Finally tore into the clutch. Probably not too soon either. Driven disc is down to the rivets - started to wear them. Couple loose areas on the disc plates. After scotch bright abrasive pads on the pressure plate I don't think I'm going for resurfacing on it but the flywheel clutch plate probably needs it. The flywheel doesn't contact the driven disc directly, there is a "flywheel clutch plate" bolted to the flywheel that contacts the driven disc. Da book says to resurface only with them bolted together. I decided to recondition the pressure plate myself on the bench - hope I don't need any parts. Release bearing is ok but will be replaced. The pilot bearing was getting close to seizing, it is a sealed bearing so all the times over the last 38 years I climbed under the bus to grease the pilot bearing - it was in vane! Will replace the main crankshaft seal. It has a double lip seal installed that sticks out too far and scored a little on the flywheel. Powerline Components informed me that it only requires a single lip seal cause of "dry" transmission which is the reason for it protruding more than it should (5/8'' verses 7/8'' thicknesses). There's also a sleeve installed on the seal area of the crankshaft I ordered. Does anyone know where I can get two pull back springs that mount on the release bearing sleeve? I'm hunting to find a place that could reline the driven disc. It was so much more time "thinking" about doing the work than actually performing the work. (story of my life). Decided not to do any modifications to the six bolt pattern on the crank. All supersessions &/or service bulletins pertaining to changing out the two dowels to additional bolts only referenced the V configured engines, no mention of the in line series. The old girl is a beast but really simple to work on, thanks to Scott building up my confidence level. It actually reminds me of my Vee Dub days - just a lot bigger! & heavier too...
Got an education today chatting with a senior master clutch mechanic. Real enjoyable too! Jim @ Tampa Clutch Supply, Inc. Him & his wife running the business there for 38 years are down to just the two of them. I brought the clutch disc to him for relining. I had all the parts lined up across the bed of the truck & he walked through & explained a lot of stuff - not patting myself he versed admiration on how many years I got out of the clutch with added intensity knowing I towed the full size truck! It isn't a velvetouch clutch as I was told, and it has semi metallic lining which he contributed to its longevity. The biggest perk was that he had one brand new old stock lining & two "take off" linings that were identical including thickness. So he suggested because of the long life that same material exhibited under my belt for so many years that he would hand me back an exact disc "of the year it was put in service". Ed @ Jefferson Bus suggested lining no. VLG1606. Jim @ Tampa Clutch is relining with SM1606, so I'm thankful to have found unobtainium new old stock - the "good stuff". :-)
Making headway on the clutch work, parts pouring in... Completely rebuilding the pressure plate, its an awesome piece of work, wouldn't want to part with it - once you get your hands on it, its not as intimidating as it looks in da book. These parts are HEAVY!!! by themselves (Flywheel, clutch plate, pressure plate) but when they're all bolted up - holy crap, no way... My main concern going forward is getting the rear main crank seal and sleeve installed successfully not to mention my bad shoulder.
Check the input shaft of your transmission for hammering or denting of the splines. At the end of the day that is what caused my clutch to fail. The dents in the splines would keep the discs up tight to the plates even when the clutch was fully out, and caused tremendous overheating and drag.
Interesting! There is some wear on the input shaft but doesn't seem like enough to hold the driven disc in an adjacent (disc up tight to the plates) position. When I get the driven disc out of the shop (being relined) I'll check into that closer... Can you elaborate on the degree of hammering or denting? I'll post a photo of what mine looks like if it helps. You got my attention on that one.
Obviously the splines are supposed to be of uniform size and completely smooth. Mine show distinct shiny wear marks where the clutch splines bear in normal use. They look like shiny spots on the drive side of the spline, but were measurable at .015" to .020" deep. You could catch your fingernail on them where they transition to unworn (or less worn) parts of the shaft. I guess you could just look with a magnifying glass, and take your clutch disc, slip on onto the input shaft, and try sliding it back and forth while putting torque on it by grabbing it and twisting one way and then the other. The disc should slide smoothly and evenly even with some pretty good twist on it. If it catches, you need to find and address the issue. If I had to do it I would rig a way to use a dremel tool as a grinder to polish out any transitions from worn to unworn on the shaft. When I figured out this was my issue I found a ton of references in truck forums where they flat out said a clutch job includes a new input shaft, if you don't get one you got a lousy clutch job. Exception is apparently new "spline saver" clutches, but I have been unable to find out what that actually means. The input shaft is probably case hardened, and when you have a hammered out step .020" deep like I have you're probably getting through the hardening so it starts to wear faster.
Quote from: dtcerrato on September 04, 2017, 08:29:01 AM
Interesting! There is some wear on the input shaft but doesn't seem like enough to ...
any is too much.
Bevans I see what you are explaining. Upon closer inspection the input shaft has wear on it where the driven disc mates. Sounds like in your case it was excessive enough to "trap" the disc in a position detrimental to normal operation. The mention of lightly grinding "steps" or burrs off would be a fix to keep it from getting "trapped". The condition on ours is not that bad (yet) - a smooth step, no burrs to hook a fingernail but point well taken. I will dress the transition some for peace of mind. Thanks for pointing that condition out! Eagle as far as "any being too much" - IMO that's a little extreme. A year after manufacture is a little. For a vintage antique to be able to offer so many years of service - yes it's wore & more than a little but not wore out by a long shot. Appreciate the input & the ability to share all our knowledge as a collective in real time during repair.
Quote from: dtcerrato on September 04, 2017, 08:43:22 PM
Bevans I see what you are explaining. Upon closer inspection the input shaft has wear on it where the driven disc mates. Sounds like in your case it was excessive enough to "trap" the disc in a position detrimental to normal operation. The mention of lightly grinding "steps" or burrs off would be a fix to keep it from getting "trapped". The condition on ours is not that bad (yet) - a smooth step, no burrs to hook a fingernail but point well taken. I will dress the transition some for peace of mind. Thanks for pointing that condition out! Eagle as far as "any being too much" - IMO that's a little extreme. A year after manufacture is a little. For a vintage antique to be able to offer so many years of service - yes it's wore & more than a little but not wore out by a long shot. Appreciate the input & the ability to share all our knowledge as a collective in real time during repair.
not ragging on you or it...but time will tell. without pictures ... any is too much :)
further, that shaft shouldn't be that hard to find. but as they say, there are as many ways as there are owners.
Tranny input shaft spline photos
That looks OK to me. I would just polish them a bit to make sure they are really clean and use some clutch spline lube on them. Apparently such a thing exists, I didn't know of it till yesterday when I asked Google about it. Very persistent grease.
Brian
Thanks Brian
Just ordered that spline grease - thanks for the heads up.