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worrying noise

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Adrio

Jedi Knight
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I have a noise that I thought was benign in my TR4A IRS but now I am starting to wonder (because of an accumulation of things I will describe).

When I start moving (forward or back) sometimes there is a "klunk" from the back some place. I have always assumed this was from the rear brakes "sticking a bit".

Now I have too many other possibly related symptoms to go on thinking like this.
First when I roll the car back out of the garage without the engine running and not having used the parking brake while it was in the garage I hear this faint "click ... click" that could be about once per revolution of the wheels or of the prop shaft (I have not measured it exactly).
Second, I have a vibration at about 55 to 65 MPH that I thought was poor wheel balance but now I wonder.
Third, I have this memory about reading something here regarding the diff mounts and that memory does not give me good feelings.

Does the collective wisdom of this forum have any suggestions???
 
Usually it is the passenger's side, front diffy mount
that breaks.

You should hear the clunk in 1st and 2nd gear the
loudest.

Sit in the car, engine running, tranny in 1st, clutch
pedal pushed to floor. Release the clutch pedal rather
abruptly and listen for a thunk.

Drive down the road a piece is 1st. Push in clutch
and select 2nd gear. Again release the clutch pedal
rather abruptly and listen for a thunk.

The thunk could be diffy mount, diffy itself or a
u-joint.

Put the car on jack stands or a shop lift. A broken
diff mount can be seen with your eyes.

Rotating a wheel with tranny in neutral you can listen
to the diffy and check a few u-joints.

d
 
Check your rear differential mounts. Make the necessary repairs ASAP. My TR6 has been completely dismantled for four years now for this very reason. You have been warned.
 
I disagree with the rear diff mount theory, although you should check it this is a rotational sound, & vibration which points to more than likely a u joint. Remember you have six u-joints, two on the drive shaft, two on each side of the diff at each axle.

Bad U joints are usually easy to find, lift each side of the car & rotate slowly watching & listening for play. This assumes that your axle splines are not the culprit.

A bad u joint in the drive shaft will usually give a vibration in the seat of your pants, or the mirror may shake, but that doesn't rule out the axles.


Good luck, keep us posted.
 
I agree with the U-joint theory because of the sounds only when rolling. The broken mount really only sounds when under stress; the car, not you.
 
gjh said:
I disagree with the rear diff mount theory, although you should check it this is a rotational sound, & vibration which points to more than likely a u joint. Remember you have six u-joints, two on the drive shaft, two on each side of the diff at each axle.

Bad U joints are usually easy to find, lift each side of the car & rotate slowly watching & listening for play. This assumes that your axle splines are not the culprit.

A bad u joint in the drive shaft will usually give a vibration in the seat of your pants, or the mirror may shake, but that doesn't rule out the axles.


Good luck, keep us posted.
Click to expand...

I Agree.
 
I agree with the rear U-Joint theroy!!

DSC02107.jpg

DSC02106.jpg

1147.jpg
 
Andrew Mace said:
It's also worth looking for loose bolts on a lever shock....
Click to expand...

<span style="color: #000099">Lever shocks have bolts??

Oh, now I recall. My rear shocks had no bolts
when we BOUGHT the car. They were kinda floating
back there. I installed some grade 8s.

My bad- forget about it. :shocked:

d</span>
 
thanks for the replies so far. How "obvious" is a diff mount break? My car was a frame off restoration I did myself (though the diff was mounted to the frame when I aquired the project). I did a visual inspection of the diff mount area at the time before mating the body to the frame and did not find anything.

Yes I have wire wheels, I will check those also. Sounds like I need to get under the car. I wish there was some way to measure the frequency of the vibration simply, as the wheels, and drive shaft are going at different speeds.

More as I discover it.
 
The vibration you feel leads me to believe it's a U-joint in the drive shaft.
I recently replaced axle U-joints that made the clicking noise and as bad as it got, I didn't experience vibrations, just noise.
On the other hand, I've had bad U-jounts on my truck's drive shaft that did cause vibrations.
 
Re: UPDATE worrying noise

I took a look under the car and found nothing obvious, but I did find some (and I mean very little but noticeable) play in the rear u-joint of the fore-and-aft drive shaft. The play is just a bit and much less then what appears to be in the diff itself.

How does one check these U-joints other they try to move them by hand as I did.

Also I measured the distance between the clicks as I backed out the car and they seem to be about 4 or so per revolution of the road wheel. Very rough measurement.

Any more thoughts from the experts out there?

Adrio
 
Re: UPDATE worrying noise

ANY play in a U-joint is reason to replace it, IMO. They don't always give warning before they break. And if you can detect the play, chances are good that the rollers are closer to square than round. Plus replacing U-joints is cheap and easy, compared to the potential damage if one fails at speed.

4 clicks per wheel revolution would be about propshaft speed.

A clunk when first starting out or backing up is frequently just excess play in the differential; which seems to be a common complaint with Triumphs. Eventually something will break no doubt, but my TR3A was like that for many years and never broke. Of course, it could also be a loose U-joint.

Bottom line, I'd service the U-joints first, and go from there.
 
Re: UPDATE worrying noise

Speaking of U-joints, does anybody have any tricks for accessing the rear U-joints on the TR6 independent rear suspension next to the hubs. Mine are quality aftermarket replacement joints that have grease nipples and short of disassembling the darn thing, they are virtually impossible to access to get a grease gun in there. I have tried every tip I can find, even a long pointed injection tip, and cannot get any grease in the joint. Gotta be a way.
 
Re: UPDATE worrying noise

TR6BILL said:
Mine are quality aftermarket replacement joints that have grease nipples
Click to expand...
Are they the proper long nipples? Should be about 1" long as I recall. With the suspension at full droop, you may have to turn the joint so the nipple is pointing upwards (like 45 degrees from vertical) to get room enough for the coupler. A thinner coupler might help too, eg
https://tinyurl.com/5tfprl
 
Re: UPDATE worrying noise

Adrio-

Let us know what you determined was
causing the noise and vibration.

tinster
 
Re: UPDATE worrying noise

Bill
No, there's no way I've figured out to get grease in them outboard joints
 
Re: UPDATE worrying noise

What? You don't pull the hub loose from the splines and grease them annually? That's the perfect time to grease that U-joint along with the splines.
I don't either but it's not a bad idea.
 
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