Ultra Low Range Gearbox

[SnapHead101]

HI all,
My local Landrover Mechanic has suggested I get an ulta low range gearbox for my 130 defender in order to tow a large boat out of the water. He states the gearbox can be taken out and the low range gears recut to give about 30% more pulling power. This does not affect high range, but the cost is around $ 2000 to 3000 . Does anyone have experience with these gearboxes or know where they are made/modified.
Many thanks to any replies.

[abaddonxi]

What about one of these?

http://www.ashcroft-transmissions.co.uk/category_12.html
and more on same -
http://www.eastcoastrover.com/Underdrive.html

Sounds like you want a set of rock crawler gears. Or maybe air down the tyres to dip it in and out of the water.

Have you actually had trouble yet? I'm guessing not or you wouldn't be questioning the dollars, just reliving the embarrassment and punishing your credit card.

That is a bloody big boat.

Cheers,
Simon

[SnapHead101]

I've only retrieved and launched the boat twice yet, it's a new arrival and so is the subcylonic winds and rain we now have in Far North QLD. The retrievals where puzzling. The first time was easy, a little revving in low range and it was simple. The second was an absolute b*tch. I revved a bit, let out the clutch and got no forward motion but almost stalled. Finally got under way but had low power. Talked to the mechanic who states that as the second retrieval was done with a relatively cold engine (had only been running for 3 mins) I wouldn't have had enough power. Also I engaged diff lock 2 metres from the waters edge and thus may have not really engaged it despite the light being on, thus may have been spinning a wheel. I'm planning on retrieving next time with a well warmed engine, but if necessary may get low range modified or possbily 15 inch tyres. It's certainly cheaper than buying a tractor!
Yes the boat is large ... I get quite a few comments re am I trying to compensate for something. The reply "well your missus doesn't think so" normally quietens most people !

[SnapHead101]

These units look good. I think I'm running a 380 gearbox, not the LT230 however I'll need to check my manual and find out ! (Can't get to the car in the front garden at the moment without getting soaked)!!

[Blknight.aus]

your landrover comes with the lowest of the low low range gears fresh out of the box... IF you cant haul something with that in 1 low going to a lower ratio will in all likely hood result in one of 4 things happening

having the wheels break traction from too much torque and not enough grip (especially on wet boat ramps)
breaking the diff, axle or propshaft
physical damage to the towing equipment on the vehicle
spinning the rim inside the wheel


Most rock crawling gears are used not for the torque multiplication factor but the lower speed that they offer.

An auto offeres the best torque delivery and due to the TC more torque for start off. The number of times Ive seen people spinning the rubber on auto equiped vehicles (and overpowered manuals) trying to pull boats up boat ramps is just stupid. at one stage I made a good weeks drinking $$$$ from parking a winch equipped rover at the top of the local boatramp whenever it had been raining and for $5 a pop Id winch the stuck vehicle up the ramp.

Letting the tyres down is not a smart option.. The rims get wet then when you apply the power they spin inside the rubber, if your lucky they stay up, unlucky they go down then can be reinflated with the onboard compressor and really unlucky you dont notice it till youve ripped the bead to shreds then have to be recovered out or change the tyre with the trailer on the back to get the boat out.

The smartest solution Ive seen is a dolly for the front of the trailer and a winch or tow rope from the vehicle to the trailer, this way the weight of the vehicle is up on the flat and is less to over come.

The next best would be once the boat is on the trailer and secured at the bow and stern (put your tie down straps on bouys so they float past the hull and can be gaffed) backing the whole lot down the ramp till the boat floats part of its weight then go forth, the momentum gained is usually enough to get the motor up to full steam and your not trying to over come all the inertia uphill.

but be careful.. I saw one guy do this and get too far down the ramp...the boat caught some sideways action pulled him off line and off the boat ramp into the briney....

[cartm58]

or like a guy in Perth this week, well known identity reversed down ramp with boat on, lept out of cruiser, didn't have it in park or handbrake on, cruiser and boat reversed into marina till cruiser submerged to roof line.

apparently done while hob knob luncheon on at marina so plenty of photos taken of event

[weeds]

could you have somebody in boat to assist in getting while the prop is still in the water than cut the engine once moving

[Bush65]

FYI

Defenders should have the LT230 transfer case. Maxi-Drive Engineering make a conversion for your LT230 to reduce the low range by 30% or by 49% (2 options).

