ANOTHER Syncro trans question

[21-window]

I searched the interweb and here:

Do some syncros have aluminum trans cases and some have magnesium trans cases?

Which is better and why?

[gears]

The low gear housing of all Syncros are aluminum. I believe the aluminum main cases and intermediate housing all originated in South Africa for added strength (to go with their larger engines).

While the mag alloy version is lighter and is said to have better "memory", the AL version resists ovaling in the two critical bearing bores subject to long term wear.

[21-window]

Any way to tell for sure?

The one in my 86 appears silver in color

I got a spare one that appears grayish (mag color)

They definitely look different.

I want to get one rebuilt, but want to use the "correct" one.

[gears]

One way would be to use a file on both and burn/ignite the filings. Compare with known low gear housing (aluminum) and bell housing (mag) filings. You'll know pretty quick which are which.

[D Clymer]

I don't think any Syncro transmission cases were magnesium. They should all be aluminum. But keep in mind that a corroded aluminum case that has spent it's life in the salt belt will be grayish and look very different than a well preserved west coast example.

D

[gears]

I believe that the only aluminum section in U.S. Syncros is the low gear housing. The main case and intermediate housings are mag alloy. I don't know about Canadian imports.

[SyncroGhia]

Although they've been called Aluminium and Magnesium cases, they're more of an alloy of Magnesium and Aluminium and it's the varying amounts of this alloy which gives the different properties... not trying to teach you how to suck eggs or anything

I tend to refer to them as light and heavy cases... the heavy case being the stronger.

I have both heavy and light cases and they both work well. The light case tends to corrode more (more magnesium) and have to be replaced just because of this.

The weight difference can be a lot!

I have always tried to use heavy cases for my Syncros just to give them a fighting chance.

MG
_________________
1989 Syncro 16 S6 Westy Limey
1991 Syncro Lightweight SWB
1989 S8 Bluestar
1990 Tristar

[21-window]

Thanks

I suppose I will have the "heavy" more silver looking trans currently in my syncro rebuilt.

[insyncro]

MG,
If you don't mind I am going to start using your description of cases.
Very easily unbderstood.
Well done.

dylan

[Bruce]