Engine and Transmission Tech

Gents, I was getting my Ford 5.0. T5 5 speed MGB ready for spring driving by putting on a Weiand Stealth intake and MSD 6AL. Everything went great and the car runs much better above 5000RPM, but after it warmed up a squeal began from the transmission area, which I never touched. It sounds a lot like a loose fan belt, a high pitch squeal! The throwout bearing seems to be working properly and doesn't seem to be the source and the trans shifts fine. The squeal only starts after the motor warms up and all is quiet when it is cold. It also varies quite a bit, sometimes barely audible and sometimes quite loud.

Praying this is something simple and does not require tranny removal as that requires pulling the engine. Not something I want to do...

Sounds like it could be a bad bearing....

Also the transmission was freshly rebuilt and the car has about 500 miles on it.

Does the noise change if you push the clutch in a little or all the way?

Yes, it does change sound. Loudest when the clutch pedal is out. A bit quieter when the pedal is in and when the car is in gear.

Sounds like a T/O bearing to me. I'm not a fan of Ford "constant contact" T/O bearings but from what my Ford buddies say, the T/O bearing must be in contact with the pressure plate with 5 lbs. of pressure or it will make noise. Sounds like a stupid design to me.

Well, I completely disconnected the throwout bearing from contact with the clutch and it is not touching at all. Still squeals like a pig after it warms up. I assume that can only mean the input shaft bearing, yet another new part that has less than 500 miles on it. Lots of pain coming!

Stupid question, did you check the oil level?

Yes, I checked the oil. This noise is coming from way up in front of the trans, not the trans itself.

I'm at loss for a suggestion. The only source of a "squeal" sound that I can think of would be the T/O or pilot bearing. You've eliminated the T/O bearing and if it was a pilot bearing, it would only squeal when the clutch was dis-engaged. I've never heard a trans. bearing do anything but growl since it's so well lubricated. Keep us posted on what you find. Good luck.

Yes, Ive got a TR6 that needs shaft bearings and it is a definite low growl. This one does change sound when the clutch is in but doesn't completely go away. It is much louder when the clutch is out and seems to go away when driving. My plan is to remove the transmission 1st then run the motor up to operating temp, since this doesn't happen when its cold. I assume that if the squeal goes away, it has to be the pilot bearing. Then I will pull the motor and replace.

It is a shame, since the pilot bearing, like everything else in this drivetrain, has less than 500 miles on it. Given my limited time right now, my spring driving wont happen.....

Keith,

Don't need to pull motor for a pilot brg. At least not on what I have seen. Grease and a close fit dowel should pop it out, or some take a slide hammer to pull out.

Kieth,

Are you positive it's the trans?
A couple of other possibilities are, the intake manifold and or hoses and gaskets. They can produced a pronounced "squeal'' noise if not perfectly sealed. Another could be crankase vacuum. If a breather or vent isn't working or miss connected the crankcase goes into negative pressure and the rear main seal will squeal like a pig.
Hope that helps.

Live like you mean it.
Fred

Unfortunately, in my MGB, you cant get the bellhousing off without pulling the motor. Actually, I hope I can just disconnect motor mounts, headers, radiator etc and just lift the motor and move it forward enough to get the bellhousing out. It will still require renting a hoist and it's almost as labor intensive as just pulling the motor all the way out.

When the input shaft bearing on my TR4A transmission went, there was squealing, just not all of it coming from the transmission...;)

I made the mistake of using a synthetic gear oil and it leaked out, leaving the bearing dry. Smaller, slicker molecules leak faster.

Quote:

Well, I completely disconnected the throwout bearing from contact with the clutch and it is not touching at all...

That's the point that Jim was trying to make above - the Ford constant contact TOB does NOT need a clearance gap to the clutch fingers - it needs to be in constant engagement with the fingers.

Fred was right! I pulled one of the breathers and the motor is creating a huge suction on the driver side. With that breather off, the squeal goes away. Pretty sure it shouldn't be sucking massive amounts of air through the valve cover though!

Kieth,

Are you positive it's the trans?
A couple of other possibilities are, the intake manifold and or hoses and gaskets. They can produced a pronounced "squeal'' noise if not perfectly sealed. Another could be crankase vacuum. If a breather or vent isn't working or miss connected the crankcase goes into negative pressure and the rear main seal will squeal like a pig.
Hope that helps.

Live like you mean it.
Fred