New Auto Trannies

  • Thread starter Thread starter AJ MacLeod
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AJ MacLeod

<misc rant> Volvo need to work on their damn autos.
Click to expand...

I don't think they (like most manufacturers) actually design any auto
gearboxes - aren't they all bought in?
All the japense makes have such silky autos you can't tell the
shift points. Many have CVT on their lower power cars.
Click to expand...

My 1993 850 with over 100k miles on it is every bit as smooth as a year
old Honda Accord. Haven't Volvo had CVT in the past with the 300
series?
Audi has CVT on normal powered cars and is roumered to be working on
higher power models - Probably have CVT in conjunction with AWD as well.
They also have their new DSG which is a crossover auto. Built like a
manual only it can engage two adjacent gears at the same time then shift
the clutches to transfer power seamlessly under full load.
Click to expand...

I've read about this. Very clever, I'm sure (although hardly
new.) Personally I think they'd be better off returning to the
type of quality components and build quality that went into their cars
about ten years ago. The original A4 had major problems with suspension
and brake components not even outlasting the warranty period and the
interiors of their cars show horrible signs of wear and broken mechanisms
after 20-30k miles of very light use.
Volvo have these crappy boxes that loose significant engine power. Blah!
Click to expand...

Don't buy one then :-) I like mine.

Cheers,

AJ
 
<misc rant> Volvo need to work on their damn autos.

All the japense makes have such silky autos you can't tell the shift points.
Many have CVT on their lower power cars.

Audi has CVT on normal powered cars and is roumered to be working on higher
power models - Probably have CVT in conjunction with AWD as well. They also
have their new DSG which is a crossover auto. Built like a manual only it
can engage two adjacent gears at the same time then shift the clutches to
transfer power seamlessly under full load.

Volvo have these crappy boxes that loose significant engine power. Blah!

</misc rant>
 
LiFe said:
<misc rant> Volvo need to work on their damn autos.

All the japense makes have such silky autos you can't tell the shift points.
Many have CVT on their lower power cars.

Audi has CVT on normal powered cars and is roumered to be working on higher
power models - Probably have CVT in conjunction with AWD as well. They also
have their new DSG which is a crossover auto. Built like a manual only it
can engage two adjacent gears at the same time then shift the clutches to
transfer power seamlessly under full load.

Volvo have these crappy boxes that loose significant engine power. Blah!

</misc rant>
Click to expand...

Which models are you talking about? The 240's and most 740's use a Japanese
auto gearbox, I'm not sure what the newer cars use but I don't think Volvo
builds the automatic on those either. Still there's an easy solution to
this, don't buy the slushbox in the first place, most models can still be
found with a manual gearbox that avoids all the problems of automatics.
 
The 4 speed GM tranny in the families 960 is smooth as silk as long as the
fluid changes are done... The trannies in the V70 2.4T's are quite buttery
smooth... what are you talking about?
 
Rob,6cyl 960's with autobox also have a japanese gearbox(aw30 43 aisin
warner)4cyl 16v turbo 960's have a aw72 and i think the turbodiesel had
a aw71 or a zf

only the s80 6cyl have a GM box



marc
4 x 960
1 x 74016v
1 x tatra613-4
 
Hmm... perhaps I should read the owners manual and not something from
another source.
 
Funny that LiFe mentions CVT as an example of the superiority of Japanese
gearboxes. CVT was invented by a Dutch company - either DAF or Van Doorne,
I forget - and early versions were fitted in DAF cars since 1960 or so. The
owner of DAF in the 70's & 80's? Volvo. Volvo used CVT's in the 300
series.
 
"All the problems of automatics"? See thing I like about autos? Do them
right and there's no problems.

Got an S40T in the family and while it's smooth, it's sluggish and very
hesitant to kick down unless in S mode (which shouldn't be neccessary). It's
also not nearly as fast, precise and smooth as our cheaper camry's auto
which is so silky it's quite stunning.

The latest R series have shoddy autos that sap power. Sticking a DSG in them
might improve things considerably : )

LiFe.
 
But they have been unable to make CVT scale to higher powered cars?

