Clutch actuating arm on bottom of transmission - adjustment dilemma

DaytonaCoupe66 · 05:59 AM

Hello; I don't expect I'm the first to encounter this dilemma, so putting it out there for comment. 1982 930 Cdn car with a freshly rebuilt transmission, new Sachs clutch, new pilot and throwout bearings, resurfaced flywheel and new rear main seal. All new hardware torqued to spec.

I've included a diagram from the bible for clarity. When I removed the transmission the adjusting bolt on the bottom clutch actuating shaft (item 8 in the diagram) was screwed into the arm almost to it's end. The bolt doesn't want to turn completely out of the arm (as in trying to remove it) because it seems to bind as the final threads reach the face of the arm, so I'm thinking the intent was to ensure a longer bolt isn't inserted.

I've included a pic of what things looked like before being removed (large space between items 2 and 8). When I re-installed the actuating arm (item 2) to the bottom shaft of the rebuilt transmission the adjusting bolt in item 8, when screwed all of the way in, was short by 4-5 mm. I backed off the bolt and reinstalled the arm on the next available spline but now I'm right up against the item number 8 as per the pic. Actually it looks like the helper spring will be contacted before the two surfaces that are designed to meet, so we know the spring is going to wear unless I settle for approx .4 mm-ish of daylight between the bolt end and item 2. There is now no free play at the top of the pedal. The clutch pedal otherwise appears to work as it should, so I don't believe I messed up the clutch installation, but haven't taken it for a drive yet.

Thoughts, suggestions are appreciated. Should a guy look for a way to install a longer bolt in item 8, or drive with no freeplay and wait for thing to settle in? I'm waiting on some paintwork to the bumper and valence before taking it out.

Rodsrsr · Rodsrsr's Garage

If there's no free play your clutch will most likely slip.

DaytonaCoupe66 · 05-27-2022, 03:43 AM

Quote:

Originally Posted by Rodsrsr

If there's no free play your clutch will most likely slip.

If I move the arm one spline counter-clockwise there's enough excess space between the adjustment bolt and the arm that when I push the clutch in the omega spring unloads. In the current setup, one spline over clockwise, the arm isn't touching the spring/bolt end, but I've only got between .2-.3 mm. I'll unhook the cable, take it off, and try again. I seem to be between two extremes.

Thanks for taking the time to comment.

Cheers...

Bucketlist · Bucketlist's Garage

So I pulled up this picture to compare clutch linkage.......

T77911S · 05-27-2022, 06:09 AM

you need to put the arm back on how it is suppose to be and use the bolt to adjust it.

if you can screw the bolt all the way in try to clean the threads one the end with a thread file or a die. .
if you can screw it in enough to adjust it then do that.

DaytonaCoupe66 · 05-27-2022, 08:14 AM

Quote:

Originally Posted by Bucketlist

So I pulled up this picture to compare clutch linkage.......

Dude, that is pristine! I don't see an omega spring?

DaytonaCoupe66 · 05-27-2022, 08:16 AM

Quote:

Originally Posted by T77911S

you need to put the arm back on how it is suppose to be and use the bolt to adjust it.

if you can screw the bolt all the way in try to clean the threads one the end with a thread file or a die. .
if you can screw it in enough to adjust it then do that.

I'll take it apart and retry.

Bucketlist · Bucketlist's Garage

Quote:

Originally Posted by DaytonaCoupe66

Dude, that is pristine! I don't see an omega spring?

Thanks, when I posted this picture was the first time that I noticed no omega spring. I have had the car for 8 years and never noticed a problem with the clutch.

kamaro · 05-27-2022, 09:48 AM

Quote:

Originally Posted by DaytonaCoupe66

Dude, that is pristine! I don't see an omega spring?

Indeed, thats a very clean setup. I have used my car without an omega spring for a while, and the clutch feel was not so bad, actually it was similar to a G50 hyd. clutch pedal feel, and when I added it last year it turned it into a very light clutch, in fact its now too easy for my feel to the point that I'm thinking of just removing it again!

Alan L · Alan L's Garage

I set mine with about 1mm gap. You need to allow for heat expansion.
Alan

DaytonaCoupe66 · 11:45 AM

Thanks to All for the helpful comments. I crawled back under the car, snapped a photo of the current setup with almost no air between items 2 and 8, removed the arm (+ spring, disconnected cable), rotated the lower arm carefully one spline counter-clockwise, and reinstalled the arm. In the photo with separation between items 8 and 2, you can see that with the bolt screwed all of the way into the item 8, I'm left with no more adjustability to achieve that 1mm mark. I've got 5mm+ of real estate that can't be bridged because the bolt won't turn anymore. If I run the car like this the omega unloads. If I remove the omega as some have done, and if I keep the setup with excess separation, I expect the clutch may not fully disengage when the pedal is depressed. So, the lesser of two evils presently is to run with limited freeplay.

Pedal feels fine except the lack of freeplay at the top, and the freshly rebuilt transmission is going to all gears. There is a sliver of daylight between the end of the bolt and the arm, although in the photo it looks like they are together.

I'm still a couple of weeks away from turning the key and will report back on driveability.

Cheers!

