Spitfire Can I remove the nut on the front of a Spit diff?

[AustinJim]

Hi all.
I'm swapping the noisy diff in my 78 Spitfire for a newer used one. The front flange for the drive shaft has a slight bend in it and I'd like to swap the good one from my old diff onto the new diff. I know there are some crush washers in the front of the diff and I'm wondering if removing the front nut, swapping the flanges and retightening the nut will affect anything internal.

I's appreciate any advice.

Jim

 

[AEW]

I'm not a Spit person but... isn't it the same as just an oil seal replacement? And on that thought, why is your old diff noisy?

 

[AustinJim]

I don't know why the old diff is noisy but it whines quite a lot. I know they all do to some extent but I have the opportunity to swap a different one in so I thought I'd try it and see if it's any better.

 

[Andrew Mace]

I hear you, Jim (yes, even over the whining :laugh: )! It's only about a three-hour job start-to-finish, so it's probably worth the gamble. But I have to disagree about "they all do to some extent"; odds are that any diff. you hear whining has run low or dry at some point or has hundreds of thousands of miles on it already, or ????

Several years ago, I had an inner axle shaft bearing disintegrate on my Herald's diff (long, slow ride, but I did get home). I took a chance and pulled a diff. out of a Spitfire that I'd gotten as a parts car maybe 20 years before that. I cleaned it off, topped it up and bolted it into the Herald...and it's been quiet as the proverbial mouse ever since!

 

[TR3driver]

If I remember correctly, late Spits do have the collapsible spacer, which the book insists should be replaced any time that the flange/nut is disturbed. The problem is that the spacer collapses to set the preload for the pinion bearings, which in turn is important to hold the pinion in position.

If you are reinstalling the same components (flange, washer, nut), you can probably get away with marking the position and turning the nut back to the same position. But that won't work with a different flange that may be slightly longer or shorter than your old one.

I don't have any experience with Spit diffs in particular, so I may be off base here. But if it were my car, I would either leave well enough alone, or plan on disassembling it enough to change the spacer and reset the preload. (Actually, if it were my car, I'd be looking at replacing the collapsible spacer with a fixed one & shims, but I'm funny that way.)