Overdrive Gear Box

[Andrew]

Well perhaps this is your best option, swap out the S5 trans for your S2 and shorten your tailshaft, as others have said this is not a big deal, the fact that you have the electrics makes it pretty straightforward.

Thanks for the clarity. I over worked my S3 engine on the highway so I thought the S2/OD swap would be smart?
Is the S5 Trans superior to the S2?
Regards,
Andrew

 

[sunalp]

The main difference is the S5 trans has a synchro first gear.

 

[RootesRacer]

The SII trans is a non-sync first gear, first gear is a straight cut gear which is usually a bit noisier than the helical cut gears in the all-synch . The SV trans would certainly be nicer but a good condition non-sync is not drastically inferior and if the lack of a first gear synchro doesnt bother you, the early trans should be fine.
Also it is well known that the earlier transmissions have a thicker mainshaft which is less likley to get twisted with a jackrabbit start, and yes this is a thing.
If your SV trans is a non-od trans, you are out of luck. The transmission, particularly the mainshaft is what makes the transmission for an OD.

 

[alpine_64]

Andrew,

You cant add the OD unit from the SII trans to the SV 'box with the parts you have.

The SV box is all syncro and the SII no sync first. The mainshaft is different and not interchangeable. You would need a full syncro OD mainshaft to use the OD unit.

Now.... A very compotent machine shop can splice and sleeve the OD mainshaft end to a standard full sync mainshaft... There is a guy in australia who used to do this.. But was a gearbox engineering shop building high end race boxes.

What are the clutch faces and cone surfaces like in the OD unit? Is the sii box nice and free turning?

Id fit a non sync OD trans over a standrad all sync trans. The OD transforms the practicality of the car.

 

[Andrew]

Thanks for all of the help guys. I went into my parts garage and I only have one transmission with OD. I have two others but they are not with OD and not sure what they are out of. I was trying to reference each of them from the number on the sides of the cases but they don't seem to match any number in my Rootes parts book. I only jotted down one and it is hard to make out but there is a number that I believe is 1981060 3DA21055 22 6 66 on the case. I can only assume this one is a SV. I am also thinking now that the SII OD I have is actually a SI Trans with OD. Are the numbers on the cases documented anywhere? All of the numbers I see in my Rootes book for the Casing are a 7 digit number that starts with 120 to 122.
I will check out each trans today but I think I will swap the entire trans with the SI/SII OD setup. The only real issue is the wiring and drive shaft.
Thanks again for the knowledge/help.

 

[Andrew]

It looks like the OD I have is a SI trans and OD. Number: 16 8 60 5DA15778 1980643

The next one I have I think is a SIV, can anyone tell me?
Number: 20 1 64 4DA15778 1980837

The final trans have I believe is a SV.
Number: 1981060 3DA21055 22 6 66

Thanks
Andrew

 

[beamdream]

It looks like the OD I have is a SI trans and OD. Number: 16 8 60 5DA15778 1980643

The next one I have I think is a SIV, can anyone tell me?
Number: 20 1 64 4DA15778 1980837

The final trans have I believe is a SV.
Number: 1981060 3DA21055 22 6 66

Thanks
Andrew

If you are looking to choose between syncro and non syncro, the easiest way is to select reverse - non syncro is left and back, syncro is right and back.

The casting dates you have quoted are a pretty good indicator of which series they come from.

 

[sunalp]

Andrew,
To tell the difference between the two, there are dates on the boxes. For instance the one you have correctly
identified as a series IV has a date of 20 1 64. the other is indeed a SV trans with a date of 22 6 66. January 20
1964 for the SIV, June 22, 1966 for the SV. Your O/D trans is indeed an S1. I don't think there were any significant
differences between s1 and s2 transmissions.
Cheers!
Steve

 

[Andrew]

Andrew,
To tell the difference between the two, there are dates on the boxes. For instance the one you have correctly
identified as a series IV has a date of 20 1 64. the other is indeed a SV trans with a date of 22 6 66. January 20
1964 for the SIV, June 22, 1966 for the SV. Your O/D trans is indeed an S1. I don't think there were any significant
differences between s1 and s2 transmissions.
Cheers!
Steve

Fantastic Steve, thank you for confirming this and adding your notes. It looks like the SI Trans & OD is the way to go. The snow is now melted away and I hope to get at things this weekend to take a look at what will need to be done. There is a minimum of 5 jobs that need to be done before I can get her back on the road. As always, the support here is great! I will try and document things and share.

 

[Andrew]

Found the SI OD drive shaft! So I have everything but the wiring. Would anyone know if there is company that can provide or make this loom?

OD drive shaft on the right, it was a nice surprise.

 

[sunalp]

Andrew,
You can most likely make one yourself by following the wiring diagram in the manual.
Either that or contact Jeff Howarth as he usually has them. I've purchased a couple from him
and they work really well. He also has the relay as well if that's needed.

Steve

 

[Tom H]

I assume the relay and switch you have is from an SII, If so the wiring is quite simple , just follow the wiring shown on the SII wiring diagram, available on this site.

If you have a S3 to SV switch and relay it's a little more complex, but still pretty easy.

Before you do the swap, how confident are you that the trans and OD are all in good working order?

Tom

 

[Andrew]

I assume the relay and switch you have is from an SII, If so the wiring is quite simple , just follow the wiring shown on the SII wiring diagram, available on this site.

If you have a S3 to SV switch and relay it's a little more complex, but still pretty easy.

Before you do the swap, how confident are you that the trans and OD are all in good working order?

Tom

Hi Tom,
I have no history on the trans & OD, I guess it is a bit of a gamble. What are your thoughts? I guess there may be a way to hook it up to an electric motor and VFD to test it, is that possible? I am unaware of anyone near me who provided rebuild or service testing.
Andrew

 

[sunalp]

The only bench test that I know of is ti power the solenoid on the trans to see if it works. It's pretty simple to do
and will let you know if that part is good or not.

 

[Alpine 1789]

Andrew: If you buy the harness from the UK, make sure they know it is for a left hand drive car. The one I bought there was way too short and I had to splice it to get it to fit. They are very simple and would only take minutes to make your own, so from my perspective the only reason to buy one is for originality.

 

[Andrew]

Andrew: If you buy the harness from the UK, make sure they know it is for a left hand drive car. The one I bought there was way too short and I had to splice it to get it to fit. They are very simple and would only take minutes to make your own, so from my perspective the only reason to buy one is for originality.

Yes, I think I will make one. Any idea of the gauge of wire that should be used?

 

[Alpine 1789]

The one I bought from Alpine West Midlands (which is where I got my OD 20 years ago) was the same gauge as all of the other dash wires. And, I am currently having a brain fart on the gauge. 14?

 

[Andrew]

The one I bought from Alpine West Midlands (which is where I got my OD 20 years ago) was the same gauge as all of the other dash wires. And, I am currently having a brain fart on the gauge. 14?

Thanks, that is good info.

 

[Andrew]

Found 2 relays, no sure what the difference is other that the double contact. Would it matter which one is used? Are all the switches the same for all SI to SV?

Thanks
Andrew

 

[Tom H]

For your SII there is no difference between the two relays, the extra connection is unneeded, but not a problem. The switch and relay for SI and SII are the same, but quite different for the SIII -SV.