darbji928

I'm getting some grinding when I try to go into first and second gear (unless at a VERY low speed). Clutch slave cylinder is leaking but the fluid level is not low. I am ordering a replacement. But in the meantime, how can I tell if my clutch is not fully disengaging when the pedal is depressed? Is it as simple as lifting the rear end, depressing the clutch pedal while the car is in gear and seeing whether or not the wheels spin? (They don't.) I'm trying to explore all the possibilities before assuming my synchros are bad. I really don't believe this to be the case, since the problem is also in first gear. Also, the problem with second didn't happen until I replaced the ball cup. Second used to be a little tricky to get into at speed, but I could do it. Now, there is no going into second unless the car is at a low speed or stopped. I have adjusted the ball cup so that the shifter sits roughly 90° as per instructions in the WSM.

Another weird thing I noticed: With the engine off, shifting into gear is sometimes difficult unless clutch pedal is depressed. As I work my way up and down the shift pattern, I find it to be very random. Sometimes it's fourth that's tough to get into. Sometimes it's second. Sometimes first, and so on throughout all the gears. But with the pedal down, no trouble at all. It just doesn't make sense to me. If anyone can enlighten me, I'd appreciate it.

1983 928s

dr bob

Your testing method is pretty close. There's an inspection hole in the rear of the torque tube for access to the bolt in the rear clamp. Pull that, and either put a mirror under it so you can see or have the car up so you can safely look up through the hole to see the shaft and clamp. With the gearbox warm and in neutral, engine running and clutch depressed (requires trusty assistant...), the shaft should not turn.

You also have the option of pulling the lower bellhousing cover and looking up into the clutch pack. Same test conditions -- engine running, gearbox warm and in neutral, clutch depressed. Disks and the rear splined shaft to the torque tube should not be turning.

The pilot bearing in the tail of the crankshaft is a sealed ball bearing that suffers from old age and heat. Deterioration causes it to drag, which then causes the front splined shaft to turn.

The short splined shaft that carries the disks, fits in pilot bearing in front and the shaft in the torque tube to the rear, is known to wear to the point where the disks no longer slide freely when the clutch is disengaged. The disk(s) then drag on the cover and flywheel, and also on the intermediate plate in the dual-disk clutches.

The intermediate plate on the dual-disk clutches "floats" with a little help when the clutch is disengaged. If it isn't floating correctly, it may drag on the forward disk.

There are a couple other wear parts that deserve attention while the clutch has your focus. The throwout bearing, the release arm bushing and pivot ball, and the bearing guide tube all deserve a good inspection. The bearing, and pivot bushing and ball are wear items that can prevent the clutch from completely disengaging.

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The workshop manual has a pretty good explanation of how all these pieces play together. Considering how expensive and even unavailable many gearbox pieces seem to be, it's in your best interest to get to the bottom of the problem ASAP. The Good News is that the 928 may be the second-easiest car for clutch access and replacement. Except for the part where it can be a bit heavy. My normal recommendation of course is to "do it like you mean it!". That is, do the diagnosis and all, then drop the while thing out so you can bring everything back into working condition again.

darbji928

Thank you so much! That is fantastic information! I am going to check it out as soon possible and report back. I pawed through the manual earlier to try and gain an understanding of how it all works. Hopefully, I can get this car running right just in time to out it away for the winter. Lol.

dr bob

There's still at least a couple months before salt takes over for asphalt, at least around these latitudes. We are choking on forest fire smoke right now, bad enough that I think a decent early blizzard would at least put the fires out. Like you though, I'm not quite ready to mothball the car for the winter... not quite yet anyway.

Share more about the car and your projects when you get a chance. Since everybody else here has perfect cars [cough cough], we get to live vicariously through the shared experiences from others. Truth be told I still have a couple little things left over from last winter's while-it's-hibernating list. Nothing serious really, just electrical and interior stuff. Nothing to see here.

Dave928S

Did you check the rear coupler as suggested? ... https://rennlist.com/forums/928-foru...kage-help.html

You certainly need to check the clutch, but a sloppy rear coupler could explain your random gear shifting problems.

darbji928

Indeed I did. And it doesn't seem like it's in terrible condition. I have very little side to side play. I also got under the car and watched it as my husband shifted. It's not terrible. But I will replace it. I'm just trying to gather a good understanding about how everything works. I don't exactly have the resources to throw parts at this car all at once. I wish I did. Someone damaged it shortly after we got it, and it sat in a body shop for almost a year (and cost us thousands of dollars). I am desperate to drive it, and I know he is, too. I am putting together a list of parts. The coupler is on it. As well as the slave and most likely a short shifter.

