Gearbox gaskets and O-rings

Alex(Tenerife)

Alex(Tenerife)

True Classic
I am rebuilding my 5 speed gearbox (thanks for the invaluable help from the 5sp 101) to finally get the 3rd gear syncromesh sorted (been like it since I bought the car 12 years ago!) and I am having problems identifying where all of the gaskets from the gasket set go.

Gearbox%20Gaskets.jpg


I think O ring D is the one for the reverse idle shaft (or it could be the slightly thicker C) Can anyone confirm this?

As for the rest I don't have any idea where they could go - I know there wasn't a gasket on the input shaft housing (pictured but not labeled) this was sealed with silicon sealant. So I know my gearbox has been worked on before. Maybe it was missing some o rings and gaskets.

Does anyone know where the rest of them go?

Cheers

Alex
 
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A or B (but most likely A as it's bigger) is the o-ring seal that lives between the left side final drive bearing cover and the gearbox case.

G is the gasket that seals the release bearing tube flange (at the top of your pic) to the gearbox case.

C and D could be as you mentioned the o-ring that seals the reverse idler shaft to the gearbox case. There were two diameters of reverse shaft, wih early cases having the lesser diameter and later having the 2 mm greater diameter, so it could be the kit maker including both for compatibility. Or they could be the o-ring that seal the top of the clutch release bearing operating arm to the top of the bell housing.

Not sure what B, E, and F are.
 
Kit is most likely a combined 4 and 5 speed gasket kit...as some 5 speeds (like Strada) use tripode type joints and other like the X 19 doesn't and has inner flanged CV's

Larger O ring (a) will be for the LH cover of tripode type 4 or 5 speed, (b) will be in similar position on 5 speed that has inner flanged CV's.

(c) and (d) will be as Dan said, for the two different sizes of reverse idler shaft.

E might be the o ring for the speedo drive gear??

G is the gasket for the release brg sleeve.

F look like the gasket that suits very early gearboxes which have the selector shaft seal mounted in a separate housing that bolts to the main case.

SteveC
 
Thanks for the help, it hadn't occured to me that I might have some gaskets I didn't need as they could be from the 4sp gearbox.

One thing is that gasket G is not the same as the gasket on the input shaft housing. I am not sure if it is easy to spot but this already has it's gasket in the photo. Gaskget G is from something else - maybe on the 4sp gearbox it was a slightly different gasket and this is where the gasket is from.

Even with your help I can't see where the A and B o-rings go, reading your post again fiatfactory are you saying they may not be for my gearbox?
 
In the pic below, the flange with the four bolts joins with the differential case at the red line. The shims under this flange determine the preload on the differential bearings.

One of the two large o-rings (my guess is the bigger one) seals the joint between this flange and the differential case.

IMG_0334-1.jpg
 
Thanks that is the one part of my gearbox I have not stripped back, I can't get a new seal for that side so I thought I would leave it un touched as there is not a problem there. Which explains why I didn't spot that one.

Many thanks all for the help.

Alex
 
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