Thread: LT230 operating temperature

Have you considered fitting a Puma gearbox, think I saw a kit on evil bay some time ago.

Can some one explain how altering the gearbox will lower TC tempsapart from the contact between the two contact faces



AM

They do seem to run hot here in Oz. I've got 200hp and 5.9 litres hooked up to my LT230 and so far it seems to be taking it. Same as you, I've got the Ashcroft extended sump, but I've also put a piece of 3mm plate between the box and sump to help keep the casing from spreading under load. Also contemplating fitting two unions to the sump and locating a cooler somewhere on the chassis which will increase the capacity again.

Originally Posted by Ancient Mariner

Can some one explain how altering the gearbox will lower TC temps Thanks AM

Lower the ratio (higher speed) requires more torque to drive the box, and that increases the load thus increasing the temp... The old 1.667:1 box in a 2.5 diesel 110 was always cool as the vehicle was flat out at 90kph and had stuff all power.. The 1.003:1's always run hot as they are in a Range Rover being driven flat out with 100+hp at 120+kmh. Might be totally wrong with what I've said, but think Im along the right lines.

AM my reference was to the Roamer drive
The design of the box generates more heat than the standard gearbox
If I only have 10 degrees to play with then the elliptical gear train will have no hope in light of the amount of heat it will generate

TC ratios , Tyre sizes ,Diff ratios , loads and conditions, oils all have a bearing on TC temps .The gearbox stuff all with a direct drive no overdrive being the coolest


AM

AM the overdrive bolts onto the transfer case where the PTO would normally go
They also have a common oil supply
My point is for my conditions I should forget the overdrive

Interestingly the R380 was a constant 12 degrees cooler than the TC

Originally Posted by Sitec

Lower the ratio (higher speed) requires more torque to drive the box, and that increases the load thus increasing the temp... The old 1.667:1 box in a 2.5 diesel 110 was always cool as the vehicle was flat out at 90kph and had stuff all power.. The 1.003:1's always run hot as they are in a Range Rover being driven flat out with 100+hp at 120+kmh. Might be totally wrong with what I've said, but think Im along the right lines.

I think you have mixed up your ratio's and speed results.
If you put a higher ratio box or T/C in place of a lower one, then at any given speed under similar loads like hills ( before and after the box or T/C change ) you will be back a gear. So once you were in 4th , you are now in 3rd, ( unless you also increase your engine power significantly at the same time).I recently went from a lower to higher ( or taller ) ratio setup, 1.4:1 to 1.2:1 in the T/C and my real world result is that I have lost 1st gear and gained a 6th !
Once I might have gone down into 4th I now go down to 3rd so the load on the gears generating heat should be similar according to the above reference.
At the end of the day I think the biggest factor on heat build up is the 2.5 tons of scrap metal pushing a head of air with next to no help from aerodynamics.