Thread: LT230 operating temperature

Originally Posted by Sitec

Nope.. Common miss conception that a 'higher ratio' box is for faster travel speed.. All in the wording. A high ratio Transfercase is just that.. 1.667 input turns to 1.0 output turns. There's a higher ratio between the two figures.. A low ratio box... 1.003 input turns to 1.0 output turns is not a lot of difference.. therefore a low ratio. The problem arose years ago when a truck gearbox manufacturer correctly named the transfer case speeds as low box for slow stuff and high box for fast stuff.. Some fourby manufacturer came along and stuck the word 'ratio' in there for ****s and giggles and everyone ran with it.... Sounds daft but when u think about it its correct.

It all depends on the use of higher to describe the numerical ratio of teeth or higher to describe the numerical ratio of shaft speeds.

The latter is more common usage, but both are technically correct.

Sitec is right, most people dont understand gearing terminology.

Ratio means 'difference' between two gears. A big difference in gear size = a high ratio = low ground speed. This is not the same as high 'gear'

Regarding high and low range, high range gives low (short) 'ratios' and low range gives high (tall) 'ratios'.

Basically when describing 'gears' and 'ratios', they are the opposite of each other.

Cheers
Tom

Td5 stg 2 map + vnt, bigger intercooler etc.
With a roamerdrive fitted I tow a KK platinum camper in 4th overdrive to save 5th and T/C temps are usually around 85 and never over 90 degrees mind you I only sit on 90-95 km/h.

When not towing I go overdrive and 5th still sit on the same speed and T/C temps around 75-85 degrees depending on ambient temp.

These temps include runs out west with ambient of 35-40 degrees

And up here it is always fairly warm anyway.

But if I sat on 120 km/h which I never do I am sure those temps would be a lot different.
The Defender is a brick and when we are on the back roads and not impeding traffic I am happy to sit on 80-85 km/h all day
Vehicle happier and fuel economy so much better which means more money for
Cheers,
Paul.

Thanks Paul I agree the speed is the problem if it is a problem
Sadly I had to do 2500 Ks in a few days just to get to a 6 hour wedding ceremony.
80 Ks wouldn't cut it
$5000 in airfares and associated costs make driving the only economical way.

So from a standing start we change down the gears (ratios) from 1st to 4th and then 5th (or high to low) while all the time increasing speed.
That make sense now . I used to laugh when people say I have a 5 speed Toyota /Mazda /Datsun , I would think is that 20km 40km 60km 80km and 100km when I had a 3 geared infinitely variable speed up and to a point old Holden crash box, with a tall ( or is that short ) , but low ratio 3.08 diff

Originally Posted by harro

Td5 stg 2 map + vnt, bigger intercooler etc.
With a roamerdrive fitted I tow a KK platinum camper in 4th overdrive to save 5th and T/C temps are usually around 85 and never over 90 degrees mind you I only sit on 90-95 km/h.

When not towing I go overdrive and 5th still sit on the same speed and T/C temps around 75-85 degrees depending on ambient temp.

These temps include runs out west with ambient of 35-40 degrees

And up here it is always fairly warm anyway.

But if I sat on 120 km/h which I never do I am sure those temps would be a lot different.
The Defender is a brick and when we are on the back roads and not impeding traffic I am happy to sit on 80-85 km/h all day
Vehicle happier and fuel economy so much better which means more money for
Cheers,
Paul.

Paul, I am using the same set up to tow my 3000kg pop top van, re 4th gear/ roamerdrive around 90kms per hour but my TC temps are always over 100 degrees so I wonder why this differs from your temps considering I have been in sub 30 outside air temps. Let me know if you use other than the recomended HP 90 gear oil in your rig. Regards Peter

Originally Posted by pjh4159

Paul, I am using the same set up to tow my 3000kg pop top van, re 4th gear/ roamerdrive around 90kms per hour but my TC temps are always over 100 degrees so I wonder why this differs from your temps considering I have been in sub 30 outside air temps. Let me know if you use other than the recomended HP 90 gear oil in your rig. Regards Peter

Use a good synthetic 75W-90 and I'd expect the temps to drop 5-10°

Originally Posted by djam1

Travelled from Karratha to Geraldton in the last 24 hours or so
2002 TD5 Defender with transfer case that was rebuilt 12 months ago
Travelled at about 120 Kmh (on the clock) with strong headwind and high temperatures
The transfer oil was running up to 98 degrees C this is with an extended sump and Castrol Syntrans.
I have often thought of buying an overdrive but with the manufacturer saying keep the temp below 110 degrees C
I just can't see how they would cut it under these conditions
I suspect a modified Ashcroft R380 with a different 5th gear ratio would be the way to go.

Recently I suffered a serious overheating of my Roamerdrive from oil temperatures reaching 150 C before I became aware seeing the gauge, because of this and the need to purchase another Roamerdrive after the thirteen years of trouble free motoring with the Roamerdrive installed. I was determined to permanently solve the high oil temps that can occur in the LT230 with or without an overdrive fitted. My approach was to design a system driven by a 12 volt low volume oil pump circulating the transfer case oil through an additional oil cooler and returning at the top near the gearbox output shaft. Although this turned out to be a reasonably easy installation I needed to build my own oil pump as all the off the self ones had a much to high flow rate or cannot continuously run at 80C + oil temps. Anyway after working out my final design and installation with test runs of 300klms at highway speeds in overdrive the oil temperature in the transfer case maxed at 80 C. in summer in Queensland so very happy with the results. I have posted photographs on AULRO Facebook site for further information.