PT81PlymouthPickup

Yeah Ed! That's why I had the custom disc made. I'm not sure if it would be OK either? It might work OK, It's actually only 1/2 inch hanging out per side, but I'll most likely be dead by the time I wear this clutch out. Lols!

Well, I crawled up in the attic and yep, the original disc was definitely a 10 inch diameter. Sounds like a 9 inch disc S10 disc would have worked OK with a 10 inch pressure plate. I guess I was too fussy? I had a custom 10 inch disc made with a splline that matched the T5. Well, if I live long enough to replace it, I'll go with a 9" off the shelf disc. All this brings me back to my original dilemma. The harmonic balancer! I just ordered a hub and a balancer I found on ebay. (for almost $200.) Geez! I must be nuts, but hell or high water, I'm going to adapt it to my wide belt pulley. If it does not improve the vibration, the transmission comes out and I'll see if I can get the flywheel and pressure plate checked out for balance.

I'll crawl up in the attic tonight. I've got a spare original disc and pressure plate up there to measure. Sure would make things easier if I could use an S10 disc. I thought at the time I did the swap, I should have a disc that matched the pressure plate diameter. I have no idea now if there were additional holes in the flywheel for a smaller pressure plate. I kinda doubt it. My truck was built in 1939. The first year of this design. Did you guys use the S10 pressure plate in your installs? I can't imagine they would bolt in without drilling the flywheel?

Yeah! I'm pretty sure my clutch disc is a larger diameter than yours. I guess that makes sense being mine is a truck.

Don, I like your approach on the pilot bearing. That may have worked for mine as well? But, I'm not sure. I think our flywheels might be different? Problem I had was finding a clutch disc with the same outside diameter and the right spline to fit the shaft.

Jerry, I did not like that approach. Probably would work OK, but seemed too flimsy to me, so if I remember correctly, I machined a step in the front bearing retainer and made a steel adapter ring to fit that and the bell housing hole diameter. Made it with a close fit. When you tighten the front bearing retainer bolts it's not going anywhere! It's more robust then just a thin spacer. If you have acess to a lathe and a little experience, it's a fairly easy job. Toughest part is locating a piece of steel tubing to make the adapter from. You could machine it from a solid, but would be more difficult.

Don, Cool! Looks like a robust repair.What is holding the bushing into the flywheel? Just a precise fit?

So what do you think Dave? The harmonic damper just a waste of time? If I pull the pressure plate, clutch, and flywheel what then? I'm not sure where to take them to be dynamically balanced?

Yeah! I do the same thing Jeff. Too much thinking and getting too fussy is not always the best thing. One thing for sure! It takes way too long! Lols! As far as your question Don, I did not alter the crankshaft. It's been a while, but I'm thinking I found a 15 mm needle roller bearing that fit the T5 input shaft and I machined a bushing to adapt it to the Crank. Like I said earlier, I don't document much and my 60 year old beer pickled brain doesn't work like it used too. Lols!

Oh yeah! Anybody knowing of a really good rebuildable mopar flathead L6 engine laying around for sale in my area I would like to know about it. Did I mention, I'm pretty cheap too. Lols!

I wish it were simple Jeff. I've pretty much eliminated those things. My father was a master mechanic who owned and operated a small auto repair business his entire career. He served his apprenticeship during ww2 on the carrier Midway as an aircraft mechanic. Anyhow, I grew up around this stuff and I have some skill, but I wish he were still alive to guide me like he once did. I'll never achieve that level. I'm pretty much old school and don't even have a cell phone which brings me to topic of not taking many pictures or documenting the stuff I should. I do remember installing the pilot bearing without any trouble. I did however have to change out the input shaft on the T5 for the correct length and had to have a custom clutch made to match the spline. I may have some info in my files, but no pics. God help the next guy who has to work on this truck! Lols! t

I did not use a kit. Bell housing was removed and machined to perfectly adapt the T5 and installed a roller pilot bearing. I don't believe the install has anything to do with the vibration. It did the same thing with the original 3 speed. Yes, I believe the vibration occurs both when clutch pedal is enagaged or disengaged. I think what I'm going to do, is go ahead with installing a harmonic balancer and if problem still exists after that I'll concentrate on flywheel and pressure plate.

I found a hub and balancer that will fit, but it uses a narrower pulley than the original on my vehicle. I am a machinist by trade, so I can fabricate a pulley OK to match the others. Just not sure if it's worth the effort? Also the balancer I located on ebay is an NOS part. Probably sixty year old rubber. I hear there are companies that can re vulcanize them?

Yes, ever since the rebuild. I don't know if it vibrated before that, because it was not in driveable condition back then. I did change the clutch and pilot bearing when I installed the T5 but the flywheel and pressure pressure plate are the same that have been in there ever since restoration. Perhaps they could be suspect?

Oh yeah! And engine mounts are new as well.

After restoring this truck many years ago it had this vibration. I thought then possibly the drive shaft? I recently have made many changes. Replaced transmission with a Borg Warner T5, new differential with 3.73 gear, brand new drive shaft with a double cardan cv u joint. Runs and shifts great, but still vibrates on acceleration. So, I've pretty much narrowed it down to the engine. I can get it to vibrate a little by revving in neutral, but it seems more pronounced when driving. I rebuilt this engine about 30 years ago. We bored it and replaced pistons with new. All other components were in good condition. All new bearings and valve grind of course. It's been so long, I can't remember weighing the pistons, however I'm fairly sure I would have. This truck has not been used hardly at all over the years having racked up only a couple thousand miles. It's not bad enough to warrant a tear down, which is why I'm considering the harmonic balancer. It's a bit of a project to do correctly, but I'm guessing it won't hurt anything? I should have been more articulate about when this happens (rpm, which gears, etc.). I'm fairly sure it does it in all gears. Right now I'm replacing the water pump so, I figured this might be a good time to install a damper?

Any thoughts on what might cause a high frequency vibration on acceleration in my 218 flathead engine? It runs flawlessly otherwise. Smooth idle and smooth at cruising speed with no noises. I've eliminated all other potential sources. Seems consistant at a certain rpm. All the mirrors on my truck momentarily vibrate at this frequency that you can not use them to see. I'm toying with the idea of adding a harmonic balancer. The truck never had one, but if it would eliminate the vibration, I'm fairly sure I can adapt one to fit. My engine uses the wide belt pulleys. I'm not sure if they ever used the balancers with the wide belts? I'm thinking I could get hold of a 6 hole hub and a harmonic balancer and adapt a wide belt pulley to the hub. Any experiences or advice on this topic and where to buy parts would be most helpful.