knock knock knock...oops.::o

tried again today - moved the car by rolling it back and forth in the garage to see where the weird knocking or tocking sound was coming from...this time with a friend's help so I could listen while he pushed. It definitely sounds like it's coming from the area around the clutch or rear of the engine or possibly the forward u-joint.

I am soooo close to being "done" and starting and hopefully driving the damn thing - now I fear that I have installed the clutch pack backwards or some such and will have to pull the engine again to get it sorted!

Next step is to put it up on ramps (front) and jack stands (rear) and turn the wheels whilst lying under the car to see what I can see....no idea how to proceed otherwise at the moment.

Any ideas?

JIM

If it's a ticking my guess would be the U-joints. The cups are dry of grease. The noise is traveling up the drive shaft.But that my guess. Did you ever replace the u-joints?

I didn't replace them, but I removed the shaft and cleaned and painted everything.

I probably need to use my new grease gun to lube them.

I hope that is all this is!

Step on the clutch and put it in gear. Then try to push the car. If the car goes into gear and the car doesn't move with the pedal out, you put the clutch in right. I can't imagine getting u-joint noise at pushing speeds unless they're really, really bad. Is the knock frequency synchronous with the pushing speed? Basil

If it is the u-joints greasing them will not help. The bearings are dry. You need to replace them or they might go out later. (MY thoughts) I had them happen to me a little while ago. You get a tick tick tick as the drive shaft rotates. Pushing the car forward then backwards the noise will be a clunk like it is coming from the rear end or tranney. When checking u-joints by hand they fill tight. But that is my guess and I could be wrong. From what I read of Basil Adams. He's a sharp cookie and know his business. A lot sharper then me. Let me know what you find.

No fluid in the clutch cylinder yet - I can do that tomorrow, Basil...thanks.

Car goes into gear without the clutch if I wiggle it (the car) back and forth though.

Noise is synchronous with the car moving - about once every two or three feet maybe - I haven't measured to see if it's one or four tire rotations.

JIM

Tire does one turn in about 6-1/2 feet of travel. Propshaft does 4.3 turns for one tire rotation., or one turn every 1.5 feet of travel.

With engine off, gearbox in neutral and pushing the car, the only parts rotating would be gearbox mainshaft with 1st gear only, propshaft, ring and pinion gears, brake drums, halfshafts and wheel bearings. Nothing inside the bellhousing would be moving.

It's a little odd to think that even a bad U-joint would make noise when pushing it, but maybe. If it was bad enough to make any noise at all under any conditions, you would be able to wiggle it noticeably by hand.

The mid-1500 type propshaft (most likely resident in a 1957 MGA) has a stamped steel dust cover at the front end that is press fit on the front yoke. Occasionally this may come loose in which case it makes a jingling noise like a small cow bell when driving. It might "tink" periodically when pushing by hand.

Drop a spring off of a brake shoe and it might clunk each 1 turn of the brake drum when rolling.

Jack up the rear of the car and turn a wheel by hand to see what makes noise.

Thanks Barney - very clear - and somewhat encouraging. I will do this and report back as soon as possible.

JIM

The drive shaft comes off pretty easily. Good time to inspect/lubricate. Also, you can spin the rear wheels to see if noise persists.

'K Larry - you come down and we'll do this thing. I'll turn the wheels while you lie on the ground under the car and inspect the driveshaft...

Sounds like a plan.

I'll buy the beer...they sell OSH in the local packy.

JIM

Jim,

You noted that you had removed and reinstalled the drive shaft. It is important that the drive shaft is installed such that the front and rear U-joints are "in phase." If they are not, they'll "fight" each other and can cause a binding or vibration. I suggest you double-check to be sure they're in phase. See attached illustration.

Good luck,

Dick Moritz

I am pretty certain I installed them in phase...

I pulled the left rear wheel and turned the driveshaft - noise is 4 times per rotation - so that should be the drive shaft.

I need to lubricate the rear diff and the drive shaft and see what happens.

JIM

This sounds to me like a sticking speedo cable. It winds up then lets go. Does the speedo bounce even slightly with the tick?

Otherwise, I'd suggest a piece of something resting on the spinning driveshaft yoke - is your e-brake cable hanging down? E-brake handle bolt too long? (Grasping at straws here)

Your driveshaft u-joints are not making the sound. The rear axle and the tranny are almost inline on the car at rest, so your u-joint bearings are not actually moving! You have to have the rear suspension really compressed, or drooped, in order to have the u-joint bearings move much at all. Certainly not enough to tick on a car at normal ride height.

It certainly could be a part of the e-brake system bonking on the cable. When I jacked up the car, it was not as loud as when the car was actually rolling.

I'll have to crawl under and see. Thanks for the suggestion.

JIM