Building the gearbox of my dreams

min200 said:

Been a good read this and if I still had the series I would have been tempted to fit an overdrive. The 110 has a five speed box though (not showing off really!) so one less thing to worry about!

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Thanks, Mr Min. I'm pretty convinced the overdrive is a good idea. I wish this sort of thing had been available when we had our Series back in the 1980s. It was hard to break the 20 mpg barrier but with lower revs at cruising speed we might have made it into something approaching an economical vehicle. Engines were a lot thirstier in the old days. Even the Morris Oxford we had, with its 1622 cc engine, struggled to get past about 24 mpg. We often threatened my mother, whose car it was, with putting a Rover V8 in. This would have been lighter than the BMC B series pre-rusted iron ingot, and probably more economical.

Seeing as it is hard to take pictures of things working properly, here's a picture of yesterday's test run instead:

That looks like a random route! Glad it's all working ok now My friend has an overdrive fitted and swears by it on his series 3.

Not really gearbox related but I put a fire extinguisher in just now:

Something I've been thinking about for ages but just not got round to until today.

I thought about putting mine there, but thought it wasn't the best spot for access. I fitted it to the front of the seat box on the drivers' side. You'd think it would get in the way of your feet but it doesn't. Means you can get of the Landy first and grab it from the outside.

FlyingPete said:

I thought about putting mine there, but thought it wasn't the best spot for access. I fitted it to the front of the seat box on the drivers' side. You'd think it would get in the way of your feet but it doesn't. Means you can get of the Landy first and grab it from the outside.

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Yes,I tried it in various places, and decided against the seatbox because I could see that I was going to kick it getting in and out. Plus, there's a lot of acoustic matting over my floor and seatbox so I'd have to take the extinguisher bracket off every time I want to take the mats up. On the B pillars I'd probably hit my head on it, especially if it came loose in an accident, so in the end there weren't very many places to choose from!

Ive just had a good read Brown. I havnt the foggiest idea what any of it means but good on you. I mean I know what a gear box does and an overdrive. I can even find mine and point at it. Well the bit where an overdrive would go but thats it. I think I'll stick with 40mph for now.

Bobsticle said:

Ive just had a good read Brown. I havnt the foggiest idea what any of it means but good on you. I mean I know what a gear box does and an overdrive. I can even find mine and point at it. Well the bit where an overdrive would go but thats it. I think I'll stick with 40mph for now.

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Well, most of it isn't entirely glamorous. It's just freeing up seized and rusted bolts and screws or finding ways to work around them. The steel must have been very busy welding itself to the alloy in the first nine years of the Land Rover's life. There are a few little jobs I have yet to do to get it the way I want it, but it's just a matter of running in now. Thanks for your good wishes anyway!

How is the selection of the overdrive unit now? Has it eased up with use at all?

jonny2tanx said:

How is the selection of the overdrive unit now? Has it eased up with use at all?

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I've been so tied up with work at the moment I haven't been out in the Land Rover for a few days. It seemed to be working on Sunday last time I was out on a bit of dual carriageway. I'll give it another workout soon.

That reminds me I need to put my fire extinguisher in the Discovery...

Drove around a bit today and all seems well. I'm doing a little bit of finishing off with a few small jobs. For example, there was an earth wire from the back of the transfer box to the battery:

This is now too short and anyway is fraying where the wire joins the terminal at one end. So I've made another one:

Longer, thicker and with terminals crimped, soldered and heat shrunk. I was so pleased I crawled underneath in the dark and fitted it.

I've been out and given it a good thrash on the motorway:



I'm pleased to report that the temperature was nowhere near as high as the last time. I was also doing things with it that I thought would heat it up. That stretch of the M1 has several hills and I was keeping my foot down up the gradients in order to put a lot of energy through it, but it didn't get past 80 C or so. The high temperatures last time must just have been to do with running in. No hot smells either, and no missed gearchanges, so it feels like I've got the adjustment on the linkage about right. The take home message is that if you fit one of these yourself be prepared to adjust and experiment. Just because it works in your street or on a trip round the block doesn't mean it'll be OK out on a road trip. There's a small annoyance in that my door mirror on the driver's side keeps blowing back at motorway speeds so I can't see anything in it. It's new and the ball is really smooth so the clamp mechanism isn't gripping it. I've tightened it up 'til the Allen screw adjuster is nearly stripping but it's still not quite enough. I'll have to ridge it or notch it in some way.
In other news I have a new tool box:

My three year old Stanley one is getting tired and the plastic is cracking, as it's a little flimsy for the weight of all my sockets and pairs of pliers. So I've taken a step up to something a bit more geared towards professionals from Beta Tools which might be a bit stronger. What I want is something with different compartments in and wheels that I can sling in the back of the Land Rover. There's also the De Walt Tough System which I was looking at, but I've ended up with this. The Stanley can be retired for occasional use whilst it is still in one piece.