[Blknight.aus]

could you have somebody in boat to assist in getting while the prop is still in the water than cut the engine once moving

thats not bad either, youd want a pretty good bow mount on the trailer tho

[Quiggers]

Might be time for a F250/350 tow truck given the weight of the vessel, snappy. That's what Sailfish use... (much as i like LR products), but........

I'm quite amazed your rig is street legal....nice ship tho'!

GQ

[George130]

You probably want the setup in my beastie. But as blacknight said it's easy to spin the tyres even in the dry!
I have a ZF 4 speed beefed up with a 2000-2500 stall converter and the rock crawlers in the LT230 transfer case. It was setup for cable pulling.

[SnapHead101]

I'm not keen to use the boat engines to move the trailer for the risk of breaking the front mounts on the trailer and also stirring up debris at the ramp which then goes into the intake. Thanks very much for the tip on the Rock Crawler from maxi drive. My idea boat retrieve is one where you just idle up the ramp. Currently I need to rev the engine to prevent a stall which means the tyres initially move quickly thus increasing the chance of slip. Having lower low range means I should be able to drop engine revs, preserve my clutch and reduce the speed of take off, hence decrease the chance of tyre slip. Thus I can see the rock crawlers decreasing trye slip as I don't intend to take off quickly. Thanks for the tip on not deflating tyres, the mechanic had suggested this !
I'll contact maxi drive and see what happens.
As for going for a F250. Not keen on driving one. Poorer build quality than Landrover, very long , and I don't need the highway speeds that often. Now if the new Toyota V8 diesel has a tow capacity of 4.5 ton ..........

[Utemad]

I think I'm running a 380 gearbox, not the LT230 however I'll need to check my manual and find out !

R380 is the 5 speed manual and the LT230 is the transfer case. So you have both.


or possbily 15 inch tyres.

Changing your tyre diameter to a smaller one would make a Defender scream on the road I'd think. Just changing to a 15in rim would do nothing if the overall tyre diameter did not change.

Since it did it easy with a warmed up engine then it sounds like your cheapest option is just to ensure the engine is warmed up first. No engine likes to be worked that hard when it is cold.

[Utemad]

As for going for a F250. Not keen on driving one. Poorer build quality than Landrover

I'll vouch for that.

Bloody expensive option just for pulling a boat out of the water. But then given the boat you have .......

[uninformed]

i have the 49% lower gear set from Maxi-drive in my 110 def trayback.

i tow an 8x5 dual axle trailer full of tools, must weigh about 2t

for tight sites that are hilly etc it kicks ass. can reverse IDLE my trailer up a 200mm concrete kerb.

made from the best material for gears and staight cut for greater strenght. all Australian made

serg

[SnapHead101]

sounds good, do you remember where you got it installed and how much it set you back. The website lists only 30 and 40% reduction, but I'll ask about the 49%.

[George130]

I have the Maxidrive reduction gears. Noisy as but they are great!

[mark2]

For the same sort of money, you could convert it to a ZF auto (fit a big cooler) - will give you much smoother power delivery and no risk of stalling.
I had a ZF auto/LT230 in a Rangie fitted with 4.7 diffs - it pullled like a train.

[Tusker]

The maxidrive conversion should set you back about $1600, $1700 or so.

I've now got the 49% version, well worth it.

I've never had trouble on a boat ramp. If wheel spin is an issue, do you engage CDL? I'd have thought that using low range & the CDL, & knocking the CDL out on the move once you're mobile will get anything up any ramp.

Regards
Max P

[nobbydoldrums]

or like a guy in Perth this week, well known identity reversed down ramp with boat on, lept out of cruiser, didn't have it in park or handbrake on, cruiser and boat reversed into marina till cruiser submerged to roof line.

apparently done while hob knob luncheon on at marina so plenty of photos taken of event

Have you got a link to any sites with pics? I could do with a laugh today.

[Bigbjorn]

A guy a Wellington Point boat ramp near Brisbane reversed his old Landcruiser SWB hardtop and trailer down the ramp, put it into gear and handbrake on. As the weight of the largish boat came onto the trailer, it lifted the rear of the Landcruiser enough to break traction and the whole rig started sliding down the ramp. The owner ran to open the door and jump in, only to find he had automatically locked the door when alighting. Glug, glug, glug. I worked with the guy and once we heard about it, his caring work mates decorated his work station with pictures of submarines, submariners peering through periscopes, ads from defence surplus stores for periscopes, etc.