I appreciate everyone's help and patience with me. This is my first experience with Porsche. You guys have been a huge help!

James Bailey

Do not waste your money on a short shifter it simply INCREASES the effort and the vagueness....many of the touted "updates" improvements at best are no better than the original parts. Do not believe everything that you see written on a website and the rear coupler is designed to have a slight amount of front to rear play so yours is probably just fine.

dr bob

^^^ What Jim says.

Get everything working correctly first before throwing modifications in the mix. The 928 doesn't offer the buddah-smooth relatively-effortless snick-snick shifting that some other cars have. A short shifter multiplies effort as it offers less throw at the ****. Decide if a NN% reduction in throw is worth the same NN% increase in effort. For many folks it's worth the trade-off, and for many others the short-shifter comes out in favor of the original after some test-time.

Dave928S

You've checked it which is what matters. If it doesn't seem sloppy, then as Jim suggested, it may be OK. In the other thread I posted a link to a linkage thread which has pics of all the components. You can see in those pics that the coupler bushings have oval holes and allow some play even when new. If you think that the bushings look no more worn than those I pictured, and if you haven't got alarming play, then save your money for something else that does need replacement. It's usually very obvious if the coupler bushings are shot.

To save you searching, here's a pic of a new one, which clearly shows the slight factory bushing oval gap which gives some play. If yours looks the same, and doesn't feel or look to have significant slop, and it's firmly attached ... leave it.

darbji928

Thank your for that! That's good advice. Mine doesn't look to be much more worn looking than the new one you pictured. However, I plan to get up under there and take some better picrures. Then onto the slave cylinder. If that doesn't fix it, it looks like I'll be pulling the gear box this winter.

dr bob

There are more than a few recommendations for different gearbox lubricants. Maybe not as popular as choosing the "right" engine oil, but you get the idea. Lots of oils start out so stiff that it's almost impossible to shift without a little grunching until the oil warms up. At the same time, a clutch or pilot bearing that drags will force the synchronizers to block shifting with normal pressure of the gearset speeds in the gearbox can't be matched.

The clutch drops out from the back of the engine without removing the gearbox at all. The workshop manuals have good guidance on what to do, including alignment marks and little holding clips that fit in the clutch cover to hold the pack slightly released during remove/replace. The biggest struggle with the job is usually the weight, trying to gold it all in place with one hand while the other is busy inserting bolts. Otherwise, the little stub shaft retracts back to allow the assembly to go up into place. The only easier clutch, in my experience, is Saab 99/900 series where a stub shaft slides out and the clutch pack comes out the top.

rjtw

Here's a thumbs up for the Saab 99/900 and an easy clutch job! I had a '78 99 turbo back in the day and yes, the clutch was at the front of the engine. Didn't even have to get under the car to change it! Come to think of it just about any maintenance item was pretty easy on that car... the whole engine/transmission came out as a unit and you could get it out and in the same afternoon easily lol!

I've never changed the clutch on my 928 so very encouraging to hear that at least it's the SECOND easiest clutch job ever. Nice to know for when I have to cross that bridge.

Back on topic to the OP: +1 on the recommendations about NOT going aftermarket and +1 on experimenting with different transmission oils. Also, having just changed the rear coupler on my car, and although it sounds from your check under the car that the coupler seems OK, here's another check: With the transmission in neutral, there should be very little side-to-side play of the gearshift. If you move it gently to either side, you should immediately feel the gearshift pushing back and it should return to where it started when you let go. If the coupler is shot, the gearshift will move without resistance side to side... a couple of inches as I recall if one or both of the plastic bushings in the coupler are shot. A tiny amount of play is built in though the bushings as already mentioned and thus OK. If you're getting no appreciable side to side play (and likewise little or no fore-and-aft play) it's not the coupler. Having said all that, when my rear coupler started to go out, it made shifting a real guesswork affair something like stirring oatmeal. If you are sure you're finding 2nd gear but it's not going in, that doesn't sound like the coupler to me FWIW.

Cheers!
Rick

darbji928

I will definitely pull the cover and check the clutch. (More questions to follow when I get to that point.) I've been warned about its weight, and I do not look forward to fighting it with my girl arms. Lol. I took a break and had an interior day today. Tomorrow, I'll be back at it. Most likely inspecting the clutch. The WSM will be my reading companion for the evening. Thanks for all the help. I hope to contribute something to the community one day, as you've all been so helpful.

skpyle

darbji982, you are interacting and asking really good questions. You ARE contributing. Thanks for being here, and good luck with your 928!

Dave928S

^^ +1

If you pull the clutch pack you'll get all the help you need here to assess its condition, and guide you on what to do. Pulling the complete clutch pack is a lot easier than you might think ... don't be afraid