Diff Front Mount Nut Torque

[Roy]

Do any of you know what the torque setting is for tightening the diff front mounting nuts. The one's which secure over the rubber bushes.

 

Car is an early Spitfire but with GT6 diff fitted.  

 

Thanks 

[Pete Lewis]

7/16unf  bolt is  38/40lbft

 

the  2  welded in drop pins for the front rubbers   3/8"unf is 26/28lbft

 

the  4 special bolts (wedge lok ) carrier to axle case  26lbft ( these have a tapered shank and internal star washers due to hole in brkt is 7/16 for a 3/8 threaded bolt, so shank is tapered )

 

Pete

[KevinR]

The fact that it is a GT6 diff is not relevant, its a small chassis diff, and they all mount the same way and use the same torque for the mounting bolts.

 

From the GT6 workshop manual (which I happen to have quickly to hand) the torque is 26-28 lb-ft, or 35 to 38 Nm in new money.

[Roy]

Many thanks for the info

[SpitFire6]

Hi,

 is it possible for the front nyloc to unscrew and hence need tightening?

 

I ask, because many years ago my spit/gt6 diff started whining and a local garage tightened it up and noise was gone. Ten years later and now with a quaife fitted the noise is back.

Can I just tighten again to the spec. torque?

 

Anybody else done this?

 

Cheers,

Iain.

 

 

[Clive]

Try, but I am pretty certain the nuts bottom out and you can't over-compress the bushes.

If they are slack, maybe an extra washer?? Saying that, never had an issue with the original bushes on diffs, even at nearly 50 years old they seem good.

[SpitFire6]

Clive,

 If you are referring to the pinion nut; this is what I want to hear.

Cheers,

Iain.

[Pete Lewis]

No the pinion nut is most unlikely to loose torque, there are two types of spacer inbetween the pinion bearings

a solid one with shims to calibrate the pre load

 

and a collapsible one that crushes to known amount to given predetermined pre load

This could be retightend to acheive more pre load but not normal operation

too much pre load will seize the bearings

 

Any action on the nut with a solid spacer will have no effect

 

There are two pinion nut threads 5/8 90-100lbft 9/16 70-80 lbft

 

 

always fit two bolts in the flange and hold the coupling with a bar through not use the transmission which will wind up

 

 

really best left alone , to check the pre load really needs the crownwheel and diff case removed

[SpitFire6]

Not what I wanted to hear but what I thought.

 

The pinion needs resetting and set and held so it cannot move!

 

I thought having a new diff with a quaife would last a lifetime. Two blown 3.27's and now this one is going the wrong way.

 

Cheers,

Iain.

[Pete Lewis]

If it1s a whine thats most likely bearing on the pinion giving out.

 

if its the outer , whine on overun can change without stripping out,

if whine on drive its the inner pinion thrust bearing and needs the cw and diff case out to remove the pinion, then the bearing set must be set to the correct height, mounting distance from the CW centreline

not easy without carefull measuring equipment

pete