grea235 Posted October 14, 2023 Report Share Posted October 14, 2023 While the motor was out on my 1952 Plymouth Concord, I saw that the clutch disc was worn, so I replaced it. It was a 9 1/8 disc with a Borg and Beck 9 1/4 pressure plate and the disc fit onto the transmission splines with no wobble. I replaced it with a 9 1/8 disc, but it had a about an 1/8 wobble side to side. Not knowing any different, I installed it and then had some clutch shudder. The faster you rev, the more chatter you get. There was a lot wrong on the car before so I can't say for certain that it had clutch shudder originally because of bad motor mounts, bad shackles, etc. Motor was changed out and does not have a rear main seal leak and has new motor mounts, not hard ones, new leaf springs and shackles, new u-joint driveshaft, etc, pilot bearing is ok, flywheel has been resurfaced and it still has clutch shudder. I pulled the transmission and motor to do some other work and to check the bellhousing face. I found that the bellhousing needed to be shimmed at the top right about .008 of an inch. I checked the pressure plate with a press and didn't find any variance. Thinking the 1/8 wobble is contributing to the clutch shudder, I ordered a 9 1/4 inch disc from a vendor and received a 9 1/8 inch disc and it has the same wobble. It's not the transmission input shaft because the original disc fits with no wobble. I'll be calling on Monday and returning it, but I would like to know if anyone has gotten a 9 1/4 from any vendor and if it fit ok. Also, is a 9 1/8 disc appropriate for a 9 1/4 pressure plate? If I can't get a good fitting pressure plate I will have to get the old one rebuilt. Any information or advice would be appreciated. Quote Link to comment Share on other sites More sharing options...
Sniper Posted October 14, 2023 Report Share Posted October 14, 2023 It's been a long time since I changed a clutch but I don't remember them wobbling on the input shaft. I would highly recommend you just get your old one rebuilt. There's a place in Tennessee I think that seems to be a good one maybe somebody could pipe up with the name? Quote Link to comment Share on other sites More sharing options...
grea235 Posted October 14, 2023 Author Report Share Posted October 14, 2023 7 minutes ago, Sniper said: It's been a long time since I changed a clutch but I don't remember them wobbling on the input shaft. I would highly recommend you just get your old one rebuilt. There's a place in Tennessee I think that seems to be a good one maybe somebody could pipe up with the name? Thank you for responding. Yes, I've seen their address in posts. I'll try to find a place around here, then Tennessee. Quote Link to comment Share on other sites More sharing options...
Sam Buchanan Posted October 14, 2023 Report Share Posted October 14, 2023 1 Quote Link to comment Share on other sites More sharing options...
grea235 Posted October 14, 2023 Author Report Share Posted October 14, 2023 3 minutes ago, Sam Buchanan said: Thank you! I appreciate it! Quote Link to comment Share on other sites More sharing options...
kencombs Posted October 14, 2023 Report Share Posted October 14, 2023 If that 1/8" is measured at the outer rim of the plate while moving fore and aft on the shaft, it is not the source of the problem. It can't move when sandwiched between the pressure plate and flywheel. Only if it off center or out of balance will it be an issue. The 1/8" difference is size in inconsequential also IMO. Lots of pressure plates are slightly larger than their matching disk. Is your shudder actually a vibration? seems to be from the description as it changes with speed. Is this when revving in neutral or actually driving? If it is a vibration when not moving then the flywheel, pressure plate and disk are under suspicion as well as the crank pulley and internals of the engine. A badly worn pilot bushing that doesn't center the main drive gear well can also cause a vibration. Quote Link to comment Share on other sites More sharing options...
grea235 Posted October 14, 2023 Author Report Share Posted October 14, 2023 It only occurs when letting off the clutch. Once it's engaged it's fine. No vibration when driving. If I keep the rpms down and dump the clutch there's no shudder. The more I rev the motor and slip the clutch the more shudder, especially going up hill. No vibration in neutral and reving the motor. As far as I know clutch discs should slide on without play. The original disc has no play. Quote Link to comment Share on other sites More sharing options...
kencombs Posted October 15, 2023 Report Share Posted October 15, 2023 So, the problem appears to be uneven engagement. Was the flywheel resurfaced at the time of the clutch change? Hard spots, usually indicated by blue spots on the flywheel can cause this symptom. It is possible that the symptom will get better or disappear with use. As far a play between the female and male parts, there has to be some or it wouldn't function. How much is too much is the question. I can't imagine a case where this would cause the symptom you describe, but I've been wrong before, many times! Quote Link to comment Share on other sites More sharing options...
grea235 Posted October 15, 2023 Author Report Share Posted October 15, 2023 1 hour ago, kencombs said: So, the problem appears to be uneven engagement. Was the flywheel resurfaced at the time of the clutch change? Hard spots, usually indicated by blue spots on the flywheel can cause this symptom. It is possible that the symptom will get better or disappear with use. As far a play between the female and male parts, there has to be some or it wouldn't function. How much is too much is the question. I can't imagine a case where this would cause the symptom you describe, but I've been wrong before, many times! It feels like uneven engagement for sure. The flywheel was resurfaced after the clutch change and it has a could spots on it. I've been trying to make incremental changes when I have the transmission out to troubleshoot overdrive issues. You are correct in how much play can you have. I will do more research on that. The original clutch has some wear left. I could put it back in along with the bell housing shim and see what happens. But I have the overdrive out to replace a part so I may just send it in to get rebuilt just like sniper suggested. I'll also double check the pressure plate. I'll report back, but it will be awile. Thank you for your advice. I appreciate it. Quote Link to comment Share on other sites More sharing options...
soth122003 Posted October 15, 2023 Report Share Posted October 15, 2023 Is it all gears or just first? I replaced my clutch and I have a slight shudder, but only with first gear. I am attributing this to a new disc. that hasn't been worn in yet. Joe Lee Quote Link to comment Share on other sites More sharing options...
grea235 Posted October 15, 2023 Author Report Share Posted October 15, 2023 7 hours ago, soth122003 said: Is it all gears or just first? I replaced my clutch and I have a slight shudder, but only with first gear. I am attributing this to a new disc. that hasn't been worn in yet. Joe Lee Thank you for posting. It's in first and second. It's a moderate shudder. The clutch and pressure plate have been in for at least 200 miles and hasn't gotten any better or worse. Way more pronounced when starting up a hill than downhill. Quote Link to comment Share on other sites More sharing options...
Sniper Posted October 15, 2023 Report Share Posted October 15, 2023 A resurfaced flywheel doesn't mean it's evenly resurfaced, ran into that issue before. Put a dial indicator on it and see what the run out is. Quote Link to comment Share on other sites More sharing options...
grea235 Posted October 15, 2023 Author Report Share Posted October 15, 2023 1 hour ago, Sniper said: A resurfaced flywheel doesn't mean it's evenly resurfaced, ran into that issue before. Put a dial indicator on it and see what the run out is. True. I checked when it was in the car and it was ok. I'll check it again. It's easier now that it's out. Thank you. Quote Link to comment Share on other sites More sharing options...
grea235 Posted October 16, 2023 Author Report Share Posted October 16, 2023 Flywheel runout was fine. Had my neighbor come over and look at the discs. He a contractor/mechanic fir the military. Has worked on more vehicles that I can list. He didn't like the disc wobble. We looked at the original disc and it has life left in it and we decided to put it in and see what happens. I'll return the new one. It will be awhile before I get the OD part to test it. I appreciate everyone's help! Quote Link to comment Share on other sites More sharing options...
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