Torque converters
Submitted: Saturday, Jul 26, 2014 at 12:42
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108889
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Seastar
Does any one have experience with torque converters. I am looking at fitting to a new 200 series diesel land cruiser, to help when towing my 3 ton caravan. I find trying to stay in six gear very difficult. I get about 22lites per 100 km. My van is off road so it is high to start with and I have a boat on top of the car. I drive when the conditions are OK to speed limit say 90 to 100 km per hr.
Is there any downside with them and do they help fuel efficiency.
Reply By: The Bantam - Saturday, Jul 26, 2014 at 12:51
Saturday, Jul 26, 2014 at 12:51
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
AnswerID:
536625
Reply By: garrycol - Saturday, Jul 26, 2014 at 13:16
Saturday, Jul 26, 2014 at 13:16
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
AnswerID:
536626
Follow Up By: Seastar - Saturday, Jul 26, 2014 at 19:22
Saturday, Jul 26, 2014 at 19:22
Garry you are correct I should have written a manual override switch that allows you to lock up, so it stays locked. I appreciate the 5and 6 gears are override, sometimes out west you get on very straight long roads and the smallest rise in the road can through it out.
FollowupID:
820831
Reply By: Athol W1 - Saturday, Jul 26, 2014 at 15:30
Saturday, Jul 26, 2014 at 15:30
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)
AnswerID:
536636
Follow Up By: Seastar - Saturday, Jul 26, 2014 at 19:54
Saturday, Jul 26, 2014 at 19:54
Athol Thanks for your reply you have given me a lot of good info and in away that has given me a better understanding of the issues.
FollowupID:
820832
Reply By: Ross M - Saturday, Jul 26, 2014 at 17:17
Saturday, Jul 26, 2014 at 17:17
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.
AnswerID:
536641
Follow Up By: garrycol - Saturday, Jul 26, 2014 at 17:22
Saturday, Jul 26, 2014 at 17:22
I thought I had already raised that above. :-).
Seastar has posted a followup but hasn't addressed the issues that you and I have posed.
Garry
FollowupID:
820826
Follow Up By: pop2jocem - Saturday, Jul 26, 2014 at 17:39
Saturday, Jul 26, 2014 at 17:39
I get the feeling from Seastar's query that either he has at best a nodding acquaintance with things mechanical or English is not his first language. Possibly both.
I think all the above posts have pretty
well summed up the best practice required. Hopefully they help.
Cheers
Pop
FollowupID:
820828