ebaker

Putting some grease in the input shaft splines where the disk rides will sometimes help a clutch that won't fully release. I think the TSB about putting grease on the throwout bearing guide was to help a clutch that squeaks when depressed.

Kiko

Has I stated before I've done this procedure to 10 or 15 cars (4 of them mine) with 95% sucess to cure this stiff gear changing although some of them I changed the clutch as well, the only problem is that in some cases in a year or two (depending on use) it gets a bit stiff again... but then again I don't have 35 years of engine building and racing, actually I'm not even 35!

1999Porsche911

Part of a proper install of the clutch assembly is to grease the input shaft and/or bearing. If you use the proper grease, it will last well beyond the life of the clutch, regardless of the number of years gone by. If the shaft becomes dry and causes binding, or the bearing wears, then the proper grease was not used, the shaft is defected, or the bearing is defective. Apply grease at this time is nothing more than patch work and temporarily masking a bigger problem, or correcting improper install to begin with.

Personally, I never grease the shaft,only the inside of the bearing. Never had one bind yet, even after 165,000 miles on the Mopar.

Kiko

You may be right about using the wrong grease, I use copper grease on the shaft... What do you find to be the correct one?

About the fact that cleaning and greasing the shaft smooths shifting... Just give it a try man! You've got 3 persons telling you otherwise... don't you reckon that for one second someone else might be right? I honestly apologise for the words I just wrote, specially to someone who's been in the industry longer than my age... but the thing is I've done and seen it done so many times and the silk smooth gear change afterwards that I have to insist...

JasonAndreas

What I wrote was, "In July of 2000 Porsche issued another TSB (for the 996) recommending reapplying grease to the guide sleeve as part of a solution to another problem, noise". The original 996 workshop manuals warn not to use lubrication on the sliding surfaces of the release bearing and guide sleeve. The TSB dated 12/22/2000 "Creaking Noise in Clutch Bell Housing Area" changed that recommendation to, "Coat the guide tube on the sliding surface of the release bearing with the paste "Optimol MPO." Which was the prior (911/964/993) solution to a sticky release bearing.

The release bearing with a "material failure" actually has a compression slit which is by design (see drawing below). I took the photos to document the difference between an OE "genuine" Porsche release bearing and an OEM Sachs version which lacks the plastic insert.




The 911 problem involves corrosion on the input shaft and guide sleeve. So in this case you can't generalize between Chrysler and Porsche. Its usually not even safe to generalize between different models of 911. You have different materials in different locations exposed to the elements in different ways.

From Porsche,

• Do not grease the ball journal or the ball journal recess.
• Coat the guide tube on the sliding surface of the release bearing with the paste "Optimol MPO".
• Grease the contact point between the release bearing and the release lever with the grease "Olista Longtime 3EP"

The part numbers are,

996-917-788-00 - Optimol MPO
000-043-024-00 - Olista Longtime 3EP

1999Porsche911

I use whatever wheel bearing grease I have in the garage. I am not questioning that regreasing an improperly greased bearing and shaft will make the cllutch smoother to operate, but am saying that even on a dry shaft, the THOUSANDS of pounds of pressure applied against the throwout bearing will insure that the clutch disc is fully disengaged from the flywheel and that greasing it up will do nothing but make the disengaement smoother; NOT more complete. This, of coarse assumes that there is not a material defect in the bearing or shaft.

I have seen improperly sized bearings bind on the shaft because they have cocked while engaging. Perhaps a thicker coat of grease on the shaft can take up the slack and make these bearings work better. I've seen guys use motor oil on the shaft and they always have problems down the road. We all know that a clean shaft allows for faster and smoother movement, no matter what is sliding up and down it.

cgeorgan

Question - could it be "how" you're shifting? I thought I had this problem at first as well ( so did my buddy, who owned a '85 Targa). Like yourself, I experienced trouble shifting into different gears - well, not necessarily difficulty, but there was resistance.

What I learned, after reading "The 911 Story", was that it was likely the synchronizers kicking in - normally - than it was any other problem.

I read that Porsche developed the synchromesh system...I was familiar with the concept but not with how it actually worked. The synchros work in such a way as to prevent you from shifting into gear before the engine's mechanics deem this to be appropriate. By this I mean you can't go from 6k RPM in 5th straight into 2nd...the engine speed and the speed of the driveshaft, etc are just not at the same point.

