Please help!! grinding from toploader

priobe · #1 (**permalink**) 10-01-2007, 08:34 AM

Hello All,

I am experiencing a grinding noise from my tranny when I engage it in gear. Everything was fine before I removed the trans to get to the back of the block to fix my pressure releif valve on my 427 FE.

Here is the problem:

When I start the motor and idle everything is fine. When I press the clutch I hear a grinding noise in netural. As soon as I release the clutch the noise goes away. If I try to turn off the motor and put it in gear then start the motor with the clutch pressed in, the noise is there even louder. I have tried releasing the clutch while making the noise and the car moves without the grinding noise. The noise is intermittent.

Here is my setup:

Centerforce flywheel
Brass pilot bearing
Centerforce clutch
Centerforce pressure Plate
Lakewood Bellhousing
Top Loader Trans
Tilton Hydraulic Release Bearing

I verified through the fork hole in the side of the bell housing that the release bearing moves about 3/4 to 1 in. travel. I have also bled the system several times.

Can someone shed some light before I pull the tranny.

Please help

Rick Parker · #2 (**permalink**) 10-01-2007, 09:42 AM

Sounds like something in your clutch release bearing.

Coloradocobra · #3 (**permalink**) 10-01-2007, 09:49 AM

Not sure from your description but it almost sounds like you are pushing your pressure plate too far. Try to put your car on a slight incline. With the engine off, put it in gear and make sure the clutch is fully released. Slowly press the pedal until the car starts to roll. The desired full release of the clutch should only be slightly below this point. Now start the car and push the pedal to this point and see if the noise is present. If this seems to work, install a stop on the clutch pedal or adjust your linkage to limit travel.

Alternatively, you can lift the back of the car so both wheels are off the ground. Try to rotate the wheels as someone else pushes the clutch down...

Other possibilities include an incorrect throwout bearing that is too large for the transmission nose, an incorrect pilot bearing (too large diameter), or pilot bearing damged during transmission installation.

priobe · #4 (**permalink**) 10-01-2007, 12:06 PM

Rick,

I am able to look at the release bearing from the clutch fork hole and all looks good. What gets me is that sometimes it makes the noise and sometimes it does not.

ColoradoCobra,

I have done exactly what you have described. As a matter of fact I have tried shutting off the motor when it makes the noise. Then placing the tranmission in netural and slowly pushing the clutch pedal until I hear the noise and it makes the noise as soon as I start to disengage the clutch.

I have spoken to Centerforce and they told me that it may be a pilot bearing. I would not doubt that the pilot bearing was damaged durning installation. I was by myself on my back with this 100 + transmission trting to push it into this little hole

But I dont see how it will make a grinding sound only sometimes. Can you please explain.

Also, do you guys know if you can remove the tranny without removing the bellhousing with a hydraulic release bearing?

Clois Harlan · #5 (**permalink**) 10-01-2007, 12:58 PM

Yes, you can but it is a pain in the a$$. I know you hate bleeding the t/o/b but you will be glad you did. Find a plastic thread protector to slip over the braided lines as you remove them and also a couple for the female part of the t/o/b lines. This will prevent your fluid from leaking out and it will make bleeding a 15 min operation. I am not using a spacer on my t/o/b, in fact my bearing is back almost as far as it will go to obtain the .125 clearance.

Clois

priobe · #6 (**permalink**) 10-01-2007, 02:02 PM

clois,

I was not asking about removing the tranny because of bleeding purposes. My reason for asking about the removal of only the tranny was because,

I dont have a removalable tunnel in the car and the bellhousing will not make thru the frame rails. So, the first time I removed the tranny I unbolted the bellhousing from the motor. Then unbolted the bell housing from the tranny. I twisted the bellhousing to slip it thru the rails. Finally, lowered the tranny to the floor. This was a pain in the @$$.

Also, I was told to try to bleed the bearing without the pedal stop in place?????
Wouldn't that over stroke the bearing and cause a leak. Can you explain how you bleed your system?

Excaliber · #7 (**permalink**) 10-01-2007, 02:30 PM

If your in their I would SERIOUSLY consider removing the internal hyd throw out bearing assembly and going with an external slave. ESPECIALLY considering how hard this thing is to work on.

That internal bearing WILL fail, gaurentee it!

priobe · #8 (**permalink**) 10-01-2007, 02:46 PM

Excaliber,

I have heard complaints only from users that were unsuccessful with the intallation of the bearing.

I understand what you are saying about the bearing and I am too considering moving away from this bearing.

Do you have any pictures or know where I might be able to pick up the assembly for the external system.

This might make me get away from this system if it is not too much more work.

Jac Mac · #9 (**permalink**) 10-01-2007, 02:57 PM

Do you use the thin sandvich plate between Bell housing & Block, could it have been bent while out and is now just touching the front face of flywheel - does the relief now stand proud of the block surface & warp that plate - has the starter ever 'kicked back' from an over advance ignition start, I have seen this bend those plates & cause the problems you speak of.

Jac Mac

priobe · #10 (**permalink**) 10-01-2007, 03:11 PM

Jac,

If you are referring to the back plate that comes with the bellhousing .. yes I am using it. It is not bent in any way besides it is pretty thick. I will triple check again tonight. What is strange is that it is intermitient.

