Clutch job wisdom Options

[JeffBowlsby]

So my clutch has just started to slip and it chatters sometimes on launch. I thought I would first adjust it to see if it helps, but may need a new clutch. I have done thsi job before with all the recommended felts washers, flywheel O-rings etc. I don't seem to be having any leakage, burning smells and I have receipts from when I bought the car saying it has a recent new flywheel.

I will do whatever is necessary once I am in there, but don't want to remove the flywheel or do anything not needed.

Assuming nothing is worn or broken (I will replace or resurface things if they are worn), does it make sense that I can get by with just replacing the clutch disk? Can I reuse the pressure plate, T/O bearing, T/O bearing guide clips?

Pelican recommends the 6-spring disk: "We recommend using the 911 clutch package in the 914, as it gives the clutch a better feel." I tried the 6-spring disk once and it was fine of course, but what is the problem with using the stock 4-spring disk (its $125 cheaper)? My car is a daily driver street-use only and with the stiffer disk I wonder if the stronger springs contribute to clutch-tube breakage problems. Help!

[So.Cal.914]

You could just do the disk, BUT you will be REALLY bummed when the PP or TO goes bad and you have to pull all that stuff back out. (IMG:style_emoticons/default/sad.gif) IMHO

[ssstikircr]

Why do the job twice?! (IMG:style_emoticons/default/agree.gif)

[Shade Tree]

I've been told to at least replace the felt washer on the pinion shaft, the plastic bushing behind the fulcrum for the throw out bearing arm and the bushings on each side of the throw out bearing. If you end up having the flywheel turned, make sure that the bolts that hold on the flywheel don't stick out farther than the surface of the flywheel. I had to grind off the tops of the bolts. That last part was new to me but came from a very trusted source.

[Eddie914]

What is more precious to you right now? Time or money?

If the answer is time - replace it all!

If the answer is money - replace just the disk!

When I was less old and had more time than money, I had a Triumph I nicknamed "Re-run". Everytime I tried to save a few dollars by replacing only the obviously worn out or broken part(s), it came back to cost me ... in time AND money.

Eddie

[JeffBowlsby]

I understand the felt washer is only there to contain the lube for the pinion shaft bearing (and BTW, I have not found a source that says this bearing needs to be lubed have you? I always lube it with wheel bearing grease). To replace the felt washer, the flywheel crush plate and bolts need to be removed and I don't think I will need to do that...its a new flywheel.

The reason the flywheel bolts may need clearancing is only if the flywheel has been resurfaced down to a dimension where the bolts may interfere with the clutch disk function...I don't think I will encounter that condition on this job...see above.

--> Any insight on the pros/cons of using the 4-spring or 6-spring disk? (IMG:style_emoticons/default/biggrin.gif)

--> Can the T/O bearing be reused..how long do they last under normal service? Its $120 to replace it...

[maf914]

I suggest you also check and replace the plastic pivot bushing and small forked retaining clip on the clutch release arm. I found the bushing to be worn and breaking up and the retaining clip had a fatigue crack. While you are in there... (IMG:style_emoticons/default/laugh.gif)

[jcd914]

You can of course reuse most anything if you really want to.

If the clutch is slipping and chattering you may have hot spots on the surface of the flywheel and pressure plate. When the hot spots develop the expanding metal actually creates a high spot on the surface of the flywheel or pressure plate contributing to the chatter that is common with a worn clutch. So even though your flywheel is new it may need to be resurfaced to get rid of the hot spots or other bad wear conditions. If the flywheel is in good condition and not leaking oil at the main seal then I would leave it in place but I would check the end play on the crank.

I believe I have only seen 1 pressure plate fail mechanically (spring broke) so if the contact surface is OK and the wear on the fingers (where the TO bearing presses) is minor you may be able to reuse it. You also want to check that all the fingers on the pressure plate line up even with each other. If the fingers are not even the diaphram spring is distored and the pressure plate will not engae or retract evening, one edge will contact before the other.

The springs in the clutch disc are there to absorb rotation pulses of the engine. They are under the most load as you start off and engage the clutch but they are also under load when accelerating and just cruising along since the engine is always pulsing. I suspect the primary reason to use the 911 6 spring disc is to spread the load over 6 springs instead of 4. Under heavy loads the springs will be compressed to the point of coil bind and in time they may fatigue and break.

I would replace all the plastic wear parts because that are cheap and made to wear. I would think twice before reusing the TO bearing or the pilot bearing. Bearings are hard to inspect and evaluate their condition and their failure could be more costly than not replacing them. The TO bearing take out the pressure plate, seizing and chewing up the PP fingers. The pilot bearing could take out the mainshaft, seizing and chewing up the end of the shaft. On a clutch job for a customer only rare occasions would any of the parts be optional.

Good Luck
Jim

[r_towle]

Throw in a new disk.
four versus six...I thought the six spring was now cheaper than the four spring...yes/no?

If you move quickly, you can get it done in a few hours...with a lift...probably less than an hour.

then DRIVE the car for the season.
deal with the rest next winter.

Rich

[rick 918-S]

Hi Jeff!

I would change the disk and PP and leave the rest. You will be able to tell if you need the TB as soon as you get access to it.

I made the mistake of having a disk only done on Sandy's old Trooper against the advice on the mechanic friend that was doing the job. I didn't make is 3 miles and the clutch was slipping from a failed PP. Even having the PP tested doesn't mean the depth is still correct with means the clamping force is deminished.

Just because my friend was doing the job don't think for a minute he pulled the transmission and tranfer case for free to fix my screw up. I ended up paying double for my decision. (IMG:style_emoticons/default/confused24.gif) Chit happens.