Carzy Driver

What are the torque specs used while rebuiding a S4 turbo? looking for specs for the housing bolts and compressor wheel lock nut.



Yes, I searched...

ericgrau

iTrader: (1)

You try the FSM? Haynes manual?

Carzy Driver

rebuilding the turbocharger is not covered in either of them.

NZConvertible

The turbo is not a dealer-serviceable item, so it's not covered in the FSM.

Read this: https://www.rx7club.com/attachment.p...chmentid=76207

mazdaverx713b

iTrader: (91)

the turbo cannot be rebuilt correctly without being balanced. the the compressor wheel and shaft are out of balance, it will eat your cold side housing and murder itself.

NZConvertible

Yes it can, read the link I posted.

mazdaverx713b

iTrader: (91)

i understand the markings, but what keeps it in balance once you rebuild it yourself and why do shops balance their tutbos? perhaps they dont use the same turbine wheel or shaft...i dunno. you make a valid point, i have just always read that they would be out of balance if you attempted to rebuild yourself.

Carzy Driver

Thanks Jason for that file. So the torque specs for the compressor housing bolts are around 40-50 ft/lbs, but that still leaves the compressor back plate bolts, turbine housing bolts, and compressor wheel lock nut.

Anyone else have specs ideas? ReTed? 1Revvin7?

NZConvertible

If the rotating assembly had no balance problems before disassembly, and none of the rotating parts were changed, then if you put it back together exactly as it was before it will still be in balance. The markings you apply before disassembly are critical. Keep in mind that when a shop balaces the rotating assembly, it has to be done as a complete unit and them pulled apart to put it back in the centre housing. So the same procedure of marking the parts and realigning them during reassembly has to be used.

The lock nut should be tight along the whole thread and then the marks has to be lined up correctly, so a torque fugure isn't relevant. For the rest of it just use common sense. They should be tight, but only as tight as is safe with the material. The bolts in the aluminium compressor housing should not be tighened as much as those in the cast iron turbine housing. I've only ever done this by feel and never had a problem.

mazdaverx713b

iTrader: (91)

cool, makes sense! thanks for clairifying that, nzconvertible!