Gentlemen, I've got a problem

[racertb]

As many of you know, I recently did some work to my '29 roadster (new blackwall tires, etc.) to get it ready to show last Thanksgiving in Ormond Beach; I even posted several photos from the show.  I had the car trailored down, so it was not driven much.  Even from the hotel to the show, it was only a couple of miles and the issue not really noticeable.  Well, here is the issue.  If you remember, I got new u-joint discs that I was going to install.  I attempted to install them at the time, but couldn't get them to compress for the life of me (I only worked with the REAR discs and never touched the front).  I ended up putting the old (rear) discs back on.  I also adjusted the emergency brake at the time as well...

Here is the problem:

1. I have a bad drivetrain vibration that was never there before I "messed" with the discs.  I occurs around 20-25mph and gets worse the faster I go.

2. There is a "ticking" sound that comes from the transmission that is most evident when I engage the clutch while the car is in gear; it goes away when I shift into neutral

I think I may have done something wrong when putting the original discs back on and after adjusting the e-brake.  Something is just not right.

Again, this never was a problem before I tried to replace the rear discs and adjust the e-brake...help!

[wellery]

Racertb

It sound like the vibration is coming from the tail shaft as it is out of balance, as the discs over the years have bedded down (did u but them back in the way they came out – aligning the original holes and same bolts, as well as placement on the rear plate?).

The noise from the gear box when in gear is the strain from the tail shaft being loaded up and sending the vibration down the main shaft of the gear box thus putting that strain through the whole gear box.

It should be a relatively easy fix – If you can answer the above questions we can get down to a fix– If I may suggest I wouldn't drive her at the moment as you are liable to have something go in the box as it sounds she under a bit of stress.

Hope this makes sense and is of help

Cheers

Wayne

[racertb]

Thanks Wayne...I did put the discs back together exactly the same way - it was easy to see how they fit back together the way they were "molded" and slightly curved in places.  It was almost like putting a puzzle together; I also put the washers in between the layers as well.

When I reinstalled, I thought I was pretty careful about tightening the bolts in sequence (like a tire, like you mentioned in an earlier post).  What you said above makes sense and I'm sure the problem is in this area (tailshaft) of the car since this is the only thing I worked on under the car (other than the emergency brake).

I doubt I bent the drive shaft in any way, so the discs/tailshaft has got to be the issue like you said.  I don't plan on driving the car until I get this fixed.

Any ideas at this point?

[wellery]

Hi

Do you have any photos as it looks now?

Did you remove the shaft completely from the car - front and rear and did you try new bolts?

When you tried to install the new ones would they still take up with one missing of the discs missing?

Sorry a bit hard when you cant touch and feel it and I am 8000 miles away


Cheers

Wayne

[Tinkeys]

The ticking sound could be coming from hand brake drum, when turning and if there is not enough clearance the brake band moves a little in the side suports, another thing to check is flange nut is tight on end of gearbox also diff flange.
Try using longer bolts for new disks as well !
cheers Tony.

[racertb]

Never took out the drive shaft, only worked on the rear discs.  I could never get the new ones to compress enough...did not try two, but it looked like too much space when I put two up there.  I had to replace one of the bolts (one got stripped) , the rest were the original.   I could get longer bolts, but I guess I would need to drill holes for cotter pins.  I looked for longer bolts before with pre-drilled holes, but couldn't find them.

I know this is hard when you can't see it in person...I appreciate the help though!

Ted

[SDGlenn]

If I remember right, I had a simular problem when I done a bit of work on my drive disks. I found one of the bolts (that hold the disks) was clicking on a bolt (or something) on the 3rd member. Check to see if there is enough clearance there. Hope you find it soon without it driving you nuts. lol
SDGlenn

[Gary 30U]

I know there is very little clearance between the front of the yoke and the back of the transmission. I had trouble there when I did my car.  If I remember you have to have the bolts with the heads toward the rear,becuase if you tighten to much the bolts will pull through enough to hit the back of transmission case.

Just something to look at.

Gary

[Tinkeys]

Gary is correct I did the same thing ! Front and rear I used high tensile bolts and drilled wire holes or use nyloc nuts .it did work fine then made edapters and put in a modern tail shaft for everyday use ' original can be put back at any time .
There is less rotating friction with cross universals.

[racertb]

I'll check the bolt clearance - I'm pretty sure it's ok - but the ticking sound seems to be coming from the shifter/transmission area.

[Tinkeys]

Another possibility is speedo drive in gearbox ,
I did not mine skipping a little when back of car jacked up of ground  and running in gear.

[racertb]

Well I got the car totally off the ground and up on jackstands...got it running in 1st gear as I looked underneath to see if I could see any obvious vibration, hoping I would.  And there it was, it was very obvious how much the driveshaft was bouncing around under there because something just wasn't right.  It look like the driveshaft was warped!

Now I'm sure the problem is with the discs, since that's what I messed with, yet only the rear ones.  So, I will be getting some longer lag bolts, drilling holes for the cotter pins and installing the new discs that I had bought.  Hopefully that will help (never had the issue before!).  Before I attempt the front discs, I'll see what happens after just doing the rears...if that goes well, I'll tackle the fronts.

I didn't think those things (discs) could be that sensative...I'm assuming the old ones are well worn and when I put them back on, I must have done something wrong...

If there's anything else I need to know about this project, please let me know!

Thanks...

[chetbrz]

The disks are supposed to flex to compensate for differences.  You didn't by any chance bolt the metal driveshaft to the metal differential drive.  Sorry I had to ask and I am not even sure if that is possible.  

Ok.., here is something more realistic.  The driveshaft should be on an arc tangent with the differential.  If the differential has shifted or twisted on it's spring mounts this might possibly create the excessive wobble.

Chet...

[racertb]

Now you've got me thinking on how I bolted it up...On the three arms with bolt holes coming off the differential, should they or should they not bolt up to the three arms with bolt holes on the drive shaft???  I did it that way, "metal to metal"...I swear that's that way it was, but now you have me thinking...maybe this is why I had the problem earlier with getting the bolts to back in???

If I screwed up, sounds like it's an easy fix now...do you have a photo to compare on how it should be?

[chetbrz]

No.., It should not be metal to metal.  The purpose of bolting to the disks is to allow for a little give in the joint.  The arms should straddle each other.  Sorry I don't have a picture.  Look at the connection on the transmission.  Unless that one is also incorrect

Chet...