How to lube clutch splines for Classic 900

4638 Views 34 Replies 13 Participants Last post by 900t, May 13, 2012

wired1000

Discussion Starter · May 8, 2012

Hello all,

A few years ago, I replaced the clutch on my 88 turbo sedan. I mention this just so you know I've been through this, sort of, once before.

My girlfriend's 92 turbo coupe is exhibiting signs of a clutch that is "sticky". That is to say, push the petal down, the clutch will not diengage right away. Let it out, it will not re-engage right away. It's not remotely driveable. The thing is, it feels like everything's working properly, so I'm thinking that the bearings/splines, need to get lubed. Does this sound like a correct assumption?

Money's tight, and since the clutch seemed to be working completely fine (no signs of it wearing out), I'm reluctant to replace the whole thing. On my BMW airhead motorcycle, lubricating the clutch splines is a 40,000 mile service, so I'm hanging onto the hope I can take it somewhat apart, put some moly grease on something, put it back together, and be back on the road.

Any advice? Hints? Appropriate threads that discuss this? (Having trouble isolating the Classic 900 forum in the search feature)

Thanks in advance

Parker

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wired1000

Discussion Starter · #2 · May 8, 2012

Ooh... found this thread...

http://www.saabcentral.com/forums/showthread.php?t=99499&highlight=lube+clutch+release+bearing

If the release bearing lost its lube, would this cause the sticky behavior I talk about above? I think it may be that the plate isn't traveling on the splines correctly, and that I need to lubricate the splines, but I would be so grateful for a second opinion.

stubear334

· #3 · May 8, 2012

Having owned a R75/5 over 15 years ago, I may be qualified to answer your question. I believe the splines on an airhead bike pertain to the driveshaft only. As the bike's rear suspension moves up & down, the driveshaft's splined end moves in & out of the rear of the transmission. If not lubed regularly, the splines begin to wear out causing play in the driveshaft. It has nothing to do with the clutch (I think!)

Now, I have limited experience with the 900. But, I would try the simple stuff first, like checking the clutch pedal bearing under the dash, a collapsed clutch hydraulic line, then finally a wacked out slave cylinder in the tranny.

Stu

wired1000

Discussion Starter · #4 · May 8, 2012

stubear334 said:
Having owned a R75/5 over 15 years ago, I may be qualified to answer your question. I believe the splines on an airhead bike pertain to the driveshaft only. As the bike's rear suspension moves up & down, the driveshaft's splined end moves in & out of the rear of the transmission. If not lubed regularly, the splines begin to wear out causing play in the driveshaft. It has nothing to do with the clutch (I think!)

Now, I have limited experience with the 900. But, I would try the simple stuff first, like checking the clutch pedal bearing under the dash, a collapsed clutch hydraulic line, then finally a wacked out slave cylinder in the tranny.

Stu

Thanks Stu. On the R90, the spline lube happens between the engine and transmission and is definitely to let the plates move back and forth on the splined shaft. It may also be necessary to lube the other side... I'll have to look.

Anyway, I've checked the pedal area and that's fine. I'll look at the hydraulic lines today. How would I go about checking the slave cylinder? The shop manual suggested bleeding the system and I did this (2-person method) and all seemed to be well, though the fluid was darker than I had expected (watered-down coke)

Thanks,

Jim Mesthene

· #5 · May 8, 2012

You could just take the clutch shaft out and lube it.
If you don't step on the clutch while the shaft is out, it should pop right back in. Moly grease is the best stuff, but any grease will do.

nutcase

· #6 · May 8, 2012

I think I would add sparingly - don't want any excess to centrifuge off onto the clutch itself

wired1000

Discussion Starter · #7 · May 8, 2012

Jim Mesthene said:
You could just take the clutch shaft out and lube it.
If you don't step on the clutch while the shaft is out, it should pop right back in. Moly grease is the best stuff, but any grease will do.

