TR2/3/3A TR3 Differential Differances?

[karls59tr]

I've heard that the early TR3 diffs were not as strong as the later versions.When was the change over to the better ones. Is there anything in their outward appearance that indicates which one is which? I suspect a later Tr3 I saw may have had the earlier diff swapped in? Karl

 

[jwolff]

The earlier "Lockheed" axle had a square flange with four bolts and the "Girling" axle had a round flange with six bolts where the brake backing plates bolt up. I thought the differential innards were actually the same and that the issues were with the weak axle design and leaking oil seals. I'm about to swap out my Lockheed axle with a later Girling one while my body is off the frame to avoid issues down the road. I'm sure someone more knowledgeable will chime in and correct whatever I got wrong here...

 

[TR3driver]

I thought the differential innards were actually the same and that the issues were with the weak axle design and leaking oil seals.

That's correct, except for a few very early units that had smaller bolts between the ring gear & carrier. I forget the change point offhand, but ISTR it was before the end of the TR2 so no worries.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]
I'm about to swap out my Lockheed axle with a later Girling one while my body is off the frame to avoid issues down the road.[/QUOTE]
Let me dig back through my email; there was someone a few months back searching for an early axle assembly for a 'correct' restoration.

 

[jwolff]

Randall, just curious, do yo still have the Lockheed axle on your '56 or was yours after the switch?

 

[TR3driver]

I very definitely wanted disc brakes, so this one is shortly after the change. TS13046 was the first car with Girling brakes, I have TS13571. But it very likely doesn't have it's original axle anyway, since it had 4.10 gears with a 3.70 speedo and no sign that it ever had overdrive when it came to me.

I previously owned an earlier 56 (TS11xxx) with the front drum Lockheed brakes but I sold it years ago as a project. Don't remember for certain, but ISTR it had been converted with the later axle, with the Lockheed brakes mounted to it.

 

[jwolff]

Thanks Randall... I'm converting my front drums to disc brakes using the Toyota caliper setup so I guess I'll continue with my plan to swap out the rear axle and not worry about originality at this time. I'm thinking I might want to retain my original front hubs and rear axle in case I ever decide to go back to the correct setup though. My car came from the factory with wire wheels and I understand that on Lockheed cars these hubs were different than the ones on cars that came with steel wheels and might be sort of rare. For now with my budget and skills this car will definitely be just a fun driver.

 

[vivdownunder]

That's right, the Lockheed diff had different wire wheel splines to the Girling diff, and they are scarce. But there's a fix. Badly worn Lockheed splined hubs can be swapped for Lockheed steel wheel hubs which accept the splined adaptors used on Girling diffs.

The same applies to worn front splines on drum braked cars - swap to steel wheel hubs and use later spline adaptors.

It's true that Lockheed diff axles were somewhat weak and prone to breakage. Also, the axle seals tended to leak and contaminate the brakes.

Strangely, the crown wheel and pinion was interchangeable between the two makes of diff.

To swap in a Girling diff, you also need Girling backing plates (either 9" or 10"), brake shoes, wheel cylinders etc., but the drums are interchangeable.

Viv.