Roverdrive vs Fairey OD's

[msggunny]

Ok, im buying one but i need some input from people who have run or are running them on their series rigs.

pros/cons, good, bad and ugly please.

Thanks!
Richard

[jp-]

I have a Fairey in my 109, which has given no trouble and is still as quiet as when new. Shifts and engages fine. I know that others have not had as much luck with their Fairey's.

I have a Roverdrive in the 88". It was quite loud during the first 100 miles or so, but has quieted some. It also has a neutral position that is very close to the engaged position. This leads to the occasional mis-shift and a gear grind. I am hoping that the tendency of the shifter to stop in the neutral position will diminish over time. Other than that, I like it and it is nice that the oil level keeps itself in check by feeding off the T-case oil supply. The Fairey's oil level must be checked independently.

However, despite those few shortcomings, the Roverdrive does feel and look much more robust than the Fairey.

I also only use my overdrives in top gear (and very rarely in 3rd).

[Jeff Aronson]

Fairey Overdrive

I have a Fairey Overdrive on my II-A 88". The current one has well over 100,000 miles on it.

I've had one new one wear out around this same point; it was slipping out of gear when coming to a stop and sliding into neutral. I exchanged it for a rebuilt unit from Rovers North. That one lasted for a short while because the drain plug unscrewed itself and dumped all the hypoid somewhere over a 240 mile trip over rural roads and an interstate. The current one makes mechanical sounds at speed, but the whining does not sound louder than the 4th gear.

I don't know the Roverdrive, but I see one at a Land Rover event in England in 2003. It looked handsome off the car.

I'll be interested in the new high ratio transfer case that Rovers North is selling. At the same price as a Fairey, it would also provide a new transmission brake assembly.

Jeff

[giorgio]

I, too, could be interested in the new high ratio transfer case. I read about it, and wanted to know more. It is about the same price, and looks like it might be an easier retro-fit. Please keep us posted if/as you learn more. I currently do not have an overdrive.

Giorgio
1968 109 2.6L Carawagon

[hackneyed1]

I've been using a high ratio transfer case now for a week

I had the option of either the high ratio xfer case or a fairey OD, and decided to use the xfer case. After weighing both options, I chose the HRTC because is just simpler. No meshing in the OD while at speed, no worries about gear/bearing whine, fluid levels, forgetting to take it out of OD when downshifting, etc.
That said, it is much easier to install an OD than swap the HRTC. But I needed to reseal my original case and as such my brake shoes were oily.
Who knows, after I clean up my original case, maybe I'll swap it back..I'll post here if I decide to sell either the OD or the HRTC. Good luck in deciding.

[Jim-ME]

I have to admit that at present I do not have either an overdrive or a HRTC but I do remember the Fairey OD that I had about 30 years ago when they first came out. It was like a breath of fresh air and made the Rover a totaly different and more fun/pleasant vehicle to drive simply because you had so many more options for gearing between the underdrive and the overdrive functions. At no time did I use it to go any faster. I have been reading a lot about HRTCs, ODs and ECRs 5 speed conversion and I will offer my 2 cents. With either an OD or 5 speed conversion you always have the option of using standard gearing because it is still there. I remember using the underdrive gearing on my Fairey almost more than the OD function. My concern with the HRTC is that you loose the option of "going back" to standard gearing and I question if the engine has the power to handle different gearing on a full time basis. ECR claims no and I do feel that Mike's opinion make a lot of sense when you think things out. FWIW, when the time comes, unless I end up putting in a more powerful engine, I will be going the OD route and from what I've read so far i will go with the Roverdrive.

[yorker]

The hrtc is a great option if you have an engine that has more power or if you live some place flat like FL. If not you'll be spending a lot of time in 3rd gear. At least an OD preserves the existing gear ratios. If you want to get an idea what the hrtc is like driving-engage your OD and drive around with it for a while.

Crunch the numbers: Take the transmission ratios and you'll see what I mean, I wouldn't want that permanent reduction when behind an engine that has only 120ft lbs @ 2000rpm.
3.6:1 3.12
2.22 :1 1.93
1.5 :1 1.3
1:1 .87

[giorgio]

Thanks, guys, for all the good responses. Looks like I am back in the Roverdrive camp now. I do believe that there is a little extra modification required with the 2.6L engine. Seems that a bracket needs a 2 inch extension welded on to it, but guess I can someone to do that for me, if and when I get around to it.

Giorgio
1968 Series IIA 109 2.6L Carawagon

[yorker]

roverdrive

http://www.pirate4x4.com/forum/showthread.php?t=549911

[jp-]

There is another reason that you should not go with the HRTC.

Think of the children…

You have to admit that when some kid looks in through the door, and says, “my gosh, what the heck do you need all those knobs for!”, it really makes it worth it.

-“Well this red one is for pulling stuck elephants out of mud holes…”

-“This yellow one is for pulling the elephant out of the hole very fast…”

-“And of course this one, well, I can’t tell you what this one does. It’s classified.”