Got the correct grease and am at the step where the clutch cover is off and I can see everything. Nothing looks amiss. How would I go about removing only the clutch shaft? Take off the drive chain unit?

crwchf01

· #8 · May 8, 2012

Cover on the end of the transmission housing. Remove clip holding that on, remove it, then remove the plastic impeller (cross) and thread a bolt into the hole just vacated by the impeller. Shaft is retained by an external snap ring so you have to pop it out. I would advise a piece of wood or cardboard to protect the radiator core if this is the first time you have done this. Installation will be the reverse. Do not forget to reinstall the impeller, as it assists in lubricating the upper bearings.

900power

· #9 · May 8, 2012 (Edited)

I think you'll need to remove the radiator to slide the shaft all the way forward out of the transmission.

-Disconnect the two radiator hoses from the radiator (the air filter will probably need to be removed to disconnect the lower hose)
-Unbolt the coil and move it out of the way
-remove the two bolts holding the radiator (at the top I think)
-Tilt the top of the radiator towards the windshield, then lift it out

As crwchf01 said you should thread a bolt into the shaft. I put a thick washer on the bolt and pry it with a pry bar. Place some cardboard to protect the AC condensor (that other radiator). I pry against the top of the transmission case.

Unless the shaft goes back together easily like Jim wrote, follow the advice written below. [But don't proceed with the following advice below if you are able to slide the shaft back into position. The advice below is to help you guide the shaft back into position if the clutch disc has shifted out of alignment]

You may have trouble pushing the clutch shaft all the way in (the last cm or so). That shaft actually fits in the middle of the pilot bearing in the flywheel. Next you will need to remove the black plastic clutch cover. There are maybe four or five bolts holding it to the engine and transmission. Then it pulls out, with a lot of effort sometimes. A clutch spacer tool must now be inserted in the pressure plate to allow the clutch disc to move freely. To make the shaft align correctly, I reach under the pressure plate and push up and side to side on the clutch disc while taping on the end of the clutch shaft with a small hammer. It'll magically align after working with it.

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Jim Mesthene

· #10 · May 8, 2012

900power said:
To make the shaft align correctly, I reach under the pressure plate and push up and side to side on the clutch disc while taping on the end of the clutch shaft with a small hammer. It'll magically align after working with it.

It will remain perfectly aligned unless you step on the Clutch. Don't step on the clutch with the shaft removed.

wired1000

Discussion Starter · #11 · May 8, 2012

Well... I misunderstood what was going on here, exactly... so this is what I did and where I'm at now.

Removed a bunch of crap to get the plastic clutch cover off. Took off spring clip and plastic impeller from the end of the clutch input shaft. Attached 8mm bolt, but could not pry it out. Thought that perhaps I needed to partially compress the clutch (that spacer ring deal... I used a piece of solid copper wire slightly larger diameter than a coat hanger). Tried again on the shaft and got it out this time. Did not remove radiator, as I had not seen that post. Couldn't get the shaft all the way out, but was able to lube it up with moly grease using a Q-tip, as there is some extra room on the chain drive side. Q-tip came back with rust coloration every time.

So this is where I'm at now. The clutch still has that wire in it. I'm sure it's pretty much disengaged, and it has not been touched since removing the input shaft. Problem is, I can't seem to get it back in. Taking it out required a TON of force. Can't believe I didn't damage the radiator (despite two layers of thick cardboard)... but it seems to be fine. But there isn't a ton of space, and while it seems to line up OK, I've been hammering and hammering on it (progressively harder with heavier instruments) but it doesn't want to go in. Is there some "last resort" method to get this thing back in? Is there a way to tell if the clutch disk has slipped out of line and I need to line it back up?

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900power

· #12 · May 8, 2012 (Edited)

Because you have inserted a spacer, the pressure plate has probably relaxed its grip on the clutch disc and allowed it to move out its previous alignment.

Are you able to move the clutch disc? If the spacer has been properly installed in the pressure plate, the clutch disc should be loose.

