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View Full Version : Fairey Drive Swap - IIa to III Not Good



WilsBoar
04-01-2012, 09:54 PM
So, my quest to find a SIII bellhousig/gearbox/transfer case was a success. Pulled from the donor today and now she is sitting in my IIa 109. Unfortunately when I when to install the fairey drive I took out the gear as described in the actual online manual, however, the main shaft is too long for the fairey to mate up. So, is the IIa fairey drive not mean to work on a SIII? I hope I don't have to start swapping out shafts to make this thing work. If so, I might have a fairey drive for sale......

leafsprung
04-01-2012, 11:55 PM
should work - something is amiss

I Leak Oil
04-02-2012, 04:46 AM
Did you use the right lock washer when you reinstalled the Fairey drive clutch or did you try to reuse the existing lock washer? That could keep the OD from seating all the way.
If you did use the right washer, try turning the parking brake drum back and forth while you push the OD into place. Should slide in.

WilsBoar
04-02-2012, 07:06 AM
I tried to put the OD on the SIII just like it sat on the SII. I didn't take anything off or out of the OD. Should I have? It is like the shaft is to long in the SIII and it didn't seem possible that it could even engage the gearing. It will not mate up because it doesn't seem like it goes into the housing far enough. I will have to look at a diagram of the OD to see what lock washer you are referencing.

WilsBoar
04-02-2012, 07:19 AM
I used the same lock washer when reinstalling. I see what you mean. If that lock washer is all that is holding this back that is pretty impressive. Oh, man....looking at the manual (http://www.faireyoverdrive.com/manual.htm) I thought that the OD unit replaced gear "D" as shown on page 8. I never put that gear back in....nice. Okay. Will try that then. Still not sure if I have the right lock washer though.

I Leak Oil
04-02-2012, 08:59 AM
OK, so you need to remove the gear off the SIII transmission.
Remove the clutch/gear from the SII that came with the OD.
Reinstall this same gear on the SIII transmission.
You can just file down the tabs on the old lock washer to make it fit if needed. They need to be shorter IIRC....

WilsBoar
04-02-2012, 02:44 PM
OK, so you need to remove the gear off the SIII transmission.
Remove the clutch/gear from the SII that came with the OD.
Reinstall this same gear on the SIII transmission.
You can just file down the tabs on the old lock washer to make it fit if needed. They need to be shorter IIRC....

Let me start off with some pictures of what I am dealing with. It will help me with help with the terminology here. See attached photos.

When you say remove the clutch/gear from the SII that came with the OD what do you mean? I pulled the entire unit out in one piece...and it seemed to directly engage with the big gear shown in the picture of the SIIa.

Derek

WilsBoar
04-02-2012, 03:13 PM
Let me start off with some pictures of what I am dealing with. It will help me with help with the terminology here. See attached photos.

When you say remove the clutch/gear from the SII that came with the OD what do you mean? I pulled the entire unit out in one piece...and it seemed to directly engage with the big gear shown in the picture of the SIIa.

Derek

I can pull this piece out of the OD.

I Leak Oil
04-02-2012, 03:15 PM
Holy cow! you're missing part of the main shaft from the IIA! Just a guess, if you look inside the big gear on the end of the OD do you see it in there along with the OD clutch?
If you remove the output gear from the SIII unit you'll see what your IIa should look like. The OD clutch replaces that output gear.

I Leak Oil
04-02-2012, 03:15 PM
I can pull this piece out of the OD.
Yup, that's the clutch that replaces the output gear.

WilsBoar
04-02-2012, 10:14 PM
Holy cow! you're missing part of the main shaft from the IIA! Just a guess, if you look inside the big gear on the end of the OD do you see it in there along with the OD clutch?
If you remove the output gear from the SIII unit you'll see what your IIa should look like. The OD clutch replaces that output gear.

Oh no...so the main shaft in the IIa is supposed to be as long as the main shaft in the III?

I am away from the vehicle until Friday....will have see if the other piece is still in the OD.

Thanks! It is starting to make some sense now.

WilsBoar
04-03-2012, 02:01 PM
Oh no...so the main shaft in the IIa is supposed to be as long as the main shaft in the III?

I am away from the vehicle until Friday....will have see if the other piece is still in the OD.

Thanks! It is starting to make some sense now.


yep, the other end of the shaft is still in the OD. Probably not good. Not sure how anything could seize up to break the shaft. The end that goes in to the OD just sits on a bearing right? What the heck could cause this???

SafeAirOne
04-03-2012, 02:06 PM
What the heck could cause this???


Bearing cage failure on the overdrive at speed? (note question mark).

WilsBoar
04-03-2012, 02:14 PM
Bearing cage failure on the overdrive at speed? (note question mark).

If that is the case then I guess I am out of an overdrive. I understand them to be a very expensive rebuild...

How easily is the large gear on the OD supposed to spin? Pretty easily and freely by hand?

SafeAirOne
04-03-2012, 03:51 PM
If that is the case then I guess I am out of an overdrive.

That might not be the case--I'm just trying to work out what would cause such a failure of the mainshaft. You'll have to determine the cause by exmining the parts in front of you.

Out of curiosity, were you able to get the end of the shaft out of the overdrive yet?

WilsBoar
04-03-2012, 06:51 PM
That might not be the case--I'm just trying to work out what would cause such a failure of the mainshaft. You'll have to determine the cause by exmining the parts in front of you.

Out of curiosity, were you able to get the end of the shaft out of the overdrive yet?

So here is the other end of the shaft that was left in the overdrive. There was also a lockwasher in the OD.

So...any thoughts? The OD spins nicely with no grinding or rattling.

Now that this is out, should I go ahead and install the Fairey to see what happens?

SafeAirOne
04-03-2012, 07:11 PM
Now that this is out, should I go ahead and install the Fairey to see what happens?

Oh, wow. I didn't realize that the nut was still attached. Interesting. Maybe it's just the pic, but it almost appears as if the broken off end is a little tapered where it rode in the bearing.

I'd examine the bearing assembly that the rear end of the mainshaft rides in on the OD to make sure it is good. If it is, I'd just run it. If not change the bearing and run it.

I'm confident that beating the nut tight with a drift instead of using the proper special tool contributed to its untimely demise.

WilsBoar
04-03-2012, 08:06 PM
Oh, wow. I didn't realize that the nut was still attached. Interesting. Maybe it's just the pic, but it almost appears as if the broken off end is a little tapered where it rode in the bearing.

I'd examine the bearing assembly that the rear end of the mainshaft rides in on the OD to make sure it is good. If it is, I'd just run it. If not change the bearing and run it.

I'm confident that beating the nut tight with a drift instead of using the proper special tool contributed to its untimely demise.

Well, it looks likes things may be okay from the visual inspection. I guess we won't really know until we put put some torque on it.

Here are some of the inspection photos:

Apis Mellifera
04-03-2012, 09:07 PM
That looks like an old break and it doesn't look like things flopped around too much.