LT 95 Fairey overdrive (Devon) reconditioning

[Gazzar]

I've a 101 project. The standard gearing is quite low, so I'm fitting an over drive. Not because it's a cool name for a device, nor because I like having loads of levers in the cab. 

Purely for economy and having the option for a decent road speed.

 

The 101 gearbox is from the same design as used in the original range rover, a rugged 4 speed manual box designed for the V8. The box was designed for use in both vehicles to spread the development costs.

There are new overdrives for this box, but they are quite expensive, so I went with a second hand Fairey, which, to ensure it came complete, was still fitted to a gearbox.

Parts availability isn't great, with the clutch sleeve that connects the over drive to the main box being unobtainable.

I have a second scrap overdrive for parts, so aim to make one good from two.

Bearings are available and I've bought I kit from Gavin, who has a good supply of parts.

 

Note the modified selector shaft pin hole.

[Gazzar]

GLF classics.

[Gazzar]

I'm following Gavin's instructions, mostly.

Take off the top plate to reveal the selector fork.

[Gazzar]

That's an allen key retainer in there.

[Gazzar]

Gentle cleaning of the thread and user of penetrating oil and the screw came out.

Some imperial fitting, this just stops the shaft from coming out of the casing.

[Gazzar]

The bolt for the selector fork is 1/2 socket.

 

[Gazzar]

Removing the selector shaft wasn't difficult, I twisted it and pulled at the same time. 

Once the fork was loose, I stopped pulling out the shaft, and carefully pivoted the fork and pads around the synchro hub until I could lift it out easily.

[Gazzar]

Then pull the shaft all the way out.

A ball bearing came out, so I undid the hex socket screw underneath, pulling out a spring and a plunger.

[Gazzar]

Then remove the back plate, according to the instructions.

[Gazzar]

Revealing big gear stuff.

[Gazzar]

I cleaned around the layshaft then used a drift to gently rotate the shaft prior to pulling the shaft out with a strong magnet. It was slow at first, but no real drama.

 

[Gazzar]

Out.

[Gazzar]

Removing the smaller of the two circlips allows the mainshaft to come out from the front. Carefully, as there are a lot of bearings and thrust washers at the back, note the taper on the washers.

[Gazzar]

Four things. Taper away from the needle bearing.

[Gazzar]

The mainshaft, and the scrap one.

And the bearing that was in front of it.

[Gazzar]

Then I did this different to Gavin's instructions. I took out the synchro baulk rings and associated washers.

One comes out the front.

[Gazzar]

Then I moved the hub aside and removed the other baulk ring through the inspection hole.

[Gazzar]

And, careful not to move the inner, the hub out the same way 

[Gazzar]

Note the orientation.

[Snagger]

It looks very similar in construction to the monstrously bad unit you handled for me a couple of years ago.  They are a fun little project.  I hope you don’t find parts that have welded themselves together and need a great deal of brutality to strip like mine did!

[Gazzar]

And lots of washers.

[Gazzar]

Then, as I'd fully removed the hub and man shaft, I used a hammer handle to drift out the rear bearing.

[Gazzar]

The lay gear is sandwiched between more needle bearing sets and a shim.

This is the rear set.

[Gazzar]

And this the front.

[Gazzar]

The lay gear just comes out. I stuck the lot together for tidiness.