Reach under the pressure plate and push up and side to side on the clutch disc while taping on the end of the clutch shaft with a small hammer. The very end of the shaft (about 1cm) needs to fit inside the pilot bearing in the flywheel. How much further, in your case, does the shaft need to pushed before it's fully installed?

Geoff Weeks

· #13 · May 9, 2012

Clutch disk splines are not lubed and are installed dry. Any lube placed on the splines will be thown off by rotational forces and end up on the disk or friction surfaces.
ALWAYS check the fit of the input shaft to the disk before installing, it should fit on snug but not stiffly or loose, I have got the wrong disk before in clutch kits, don't assume its right. Look at the splines on the shaft for wear (not useally a problem on car clutches, but trucks and heavy machinery can wear the splines preventing the disk from slideing and causeing clutch drag).
The disk must be aligned for the shaft to pass though and into the pilot bearing. With the Saab, that is accomplished with the ring, which holds the clutch diaphram spring compressed so the disk can move about. Once the clutch/slave cyl combo is placed in the "hole" pass the input shaft thru the disk (might have to turn a little to line up the splines) and into the pilot bearing. Once the shaft is inplace, you can bolt the cover to the flywheel, not all at once, but working around tightening a little on each bolt at a time so to draw the cover in evenly.

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900power

· #14 · May 9, 2012

The Saab service manual says to "Lubricate the clutch shaft splines sparingly with molydenum disulphide paste or Saab Special chassis grease"

Geoff Weeks

· #15 · May 9, 2012

OK, I stand corrected, I would be very spareing with the lube. Most other clutches just call for clean, dry splines, as grease tend to hold dirt and crud and after a while does more harm then good.

jdwertz

· #16 · May 9, 2012

have someone turn the flywheel a little with a big flat head screw driver as you tap it in. It will go in no problem

wired1000

Discussion Starter · #17 · May 9, 2012

Well, yesterday evening, after posting my last reply, I headed down to the garage and started poking around. By using a flashlight and looking through the pressure plate fingers, it appeared that the clutch disk had not slipped out of place... I only had about 2cm to go before the shaft was in all the way. I also noticed that while my Q-tip method had lubricated the splines pretty well, the very end of the shaft hadn't been completely covered, and was able to accomplish this by rotating the shaft around inside the clutch disk to spread the moly around. Once this was done, decided to keep hammering. Accidentally hammered my finger. Got really mad and hammered like crazy while swearing profusely... and like magic, it went in!

I guess my makeshift wire may not have released the clutch quite enough to release the disk. Anyway, put it all back together and it seemed to work much better (didn't squeak like it used to, didn't exhibit any erratic behavior during my much-deserved trip to the beer store) My girlfriend claims that it is engaging closer to the floor than she remembers, but it may just be re-adjusting itself. She's off on a longer trip around town today, so I'm anxiously hoping I don't get an emergency call

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wired1000

Discussion Starter · #18 · May 9, 2012

Side-note... her Dad (who bought the car from original owner with 100k on it) claims that the original owner never replaced the clutch, and that he didn't replace it either. I find it hard to believe that a clutch could last 225k...

Saabturbo92

· #19 · May 9, 2012

If you use the clutch properly it surely can!

wired1000

Discussion Starter · #20 · May 9, 2012

Just got a message from my girlfriend that "the clutch is frigged".

I'll have to drive it to see if this is the same issue as before, but I'm guessing it is... The clutch seems able to perform its function properly (grab, and disengage). Pedal effort seems normal, but it doesn't *respond* to the pedal. Push the pedal in and the clutch stays engaged... let it out and it stays out. Can be sort of fixed by pumping on the pedal. It's sounding a lot like a hydraulic issue at this point. I bled the system the other day (fluid was watered-down coke color)... which wasn't reassuring. Is there a good way to tell which cylinder is causing the problem? (check for leaks I guess?) When I bled the system it didn't look like any fluid was missing.

Also, it seems to get worse as the car heats up... does that make any sense? Why would that happen?

Thanks in advance for any advice you may have.

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