using stock clutchs cheaper and work great when you use a lighter oil