Transmission for Launch Vehicle

Chris Murray · 14 July 2004, 20:23

I know that the subject has been raised before but I am not sure if having a low-ratio gear facility makes this less of an issue.

I shall be purchasing a diesel powered Landrover Discovery in the Spring, as my only car. I will have a 200 mile round trip to the boat and intend to leave it on a trailer at a suitable location. The boat (2006 Season) will be an 8.5 metre Scorpion, with the biggest outboard I can find. Most likely a single Mercury Verado. It will also have a large fuel tank, so the whole rig will be pretty heavy.

I know that there are quite a few advocates of automatic transmission but this will obviously have an impact on performance (if that is an appropriate term for a "Disco") and fuel consumption. Would the facility of a low ratio gearbox be a factor in the choice of manual or auto?

If my wife lets me (might as well be honest) buy the new model, it will weigh over two and a half tonnes. There are no fuel consumption figures yet published but there is little doubt that it will be "thirsty".

Given all of this info, please let me have your thoughts on whether or not the automatic transmission would make for the best launch vehicle (bearing in mind the low-ratio facility) or if the better performance and likely improvement in fuel consumption (say 1 mpg) of a manual box will outweigh the need/cost to replace the clutch in a manual gearbox at regular intervals. Any idea about the cost of this exercise and how often it might be necessary?

Thanks for your thoughts!

Chris.

Pete7 · 14 July 2004, 20:50

Chris, I had similar concerns when I bought my auto disco. however she tows 2.5 tonnes of Pacific 22 and trailer beautifully and the auto box with low ratio on the slip is superb. Traction control is very precise so no spinning wheels and the torque from the low ratio makes light work of even gravel slips.

I get about 25 mpg doing the normal run to work at 65-70 mph everyday. Not sure what she does towing but its way better than the V8 landrover I used to tow a rib to Poland

My biggest concern is the way the miles are racking up because I want to keep her.

Pete

gingercoastie · 14 July 2004, 21:04

My auto discovery also works very well. I have only had to use low range once as the traction control takes away most of the grief.

peter 24/7 · 14 July 2004, 22:00

How long do you plan to keep the Disco, or should I re phrase that, how long do you intend keeping it if it does not fall apart....

Salt water, then I would recommend selling it after 2 years.

Have you thought of buying an old 4x4 and keeping it with your boat at the storage yard for the launchig of the said boat. This way, your new everyday car may be better than a disco and you still have the ability to launch your boat with the peace of mind that you are not dunking your £30K disco.

Nasher · 14 July 2004, 22:20

Like pete I also use my 4X4 (3.2TD LWB Shogun) everyday for work etc, but did think about an Old 4X4 and normal car, decision was made harder as to have the 4X4 I opt out of my company car scheme where my base car is a Saab convertable.

Reasons I went for the everyday 4X4
Once you've had a decent 4X4 you won't ever want anything else.
I often tow my boat to Devon from Portsmouth and didn't want to trust an old LR to get me there a) at all b) with my hearing intact, and c) without my arse, arms, fingers etc going numb.
Two cars means two lots of insurance, tax etc.
To tow a 1.5tn boat worth thousands of pounds I want to be sure the vehicle is up to it structurely and the brakes work well.

Went for the Manual gearbox by the way, purely because I prefer it, but do worry when I can smell the clutch after manovering the boat backwards on the steep hill that passes for my road and driveway.

Nasher

jwalker · 14 July 2004, 22:45

Go for auto, absolutely no question. The low ratio will be essential if you get bogged because the torque converter has a limited drive ability and it can be forced to stall under very high load.

I've been an auto man for many, many years. Today I had to drive a manual Jeep. Jeez, why do people do that to themselves? It's nuts.

Searider · 14 July 2004, 23:31

Quote:

Originally Posted by Pete7

My biggest concern is the way the miles are racking up because I want to keep her.

Pete

Pete,

Don't worry about the miles. Discoverys used hard can go on for ever. My Dad runs a transport business delivering cars on a trailer towed by a Discovery. The last one he sold had 380000 miles on it. The engine was still good - although the injectors and pump had never been touched.
Manual gearboxes only last 100000 miles between rebuilds. (£1000)
The transfer box needed renewing at about 250000 miles. (£600)
Never any problems with the axles.
Was starting to go a bit rusty around the edges though.
Sold it unseen to one of the mechanics who maintained it.

My 1987 Range Rover V8 (Inherited) is still going strongish at 252000 miles. On the V8 the gearboxes last longer - about 200000 miles but engines only about 100000 miles each.

Both of the above were bought at about 70000 miles and then 90% of the rest of the miles was towing - sometimes a heavy load such as a Range Rover on the trailer - about 3 tons?

It's probably the electric bits falling off that would make anyone want to sell a Landrover product - some of the electrics on my RR are starting to pack up but it is now the kind of vehicle that can be allowed to get old disgracefully.

Duncan

codprawn · 15 July 2004, 02:16

Quote:

Originally Posted by peter 24/7

How long do you plan to keep the Disco, or should I re phrase that, how long do you intend keeping it if it does not fall apart....

Salt water, then I would recommend selling it after 2 years.

Have you thought of buying an old 4x4 and keeping it with your boat at the storage yard for the launchig of the said boat. This way, your new everyday car may be better than a disco and you still have the ability to launch your boat with the peace of mind that you are not dunking your £30K disco.

