Torque converters

Why do you particularly want to stay in sixth gear?

Being in higher gear may not improve your economy.

What you want is to be on the top of your power/torque curve, that is where the economy is in a diesel.

If that happens to be in other than top gear......don't worry about it.

Have a search around ....you should find a power and torque curve for a 200 series somewhere....the diesel chip sites are a good suspects.

then look at the power torque curve and your tacho...unless you are coasting down hill you need to be right on the top of that power/torque curve.......

Remember upper gears are in general overdrives.....don't expect to stay in an overdrive gear when towing.

cheers

Sorry I am a bit confused by your post - I assume you have an automatic so you already have a torque converter. So what are you asking?

Is there a better torque converter you can fit?

Do you want to fit a manual override on the torque converter lock up so it stays locked?

As Bantam says you are better off not towing in 6th anyway. If you leave it in drive the gearbox will always pick the best gear for the load but in some circumstances will hunt between gears and will change into 6th when load is low like coasting downhill. Manually putting it in 5th for flat highway use is probably best though don't forget to change down gears when required.

Do you have "sport" mode on your gearbox as this is really good for towing as it hangs on to lower gears a bit more and will rarely get up to 6th.

Towing 3 tonne - you do not want to be anywhere near 6th except for going down hill.

Garry

AS others have said you should use sports mode when towing with a LC200. They have a good torque converter adeqaute for towing upo to 3.5tonnes. Our van is just under 3 tonnes but we consistently achieve 19litres/100km when towing. The torque converter when locked produces less heat. In S4 it is unlocked below 80KPH and in S5 it is unlocked below 100kph. Very rarely if ever did we tow in S6. We achieved 19 litres/100km using S4 and S5 consistently. It pulls sweetly in S4 and S5 over all types of terrain. Cheers.

Get a Scangauge. Set it up to show Transmission temp.

Tow in S4.

Seastar
I agree with all the above posts, if you have a 200 series TTD then 6th gear is only used for very light work and then only when above 103 kph.

With what you are carrying and towing I would not expect to ever see 6th gear at any speed unless travelling down a mineshaft.

I have a similar vehicle towing a 23 ft van (2.8 tonnes) with nothing on the roof and only ever use S5 or S4 when towing, my fuel consumption varies from around 18l/100k in good conditions to 22l/100k when travelling into strong headwinds (S4 and still at 100kph on the Stuart Highway with trans temp around 70 deg with convertor clutch locked and 2350RPM when the same conditions in S5 would not allow for convertor clutch lockup resulting in trans temps around 125deg and 2500RPM)

As said above get a Scangauge 11 and monitor your transmission temps, also monitor your instant fuel consumption and you will find that it can be better to be in S4 for both reasons. Also fit an additional transmission cooler, as the life of any auto transmission is doubled for every 10 degrees that its temperature is reduced.

Also in the 200TTD 5th gear is an overdrive gear, 4th gear is the direct drive gear through the transmission, and therefore generating the least amount of heat.

Forced use of 6th gear at insufficient road and engine speeds will destroy your transmission (cause gear breakages), and possibly also the engine (piston skirt breakage) due to lugging.

Hope this helps.
Athol (retired motor mechanic)

Why not look at the torque converter lock up switch mod where you can manually lock the torque converter.

The 200 series derates engine power if under excessive load for to long.

i am gueesing here but have put larger than std wheels and tyres on you 200 sreies as this will cause aproblem when towing and not when you are not towing just a thought

No one has yet understood what the OP understands.
If an auto it already had a torque converter and you can't fit another another as well.
It is o the original or a replacement.

Seastar.

What do you mean by fitting one to the 200. Best we establish that first.
All the info can be good but may be confusing depending on the understanding of the owner.

Mate don't take this the wrong way but have a think for a minute about what your towing it's a 3 t van shaped like a brick and combined with your vehicle you would probable be pushing nearly 6 t loaded. Your getting 22lph I would call that outstanding seriously I don't know your towing history but it's a common story that people can't understand why they use more fuel when they have a heavy 4WD towing a big heavy van. As for towing in top gear I would seriously do some reasearch about that and don't be led astray by the wrong people or dodgy sales men like I was I know in a manual box 4th is the strongest I'm not sure about the new auto boxes but if you persist you could end up doing thousands of dollars worth of damage. I had a TD5 disco 5 speed manual and was told by the salesman you can easily tow 2,500kg in 5th gear I was only towing around 1.4t and ruined the gearbox which cost me $3,500 to fix 9 yrs ago I would hate to see the bill to fix a new auto.

I have to agree with Batt. 22L per 100 is good for what you are trying to do. I think your biggest problem is aerodynamics -- you haven't got any. The big van, the boat and the size and shape of the car are all against you. Try an experiment by doing a couple of hundred ks at a constant 60 kph on a day with no wind. The consumption should drop through the floor. A speed reduction might be the only way you are going to see a noticeable reduction in fuel consumption.