Towing

for starters Id forgoten about the sports mode thing.... yep thats a good idea especially for freeway running (up to say 85-90kph) and on slight "hills" sports mode basically puts the box into "power to the ground NOW" mode. so it will hold the lower gears for longer but still change up to the tall gears when very low engine torque numbers are required. It will also change down more aggressively.

I still recommend locking it back to 3rd for big climbs or if your going to be toodling round the burbs as it will stop the box from going up into fourth on the over run which will increase your ability to engine brake which saves on normal brakes and IMHO is a much better way to be driving.

for grumpy.

I dont know who told you that the lockup for the gears was in the box its all done in the torque converter. ITs basically a clutch in the TC that when the box decides that engine speed is near enough to gearbox speed input speed that the 2 primary rotating parts of the TC can be locked together because the TC is basically just wasting energy.

i have produced an overspeed fault manually shifting downhill whilst towing in 3rd and being pushed by a loaded float, just use the magic button it's safer.

Quote:

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Originally Posted by feral

And a chipped Td5 is better again. It adds a whole new layer of functionality. More power, more torque and it will give you the ability to stay locked in 4th longer without hunting for a gear or undue labouring of the engine.

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One dealer told me that a chipped TD5 runs hotter.Is that true?
John.

your not supposed to down shift it out of third...

you put it in 3rd climb the hill then leave it in third or....

your supposed to slow down using the brakes and then when the vehicles speed is low enough to accept a down shift then shift it down to a lower gear.

sort of like...

be in the correct gear for the upcoming terrain before you get there.
tighten up the wheelnuts.
dont snatch on the rust mounted bull bar
dont attempt to out do canaveral in a D2.

you know common sense stuff... :p

I have a chipped Disco two TD5 Auto and tow a 18ft dual wheel jayco and would never consider using anything than 3rd gear.
Any higher is an overdrive ratio and puts to much strain on the transmission,this applies to other makes of Autos also (Nissan patrols for example).
You could slip into 4th on downhills,but my advice from specialists is to use 3rd which also keeps the oil circulating faster and prevents overheating plus minimises transmission loadings.
Regards

Flaming heck....the fuel bill must be enormous or you putt 'round at 70kph.:o


That certainly has not been my experience.

I have posted this information before and the results were staggering. I had to tow my van @ 1400kg from Coff's to Melbourne with a pressurized headgasket. It was found that if I sat at 80 kph it would last longer before stopping to check coolant levels. It would only spit out the coolant and not overheat.

Now I have a Madman which is an engine monitoring system. It monitors water temp and auto temp amongst other things. With the pressurized head and travelling at 80 kph, water temps stayed normal but the auto temp sat around 88 degrees. The auto temp is the same as if I was in start/stop traffic.

Before the car had its problem and after it was all fixed the auto temp sits at about 44 degrees travelling at 100kph. This is 4th converter locked.

This is normal operating temperature. I know what gear and speed I would rather be doing.

Absolutely. The TC needs to be locked otherwise it is producing heat. That can happen at about 80km/h in 4th. I cant recall where lockup is in 3rd, 60km/h or something.

Anyway, its not 3rd and 4th that are the worry from my experiences with the ZF, its 1st notably and 2nd.

I used to have a V6 frontera years ago.When the tranny on that got warm it used to just lock the TC while trying to drop the temps.

Today while driving home from Sydney along the freeway towing my camper in sport mode it would come out of lockup in 4th at about 100kph, then drop back to 3rd and almost instantly go to lockup at about 90kph and I held 90kph in 3rd lockup on every hill between Sydney and the Freemans drive turnoff.

Quote:

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Originally Posted by Blknight.aus

your not supposed to down shift it out of third...

you put it in 3rd climb the hill then leave it in third or....

your supposed to slow down using the brakes and then when the vehicles speed is low enough to accept a down shift then shift it down to a lower gear.

sort of like...

be in the correct gear for the upcoming terrain before you get there.
tighten up the wheelnuts.
dont snatch on the rust mounted bull bar
dont attempt to out do canaveral in a D2.

you know common sense stuff... :p

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Who me?

I was

With brakes hot and squealing and trailer pushing down hill to the extent that the car was picking up speed rapidly, I had shifted the car to 3rd at a sensible speed but still got pushed enough to produce a momentary overspeed. The car got new brakes the next day.

Quote:

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Originally Posted by Blknight.aus

for starters Id forgoten about the sports mode thing.... yep thats a good idea especially for freeway running (up to say 85-90kph) and on slight "hills" sports mode basically puts the box into "power to the ground NOW" mode. so it will hold the lower gears for longer but still change up to the tall gears when very low engine torque numbers are required. It will also change down more aggressively.

I still recommend locking it back to 3rd for big climbs or if your going to be toodling round the burbs as it will stop the box from going up into fourth on the over run which will increase your ability to engine brake which saves on normal brakes and IMHO is a much better way to be driving.

for grumpy.

I dont know who told you that the lockup for the gears was in the box its all done in the torque converter. ITs basically a clutch in the TC that when the box decides that engine speed is near enough to gearbox speed input speed that the 2 primary rotating parts of the TC can be locked together because the TC is basically just wasting energy.

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There is another thread somewhere that relates to my original problems.
This current thread of mine was wrongly worded. The blokes who originally overhauled the box insinuated they were ZF agents. They were the ones who told me that third was locked in the box and fourth in the TC. Did not quite make sense to me but, who am I.
It wasnt until I rang the ZF office over here in Perth that I found where the true agents were. Took the vehicle to them with my sob story and the problems are well and truely fixed and only cost me $300 towards their Xmas party. :angel: The other mob are footing the bulk of it about $3500.

Incidently Feral, Did a tow test over 1200km in third and there was very little difference in consumption to what I get in fourth. The whole trip was close on 2200km. In fact, sometimes it was a little better?

Tony :wheelchair: [Grumpy]