SLOWING DOWN!!!

[MADDS1]

Hey guys,
Pretty new to the 4wding game, I have a disco 1, 2" lift on 31's AUTO.
I went out on the weekend and had some fun, but i am finding it hard to slow my bus down when coming down hills with out using the brake a little to much. I have it in 1st low range but still she seems to be coming down a little to fast.
Am I doing something wrong?? or is it a common problem???

Any ideas?????


Thanks

Alex

[GRIMACE]

http://www.outerlimits4x4.com/ftopic161151.php

[Micka]

http://www.outerlimits4x4.com/ftopic161151.php

X2.

Get on board mate.

$1265 will see a set of 30% or 49% reduction gears for your transfer.

[91rangie]

or a cheaper fix is to simlpy check your engine idle speed and lower it if possible.

[Bush65]

Or pull the handbrake on a few clicks.

[Sprover]

Ive got a 95 Disco and when i use it in 1st low gear down a hill its pretty good.Shouldnt even need your brakes.I was in the High country earlier this year and it has some pretty steep hills.On some parts i didnt even have to use the brakes.

[amtravic1]

Just use the brakes.

[Bush65]

Because you are new to 4wd, it is worth noting that steep descents are a problem with automatic transmissions, because the fluid coupling slips and can not transfer all of the engine braking torque.

The problem with using brakes on slippery descents is the greater risk of locking up the wheels (particularly the fronts, which affects steering).

At the beginning of the descent (before it becomes steep), apply a little throttle with your right foot pushed hard against the right side of the foot well (to keep your foot steady when the vehicle bumps up/down). Then brake with your left foot to control speed (and optionally pull handbrake on a little). The principle behind this technique is the small amount of throttle will help prevent the wheels from locking up.

I would also suggest you find a good 4wd club and do some training.

[amtravic1]

Because you are new to 4wd, it is worth noting that steep descents are a problem with automatic transmissions, because the fluid coupling slips and can not transfer all of the engine braking torque.

The problem with using brakes on slippery descents is the greater risk of locking up the wheels (particularly the fronts, which affects steering).

At the beginning of the descent (before it becomes steep), apply a little throttle with your right foot pushed hard against the right side of the foot well (to keep your foot steady when the vehicle bumps up/down). Then brake with your left foot to control speed (and optionally pull handbrake on a little). The principle behind this technique is the small amount of throttle will help prevent the wheels from locking up.

I would also suggest you find a good 4wd club and do some training.

good advice.

[MADDS1]

Thanks guys, BUSH65 that is exactly the info i was after about the coupling. I have been working on all the rest, and have a group of good mates that I go out with that have some good experiance behind them. So will these reduction gears actually do the job????

[GRIMACE]

So will these reduction gears actually do the job????

Of course they will mate, if you realy want to slow your vehicle down the best bet is tcase reduction gears (as seen in the group buy), followed by a reduction to the crown wheel and pinion gearing (usually to 4.11 or 4.7s).
Another thing possible with the auto is getting the torque convertor modified to lock up under engine rebutle, but doin this removes the lock up that occurs during highway driving (just above 80k/h).
The torque convertor mod is not so common and not as preferable for a tourer/highway driving rig.

[nottie]

Any link for the mod on the TC Grimass

[GRIMACE]

Any link for the mod on the TC Grimass

no link, but I have one already modified sitting in the shed at my olds place.

[MADDS1]

so 100% the diff gears will fix my problem?

[muppet_man67]

so 100% the diff gears will fix my problem?

100% engine braking down hills will be slower. Its never going to be like a manual where, so long as the engine is running you are guaranteed the wheels are turning. It will still be possible to lock them up if you have to use the brakes.

[GRIMACE]

so 100% the diff gears will fix my problem?

Gearing is the biggest factor in how your car manages decents.

Unfortunately the standard rover auto and gearing coupled with larger tyres will always try to run away a little on steep decents.

If you want to slow the car down under engine braking without using the foot brakes you need to reduce the gearing.

You can go two ways about this.
Change the Crown wheel and pinion gears in both front and rear differentials.
Or
Change the low range gears in the LT230 transfer case.

Changing the differential gears will alter all round manners, as it reduces gearing to both high and low range.
Where as the change to the low range gearset in the lt230 is exactly that, change to only low range, so your vehicle will behave exactly the same in all aspects of high range as it did previously.

Personally for your configuration I don't think the vehcile will be running away all that bad, eg. at the moment I have standard gearing and 37" tyres and it's not that bad, so for you gears may not be nessecary, but if you do feel it's too fast for your liking then for sure a set of 30% tcase reduction gears are a good option. If you are inteding on goin larger tyres in the future some 4.11 differential gears can be added then for more strength and to bring back some high range drivability.

100% the diff or tcase gears will reduce your decent speed, but will not give you 100% engine braking. Only the torque convertor mod will do this.

[cookiesa]

And I wouldn't go using the hand brake to slow you down. They are trans mounted and designed to hold the vehicle not slow it. It will get very hot, very quick and either fail or catch fire. The previous advice on throttle + brakes is a much safer and practicle one.

[swamp]

One other option is a Ashcroft underdrive box that mounts to the rear of your transfer case.
Depending on the exchange rate it would be about the same as supplied and installed reduction transfer gears.
Here's a link
http://www.ashcroft-transmissions.co.uk ... ry_12.html

[discothrasher]

so 100% the diff gears will fix my problem?

Gearing is the biggest factor in how your car manages decents.

Unfortunately the standard rover auto and gearing coupled with larger tyres will always try to run away a little on steep decents.

If you want to slow the car down under engine braking without using the foot brakes you need to reduce the gearing.

You can go two ways about this.
Change the Crown wheel and pinion gears in both front and rear differentials.



Or
Change the low range gears in the LT230 transfer case.

Changing the differential gears will alter all round manners, as it reduces gearing to both high and low range.
Where as the change to the low range gearset in the lt230 is exactly that, change to only low range, so your vehicle will behave exactly the same in all aspects of high range as it did previously.

Personally for your configuration I don't think the vehcile will be running away all that bad, eg. at the moment I have standard gearing and 37" tyres and it's not that bad, so for you gears may not be nessecary, but if you do feel it's too fast for your liking then for sure a set of 30% tcase reduction gears are a good option. If you are inteding on goin larger tyres in the future some 4.11 differential gears can be added then for more strength and to bring back some high range drivability.

100% the diff or tcase gears will reduce your decent speed, but will not give you 100% engine braking. Only the torque convertor mod will do this.

X2 what Grimace says

i am running 49% REDUCTION AND 4.14:1 diff and i am so slow most of the time i am in 4th or 3rd gear as 1st is suuuuuuppper sloooooooooow

Grimaces advice is a DEFINATE

[def90]

who makes 4.14 gears?

[discothrasher]

who makes 4.14 gears?

Great basin rovers in salt lake city usa check out there web site he said its under contruction at the moment but you can get his number off it ask to speak with Bill awesome bloke lots of very usefull knowledge and the strenght of the aus $ to US $ its a buyers market, 4.14 are tested to be 25% stronger than the 4.11
Moderators this is not intended to be a plug just a very happy owner of 4.14 diffs

[def90]

yeah cool thought it must of been GBR, how long have you had them?