Crashbox differences

[Harv]

Can I ask another favour of owners of original FE/FCs please?

I'm working my way through the Crashbox guide, and making progress. When I put a heap of gearbox casings side-by-side, there are some differences in the machining done to the casings. One subtle change is that early casings (both FX/FJ ones and FJ/EK ones) have six holes tapped into the lower half of the bellhousing flange to allow the clutch/flywheel dust cover to be bolted to the bellhousing. Later casings (apparently around the FC model) only have four holes tapped, deleting the two holes at the 4/8 o’clock position. The small flange boss inside the bellhousing for these two holes is also absent (a minor casting change).

I cannot find evidence of changes in the dust cover design to marry up to this observation though, despite hunting through the workshop manuals and MasterParts dogologue. The two dustcovers I have came from late model gearboxes (FB/EK), and have only four holes.

If you have an original FE or FC driveline, can you please check the transmission dust cover for me and see whether there are 4 or 6 holes in the dust cover? I'm trying to find out whether the extra two holes were redundant (i.e. no holes in the dust cover to use them), or if there was a change roughly what model it was made.

Cheers, and thanks,
Harv.

[OldGMHolden]

G'day Harv,
My late 59 FC has 4 studs.
Early 59 FC, 4 studs.
Late 58 FC, 4 studs.
Early 57 FE, 4 studs.
62? EK, 4 studs.
This probably won't help much, but I can't guarantee the originality of anything but the late 59er.
I THINK the other FC's are original.
FE had a serious EJ motor fitted so may have had a box change also. 

Cheers,
Ol'Gaz

[KFH]

Hi Harv,
Checked my FC which is a Sept 59 build.  It has 4 studs.  It is completely original.

Keith

[Harv]

Thanks guys - much appreciated.

Feedback from the humpie forum shows that the FX/FJ crashies are 6-bolt, and most of the cases I have here of FE/FC vintage are 4-bolt. My guess is that the change was made somewhere in the FE run. It doesn't correlate to the change in casting made during the FJ run, nor the changes in machining done to accomodate the FE hydraulic clutch slave cylinder.

This crashbox Guide document is starting to look interesting 

Cheers, and thanks again,
Harv (deputy apprentice crashbox fiddler).

[FCrob]

The gearbox in my FC Oct 58 build - has gearcase part number 7409980 plus a spare box i have same part number i'm pretty sure came from an Fc.
The parts manual indicates the gearox case part number is 7409979 FE to EK.
Both of the gearboxes have six bolts securing the flywheel cover to the case.

Is my gearbox the original, or what other model could it have originated from?

Rob

[mcl1959]

Rob what is the number stamped on the back of the main body - down the bottom close to where the extension bolts on. This will identify its origins

Ken

[Harv]

Rob,

Ken's right - the first thing we need is the number stamped into the main gearbox casing, on the back where the alloy extension housing bolts on, on the passengers side. This will give the approximate model the gearbox was in. As a very rough guide:

FX: 041-120694   
FJ: 120694 onwards   
FE: L296076-L441345   
FC: L441345 onwards   
FB: B1001- B183235   
EK: B183235 onwards   
EJ: J1001 onwards

There is plenty of variablility in these numbers, so caution is advised (remember, a casting that was made for an FE at the end of the run could readily have been put into an FC).

The second thing I need is the numbers cast into to main body of the gearbox, again on the passenger's side. The number code will be something like D218, M57, C304 etc. This is the casting date, and can help validate the numbers above.
A = January
B = February
C = March
D = April
E = May
F = June
G = July
H = August
J = September
K = October
L = November
M = December
The first two digits (or first digit and space) indicate casting day, whilst the last digit indicates the year (for example D308 being the 30th of April in a year ending in 8… could be 1948, 1958 or 1968).

Some other things that can help and are easy to get at:
a) Is the drain plug (and hence hole in the inspection cover) 1” AF (FX-FC) or ¾” AF (FC from engine number L584117 - EK)?
b) Does the casing have a flat surface machined across the drivers side of the bellhousing flange to accommodate the hydraulic clutch slave cylinder introduced  - FJ 7409980 casings  are not machined in this area
c) What size hole is on the shifter lever to connect to the gear shift linkage - 5/16” diameter (FX and FJ Holden) to 3/8” diameter (FE and FC Holden) to ¾” (FB from engine number B169037 and EK Holden)?
There are more subtle clues to use to date a gearbox, but you need to strip it to see them.

All this and more in the Crashbox Guide.... coming soon to a forum near you (in Technicolour and Panavision) 

Cheers,
Harv

[FCrob]

Thanks Ken and Harv, you guys are a wealth of knowledge and information.

The numbers I have are L507452  - J186, I assume this could be the original box my fc has genuine 51K miles.

The spare box is L403570 - L227 I recall the motor & box came from a fe ute.

Both have 1” AF plugs and machined section where the slave cylinder bolts on.

Any way with your information I can establish their origin.

Many thanks, Rob

[Harv]

L507452  - J186: Casing was cast September 18th 1956 (early part of FE run). Stamped number would indicate an FC box though. May be a box made during the FE run but not put in until FC. Could that be a J188 (1958) casting number? That would make the cast and stamped numbers line up (September 18th 1958), and suggest a box put together about the right time for your October 1958 FC.

The spare box L403570 - L227: Casing was cast November 22nd 1957. Stamped number would indicate a late FE box. Pretty certain this one is FE.

Plugs and machining match up to the above too.

Cheers,
Harv.

[FCrob]

Harv,
 With the glasses on it is J188, the myth is busted thanks for your assistance and i look forward to reading the crashbox guide.

Cheers,
 Rob

[ardiesse]

Harv,

How I wish I had read this thread before the weekend.

I had my FC's motor out to fix stubborn head gasket problems, and I could have read all the numbers off the gearbox in an instant.  I can always get under the car with a light though . . .

The drain plug's 1" AF, same as my FX, and the transmission serial number has an L prefix.

Rob

[Harv]

No drama Rob - sounds like an FE or FC box. Post the numbers and I'll digest them for you.

Cheers,
Harv.

[Dave Lakin (Davo Lako)]

Harv ... have the engine and box out at the moment so don't have to get down and dirty ...

The box from my FE is as follows ,

G261 ... so thats presumably , July 26 1961 ... could be , but isn't 1951 ...

and B203967 , which is presumably from an EK ... and 3/4 AF plug ...

Cheers , Davo .

[Harv]

G'day Davo,

Yep, G261 is July 26th in some year ending in "1" (1951 or 1961).
B203967 is probably EK.
3/4"AF plug is mid-FC onwards.

So I'd say you have a gearbox cast 26th July 1961, from an early-in-the-run EK.

Cheers,
Harv.