Modern Cruiser problems

[Guest]

John
You can only tow and auto a limited distance at low speed, even in "N",
because the pumping action that normally circulates the oil in the auto
box and cools it down will not be working and it will over-heat.
A manual box, in neutral, can be towed any distance because it doesn't
need to be cooled.
I'm told you can start an auto by towing ... if you go fast enough to
spin the torque converter, but it's not an experiment I'd like to try!
Because of my preference for manuals (!) I haven't had to locate the
dreaded brake-light fuse, but in my fuse box the brake lights are fused
by "Fuse 4 STOP 10A" in the box by my right knee. The auto may be
different.
CB
| Hi Guys
| Can somone tell me why you cant tow an Auto, what is the difference
between
| a manual in neutral and an auto in N. Also where is this fuse or
solenode .
| cheers
| john 92HDJ 80 1HDT
| SNIP
| I know I'm in a minority of one here, but if I were heading into the
| back of beyond I would *much* prefer my manual simply because the
| chances of starting it with a dead battery or starter motor are so
much
| better; and if it had real problems then towing it long distances
would
| not be an issue.
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[Guest]

Hi Christopher,
I would be surprised about that for the 80's box - once in neutral there
doesn't appear to be any resistance from the auto box.
--
Regards,
Julian Voelcker
07971 540 362
Skype: julianvoelcker
Cirencester, United Kingdom
1994 HDJ80, 2.5" OME Lift

 

[Guest]

Hi Christopher,
I would be surprised about that for the 80's box - once in neutral there
doesn't appear to be any resistance from the auto box.
--
Regards,
Julian Voelcker
07971 540 362
Skype: julianvoelcker
Cirencester, United Kingdom
1994 HDJ80, 2.5" OME Lift

 

[Guest]

Hi Christopher
Thanks for that.
But I have another question or two.
So a manual box only needs oil to lubricate and not cool is that correct.
An auto box needs the ATF to cool as well as lubricate is that correct.
So an auto box needs to be cooled even when the engine is not running if the
wheels are turning is that correct.
So is an auto and a manual box still working in some way when the engine is
off but the wheels are turning.
What is it about the auto box that makes it generate heat compared to the
manual.
I have to ask because as per usual I have no idea what either looks like
inside so need to ask.
cheers
john92HDJ 80 1HDT
SNIP
You can only tow and auto a limited distance at low speed, even in "N",
because the pumping action that normally circulates the oil in the auto
box and cools it down will not be working and it will over-heat.
A manual box, in neutral, can be towed any distance because it doesn't
need to be cooled.
I'm told you can start an auto by towing ... if you go fast enough to
spin the torque converter, but it's not an experiment I'd like to try!

 

[Guest]

Julian
Well maybe I'm wrong, but I always understood that the output shaft from
the wheels was still turning its side of the gearbox, stirring the oil
and creating heat; whereas the oil circulation pump was driven off the
input shaft from the engine.
So towing, even in "N", will stir the oil, creating heat, and therefore
the thing will over-heat fairly quickly.
CB
| -----Original Message-----
| From: [Email address removed]
[mailto:[Email address removed]] On Behalf Of Julian
| Voelcker
| Sent: 26 September 2007 16:00
| To: [Email address removed]
| Subject: Re: [ELCO] Modern Cruiser problems
|
| Hi Christopher,
|
| > You can only tow and auto a limited distance at low speed, even in
"N",
| > because the pumping action that normally circulates the oil in the
auto
| > box and cools it down will not be working and it will over-heat.
|
| I would be surprised about that for the 80's box - once in neutral
there
| doesn't appear to be any resistance from the auto box.
| --
| Regards,
|
| Julian Voelcker
| 07971 540 362
| Skype: julianvoelcker
| Cirencester, United Kingdom
| 1994 HDJ80, 2.5" OME Lift
|
|
| --
| European Land Cruiser Owners Mailing List
| Further Info: http://www.landcruisers.info/lists/
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[Guest]

CB
RE> So towing, even in "N", will stir the oil, creating heat, and
therefore the thing will over-heat fairly quickly.
Ties in with why the Haynes manual recommends limited towing distances
only
Niall