T77911S · 05-31-2022, 09:36 AM

not sure if theis will cause the issue you are having, but did you engage the TO bearing the clutch fork when putting tranny back in

Alan L · Alan L's Garage

Apart from the above (I had issues if my clutch fork was engaged the wrong way up), a possible change in the clearance dimensions in the clutch pack may do this. I had issues once with my SC with a clutch plate I had relined. It was fractionally thicker (about 1-2mm total). It screwed up the settings in the clutch and I ended up having to replace it. Not what you want to hear, but it is possible the issue is inside the bell housing.
What I would consider - to get it all working and check all is good, is fitting a longer bolt that will allow you to set the right gap. Then see if the system works as it should. If it does, why change anything? It will be a standard M10 or similar bolt. Get the next length up (5-10mm longer) from a hardware store. Cut to length if necessary to leave a few mm spare for later adjustment.
Alan

DaytonaCoupe66 · 06-01-2022, 03:59 AM

Quote:

Originally Posted by T77911S

not sure if theis will cause the issue you are having, but did you engage the TO bearing the clutch fork when putting tranny back in

I was careful to ensure that the fork captured the ears of the throwout bearing as the transmission was pushed into the bell housing. I couldn't see the bottom extrusion for the fork but worked slowly while keeping an eye on the top one as it was eased together. Wiggled the bottom shaft lightly too as it came together and and could see that the fork was firmly on the bearing. Having read of how easy it is to booger up this step I hoped to avoid taking the engine out....again.

I'm quite sure I got this right but your suggestion has crossed my mind. I'm awaiting my Amsoil oil (very high zinc) order and once it's dumped in I can start it up to see whether the clutch operates as it should.

DaytonaCoupe66 · 06-01-2022, 04:17 AM

Quote:

Originally Posted by Alan L

Apart from the above (I had issues if my clutch fork was engaged the wrong way up), a possible change in the clearance dimensions in the clutch pack may do this. I had issues once with my SC with a clutch plate I had relined. It was fractionally thicker (about 1-2mm total). It screwed up the settings in the clutch and I ended up having to replace it. Not what you want to hear, but it is possible the issue is inside the bell housing.
What I would consider - to get it all working and check all is good, is fitting a longer bolt that will allow you to set the right gap. Then see if the system works as it should. If it does, why change anything? It will be a standard M10 or similar bolt. Get the next length up (5-10mm longer) from a hardware store. Cut to length if necessary to leave a few mm spare for later adjustment.
Alan

It's also crossed my mind that wear on the fork could be uneven, and there's a 50% chance that the fork is engaged the "...wrong way up..." as you mention; perhaps this is the cause. The splines on the shaft and arm are uniform, so I'm at a loss as to why this isn't going back as it was. Also wear on the old bearing ears would have been miniscule, but could be relevant. A Sachs came out and another Sachs went in but perhaps the clearances are different? Hopefully I've not done what T77911S mentions.

I think I'll resize the bolt as you suggest. Well know for sure on startup - as soon I get oil into 'er. Then I'll report back.

I appreciate the insight!

Alan L · Alan L's Garage

I can think of no reason why the fork would have a top/bottom, either. But after 2-3 engine outs for a faulty clutch after reassembly, I marked the ears on the throw out bearing with a TOP, as to how it needs to go back together. Works every time first time after teardown now.
just something to consider if you have to get in there again. Take note which way up now, mark, and flip 180 deg.
Alan

DaytonaCoupe66 · 06-01-2022, 02:15 PM

Quote:

Originally Posted by Alan L

I can think of no reason why the fork would have a top/bottom, either. But after 2-3 engine outs for a faulty clutch after reassembly, I marked the ears on the throw out bearing with a TOP, as to how it needs to go back together. Works every time first time after teardown now.
just something to consider if you have to get in there again. Take note which way up now, mark, and flip 180 deg.
Alan

Oil is in the car so I may give it a try tomorrow. I splurged on a Rarlyl8t hooligan centre out exhaust this winter and am anxious to hear how it sounds. The bumper and valence are out for paint (converted to euro bumperettes) so I can’t drive it…. But maybe I will not be able to anyway on account of the clutch arm lol. It’s one of those situations where you almost don’t want to turn the key, only to learn that you’ve been thrust violently back in time to start over. In a twisted kind of way it’s reassuring to hear that my condundrum isn’t unique!

Alan L · Alan L's Garage

Can you imagine how disappointed I was after engine install to find I had a weird clutch. Clearly something was wrong and the sad conclusion was to pull the engine. Again.
Tearing it down I could find nothing wrong. Nothing I had screwed up. I don't know how I got to the conclusion to rotate the TOB ears, or how many engine drops in between. And I can find no visible reason why it needs to. There must be some minor distortion in there. The old clutch when I got it was badly torn up.
Alan

T77911S · 06-03-2022, 10:15 AM

did you put the ring gear back on the flywheel.
i think if you leave that off the clutch dimensions change, not to mention your car wont start

DaytonaCoupe66 · 06-04-2022, 04:39 AM

Quote:

Originally Posted by T77911S

did you put the ring gear back on the flywheel.
i think if you leave that off the clutch dimensions change, not to mention your car wont start

Yes, the ring gear was put on with same side against the pressure plate. I did have the flywheel turned and the machinist commented that it is at the 9.9 mm minimum. I didn't ask how much material he took off, but in his view it had been turned once before. Now I'm wondering if this could be a contributing factor.

I'm ready to turn the key but not until I have a few unfettered hours to double check everything and deal with any issues that nay arise. Nothing came easy on this car over the winter; trailing arm odyssey, challenges getting the rear main seal in, seized exhaust bolts, and now the thought of taking the driveline back out. I need to prepare myself mentally lol.

Cheers.