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Clutch cable adjustment - '78
Posted: Mon May 26, 2014 1:39 pm
by THall
I just re-installed my rebuilt engine and I'm wondering if the clutch cable is adjusted correctly. I'm getting some chatter when starting out in first gear. Adrian at Headflow Masters said the clutch looked good when he did the rebuild.
I did replace the throwout bearing and took apart the clutch lever assembly to clean up...not sure if that would play into this. I actually had this chatter prior to the rebuild, but far less significant. I think I have the pedal freeplay adjusted in the ballpark, but again I'm not 100% sure. In loosening the cable (backing off the wing nut) it improved a bit.
Does anything look like it may be amiss in these photos?
![Image](http://i1229.photobucket.com/albums/ee479/Timmay68/Bus/20140526_145654_zps5f3fe374.jpg)
Re: Clutch cable adjustment - '78
Posted: Mon May 26, 2014 2:43 pm
by Jivermo
Not qualified to comment on how your clutch looks, but I do have a question. Did Adrian rebuild your original engine, or did you buy a long block from him? If my case is shot, I'm exploring my options. Thanks, and good luck on the chatter.
Re: Clutch cable adjustment - '78
Posted: Mon May 26, 2014 2:55 pm
by THall
He rebuilt my original engine, so yes, same case I started with.
Re: Clutch cable adjustment - '78
Posted: Mon May 26, 2014 4:57 pm
by Amskeptic
It all looks good as far as Bowden tube and wingnut position on cable.
If engine/transaxle mounts are good, this chatter is likely an internal issue:
heat marks on flywheel/pressure plate
damaged pressure plate spring
oil leakage from any number of sources onto the clutch disk
(not necessarily a spot-on-the-driveway sort of leak).
If you have any question about the engine mounts, jack up the engine (block of wood at center drain plate) until it has unloaded the engine mounts. Look for separation between the rubber and the metal.
Colin
Re: Clutch cable adjustment - '78
Posted: Tue May 27, 2014 11:02 am
by hambone
Oil leaks have always caused this for me. An old old transmission can do it too.
After it warms up does it go away?
Re: Clutch cable adjustment - '78
Posted: Tue May 27, 2014 2:05 pm
by Amskeptic
hambone wrote:Oil leaks have always caused this for me. An old old transmission can do it too.
After it warms up does it go away?
Chloe does that! But every time I pulled the engine, it was dry. Cold chatter / smooth warm. I attribute it to the black clutch disk currently installed. Have not had that temperature-related chatter with the brown clutch disk linings.
Note, that early buses have a much more solid tripod driveline mounting, the Type 4s have a total of five soft mounts. This makes clutch chatters more noticeable.
Colin
Re: Clutch cable adjustment - '78
Posted: Tue May 27, 2014 5:34 pm
by THall
So, I just finished removing the cable assembly to investigate and I found that the cable was frayed inside the bowden tube. Whether or not this is the direct cause of my problem I'm not sure, but cable failure was imminent. I will install the new cable and tube tomorrow, readjust everything and hope for the best....I really don't want to have to drop the engine again
![scratch :scratch:](./images/smilies/icon_scratch.gif)
Re: Clutch cable adjustment - '78
Posted: Tue May 27, 2014 6:45 pm
by Amskeptic
THall wrote:So, I just finished removing the cable assembly to investigate and I found that the cable was frayed inside the bowden tube. Whether or not this is the direct cause of my problem I'm not sure, but cable failure was imminent. I will install the new cable and tube tomorrow, readjust everything and hope for the best....I really don't want to have to drop the engine again
![scratch :scratch:](./images/smilies/icon_scratch.gif)
Try a little of my attitude:
"I can't wait to drop my engine again, so I can touch up and clean and even paint with paint that actually dries."
Colin
![geek :geek:](./images/smilies/icon_geek.gif)
Re: Clutch cable adjustment - '78
Posted: Wed May 28, 2014 7:14 pm
by THall
Ok, new greased up clutch cable and bowden tube and the test drive went very well in all four forward gears.....then I got back home to back into the driveway and it was grinding going into reverse. Now what? I'll have to say that reverse has felt different since I re-installed shift rod assembly and gear shift after replacing all the bushings.
Could this be related to clutch cable adjustment, or do I need to mess with adjustment of the stop plate on the shifter?
