LT230 Max Torque

[66gaza]

Does anyone know what the torque rating is for a LT230? thanks

Gaza

[Agrover]

I've never seen an official input torque rating listed, but I have known them to survive well behind 6.5 litre GM deisels and NV4500 transmissions in hard working 130's. On the other hand I have seen the odd one or two with stripped high range gears behind 300 TDI and R380's,(probably because of loose intermediate gear bearings) Can't remember the changeover period but later models had wider primary drive gears, and some later again had finecut gear teeth on the primary and high range gears which IMO sacrifices ultimate strength for quietness.
Bill.

Edit, I just read your UJ thread where your truck weighs 10500lbs. I think this exceeds the design limits of all the vehicles structural and transmission components by a large margin. Although the manufacturers max allowable gross combination mass may be a higher number than 10500lbs, the vehicles were never intended to be operated for extended periods at those limits, and certainly not offroad.IIRC you have tandem Salisbury rear axles, which should cope or be uprated to cope ok, but aside from the transfercase ,(I assume that along with the 6BT, you are replacing the LandRover main gearbox with something more appropriate)I'd be very concerned about putting the truck in a position where you may have to reverse uphill because the front diff/axle assembly unless it's a Salisbury with 101 CV joints is not going to like it.

[Dougal]

Are you worried about input or output torque?

Input torque is highest in 1st gear, high range.
Output torque depends on traction. With that much weight you'll have plenty.

I figured out for my LT230 that the torque to spin all four wheels on tarmac would be about 2400Nm on the output shaft (1:1 ratio, 2.3t truck, 3.54 diffs, 29" wheels) which is also 2400Nm on the input shaft.

For me with a 1st gear of 5.8:1, that's an engine torque of just over 400Nm.
So my max input and output torque are almost identical. Try to put more through from the engine and the wheels spin.

What's your high range, diff ratios and tyre size?

[66gaza]

Thanks for the replies. I used to have a 6.5 chevy diesel in it. I have a chevy NV4500 with an adaptor to a LT230. The NV4500 now has a dodge bell and I/P shaft, I personally wouldn't put a Landrover gearbox behind a chevy diesel let alone a cummins. It was fine for a couple of years untill a cracked head was the last straw and I decided to put a cummins in. All 3 axles are Salisburys. Chassis is 4mm thick and deeper in section than a standard chassis so I don't expect any problems. Agrover here is a link with some pics of my chassis, you might have to join to view them though http://www.4btswaps.com/forum/showthread.php?t=19
My LT230 is a freshly rebuilt I think its a mid 80's vintage with a 1:1003 ratio.
I plan on using synthetic lube and I have fitted a ribbed cover that also increases capacity hopefully this will let it run cooler.
I wasn't thinking of input or output torque just whether it will be OK behind a 6bt. The 1st gear is 5.6 the diffs are 3.54 and tyres are 33".
If I break it I will probably get a US tcase (not sure which one yet) hopefully I wont have to. I do like the look of the LOMAX one though.
I have just read about the 101 cv conversion sounds interesting.

Gaza

[Dougal]

With the same transfer box and ratios, but twice my weight and 14% bigger tyres you've got the potential for about 5500Nm twist on the output shafts.

Holy crap.

If your cummins will give 600Nm, then your input needs to take 3400Nm. That's pretty high too. I think the input adaptor shaft I'm getting made will take that, but it's hardened tool steel.

Most of the guys running heavy rigs and big tyres are using low ratio diffs and torqueless V8's. Looks like you can do my testing for me.:grinpimp: