Trans. specialists: T-5 growling noise

Let me start by saying that my friend and I have the same problem. We also had our tailshaft and tailshaft hsgs changed by the same trans shop. Well here's the problem. I (we) get a loud growling noise with the clutch pushed in, but only when it's in gear. As soon as you start to release the clutch it stops. Sometimes mine does it when downshifting to third gear, but it usually only makes the noise when I first start the car (hot or cold). More info: we both have flatheads with stock flywheel, clutch assy, and throw out mechanism. I have a Speedway trans adapter and he has a Cornhusker. We both installed new T.O. bearings when first assembled, and he has replaced his again thinking it was the problem. Any ideas?

 

I know the sound, my T-5 does it sometimes....I have no clue as to what causes it.

 

The dampener springs in mine were barely touching the flywheel bolts until I had the bolt holes spot faced deeper per the tip from a HAMBer. I had the a stock GM t-5 clutch hub put into an early disc when I originally assembeled the thing.

 

How many miles have you put on it with that noise?

I had the same problem with the bolts so I had Fort Wayne Clutch make me a disc that is flat on the flywheel side at the hub (just like the original). I have plenty of clearance now. That's not my problem, but thanks for the input.

 

It’s inherit to the design of the T-5 transmission. This transmission doesn’t have any thrust washers, basically the aluminum case acts like the thrust washer. We had a-lot of warranty concerns about this noise. To the best of my knowledge the factory never fixed this concern.
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Steve

PS: Didn't seem to hurt the transmission's performance or longevity.

 

I've never experienced the noise you describe. What sort of pressure plate are you using? Stock Ford? Or did you replace with a diaphragm style? The only thing I can think of is using the early Ford throwout bearing with a late-model diaphragm clutch and the large diameter of the early Ford T/O bearing is riding on the flat spot of the diaphragm fingers instead of the inner raised area - that is a pure guess though.

 

another WAG, Pilot bearing.

Not a trans issue because the trans isn't turning when you are stopped with it in gear. Just the flywheel and clutch pressure plate is turning. The input shaft is stopped. And the disc is stopped.

 

Ernie,
I'm using a stock (rebuilt) 3 finger P.P.

I understand what you're saying about the disc and input shaft, but it only makes the noise when it's in gear. I'm using a thin spacer (supplied with trans adapter) on the pilot bearing end of the pilot shaft, but my buddy is using a special bronze pilot brg. which came from Cornhusker with his adapter.

 

I'm happy to see this thread. I've been having the same symptoms on my AV8 with a T5 all season. Very annoying. I thought it was the TO bearing and plan to change it when the season is finally over.

I have the cornhusker conversion kit including their clutch disc and bronze pilot bushing. Stock ford flywheel and three finger PP. Like you, it only happens when the clutch is depressed and the trans is in gear. It doesn't make the noise at idle, but as soon as I give it a little gas as I start off, the noise comes up and continues even if I put the clutch back in and allow it to idle again. Taking it out of gear stops the noise.

Sure hope someone posts soon with a cure. I don't want to put in a new TO bearing, only to have the noise still show up again.

 

As I said earlier, my friend replaced a new T.O. brg with another and no improvement. I hope so too.

 

If you are sitting still and you are in gear with the clutch in, then the input shaft is not turning at all. So what is left that is moving in there?

1) The Pilot bearing: This will be turning around the nose of the input shaft. There might be some slight pressure against the input shaft from the rear or from an angle from it being in gear and sort of locked into a position which might be causing a slightly different pressure on the pilot bearing. That could explain it only happening when in a gear.

2) The Pressure Plate/Throw Out Bearing: The pressure plate will be rotating with the throw out bearing pushing against it to release the pressure and will be rotating around the clutch disk which will be locked into the input shaft sitting still. The TOB rides on the bearing retainer nose that sticks out the front of the tranny. This nose can be worn easily and cause a noise if it is the aluminum version instead of the steel version. The bearing itself can make a noise, but I can't think of a reason it would feel the effects of the transmission being in gear or not except for the possible slight change in angle that might be caused by being in gear. This would be a very minimal if any at all, and technically, I don't think it should be there at all. But I guess if the angle of the input shaft was to change slightly, it would be amplified at the outer edges of the clutch disk, so there could be some rubbing of the clutch disk's outer edge with the pressure plate or the flywheel maybe. I'm not sure you would even be able to hear this as it would be like riding a brake slightly with the similar surface touching the machined surfaces.

3) The only other thing I can think of would be the bearing in the front of the tranny inside the bearing retainer that supports the input shaft. Being in gear it might be pushing against that bearing and that bearing could be worn or acting up causing the noise.

That is about all I can think of. I hope that might be some help, but none of it seems like it should be the culprit if the TOB has been replaced and the other parts are new.

I used to rebuild a lot of T5's in mustangs and I am not familiar with this that I can remember.

 

This is sounding not so simple now.

Did you indicate the bell to the crank? And indicate the pilot bushing as the crank turns.

I once had a 283 that the pilot bushing hole was .015 off center and it made noise in the trans.

Also the T-5 has a tapered roller bearing on the input shaft, it likes to run true. If the bell isn't true with the crank it puts wobble into the input shaft.

Whereas the older trans have a ball bearing in the nose which is a little more tolerant of mis-aligning.

I got two T-5's running and both are quiet, and I'm really suprised at all the posters with problems.

 

Sounds like the pilot bearing/bushing to me, as said above. I would replace the pilot bearing, make sure the bellhousing is true and probably replace the throwout bearing being that your in there anyway and there cheap enough.

 

Is this an S10 5 speed or WC or NWC we are talking about or doesn't it matter?

 

As mentioned, nothing should be turning in the trans, so WC vs NWC is irrelevant, I think.

Could be a pilot bearing - I always run bushings instead of bearings.

Never had this sound.

 

Well, I've had the eng/trans out 3 times and I'm not ready to do it again. Obviously I'm not the only one with the problem, so I'm just going to wait and hope that someone says "hey, mine did that and this is how I fixed it". Thanks for the input. I'd also like to mention that I understand the mechanics of the flywheel, clutch, and trans. At this point I'm leaning toward the pilot bearing as the source of the problem. I too prefer a bushing, which I'm using.

 

All the guys who posted Pilot bearing are probably correct. There is a slight chance that the pressure plate might be hitting something, to check that with it in gear making the noise, see if moving the pedal a little off the floor consistently helps. Not enough to engage.

I honestly doubt that it's the pressure plate....

It's louder when you downshift right?

Bushings will also make a horrible sound when dry.

 

This may sound "backyardish" but I would lift it up on a rack, fire it up and listen with a stethoscope or long screw driver to the ear to see if you can isolate the origin of the sound........................... Taking all safety precautions while on rack!

 

Something nobody mentioned yet is the length. Put the trans in with no clutch and stick a mirror up in there to see if the trans is to long on the snout. I had to grind 3/8 inch off both of the ones I did.

 

I wish this could be done, but with the components used it impossible. I did take as many measurements as possible before installing though. Here is a pic early in mock up.

 

I want to bump this, I have the same noise issue with my T5.
I'm sure that it is the pilot bushing as well.
Has any one found the cure?

 

ok, thinking outloud here. so when stopped at a light. trans in nuetral foot on clutch the clutch disc will spin a little. the input shaft will turn with it. some say its the bearing or bushing in the back of the crank turning the input shaft. when you put the trans in gear. the input shaft will stop turning and this will stop the clutch disc. the amount of pressure on the throwout bearing hasnt changed, so what has changed, the clutch disc has stopped completely and so has the input shaft. so could the clutch disc be rattling on the input shaft, is the input shaft loose in the pilot bearing. i cant see it being internal trans because at this point nothing in the trans is moving. throwout bearing doesnt make sense because it hasnt changed what its doing. still pressing on the pressure plate. that leaves the disc or the pilot bearing. possibly the disc is contacting the flywheel bolts or some part of the flywheel, the flywheel is spinng, the disc in not. long shot here, but i have seen people install the disc backwards, it will work but there will be noise.

 

I would add to check to see if the hub of the disc is possibly grinding on the inside diameter of the pressure plate ring.

If anything is hitting in there at all, and you've run it for any length of time, You should see metal "dust" in the bellhousing, and shinny spots somewhere on the parts once you take it apart.

 

No one mentions the type of pressure plate they are using. The original poster mentions using a stock PP. Stock what? The pressure plate may have fingers much too close in for early Ford...might be '51-up Merc or might be something else entirely.
If you used the snout sleeve that Cornhusker and Speedway supply with their kits then you must have a PP with wide enough fingers to clear it.
Here is a link to some pics that illustrate the potential problem.

http://www.jalopyjournal.com/forum/showthread.php?t=478323

It is for a 39 tranny to flathead but the info and pictures might be of some help to this thread. (The related info starts about half way down the thread.)

 

It's been several years since I've put a t-5 behind a flathead but I do recall someone telling me that I had to grind off about 1/4" off of the splined hub on the pressure plate for clearence which I did just that and had 0 problems. After selling said vehicle the new owner freshened up the flatty and installed a new pressure plate since everything was apart. I then received a phone call asking about why would the clutch not disengage. I replied to him with the modification of grinding 1/4" of the hub off and never heard from him again. Not saying that this scenario would help but might possibly point you in the right direction.

 

Mine does it too....I thought the trans was junk, and have been looking for another one!

 

what ever that noise was in my transmission went away....It hasn't made a noise in over four months...self healing I guess. My set up is 1955 Buick Nailhead with a stock Buick pressure plate and a S-10 disc. I also had to trim about a quarter inch off the input shaft where it goes in the bearing.

 

With the clutch and trans both laying on the floor, measure the length of the trans snout, from the front of the trans case. Then measure from a straight edge over the bell housing hole to the BOTTOM of the pilot bearing hole. I think you will see the trans snout needs to be 1/4 to 3/8 shorter. Just wrap a wet rag around the snout and grind slowly with a 4 1/2 inch hand held grinder.

 

Sounds like the clutch disk was rubbing on something as suggested above...whatever it was, it's worn down now.

 

With the clutch and trans both laying on the floor, measure the length of the trans snout, from the front of the trans case. Then measure from a straight edge over the bell housing hole to the BOTTOM of the pilot bearing hole. I think you will see the trans snout needs to be 1/4 to 3/8 shorter. Just wrap a wet rag around the snout and grind slowly with a 4 1/2 inch hand held grinder.

Listen to OleDon. I am sure this is what's wrong. There is pressure on the shaft while engaged, as well as when disengaged, but you can only hear it when disengaged.
The noise is just a displacement of the tension on the main drive when 'uncoupled'.
A similar noise can be heard when installing a clutch disc backward, and the disc is pushing back on the pilot. So trim the pilot 1/4" and measure with the depth gauge on your vernier calipers.