Click Clack

cobraboy

Well-Known Member
#1
I am looking for some thoughts as to what is causing a noise I am hearing.

The other day I was driving down a street with buildings ether side with my drivers window open. I thought I heard a noise when I came off throttle. So I played by moving on / off the gas whilst in a low gear and sure enough there is a clack going both ways.

I got home and put the car in 1st gear and got out and shunted the car back and forth and there is a quite loud click clack. Under normal gear shifting I do not hear it, nor pulling away. It sounds as if it is coming from the rear of the engine / bellhousing.

The prop U/J s are good and new.
I wonder if a clutch disc spring could be broke ? I have yet to jack up and have a poke around. The drivetrain has not been abused as I am aware of the chocolate diff and mediocre LT77.
Any ideas ?
 

cobraboy

Well-Known Member
#3
I will get a chance tomorrow to look thanks.
To me it sounds tinny and I could be persuaded it is echoing as if in the bell - but mind you my ears are shot to bits.

Pardon ....

Just now I tried driving with my foot lightly on the clutch to take up any free play on the throwout parts, and it still made the noise :(
 

cobraboy

Well-Known Member
#6
I dragged my weary bones under it tonight. The splines feel OK with an acceptable amount of play. I had the front up and one rear wheel just off. From under the car violently snapping a rear wheel back and forth it does sound like it may be diff ? There is certainly some CW / P lash. The bellhousing I chose has a large hole Starrett cut into it and a grommet fitted, looking in there it all looked bolted together as it should.
Normal noises seemed to be coming from the trans.
So ..... I have bit the bullet and booked Snetterton for the 30th. If the diff gives up so be it. It is very weird how the noise moves when you are under the car.
 

mrtask

Well-Known Member
#9
I recall reading that the pressed plate that the diff bolts up to can crack! Classeparts suggested I should fit their 'boxed' reinforced one, but I didn't.
 

cobraboy

Well-Known Member
#13
The plate that bolts to the diff, and is secured to the mountings. They are prone to cracking.
OK Ta

Its such a pleasant evening here I went and looked, I cannot see any cracking but noticed the nearside spacer tube looks like it has been fretting a little at the top, so will check bolt tightness tomorrow. Also the bush at the diff end of the panhard rod has some play in it.

But I also may have found the culprit. On turning the rear wheels sharply opposite each other I can produce the sharp clack, It looks like the planet gears have play, probably due to worn thrust washers.

I know these are available for the MGB live axle, but does anyone make a kit for the Rover with a central pin as well ?

Thanks
 

Demetris

Well-Known Member
#14
My old 2000 diff used to do something like click - clack noises when i was changing direction of movement i.e. reverse after moving forward, and forward after reversing. It was clear that something inside the diff made the noise, but i never dismantled it to find out because i have replaced it with a 3500 one. Now that the car has a very occasional use, i am thinking of getting back to the 2000 diff, but not before taking it apart and repairing it (wish me luck...).
 

cobraboy

Well-Known Member
#15
From experience with the MGB unit changing thrust washers is not a bad job, at least you do not have to set up the crown wheel and pinion.
But I do know as well as the washers the centre pin does wear badly.
 

cobraboy

Well-Known Member
#18
Decided to drain the diff oil and re fill with some proper old hypoid EP 150 that I keep by to quieten a noisy MGB V8 axle. It made the clack a lot softer, so there is some play there that needs to be attended to. When I took the level plug out it hissed ! So got a tube and pressurised the diff through the fill hole and the breather worked, but I discovered the breather is a one way valve, so the hiss was air rushing in, odd ?
But a crazy find is........ brake pads !!!!!!!! Yep the little blighters are moving back and forth in the calipers making a heck of a row.
Searching my spares I found some stainless shims to put in the inner pad tabs as they were missing and also replaced one of the springy anti rattle prongs on one of the outer pads.
Now when I rock the car in the garage the sharp clack is gone and all I hear is the dulled diff noise and also some from the trans.
Road test to come, maybe, just maybe it is a winner.
 

cobraboy

Well-Known Member
#19
My old 2000 diff used to do something like click - clack noises when i was changing direction of movement i.e. reverse after moving forward, and forward after reversing. It was clear that something inside the diff made the noise, but i never dismantled it to find out because i have replaced it with a 3500 one. Now that the car has a very occasional use, i am thinking of getting back to the 2000 diff, but not before taking it apart and repairing it (wish me luck...).
Could it also be brake pads ?
 

cobraboy

Well-Known Member
#20
Well, er no, still there.

Have found I can make the noise by being parked hard on the foot brake and loading the drive train back and forth. So having again gone through a nut and bolt check have returned to the top diff mount bolts where I spotted the fretting on the near side bolt.
They took a tighten with a breaker bar and with a re test it needs a lot more effort to make the noise, so I am on to something.
Question......
The bolt through the mount goes upward, is there supposed to be a washer under the bolt head ?
I wonder if it needs a washer and I have omitted it in the past. I think the diff plate is creaking with the torque in this area.

Thanks
 
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