just trying to find out abit more about changing my gear box iv got a classic impart wrx on a p reg. would i need to change the rear diff if i put a sti gear box on or what gear box should i be lookin for is ter a certon code on the box i need to look for? any help please

 

diff's and boxes need to be a match ratio's etc so if your changing the gearbox you will need a matching rear diff if its a different box to the 1 thats fitted you will find the gearbox code on the vin plate (passenger side suspesion mount) code should readsomething like ty752vn3fa etc hope this helps

 

tht helps alot mate thanks so i just have to find the same code box unless i change the rear diff are all drive shafts the same? id say my clutch is ready for changing but it isnt slipping so would i have to get a new flywheel aswell? cheers

 

yeah the shafts will be the same,i'd always do clutch and flywheel at same time personally, if its scored etc deffo change it,ya best to find a straight swap gearbox its easier i gotta change my box and diff next week sometime clutch time to

 

dont just go by the gearbox code on the vin plate, check the code on the box too as it may not be the original.
if you are looking at the vin plate from the side of the car, look under the intercooler on that side where the gearbox bolts to the engine. code should be there.
now check here:-
http://www.gearhack.com/myink/ViewPa...ission%20Chart

if the codes on vin and box match, then your rear diff will have the same ratio as the above chart shows (3.9, 4.1 or 4.444)
if the box code is different from the vin plate but has the same diff ratio on the above chart as the code on the vin plate, then your ok.
if however the code on the box shows as having a different diff ratio to the one on the vin plate, then someone in the past may have changed the box for one with a different diff ratio and you dont know for sure that they also changed the rear diff. shoudl that be the case, you may have to change the rear diff too.