_Viktor

Hi all,

I had a whining noise that increased with road speed and the local garage and I both guessed it was either the centre diff or the bearings in the gearbox extension.

Now Scooby spares kindly sent me over a extension from a box with a bad 3rd with the diff etc and the garage fitted it today.

Now the guy in hte garage says to me that there is a now another nise from the same area that he thinks could be a different pitch angle on the teeth of the cogs in the extension.
He thinks the bits are from different gearboxes.
Now I cant hear this as my ears are not that great at certain freq' due to being around too many helicopters in another life.
Now i will check with Scott as SSpares which car it came from and I dont think it would have made any difference anyway if it was a mix n match, as they should all be the same part.

My question is...
I was on the understanding that the extention was the same since.. well forever. its been the same part number on as many cars i can search for in 'opposed forces'.
Does anyine else have any information to say Im wrong on this..
or any idea what it might be..
or is the garage pulling me on.. first time iv used them under new ownership and he was on about getting new bearings and GBox out to clean and replace a bearing on 5th gear also..

I should realy learn my leason, trying to save a few quid has cost me.. now with the (large) local bill (€/h has gone up)+ parts its cost me more doing it this way that the,not so local, scooby specilist quoted me for new bearings and fitting. <sigh>

Cheers
Vik,

_Viktor

extension..
http://opposedforces.com/parts/impre...llustration_2/

rob84

iTrader: (5)

did your local garage measure the back section of the box for the correct shim sizings for the correct preload on the bearings ?

_Viktor

no idea... and I guess this being out would lead to aggressive tooth ware.

rob84

iTrader: (5)

CALCULATE THE END FLOAT OF THE TRANSFER DRIVEN GEAR SHAFT TWO MEASUREMENTS HAVE TO BE TAKEN.
FIRST MEASUREMENT IS FROM THE TOP OF THE TRANSFER GEAR BEARING (PLEASE NOTE! OUTER BEARING RACE MUST BE INSTALLED TO BEARING, ROTATE SHAFT SEVERAL TIMES TO SETTLE BEARING RACE IN ORDER TO OBTAIN AN ACCURATE MEASUREMENT) TO THE TRANSFER CASING, WHICH IS MEASUREMENT “W.”
MEASUREMENT TWO.
REMOVE THE BEARING CONE AND SHIM FROM THE EXTENSION CASING AND MEASURE THE DEPTH FROM THE CASING TO BEARING CONE RECESS, WHICH IS MEASUREMENT “X.”
CALCULATION IS
T= X - W + 0.24 - 0.2 TO 0.3=
0.2 TO 0.3= SPECIFIED CLEARANCE.
0.24 = GSK THICKNESS

CALCULATE THE SHIM VALUE BETWEEN CENTRE DIFF AND TRANSFER DRIVE GEAR.
USING SPECIAL TOOL SU3832 (SURFACE PLATE) FROM THE STi TOOL KIT, LOCATE THE SURFACE PLATE ONTO THE TRANSFER CASING SURFACE, AND USING A DEPTH GAUGE, MEASURE THE DEPTH FROM THE SURFACE PLATE TO THE TOP OF THE CENTRE DIFF, AS INDICATED IN THE PICTURE ABOVE ON THE RIGHT. THIS IS CALLED MEASUREMENT “S.”
TO PERFORM THE SECOND MEASUREMENT LOCATE THE SURFACE PLATE ONTO THE MACHINED SURFACE OF THE EXTENSION CASE, THEN USING A DEPTH GAUGE MEASURE THE DEPTH FROM THE SURFACE PLATE TO THE MACHINED SURFACE ON THE TRANSFER DRIVE GEAR. THIS IS CALLED MEASUREMENT “T.”
THE CALCULATION IS
U = S + T + 0.24 - 0.15 TO 0.35mm (PLEASE NOTE! THE THICKNESS OF THE SURFACE PLATES MUST BE DEDUCTED FROM MEASUREMENTS AND THE REMAINING FIGURES INSERTED INTO THE CALCULATION)
0.24= THICKNESS OF GSK
0.15 TO 0.35mm = SPECIFIED CLEARANCE.

Don Clark

To add to Rob's description............

_Viktor

Thanks guys,

I took the car to the not local Subaru specialist.
He replaced a couple of bearings and said that the noise was from the teeth being too close together .. this is a very bad translation with my crap Finnish and his crap English,
but happy happy now car all better

an expensive learning lesson not to use to local Estonian run garage.
(it wasnt Estonian run last time I went there and had OK service, but the owner has told up)