Glad it is all bedded in nicely chap Everyone likes a new toolbox as well

Now then, tool boxes I know about.
Does it have a little clip for your pencil.

Brown, thanks for keeping us updated on this mod. I must say you are more daring than I would be to take the transfer box apart - bolt on is about my limit (and even then I can manage to cock it up ). I was underneath the Landy yesterday trying to free off a slightly sticky handbrake and saw how the cable was running across the precise spot where the Roamerdrive would fit. I know you said that there were some cables, but how easy was it to 'persuade' them away from the rear of the transfer box? Also, when using the unit, I know the instructions say it can be left engaged unless you come to a complete stop, but how does that work in practice? You did say initially that 'You've got to plan ahead a little approaching junctions to get it out of overdrive and into normal ratios to do your manoeuvring', but is that still the case now you've got more used to it? It would need to be pretty straightforward for the other half to actually use it - she has this strange notion that I should leave the car totally standard - she clearly doesn't know that these things are meant to be altered.

jonny2tanx said:

Brown, thanks for keeping us updated on this mod. I must say you are more daring than I would be to take the transfer box apart - bolt on is about my limit (and even then I can manage to cock it up ). I was underneath the Landy yesterday trying to free off a slightly sticky handbrake and saw how the cable was running across the precise spot where the Roamerdrive would fit. I know you said that there were some cables, but how easy was it to 'persuade' them away from the rear of the transfer box? Also, when using the unit, I know the instructions say it can be left engaged unless you come to a complete stop, but how does that work in practice? You did say initially that 'You've got to plan ahead a little approaching junctions to get it out of overdrive and into normal ratios to do your manoeuvring', but is that still the case now you've got more used to it? It would need to be pretty straightforward for the other half to actually use it - she has this strange notion that I should leave the car totally standard - she clearly doesn't know that these things are meant to be altered.

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Yes, there was various stuff in the way, including an earth cable bolted to the back of the transfer case and the handbrake cable. I fitted a new handbrake cable which was much more flexible than the old one so it bends round the driver's side of the overdrive casing. It does make the speedo drive rather difficult to get to without taking the handbrake backplate off. The earth wire I dealt with by making a longer one, as above. The other tight fit was where the TD5 wiring loom goes along the passenger side of the gearbox and past the seatbox where there isn't much room for the linkage. As the wiring loom is just long enough to reach the places it needs to go you couldn't re-route it without major electrical work. Somewhere up above, you can see I've put the overdrive selector linkage in a bit of corrugated tube. This is tied on to the same mounting points as the wiring looms so it doesn't move. The rod just slides inside it. So if anything wears out, it'll only be my piece of tube.

As regards driving techniques, if I'm in overdrive and fifth and coming up to a junction I tend to come out of overdrive first, as I begin slowing down. Then do whatever I normally do - for example unless I'm pointing uphill, at most traffic lights and roundabouts it's quite happy pulling away in second, so that's pretty much the same as usual. The overdrive's gearchange feels best when you're over 40mph. If you're stationary it can be reluctant to change. However, it'll work in all gears. Joining motorway traffic I tend to leave it in 'normal' until I've filtered in, because you don;'t have much acceleration in overdrive, whereas in normal 5th you can still accelerate a bit to match your speed to the traffic.

If your partner doesn't like it, she doesn't have to use it! If she leaves the overdrive lever pointing backwards it'll be just the same as it ever was.

Thanks for the reply Brown. I'll crawl back underneath at the weekend, weather permitting, and take a closer look at all the gubbins. My handbrake cable is very stiff and when I was looking the other day I thought it would be extremely awkward to persuade it to move. May I ask where did you get the replacement cable from?

Bob - I haven't found a pencil clip yet, but I tend to keep pencils in the removable tray in the top box along with screwdrivers. There are some elastic cords on the back so you can carry longer items like saws and breaker bars.

Jonny - I was thinking the hand brake cable would be a bit of a handicap because my old one was rock hard. But the new one was more pliable. The handbrake cable, along with bearings, seals and other bits and pieces came from LR Direct, because they offer a choice of brands so you can keep away from Britpart. Roamerdrive unit, transfer box sump and temperature gauge from Rocky Mountain Spares, rev counter from Croytec, miscellaneous wires, spade terminals, heatshrink and corrugated plastic tube from Auto Electrical Supplies, oddments like non-loadbearing screws, nuts and bolts from Screwfix, coffee and cakes from Tesco.

Incidentally, I'm not finding it quite as exciting as I thought it would be having a rev counter. Most of the time I'm doing less than 2000 rpm.

Thanks for the reply. Now the really hard work - persuading the other half that we need one

Another small update. Being a good boy, I notified my insurer who wanted to charge me £18.00. Didn't seem too bad to me so I agreed to it.

I might get them to quote me as to how much extra it would cost if I had a remap. If it's reasonable, that might be one of my next big purchases. Mainly to add a bit of torque at low revs so as to make the most of all this new-found high gearing.