 

[Guest]

Niall
| Ties in with why the Haynes manual recommends limited towing distances
| only
I've often wondered if this really holds true in a vehicle with a hi/lo
transfer case downstream of the gearbox.
If you put that in "N" then the wheels shouldn't be turning the output
shaft of the auto box, so all should be well.
I would hate to find out the hard way that I was wrong though!
CB
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[Guest]

John
You've got it right: in a manual box all the oil does is lubricate the
gears and carry away the (relatively small) amount of heat generated as
the cogs slide over one another. They just rely on "splash" lubrication,
and don't require oil circulation pumps.
In an auto box the torque converter, which is a bit like two propellors
(impellors) in an oil bath, transmits all the power of the engine from
the input impellor to the output one via the ATF. Inevitably this
creates some turbulence in the ATF, and also "drag" as the ATF flows
through all the passages and blades, all of which means heat. It also
lubricates the cogs as in a manual box, but the heat from that is
minimal in comparison.
When you sit at the lights with the thing in "D", and your foot on the
brake, then ALL the power of the engine coming through to the box is
turned into heat. I don't know how many horsepower that is, but look
at it this way:
1 horsepower =3D 760 watts, or about 3/4 of a kilowatt, ie 3/4 of a bar of
an electric fire.
So if your engine is pushing - say - 2 or 3 horsepower into the box at
stationary idle that's like having a two bar electric fire in there
heating it up!
And when you accelerate away in low gear you are pushing loads more heat
into it as the engine spins fast but the wheels turn slowly until,
eventually, the road speed catches up with the engine speed and the
speed difference across the torque converter becomes relatively small
again. OK, it changes gear along the way, but the same process occurs
in each gear.
Auto gearboxes have a torque converter "lock up" in top gear to take
this stage further: this locks the input and output impellors so that
there is no speed difference. It's done to save heat, ie energy loss,
and hence increase efficiency.
The general advice if you are going to do a lot of towing with an auto
box is to fit an extra oil cooler. This is because not only will you be
passing more power through the box, but also acceleration with a heavy
load will be much slower, so the torque converter will spend more time
in the "high slip" fast input, slow output regime.
It also (in my view) explains why the auto 80 series consistently uses
more fuel than the manual, despite a TC lock-up in high gear and gearing
that gives lower engine revs vs road speed in top gear. Every time you
accelerate your 2.5 tons of J o'B + 80 series you are in that "high
slip" regime and burning fuel as heat, whereas I don't have any slip ...
although I do tend to be out-dragged by geriatric snails!
Torque converters are quite interesting beasts in themselves. The
mental model of input and output propellors in an oil bath is a huge
over-simplification because in fact you want one piece of kit to do two
different jobs at different times:
(1) When you accelerate away you want to convert high speed / low torque
input from the engine into low speed / high torque output to the wheels.
This is true "torque conversion", and it explains why auto box users
rarely use low range - they don't need it, whereas we manual types do in
order to hill start a 3 ton trailer on a steep hill without burning out
the clutch.
(2) But when you reach constant cruising speed you want more of a "fluid
clutch" effect that just transmits the power straight through with
little or no change of speed or torque conversion, and in fact torque
converter lock-up is a logical extension of this aim.
It's easy to design either (1) or (2), but rather trickier to design
something that switches from one to the other, and torque converters in
car auto boxes are inevitably something of a compromise between the two.
Sorry, quite long, but I hope it makes sense.
CB
| Hi Christopher
| Thanks for that.
| But I have another question or two.
| So a manual box only needs oil to lubricate and not cool is that
correct.
| An auto box needs the ATF to cool as well as lubricate is that
correct.
| So an auto box needs to be cooled even when the engine is not running
if the
| wheels are turning is that correct.
| So is an auto and a manual box still working in some way when the
engine is
| off but the wheels are turning.
| What is it about the auto box that makes it generate heat compared to
the
| manual.
| I have to ask because as per usual I have no idea what either looks
like
| inside so need to ask.
| cheers
| john92HDJ 80 1HDT
|
| SNIP
| You can only tow and auto a limited distance at low speed, even in
"N",
| because the pumping action that normally circulates the oil in the
auto
| box and cools it down will not be working and it will over-heat.
|
| A manual box, in neutral, can be towed any distance because it doesn't
| need to be cooled.
|
|
| I'm told you can start an auto by towing ... if you go fast enough to
| spin the torque converter, but it's not an experiment I'd like to try!
|
|
|
| --
| European Land Cruiser Owners Mailing List
| Further Info: http://www.landcruisers.info/lists/
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[Guest]

