Early Gearbox Help

[Fishcop]

Hi All

I've just bought two '68 cars, one a European S targa, and the other a US L Coupe. Every thing is dismantled and I'm working my way through the parts I've bought...

I need help identifying the gearboxes:

901/03 2281138 which both flanges turn in the same direction
902/1 3280642 which flanges turn opposite to each other.

Both appear to have nadella driveshafts rather than CV joints, is this a good thing? Can I adapt them to run CV joints if necessary?

Any advice is much appreciated

Cheers
John

[davep]

901/03 with AL case, serial series 2280001 5 spd AFMSZ gears 7:31 R&P simplified diff for 911
902/1 with AL case, serial series 3280001 5 spd AFMSX gears 7:31 diff for 911

If the 901/03 flanges turn in the same direction, then there is the possibility that the diff is LSD, and this is consistent with Nadella shafts. Check the shaft thickness compared to the other one; there are some heavy duty shafts.

[Fishcop]

Thanks Dave

I have thick and thin Nadella shafts respectively. I'll presume the heavy duty go with the LSD?

Do you do what the 228 sequence means, I'm familiar with the 328.

Cheers
John

[Jon B]

Do you do what the 228 sequence means, I'm familiar with the 328.

For 1968 transmissions, the first digit indicates:
1 = 4-cylinder engine
2 = 6-cylinder engine, 110 HP
3 = 6-cylinder engine, 130 HP
4 = 6-cylinder engine, 160 HP
9 = Non-standard transmission.
The 228 sequence means 6-cylinder 110 HP engine; 5-speed; 1968 model.

Early ZF differentials did not have preloaded clutches, so may not react like a later LSD when flange is turned. Remove a flange from each transmission; if there's a splined shaft extending from either diff, it's an early ZF LSD.

[Jon B]

Simple clue to determine if early transmission has a ZF diff:

Remove aluminum cap from center of Nadella flange- if bolt head under cap is larger than 19mm, the differential is an early ZF limited-slip.

Jon B.
Vista, CA

[Fishcop]

Thanks for the tip Jon. I'll have a look this evening.

[Fishcop]

So I opened up the 901/3 box and yippee it has the LSD. Jon B's tip proved correct, the 24mm bolts holding the flanges were attached to the early ZF LSD. it has what I'd describe as 'male' splined shafts fitting into 'female' drive flanges.

With that in mind I popped the flange caps on the 902/1... 24mm again (this is the diff that has the flanges turning opposite each other like and open diff). I opened up this gearbox and viola... another LSD! Physically it looked the same as the first. This one had some interesting numbers on the differential itself I hope someone can decipher for me... 4061004004-436856. It had clearly been worked on before with some sealants present on flanges and the cover plate. With that in mind I'll have to see if the gear-sets remain stock...

Given that I'm building a historic race car, I'm quite pleased with my 'blind' purchases...

Any further comments, observations or advice is greatly appreciated!

Cheers
John

[9er]

Observation....Score!

[Fishcop]

Yes Chris, considering I paid a very fair price for the lot in 'as is', I feel I've done well. I've also had it confirmed that the guards on the rear are real RS units also.

Here's some shots...

[DJ911]

Good to hear John - proof nice guys do win sometimes!