[Sutripta]

Originally Posted by dhanushs

Hi All,
...
Dhanush

How willing are you to get your hands dirty, and spend some time, effort, and some money?

Originally Posted by Jeroen

This might be a silly question, but did you install it correctly. Back and front might not be that apparent, but if you get them mixed up the spring dampeners won’t work.

Good luck
Jeroen

Actually would work on the overrun.
There was a discussion on this on another thread, where I couldn't make people understand this!

Regards
Sutripta

[dhanushs]

Originally Posted by Sutripta

How willing are you to get your hands dirty, and spend some time, effort, and some money?

I can find the root cause and solve it, yes, very much.

[Sutripta]

Originally Posted by dhanushs

I can find the root cause and solve it, yes, very much.

From what you describe, it is a simple case of permanent set in all the springs. That is a property of the spring, and its design limits. The number of cycles it endures (fatigue) also plays a part.

First thing to do would be to dismantle the plate (both old and new => cost!) and measure the properties of the spring (free length, spring constant). Work out the torque- angular displacement relationship, and validate it.

The maximum compression will be when the springs are coilbound. Take one of the springs, compress it till it is coilbound (dont injure yourself!) and see if the free length changes.

Was wondering if overheating of the clutch under load would cause this, but then dismissed the idea.

Regards
Sutripta

[Aroy]

Originally Posted by Sutripta

.........

Was wondering if overheating of the clutch under load would cause this, but then dismissed the idea.

Regards
Sutripta

Overheating will definitely change the spring characteristics. If it is hot enough the spring material will tend towards "plastic" state, and then it will deform permanently. If that is the case, then even a harder spring will not work. What is needed is cooling the clutch plate under severe load, or getting a clutch that has multiple plates which heat up less.

[Sutripta]

^^^
The overheating cause was rejected judging from the excellent condition of the friction material, as shown in
http://www.team-bhp.com/forum/techni...ml#post3854872

@dhanush: Do you have access to a discarded GB top shaft?

Regards
Sutripta

[SS-Traveller]

Originally Posted by Sutripta

^^^
The overheating cause was rejected judging from the excellent condition of the friction material, as shown in
http://www.team-bhp.com/forum/techni...ml#post3854872

I think dhanushs used a representational photo downloaded from the web and used it to draw the circle and demonstrate the shake pictorially.

Correct me if I am wrong, dhanushs.

[lugnut]

All good with the flywheel and adapter plate (if used) ?

[dhanushs]

Originally Posted by Aroy

Overheating will definitely change the spring characteristics.

Originally Posted by Sutripta

The overheating cause was rejected judging from the excellent condition of the friction material
http://www.team-bhp.com/forum/techni...ml#post3854872 (Clutch friction plate hub shaking: Root cause?)

Originally Posted by SS-Traveller

I think dhanushs used a representational photo downloaded from the web and used it to draw the circle and demonstrate the shake pictorially.

Hi, SST is right. However, the original Friction plate is hardly worn off. Its like new. Please give me one day. I will post the used clutch plate photo and a video with a GB main shaft into it, and shaking.

Originally Posted by lugnut

All good with the flywheel and adapter plate (if used) ?

Yes. May I ask what is the role of the adapter plate in this? GB and Engine alignment (hence GB main shaft alignment)?

Originally Posted by Sutripta

@dhanush: Do you have access to a discarded GB top shaft?

Yes, Sutripta.

[lugnut]

Originally Posted by dhanushs

Yes. May I ask what is the role of the adapter plate in this? GB and Engine alignment (hence GB main shaft alignment)?

Yes - that's what I would suspect (IIRC you mentioned earlier you've gone through 3 clutches) - something is throwing the clutch off-center.. leading to spring wear over repeated (and spirited) use

[Sutripta]

^^^
Can't visualise it. An explanation would be appreciated.

@Dhanush: Views on pilot bush/ bearing.

Regards
Sutripta

[dhanushs]

Originally Posted by Sutripta

@Dhanush: Views on pilot bush/ bearing.

You mean, bush in the crank GB side, where GB top gear sits? Well, all is good, but im sensing an early wear. Not enough kms to finalize it, yet, I guess.

Originally Posted by lugnut

Yes - that's what I would suspec

The pressure plate and the flywheel are Nissan SD25 OE ones. No change in that. Also the bell housing is Nissan OE, the adapter plate I have is on the GB side, and is evenly machined. So, I guess friction plate centering problem should be ruled out?

Originally Posted by SS-Traveller

...demonstrate the shake...

Here is a video of the shake, of the latest clutch plate.

https://www.youtube.com/watch?v=mihgr__-fh4

Originally Posted by Jeroen

This might be a silly question, but did you install it correctly. Back and front might not be that apparent, but if you get them mixed up the spring dampeners won’t work.

Hi, Just noticed, that all the clutch plates I used have markings for "flywheel side" .

[Sutripta]

^^^
The video hides more than it reveals! But I feel the problem is in the attachment of the hub to the plate.

Dismantle the plate (you will have to pop a lot of rivets) and take a long hard look at it. The problem should be fairly obvious then. One can then attempt to work out the root cause.

Pilot bush or bearing? (Yes, the one in the flywheel)

Regards
Sutripta

[Jeroen]

Originally Posted by dhanushs

Hi, Just noticed, that all the clutch plates I used have markings for "flywheel side" .

That is great. But if you only found out just now, how sure are you the clutch was installed correctly? How did you determine back from front before you noticed markings? If you instal it back to front the damper springs wont work and I can imagine the whole clutch assembly will shake itself to pieces and you end up with it looking as in the video. Maybe it is just a case of to much power/torque, but unless you are absolutely sure you cant rule it being incorrectly installed either I think.
Good luck,
Jeroen

[Sutripta]

^^^
Normally the splined hub fouls the flywheel if one tries to install it back to front. I think that will be the case here also. All Dhanush has to do is confirm that. (However if it is found that it can be installed back to front ...)

Regards
Sutripta

[dhanushs]

Originally Posted by Jeroen

That is great. But if you only found out just now, how sure are you the clutch was installed correctly? How did you determine back from front before you noticed markings? If you instal it back to front the damper springs wont work and I can imagine the whole clutch assembly will shake itself to pieces and you end up with it looking as in the video. Maybe it is just a case of to much power/torque, but unless you are absolutely sure you cant rule it being incorrectly installed either I think.
Good luck,
Jeroen

Originally Posted by Sutripta

^^^
Normally the splined hub fouls the flywheel if one tries to install it back to front. I think that will be the case here also. All Dhanush has to do is confirm that. (However if it is found that it can be installed back to front ...)

Hi Jeroen, I think I sounded wrong in the post. The clutch disc installation has not gone wrong all the 3 times. I think we can safely rule that cause out.

Let me dismantle the disc and check, in the meanwhile, would appreciate if somebody can list out the reasons why this happens. Right now, what I have noted down is the engine + gb alignment. Otherwise, the flywheel being old and being unevenly 'catchy' of the friction plate? Or the big problem of the disc not being able to handle the torque, which by seat of the pants meter and comparo to stock Thar CRDe is 30kgm+.