Many have said that it sound like to the pilot bushing but I dont see how. I will remove the tranny this weekend but would love if someone has experienced this problem to chime in so I possibly dont have to remove the tranny. And not I am debating on switch away from the hydraulic throwout bearing.

AHhhhhh fustration

Jac Mac · #11 (**permalink**) 10-01-2007, 04:28 PM

No, I was thinking of the OEM sandwich plate ( Approx 0.065" thick ).

It sounds like either a TB problem or the crank end float allowing contact.
If you roll down an incline with motor off, clutch pedal depressed, trans in gear ,does that sound remain or not. If not then its likely a flywheel/clutch cover contact problem , if it remains then its more likely to be TB or plate related.
Many internal TB systems cause problems with larger clutch assy's due to the greater distance they have to move to disengage the clutch. Tilton /QM seem to work best usually on clutches where they may only have to move fingers/diaphragm 3/8" to release. Old rule of thumb is flat brg/radius fingers or vice versa- never flat to flat or round to round, makes the brg tend to wander off center.

Jac Mac

Ibr8k4vetts · #12 (**permalink**) 10-01-2007, 04:52 PM

Is there anyway you could have the T/B on backwards? I know you can on a McLeod T/B

priobe · #13 (**permalink**) 10-01-2007, 07:48 PM

Jac,

What do you mean by crank end float? Throw out bearing possible, hell I have a new pilot bushing on the way to replace it any way when Saturday comes around.

I would have to say that it does not make a noise when rolling with the motor off. with clutch engaged. I will have to test to be sure. Again it does not happen all the time. If I shock the tranny by releasing the clucth suddenly that might fix it for a while but it will come back. When I take down the tranny I will inspect everything.

Tilton is saying that there is air still in the system because I bleed the system with the pedal stop in place.

Do you think it could be a pilot bearing ????????????????

Mike,

I dont see any way to put the Tilton unit on backwards.

Excaliber · #14 (**permalink**) 10-01-2007, 08:16 PM

Pilot BUSHING or BEARING? The bushing makes for an easier install, the clearance on the bearing and the trans pilot shaft can be VERY tight and make it darn near impossible to get the trans in the last half inch!

Jac Mac · #15 (**permalink**) 10-01-2007, 08:46 PM

Quote:

Originally Posted by priobe

Jac,

What do you mean by crank end float? Throw out bearing possible, hell I have a new pilot bushing on the way to replace it any way when Saturday comes around.

I would have to say that it does not make a noise when rolling with the motor off. with clutch engaged. I will have to test to be sure. Again it does not happen all the time. If I shock the tranny by releasing the clucth suddenly that might fix it for a while but it will come back. When I take down the tranny I will inspect everything.

Tilton is saying that there is air still in the system because I bleed the system with the pedal stop in place.

Do you think it could be a pilot bearing ????????????????

Mike,

I dont see any way to put the Tilton unit on backwards.

Just the 'normal 0.008"/0.012" ' crank endfloat, but I dont think its your problem here, only occurs if you have very tight clearance issues inside bell housing.

One other thing, are both alignment dowels still in block/bellhousing, didnt fall out while fixing the relief valve? Did you reindex the bell housing at refit? Those Lakewood housings usually need oversize dowels from what I have read.
The air in the line could explain why the noise is intermittent or returns after you 'shock' the clutch , but doesnt explain why the noise is there. If it is the TB then it must either be misaligned with the fingers or causing an issue with them to create the noise.
Ernie raised a point with the pilot brgs- the 'ball bearing' type can 'grab' on the input shaft and cause problems later, the original oil impregnated bronze bush is fine for street use, later aftermarket needle roller type are great, but dont use them on an old trans with corrosion on the front of the input shaft- the needles will fail prematurely.

Jac Mac

priobe · #16 (**permalink**) 10-01-2007, 09:24 PM

I guess this calls for a tranny removal and a reinstallation from scratch. I am using the bronze bushing and have another on the way.

Hopefully when I pull the tranny I will see what is causing the problem. I just want fix everthing so I could finally strip it down to send the body to get paint.

Coloradocobra · #17 (**permalink**) 10-02-2007, 08:24 AM

A related item to end-float and the bellhousing/block plate is starter gear clearance. This is a long-shot but can be easily checked since you intend to pull everything apart. Pushing the pressure plate will drive the crank forward slightly and if your starter gear clearance is marginal it may hit. When I installed everything I turned the crank and could hear the starter hitting the flywheel. It was close and was probably caused by stack-ups including the flywheel flange machining, the block, etc.

A standard starter shim solved the problem. In your case, it may all clear until you push on the clutch. Pull the starter and inspect the end/face of the gear as well as the flywheel gear to see if there are any signs of wear. It could be that it is so close that it was not a problem before your work and appeared when it was all put back together again.

Can't hurt to check...

priobe · #18 (**permalink**) 10-02-2007, 09:57 AM

Coloradocobra,

Thank you for your response. Hmmmmm. Its funny you should mention that. While repairing the pressure relief valve I noticed that my starter did not sit completely to the block. I had to grind alittle bit on the body of the starter to make it sit completely flush to the block. I will definitly pull the starter and check to see if this is the problem. It was not much of a grind but you never know.

Thanks