As long as you wash the salt water off there is no problem - a garden sprinkler works wonders - volume is FAR more important than pressure!

The RAF have water sprays lining the runway to drench their maritime patrol aircraft in fresh water when they land - remember lots of bare aluminium. Just shows how low they fly!!!!

codprawn · 15 July 2004, 02:18

I would also go for an auto - just as good performance as maanual but a bit less economy. Having said that for a lot of towing there will be a lot less wear and tear on the clutch etc.

You should use low range on steep slips etc - less strain on the auto box and also I have seen the linkages seize up because they never get used!

Also remember to use an auto like a manual - change down on hills etc to get engine braking so there is less wear on the brakes etc.

Pete7 · 15 July 2004, 07:48

Quote:

Originally Posted by codprawn

- less strain on the auto box and also I have seen the linkages seize up because they never get used!

Been there with a previous disco, so now use low ratio to launch and recover every time just to give the low ratio and linkages something to do, if not the linkage sieze.

Pete

Alan · 15 July 2004, 07:48

Agree with Auto box enthusiasts! I towed 7.5m Scorp on v heavy duty road trailer (so much so that it rode better when the fuel tank was full with 60 galls of fuel!) behind Auto Isuzu Trooper and it went like a dream. I don't believe the auto box makes any significant impact on fuel economy on big 4x4. Or to put it another way, if fuel economy was so important you would find another way to sort out the boat (e.g. marina berth / dry berth / old 4x4) and run a car wouldn't you?

Having the ability to use low range is a neccessity on a big boat / trailer combo IMHO.

Philip Hodson · 15 July 2004, 08:24

Chris I changed from a Range Rover V8 last year to a new Td5 manual saving a
fortune on fuel Disco returning 26 to the gallon & that’s pulling a Pacific
22. & in the winter 2 big horse’s.
PS always use low ratio on the slipway
Phil H.

Simon B · 15 July 2004, 09:17

Go for auto fundamentally better off the road in situations where you need constant torque ideal for slippy slipways etc. Not driven on but a bet its a whole lot better than my 110 Landrover in reverse backing up the slip..hmmm "Just love the smell of burning clutch plates in the morning" tends to bring out all the trainspotters too!

codprawn · 15 July 2004, 10:32

Quote:

Originally Posted by Simon B

Go for auto fundamentally better off the road in situations where you need constant torque ideal for slippy slipways etc. Not driven on but a bet its a whole lot better than my 110 Landrover in reverse backing up the slip..hmmm "Just love the smell of burning clutch plates in the morning" tends to bring out all the trainspotters too!

Don't You use low range? A diesel 110 will go up any slope backwards on tickover - don't need to touch the throttle!

I agree though an auto is better in most offroad situations other than steep decents - even locked down into 1st there isn't as much engine braking as a manual.

Simon B · 15 July 2004, 13:11

Affirmative Codprawn, it judders so badly in reverse I have to slip the clutch, I do use low box and similarly to the diesel my 4.6 v8 goes ok on tick over. I might get some lessons on more off road type driving.

Ofcourse one could wait and go for the all new Disco an acquaintance of mine works for Landrover and had one to test so brought it over to show me what a beast! drive train selection is done on a touch screen that selects gears and suspension set up. We just want see the jag v8 diesel fitted to the Defender to be in AutoNirvana.

codprawn · 15 July 2004, 13:55

[QUOTE=Simon B] Affirmative Codprawn, it judders so badly in reverse I have to slip the clutch, I do use low box and similarly to the diesel my 4.6 v8 goes ok on tick over. I might get some lessons on more off road type driving.

You don't need lessons - just loads of practice - and it's fun learning!!!!

Shouldn't judder so badly - maybe your tickover is too low - having said that diesels always amaze me - even the Vauxhall Signum 2.0dti(YUK YUK) I have at the moment will climb any steep hill you point it at in first with your feet off all the pedals. Anyone with a diesel should try it - very suprising.

My mate with a new Transit van was complaining how easily it would stall - I told him it would climb anything on tickover and he refused to believe me until I proved it!

The trick is to approach the hill on tickover - too late when you are on it - feet off and let the engine do the rest.

peter 24/7 · 15 July 2004, 19:42

If you are looking to get a new new disco (Nov) time, remember it does not have a ladder chassis construction. I am sure it will still be good at towing, but I would rather tow with a vehicle with a chassis rather than the new mono......... what ever it is.

manual / auto, no difference on a slip with the TD5, just put in low box, don't touch the throttle and she will pull anything. If you touch the gas, then you are introuble intil you spin that turbo, clutch issues etc. Economy, I would buy what ever you are comftable with. Try a Landcruiser.

Chris Murray · 16 July 2004, 06:50

Thanks Guys!

It looks like it'll be the auto then!

Regards,

Chris.

codprawn · 16 July 2004, 11:42

Quote:

Originally Posted by Chris Murray

Thanks Guys!

It looks like it'll be the auto then!

Regards,

Chris.

Just remember to check auto transmission levels and change the oil and filter in the box at the proper times - my mate has a Shogun and the gearbox played up towing his new caravan - I asked him if he had changed the fluid and filter and he said they never needed changing - scary considering he is considered to be a good mechanic!!!

LURCHER · 16 July 2004, 15:19

I have always had auto discos and last year chnged to an Isuzu Trooper also auto and a lot quicker than the LR . Trooper now for sale if you are interested 52 plate 41000 miles !