[Clive]

I have used both, the Fairey can be a leaky, noisy beast, the Roverdrive is more compact and has an oil supply from the transfer case reducing the chances of this happening:

That one lasted for a short while because the drain plug unscrewed itself and dumped all the hypoid somewhere over a 240 mile trip over rural roads and an interstate.

My 0.02 is for the Rover Drive. The HRTC is really only useful with a perfect 2.25 or a more powerful motor, and then best when you are using it on road most. the OD being completely selectable has a huge advantage, and if it goes west you just unbolt it and put the shaft plate back on the TC. The HRTC is a MUCH bigger pain to fit. The OD can be fit in 3 h, even by someone with virtually no mechaniucal aptitude.

[KevinNY]

If a gearset or a complete built case like the the RN HRTC was available that gave you an OD between stock and the somewhat tall OD gear options available AND gave you the 3.27 Lo of a 109 1 Ton T case, a 40% or so reduction from stock for a true offroad crawler gear, WOULD YOU BE INTERESTED?

This is something that I am trying to help bring to the market and I need to guage interest, I of course want it.

[yorker]

If a gearset or a complete built case like the the RN HRTC was available that gave you an OD between stock and the somewhat tall OD gear options available AND gave you the 3.27 Lo of a 109 1 Ton T case, a 40% or so reduction from stock for a true offroad crawler gear, WOULD YOU BE INTERESTED?

This is something that I am trying to help bring to the market and I need to guage interest, I of course want it.

I tried to get Ashcroft to do that a while ago, if you can find someone to do it then tere should be a market-

[TeriAnn]

I, too, could be interested in the new high ratio transfer case. I read about it, and wanted to know more. It is about the same price, and looks like it might be an easier retro-fit. Please keep us posted if/as you learn more. I currently do not have an overdrive.

Giorgio
1968 109 2.6L Carawagon

Stock gearing:
5.4:1 overall ratio @ axle, 3,682 RPM @ 65 MPH*

4.1 R&P:
4.7:1 overall ratio @ axle, 3,212 RPM @ 65 MPH*

Roverdrive stock ratio and:
4.3:1 overall ratio @ axle, 2,956 RPM @ 65 MPH*

Fairy overdrive, stock ratio and:
4.22:1 overall ratio @ axle, 2,887 @ 65 MPH*

Hi ratio kit:
4.09:1 overall ratio @ axle, 2,791 RPM @ 65 MPH*

3.54 R&P (standard coiler ratio):
4.06:1 overall ratio @ axle, 2,774 RPM @ 65 MPH*


* calculations for 1:1 fourth gear, 32 " dia tyres

As you can see the high ratio kit is very close to having 3.4 R&P diffs in high range while retaining your 4.7:1 diff ratio in low range. Its the best of both worlds IF you have the power to push the high range gears under your driving conditions. For a 2.6 Carawagon, I think it would be real iffy in the mountains and a bit slow off the line.

4.1 ring & inion gear sets should be no problem for the 2.6 but you will loose a little technical off road ability.

The overdrives require more frequent oil level checks, oil changes and can add a little to overall drive train noise, but they have the big advantage in that you keep all your old gear ratios plus gain a new set of ratios. This lets you split gears to find the best ratio for power or economy under all driving conditions.

A 3L Rover 6 in your Carawagon should have the power to push 3.54 or high ratio kit gears, but I suspect you may find things a little sluggish with the 2.6 and fuel mileage will suffer.

When I had a 2.25L SIII 8:1 petrol engine in my Dormobile I used my overdrive to split gears a lot in the mountains or into strong headwinds, but pretty much could not make much use of 4 over without a tail wind or slight downhill. Of course your 6 is a lot stronger than a LR 4. I would have spent a lot of time in lower gears if I had 3.54 R&P or high ratio kit installed.

Now that I have a V8 in the Dormobile, pushing the high ratio gear ratios are not an issue.

You know. a 4.1:1 R&P gear set is a good all around compromise if you do not do technical off road driving. You 2.6 should have no problem pushing it Just a thought.

[greenmeanie]

My 2 pennies

I've got the Roverdrive and have been very happy with it.

It's got 100K plus on it from having to spend far too much of my life using the SIIA to commute between Phoenix and Tucson. It's been very good and made (if you can consider this possible) the SWB 88 liveable on the freeway. I can cruise at about 3200rpm on 30x9.5 tyres and still keep up with the artics.

Over its life I've had to replace a couple of bearings which I got from the local bearing place. I think I may have broken a synchro spring but a conversation with Ray revealed that a lot of the parts are Land Rover items and the synchro is from a SIII. I view this as a bit of an advantage. You can also buy all the sealing washers etc. from McMaster Carr which guarrantees parts will be around for a while.

My only gripe is the selector lever rattles due to the linkage design but mine was a fairly early example so this might have been fixed. If not, a little forethought at install will eliminate this.

Cheers
Gregor