Thanks!
Re: Clutch cable adjustment - '78
Posted: Thu May 29, 2014 8:16 am
by Amskeptic
THall wrote:Ok, new greased up clutch cable and bowden tube and the test drive went very well in all four forward gears.....then I got back home to back into the driveway and it was grinding going into reverse. Now what? I'll have to say that reverse has felt different since I re-installed shift rod assembly and gear shift after replacing all the bushings.
Could this be related to clutch cable adjustment, or do I need to mess with adjustment of the stop plate on the shifter?
Thanks!
This is internal. You are not getting a clean release. When it is cold, the weight of the gear oil is helping to stop the input shaft. When it thins out warm, the input shaft is not stopping in time.
Experiment. With a warm engine, step on clutch pedal and count to three, then try to just kiss the gear teeth into reverse (find the exact initial contact point). If you catch it, you will get a harmless buzzing sound if the clutch is not releasing. See if it slows down.
If it remains buzzy, engine comes out. Do not annoy your transaxle by trying to work around this.
Pilot bearing greased?
Input shaft smooth where it goes into the pilot bearing?
Clutch plate slide easily on input shaft splines?
Colin
Colin
Re: Clutch cable adjustment - '78
Posted: Thu May 29, 2014 10:21 am
by THall
Amskeptic wrote:
This is internal. You are not getting a clean release. When it is cold, the weight of the gear oil is helping to stop the input shaft. When it thins out warm, the input shaft is not stopping in time.
Experiment. With a warm engine, step on clutch pedal and count to three, then try to just kiss the gear teeth into reverse (find the exact initial contact point). If you catch it, you will get a harmless buzzing sound if the clutch is not releasing. See if it slows down.
If it remains buzzy, engine comes out. Do not annoy your transaxle by trying to work around this.
Pilot bearing greased?
Input shaft smooth where it goes into the pilot bearing?
Clutch plate slide easily on input shaft splines?
Colin
Colin
Ok, I'll try the experiment this evening.
I did fail to grease the pilot bearing, but the input shaft did mate and slide in smoothly. Adrian gave everything on the engine side a clean bill of health...I sure hope I didn't jeopardize that.
What I did on the tranny side was take apart the clutch lever assembly to de-grime and then reassemble. I also installed a new guide sleeve, throw-out bearing, and shaft seal. Is there something I could have botched in that process that would lead to my issues?
Damn, from the sounds of it, this investigation is going to involve pulling an engine this weekend.
As always, I truly appreciate the feedback.
Re: Clutch cable adjustment - '78
Posted: Thu May 29, 2014 5:25 pm
by THall
I just experienced the exact scenario you described.
I readjusted the freeplay again for the heck of it and went through all the gears just like butter. Than took a drive and came back, pulled into the driveway and was still getting all the gears and reverse just fine. Headed out again to get her warmer came back and sure enough....just barely pushing it into reverse would give me the buzz that would not slow down. So, the engine will come back out.
What do we suspect is the culprit here? Pilot bearing, or could it be other associated issues?
Thanks
Re: Clutch cable adjustment - '78
Posted: Fri May 30, 2014 6:00 am
by asiab3
THall wrote:I did fail to grease the pilot bearing.
This worries me regardless of your diagnosis- was the bearing new? My T1 bearing didn't come pre-packed with any grease.
Re: Clutch cable adjustment - '78
Posted: Fri May 30, 2014 7:54 am
by Amskeptic
THall wrote:
What do we suspect is the culprit here?
For the diligent mechanic who seemingly dotted all "i"s and crossed all "t"s, my favorite overlooked little critical detail is the clutch disk hanging up on the input shaft splines due to an almost imperceptible nick on the input shaft splines. Get the clutch disk free of the pressure plate and walk it over to the input shaft. Do not touch or adjust or clean or grease anything, do it exactly as it came out for forensic purposes. If the clutch disk hangs up on the input shaft splines, that is a likely culprit that will give you an hour of enjoyable filing with a small triangular file on each spline's vertical walls (two per spline). Then clean and lightly grease and check for beautiful slide.
ColinBeenThereDoneThat
Re: Clutch cable adjustment - '78
Posted: Fri May 30, 2014 8:37 am
by THall
Alright...engine comes out tomorrow. I will report my findings.
Thank you