Rattling Sound !

[Hendrik]

Impreza 1,8 L , 1993 , awd , automatic , 150.000 miles , most in stop and go , big city trafic (SP)

 

Problem :

 

A rattling sound , like you tick with a small hammer on a bigger piece of iron.

At every turn of the wheel twice , only under load , independent of turning.

Passenger front side. Forward or reverse ; same thing.

Loudest at low speed.

 

Local mecanics did everything to detect the source ,after quite some tests with different mecanics they found

the main suspected item was the front axle DOJ part (transmission side)

 

 

The right front axle was taken out and carefully dismantled and every internal part inspected.

Everything was ok , new grease was inserted ,the old spring pin had quite some slack....

A new pin was not available , after widening the pin somewhat it was inserted again.

 

Problem solved , no sound anymore.....

 

Two days later and after 50 miles , the same sound is back!

 

I now suspect the outer race of the DOJ having to much play on the axle shaft of the differential.

I can feel a play of about 1 to 2 mm (0,1 inch) or even more, between them , moving transversal.

 

First question : what is the normal play between them ?

Second question : Who had this before and solved it ?

 

Solving can be as easy as buying new parts , the only withdraw is that these parts are simply not available in

the place where I live.......

Ordering them in for instance the USA will take at least 2 months to get it.

 

If the (exessive?)play is the culprit , how to solve it (by inserting material ,or reducing in an other way the play ?)

 

I came to this conclusion as it was silent after the spring pin was still holding the parts closer together.

And I guess that there should be no demonstrable play between outer race and transmission shaft.

 

Any help or advice is more then welcome !

[uniberp]

It sounds like the internal spline MAY be worn.

On the transmission end of the axle.

It would not be visually obvious.

I've never heard of it.

I don't know what would cause it.

 

Possibly, as the axle spins faster, it centers itself due to gyroscope effect, and the clicking noise stops.

 

 

 

Impreza 1,8 L , 1993 , awd , automatic , 150.000 miles , most in stop and go , big city trafic (SP)

 

Problem :

 

A rattling sound , like you tick with a small hammer on a bigger piece of iron.

At every turn of the wheel twice , only under load , independent of turning.

Passenger front side. Forward or reverse ; same thing.

Loudest at low speed.

 

Local mecanics did everything to detect the source ,after quite some tests with different mecanics they found

the main suspected item was the front axle DOJ part (transmission side)

 

 

The right front axle was taken out and carefully dismantled and every internal part inspected.

Everything was ok , new grease was inserted ,the old spring pin had quite some slack....

A new pin was not available , after widening the pin somewhat it was inserted again.

 

Problem solved , no sound anymore.....

 

Two days later and after 50 miles , the same sound is back!

 

I now suspect the outer race of the DOJ having to much play on the axle shaft of the differential.

I can feel a play of about 1 to 2 mm (0,1 inch) or even more, between them , moving transversal.

 

First question : what is the normal play between them ?

Second question : Who had this before and solved it ?

 

Solving can be as easy as buying new parts , the only withdraw is that these parts are simply not available in

the place where I live.......

Ordering them in for instance the USA will take at least 2 months to get it.

 

If the (exessive?)play is the culprit , how to solve it (by inserting material ,or reducing in an other way the play ?)

 

I came to this conclusion as it was silent after the spring pin was still holding the parts closer together.

And I guess that there should be no demonstrable play between outer race and transmission shaft.

 

Any help or advice is more then welcome !

[nipper]

This may be one of those sounds that you have to let get worse before it can be fully diagnosed, but i would guess the cv joint. i am seriously impressed that some disected the axle.

 

Let it go for a while and it will let it self be known. If these are original axles, they are due.

 

i dont have a fsm for this car, so i cant help with the tolerances.

 

 

nipper

[Gnuman]

Sounds to me like an aftermarket axle that does not fit correctly. Solution would be a MWE axle, or one from the dealer, as you say the parts are not available I'm guessing there are no junkers to pull a part from. You should get a new roll pin with the new axle. I'd order the axle from MWE and drive this one until the new one arrived. I have also never heard of the splines getting worn.

[Hendrik]

This may be one of those sounds that you have to let get worse before it can be fully diagnosed, but i would guess the cv joint. i am seriously impressed that some disected the axle.

 

Let it go for a while and it will let it self be known. If these are original axles, they are due.

 

i dont have a fsm for this car, so i cant help with the tolerances.

 

 

nipper

 

I have the correct FSM , but did no find tolerances spec. between the output shaft and axle.

I guess that the play must be in the 0,1 mm range and not mm itself , as it is now.

Can somebody just look at your own car and tell me ?

Seems to me that it must more or less the same for different engines or year .

[Reveeen]

Can somebody just look at your own car and tell me ?

 

Any Subaru I have had apart, the axle just slips on the stub, I would compare it to slipping a clutch disk on a transmission input shaft, there is some clearance there, but not something you "measure", it just fits. (enough clearance to fit, but not enough to wobble)

[Hendrik]

Can somebody just look at your own car and tell me ?

 

Any Subaru I have had apart, the axle just slips on the stub, I would compare it to slipping a clutch disk on a transmission input shaft, there is some clearance there, but not something you "measure", it just fits. (enough clearance to fit, but not enough to wobble)

 

Ok , that is something to hang on !

 

As the mecanic (which I trust) told me that the all parts of the front axle at both ends are fine , I guess that the "wobbling" as you call it , might really be the reason of the sound.

Of course it is a car with quite some heavy live behind it.

And at some time I have to give it up , but I like it very much....

 

I could do a test with some soft material in between the two ,

(tissiu , teflon ? ) just to find out if the rattling dissapears.

If so , later loctite or some other material to keep it in position ?

 

Thanks for your input !