Triumph Repair: 79 Spitfire differential, differential question, flange nut

Question
QUESTION: Jim,
I rebuilt a 79 Spitfire but didn't refurbish the diff.  It has been fine until recently.  It just started whining.  My son drives the car so I don't know what may have happened, but I suspect the pinion gear.  I have several questions.  What is the "spreader" you speak of to be used to spread the halves of the diff?  How much torque should be put on the pinion flange nut?  The book says not to put the prescribed 120lb/ft on it because it will crush the spacer.  How much then?  I'll ask you more later.  Thanks for your help.

ANSWER: Fred,

Before you disturb the pinion flange pull the back diff cover off (you need to remove the side stub axles) and look at the wear pattern on the ring gear.

A differential "spreader" is used to pull the sides of the casing apart slightly to allow the ring gear carrier to be removed and reinstalled without damaging the side bearings.  Somewhere I have a simple schematic to make one, I'll have to see if it posted anywhere online.

Which book are you using for reference?  Typically for the collapsible spacer it's advised to keep count of turns as the nut is removed and retighten the same amount.


Cheers,

Jim

---------- FOLLOW-UP ----------

QUESTION: Jim,

To answer your question, I am using the Bentley workshop manual.  I assume when you say to pull the back diff cover off, you mean to split the diff and take the back half off because there isn't a "cover" per se as there are on some other diff units.  And, to split it I would need that "spreader" you spoke of.  I could probably make the spreader if you could find that schematic you mentioned.  Is it possible to gently tap in a screwdriver  or other wedge shape object at the seal and successfully separate it?

Fred

Answer
Fred,

You don't need a diff case spreader to remove the back cover (back casing) portion.  You need the spreader to remove the differential carrier from the front (pinion) section of the differential casing.

Actually you should be able to remove the differential carrier as there is probably enough wear in the side bearings.  The problem comes in when fitting new bearings.


Cheers,

Jim