M. Requin

Hey, I was just needlin'. Back in the day this was always a big debate, and everyone who said damper corrected everyone else who said dampener. When I was an MC dealer (early 70's) I had two Cornell engineer grads working as mechanics for me, one EE, one ME, and woe to anyone who said "dampener" referencing mechanical systems. But usage changes, the majority could care less, and dictionaries are beginning to reflect the changes. I've always liked descriptive rather than prescriptive grammar anyway (I think we should go back to the 18th cent. "ain't") so my dog and I sit this hunt out. IOW, just needlin...

Bill Ball

It is confusing with reference to moisture. I wonder if this is like founder (verb: to fail utterly) and flounder (noun: a type of fish), where the grammaticists have given up and now allow flounder to mean the same as founder.

Bill Ball

You could try to isolate the TT like I did and see if the vibration changes. I did have a new vibration at 3000 RPM. It was a rather subtle buzz that I only noticed because the shifter began to vibrate noisily, something it had never done before.

Bill Ball

Wooo Hooo! Rob's care package arrived this morning! THANKS ROB!

The new damper (or dampener) carriers are nice and FAIRLY snug in the tube. So, I'm pushing the inner carrier with my length of 3" PVC pipe and bottle jack, with the tube between two posts in my garage. The assembled damper is just under 6" long. Even though it seems FAIRLY snug, I can move it in the tube by hitting the PVC pipe with a 6" block of 2x6 wood, so I'll restrict its potential movement with some set screws on both ends. It's a little tricky to insert carrier-damper-carrier one piece at a time, as the second carrier needs to mate with the damper snout which does not stay centered with the tube laying on the ground even when mated well to the inner carrier. So, I knocked the outer carrier its last few inches with the tube vertical, checking as I went to make sure the carrier was going over the snout. I did that rather than install it as one piece because that would put stress on the rubber web that broke in the original carriers. By using the PVC pipe to drive it in via the other ring, there was essentially no stress. All I need to do now is drill and tap the tube for damper set screws and put the car back together.

Speedtoys

Bingo, that's it.

Charley B

Lookin' good Bill.

Unless you intend to finish today, I'll try and come by tomorrow to help with the re-assembly.

Rob Edwards

Wow, that was fast. Didn't dump it at USPS until about 2:20 on Saturday afternoon. Hope it cures all yer ills!

NC928S4

So what we have inside the TT is a Whirling Shaft. All spinning shafts have a critical speed where the shaft hits it resonant frequency. It's been years since I took Vibration Analysis but I found this site that models the TT reasonably well, specifically case 2.

http://www.freestudy.co.uk/dynamics/forced%20vibrations.pdf

You can't get rid of a vibration, you can minimize it by materials and other design points but ultimately you need a dampener to calm the vibrational system down so it doesn't rip itself apart. I'm sure this was studied by Fritz and hence came up with dampener. It needs to be placed in a particular location for optimal effect.

When my TT failed the dampener was floating around and sliding fore and aft so my vibration problem changed constantly although it usually was most felt between 2400-3000 rpm.

Ideally, you design for a resonant frequency at a low speed and never get to the second subsequent harmonics because they have much more kinetic energy to cause a failure.

Bill Ball

UPDATE 4: I installed the damper with Rob's damper carriers, "pinned" both carriers, each with 2 small screws 180 degrees apart (drilled through the tube and just a bit into the carrier), and put the TT back in the car. I pinned the carriers because they we worn enough that I could move them in the tube with modest force, whereas my bearing carriers are very difficult to budge. The drivetrain is quiet and the vibration at 3000 RPM (that was rattling the shift lever) is gone. The vibration and rattle was high frequency, the car seemed fine otherwise. However, it seems a lot smoother over all now. Since the auto shift lever is not bolted to the TT, this vibration was being transmitted through the body as a buzziness, now gone. So, the damper DOES do something to very effectively control a somewhat subtle but annoying buzz.

Mrmerlin

Zoom Zoom!

GregBBRD

The first place to start would be to ask Mark if they even bother putting the dampers back in.

Bill Ball

I have seen other rebuilt TT's, NOT bought from Mark Anderson, that did not have a damper.

Mrmerlin

if you dont have a damper then it would be a good idea to fit one,
than may mean taking the TT apart fully to fit the part,
it would also be a good idea to pin the damper so it wont slide back and forth in the TT,
a rivet on either side should do the trick

Ducman82

do you need a dampener if you were to use super bearings?

Bill Ball

I would agree based on my experience reported here, but if you don't have a damper, you PROBABLY aren't going to find one, unless you know someone else like Rob Edwards. And there is no one else quite like Rob. The damper itself is one thing, but the carriers are the main issue. The damper is left out on rebuild because the carriers are broken, like mine were. It's hard enough for the rebuilder to find good bearing carriers, which don't get pounded to pieces like the damper carriers.