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Post 32
December 2015

Gearbox Assembly

land rover series 3 gearbox rear bearing

Here is the bearing and housing that supports the rear of the mainshaft. Also the oil seal that separates the gearbox and transfer box.

land rover series 3 gearbox rear bearing retainer

Bearing installed in housing. Circlip pliers definitely required.

The old bearing had spun in the housing. My gearbox had been apart in the past, and I suspect the last guy didn’t use bearing retainer. The bearing is a fairly lose fit in the housing, but should be installed with loctite (I used loctite 609, not thread lock). The housing should be pressed into the casing with loctite also.

land rover series 3 gearbox reverse gear

New reverse gear (Britpart). The gear comes complete with roller bearings already installed. The shaft and washers are original.

land rover series 3 gearbox reverse gear in casing

Rear bearing and reverse gear installed in the casing.

Reverse gear is easy. Just hold the gear in place and slide the shaft in from the back. The shaft on mine was just a light hammer tap into place (it can’t come out once the transfer box is installed).

The rear bearing housing was a different matter. I got this in by hitting it with a hammer through a block of wood, but this was really on the limit of sensible, and really I should have used a press. Not sure why it was so tight going in, as it came out fairly easy. I was worried I would crack the case, but all good.

The ring at the bottom is the bearing race for the layshaft. I didn’t touch this.

land rover series 3 gearbox layshaft

Layshaft in place. The large gear at the bottom actually has to be slid on at the same time as the bell housing is installed.

land rover series 3 gearbox mainshaft bearing

This is the mainshaft coming through the rear bearing. Castle nut has to be tightened and there is a lock washer arrangement. See the tool I made from an old deep socket. I wouldn’t bother. I ended up just tapping it tight with a chisel anyway. The nut only has tiny contact patches, so unless your tool is perfectly made (they can be purchased), it will slide off without much force. So save fifteen minutes and just use a small chisel. It’s easy to place the chisel right into the corner of the castle recess and tap it home without causing damage.

*Note. This is wrong. I latter found out that this nut needs to be done up to 120ft/lbs (or something like that), and there is no way you can do that with a chisel or crappy home made tool.*

land rover series 3 gearbox mainshaft

There it is. Mainshaft installed.

land rover series 3 gearbox casing and bell housing

Bell housing prepared and ready to be offered up to the gearbox casing. The gear sitting on the bench sites in behind the synchro lip of the of the gear attache to the bell housing. So you sort of have to slide it onto the layshaft at the same time as offering up the bell housing to the mainshaft.

land rover series 3 gearbox casing and bell housing

It was easier to do all of the aforementioned with the gearbox vertical. Would be easy if you had a helper.

land rover series 3 gearbox layshaft bolt

Torquing up the layshaft bolt. There is a trick to this. If you reach inside the box and engage two gears at the same time, the gearbox can’t turn, and you can easily tighten the bolt.

land rover series 3 gearbox selector forks

Installing the selector shafts and forks. Thos bolts holding the forks to the shafts have to be torqued up surprisingly tight (it’s in the manual). I didn’t do this, and one of the shafts slid slightly against the fork, so I had to pull the top of the box apart to re tighten them.

See the rubber seals at the front of the shafts. They are not as tight as I would have expected. I think there is slim to no chance that these will provide a long term seal. If they leak, I’ll replace them with normal o rings.

land rover series 3 gearbox selectors

There are two little L shaped plates that hold an o ring, spring, and ball against the selector shafts. You don’t need to hold them in place with a clamp but I figured it reduced the risk of cross threading the bolts.

land rover series 3 gearbox gearchange bracket

Main gear change lever bracket.

land rover series 3 gearbox lever

New gear lever installed in original housing with plenty of grease. My old leaver snapped at the base a while back, and I re-welded it in the car, so it was a bit rough and untrustworthy. Otherwise I would have reused the old lever. Note that there is a rubber ring at the base of the lever where it selects the gears, which can be missing. It’s not an O ring, but you could probably use an O ring to do the same job. Otherwise the lever will rattle around.

land rover series 3 gearbox reverse selector

Here is the complex little mechanism that makes reverse gear feel different from the rest. One of the original springs had snapped. New springs and plenty of grease.

land rover series 3 gearbox clutch plate

Here is the internal front cover and base for the clutch mechanism. The oil seal is installed into the cover and slides over the mainshaft.

land rover series 3 gearbox bell housing

And there it is. In place with the clutch leaver installed. That is the main gearbox complete.