What I read (in another book, which dealt with driving Porsches) is to shift out of gear first...then push (or pull) the gearshift into (or towards, etc) the correct gear...let the pressure from your shift keep the **** at the "gate" of the gear. When the synchros determine that it's OK for your car to go into gear, you will find the gearshift "slip" precisely into gear...with no other pressure than the resting pressure you had on the shifter before. In this way, the synchros are telling you "we did our job, everything is in sync, let's go."

You can, of course, punch the transmission into gear...but that's damaging and counterproductive. You don't even have to wait until the synchros to work...you can expedite the process by matching revs on the tach.

I don't know, I might be talking out of my *** but I've put a lot of time in learning about my first P-car (read several books, talked to several owners, etc.) This works for me, and it's worked for me on more than one P-car. Give a try, let me know what you think.

Smooth shifting, IMHO, does not mean instantaneous shifting from one gear to another. It means that the transmission works smoothly and flawlessly under perceived design conditions...good luck.

sym3pilot

No i drove both of the cars the same way .. and mine is definately stiffer......

im going to drop it off at evo early next week and see if they can diagnose the problem..

robertp

Clutch and bearing has worked in the past for me with the same problem. In another manufacturer's car, the output shaft was at fault for the stiff shifting.

1999Porsche911

I assume you mean INPUT shaft?

PorschePhD

LOL, then you certainly have not done many clutches in 930s, 965s and 964s. If you have bet you can name the setup that constantly did this. Pedal would stick half way on the shaft and create a ridge where eventually it would not work at all or pop instead of a steady release.

How about the 356. These had two separate issue both related to similar issues.

1999Porsche911

This topic was about whether the clutch would be held engaged because of a dry, but otherwise good condition shaft and bearing as it relates to shifting and NOT pedal smoothness. As I stated before, it would not stay engaged. Obviously, smoother operation will result if the bearing and shaft are properly greased, but not being so WILL NOT keep the bearing from moving towards the plate far enough to completely release the disc. Short of a physical barrier, a dry, and even worn out bearing is not capable of resisting 3000+ pounds of pressure applied to it. A bad bearing/shaft is more likely to cause the clutch to remain dissengaged.

PorschePhD

Again, the point is being made that it does happen and it has throughout Porsche's history. The bearing absolutely can be held up on the shaft.. Because you have not seen it personally does not mean that it doesn't exist.

I was at the track when we saw the first 930 do this. It would absolutely not go into gear and the trans was the blame, only it was not the trans and was this particular clutch setup for the 930s. This debates falls under the same parallel of the 8032 plates and the locking of the fingers. Regardless of the TTs unbelievable pressure with the hydraulic assist the clutch remains engaged and will not disengage. It starts to stick and grind then will not release at all. You will break the throw our arm before it releases.

1999Porsche911

Getting back to the original question posted:

i drove my buddies 01' turbo the other day and noticed how smooth his car shifted into all gears, my 01' has always been stiff and kinda knotchy? i have issues sometimes shifting into 2nd, and the other gears are a lot stiffer then his.. how is everyones experience with this?

And the response I responded to:

Changing gearbox oil improved things by 30%-50% the only thing that really cures is applying copper grease on main shaft where the clutch bearing runs... this will make the clutch disengage further therefore better.


This guy was not complaining about clutch pedal smoothness or operation, but that the gears did not shift smoothly.IF all componants of the clutch system are operating properly, if you can press the clutch pedal to the floor, the bearing MUST be moved against the plate and the disc MUST be released from the flywheel. No amount of grease or lack of grease can change that fact.

IF, the bearing was binding on the shaft to the extent that it did not slide the full range, the pedal would either not go all the way to the floor or not return to the upward position. This is NOT the case this specific topic.

There is no mention of smoothness problems with clutch engagement, or any other problems with depressing the clutch. Therefore, chances are that the bearing is working as designed and the problem with his shifting is unrelated to the clutch assembly.

Some people have turned this into a cliutch problem when there is NO indication that one exists. Can a dry bearing and shaft cause problems? Obviouly, yes, but not the problems introduced in this tread.

PorschePhD

It could be several things that cause this. Again are you not aware of the issue with the Sachs PP? I have changed 5 of them that pedal movement was as normal and the car would not go into gear.

Agreed it was not the TOB or guide tube but again unless you are directly handling a lot of TTs there are some issues you may or may not be familiar with. This description above is one of the issue. Not releasing fully.