TCC vibration

[TYRODD]

As some of you may know, I had my tranny rebuilt in march and had a 3k stall w/lockup (Hughs ) installed. Everything has been perfect, even after I put 2400 miles on the truck traveling to Nats.

Tuesday afternoon I go for a spin and notice a vibration while the TCC is engaged, and only around 1600-2100 RPM. Its only during lockup as I can tap the brakes and the vibration stops (clutch disengaged).

I thought that maybe it could be ignition related and I'm feeling the miss/vibration only because the tranny and engine are physically meshed and dont have a cushion of fluid? But the truck runs great :dunno:

Any ideas?

I'm running type F and am going to flush 'n fill this weekend to see if that changes anything.

TIA!

 

[Crimson93Ty]

Re: TCC vibration

Is it doing it as it is trying to lock up?
Do you have a positive lockup and then it starts doing it?
If it does it as it is trying to lock up, it's converter/trans related.
If it does it after a positive lockup, you probably have something engine/flywheel related.

 

[TYRODD]

Re: TCC vibration

Is it doing it as it is trying to lock up?
Do you have a positive lockup and then it starts doing it?
If it does it as it is trying to lock up, it's converter/trans related.
If it does it after a positive lockup, you probably have something engine/flywheel related.

Yes, It occurs after positive lockup. Just cruising, in 3rd/OD my RPMs will stay around 1500-1600 w/lockup and there is no vibration...If I raise the RPMs any more, I will get a "humm" until I am over 2100 or tap the gas a little harder.

Could the flywheel bolts be loose maybe? I will pull the inspection plate if you think so and also pull the propshaft, to rule that out as a source as well.

Thanks!

 

[SY2932]

Re: TCC vibration

Could the flywheel bolts be loose maybe? I will pull the inspection plate if you think so and also pull the propshaft, to rule that out as a source as well.

Thanks!

That would be the first thing I would check. That's why Loctite 262, the red stuff, gets used on those bolts. That way, they only come loose with the aid of a torch...

 

[Andreas]

Re: TCC vibration

Did you "final torque" the 3 bolts directly or did you torque them in steps (blurry explanation) The converter may be drawn up crooked with the first bolt. This may cause the converter to run-out and usually ruins the pump bushing.

But as you wrote...its probably lock up related.

Just added some info in the thread.

 

[TYRODD]

Re: TCC vibration

Well, I pulled the propshaft last night. Tranny shop left a little surprise for me :tdown: They stripped one of the torx head flange bolts...took me several hour to get this one of without the aid of a torch :banghead:..

Anyway, the propshaft is not the problem, nor was the flywheel bolts. Actually two of the bolts were not extremely tight, didnt even flinch when loosening them. They are re-torqued and have the hurculean red loctite on them :tup: .

I drove it after doing all this and same story...

If it were engine related, what would cause this vibration? I would think if it were ignition related I would feel more of a pulse and not the steady "humm". Once again, the vibration occurs only at 1/8th throttle, @1600-2100 RPM, and after. I can actually step on the gas a bit more after lockup and before 1600 RPM and it will not vibrate. Pretty wierd? :?

 

[SY2932]

Re: TCC vibration

Ah, another fine job botched up by those who are trusted to make your stuff "right" :roll:... Just be glad that they *tried* to put all the bolts back in, some shops like to "forget" about them. Anywho based on that propshaft fiasco, I would be VERY curious about the condition of the bolts on your cross member and the bolts that hold the TRANSMISSION MOUNT in place. A bolt here and there that is stripped and/or loose will allow the driveline to move under load causing vibration... When I pulled my trans the first time, one for the studs on the transmission mount snapped off due to being welded with rust. Got a new mount from Summit to fix that problem. HTH's