CB
RE> I would hate to find out the hard way that I was wrong though!
I wonder if the AT temp warning light would go on? - Assuming there was
juice in the battery
Cheers
Niall

 

[Guest]

Hi Christopher,
Actually, I wonder if putting the transfer case in neutral would avoid
the heat problems - then there shouldn't in theory be anything in the
auto box turning.
--
Regards,
Julian Voelcker
07971 540 362
Skype: julianvoelcker
Cirencester, United Kingdom
1994 HDJ80, 2.5" OME Lift

 

[Guest]

Hi Christopher,
Actually, I wonder if putting the transfer case in neutral would avoid
the heat problems - then there shouldn't in theory be anything in the
auto box turning.
--
Regards,
Julian Voelcker
07971 540 362
Skype: julianvoelcker
Cirencester, United Kingdom
1994 HDJ80, 2.5" OME Lift

 

[Guest]

Hi guys,
Actually, here is the standard procedure for towing on all four
wheels, as described in the user manual:
Do not tow faster than 30 mph (40 km/h) and at a distance greater than
50miles (80 km)
A/T Lever Position - NEUTRAL
High/Low Range Lever Position - NEUTRAL
Additional remark: towing with the front wheels on a dolly must not
be used because there is a danger of the drive train heating up and
causing damage
--
Rgds,
Roman (London, UK)
'92 HDJ80 (auto)
On 9/26/07, Julian Voelcker <[Email address removed]> wrote:

 

[Guest]

Hi Christopher
Thanks a lot for that explanation, ill read it a few times as usual.
Never too long can an answer be if it gives the correct information that was
asked for in the first place.
So it would seem best not to have the cruiser in D while at traffic lights.
You mention engine speed V road speed, so is it good to take off slowly or
quickly for the auto box.
Is the ATF thinner than the manual gear oil because it has smaller places to
get to or it carries heat better.
cheers
john 92HDJ 80 1HDT
SNIP
When you sit at the lights with the thing in "D", and your foot on the
brake, then ALL the power of the engine coming through to the box is
turned into heat.
And when you accelerate away in low gear you are pushing loads more heat
into it as the engine spins fast but the wheels turn slowly until,
eventually, the road speed catches up with the engine speed and the
speed difference across the torque converter becomes relatively small

 

[Guest]

John
| You mention engine speed V road speed, so is it good to take off
slowly or
| quickly for the auto box.
Only if you want to. The gearbox is designed to take the heat this
generates, so it won't hurt it, although gentler acceleration will save
you fuel. Add a 3 ton trailer though, and you will eventually cook your
ATF fluid unless you fit an extra cooler.
| Is the ATF thinner than the manual gear oil because it has smaller
places to
| get to or it carries heat better.
I don't know! "Ordinary" gearbox oil is pretty viscous stuff (75w90 is
recommended), and I think it would be too viscous ("sticky") to flow
through the passages in an auto box. Also ATF must, as you say, take a
large amount of heat.
I read somewhere that the original ATF fluid, (I'm talking 1940's and
50's here) contained a significant amount of sperm whale oil, and that
when this was banned it took a long time to find a synthetic substitute
that worked as well. I've no idea if it is true or not.
CB
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[Guest]

Well, thanks all for the feedback on the modern cruisers.
Have been reading the threads a bit more closely now about all the other
problems you lot seem to have with them. Do they really fit timing belts
(yuck) on the modern engines instead of good old gears
The old HJ60 is doing me well for the moment, and from what I have been
reading, I think I will try and keep the body shell hanging on to the
chassis a bit longer.
Anyone know of a kit car body that is designed for the HJ60?
Neil