R.
LiFe.
 
Because there's more to the internet than hits alone, Marcel van der
Stok said:
CVT was invented by a Dutch company - either DAF or Van Doorne,
I forget - and early versions were fitted in DAF cars since 1960 or so.
Click to expand...

My grandfather used to tell me about a car he had with CVT. Would
probably have been in the 20s or 30s.

My recollection of how he described its workings involved two friction
wheels at right angles to each other, with one able to move radially
in relation to the other, thus effecting continuously variable ratios.
A little different to the DAF version, but still employing the device
of picking up the drive from an ever changing output diameter. Thus
the invention of CVT pre dates the 60s by a considerable margin.

Any motoring historians able to say what car that would have been? It
*may* have been a Jowett.


--

Stewart Hargrave

I run on beans - laser beans


For email, replace 'SpamOnlyToHere' with my name
 
it can engage two adjacent gears at the same time then shift the clutches to
transfer power seamlessly under full load.
Click to expand...

Hmm... that sounds strangely similar to how any other autobox works.


--

Stewart Hargrave

I run on beans - laser beans


For email, replace 'SpamOnlyToHere' with my name
 
It's been years since Aisin (that's Japan) first licensed and later
bought the rights to manufacture the old Borg-Warner auto trannies.
Talk about making a silk purse out of a sow's ear!!

Both of our Volvo's (98 V70XC and 02 S60AWD) are fitted with the Aisin -
no complaints, though the S60 is clearly better. Part of the shifting
smoothness on the later boxes is the drive-by-wire throttle, with
clearly apparent lightening of the throttle during shifts on moderate
acceleration from rest.

When checking out the Porsche Cayenne, I was interested to see that
they, too, use the Aisin box. That must give the Porsche purists a real
twist in their knickers - V8 engine (first since the 928?) powered SUV
with a Japanese tranny. What next?! But, really, isn't that what the
Global Marketplace is really all about . . .

bob noble
Reno, NV, USA
 
Nope. An ordinary auto has to diengage one gear, shift into another, and
then engage. And during the process (AFAIK) throttle is reduced to aid the
process. Fast and often silky but not instant.

DSG has both gears engaged at the same time. Articles are all on
www.audiworld.com.

LiFe.
 
Nope. An ordinary auto has to diengage one gear, shift into another, and
then engage.
Click to expand...

Nope. Whoever told you this is talking nonsense. In an ordinary
autobox, in no sense do gears 'disengage' and 'shift into another'.
You change ratios by a configuration of clutches and brakebands, and
the quality of 'seamlessness' is a function of the control of these.
Enter 'epicyclic' into Google for more info.

There have, historically, been attempts to make automatic versions of
a manual gearbox, but even these required clutches of some form to
control the input in an attempt to produce seamless changes.

Seamlessness through clutches is standard.
And during the process (AFAIK) throttle is reduced to aid the
process.
Click to expand...

Varying the throttle input is an option on drive-by-wire setups. In
'high-end' cars (where it seems to matter) the potential of this has
revolutionised how gear changes can be made.





--

Stewart Hargrave

I run on beans - laser beans


For email, replace 'SpamOnlyToHere' with my name
 
Stewart said:
Nope. Whoever told you this is talking nonsense. In an ordinary
autobox, in no sense do gears 'disengage' and 'shift into another'.
You change ratios by a configuration of clutches and brakebands, and
the quality of 'seamlessness' is a function of the control of these.
Enter 'epicyclic' into Google for more info.

There have, historically, been attempts to make automatic versions of
a manual gearbox, but even these required clutches of some form to
control the input in an attempt to produce seamless changes.

Seamlessness through clutches is standard.


Varying the throttle input is an option on drive-by-wire setups. In
'high-end' cars (where it seems to matter) the potential of this has
revolutionised how gear changes can be made.

--

Stewart Hargrave

I run on beans - laser beans

For email, replace 'SpamOnlyToHere' with my name
Click to expand...

This Audi transmission is a manual style transmission with 2 clutches
and 2 input shafts. One set does the odd gears, the other the even
ones. The computer "thinks" about which way you're likely to shift, and
engages that (higher or lower) gear, with that clutch disengaged. When
you hit the shift lever, the one clutch disengages, the other engages,
and off you go. If you go the other direction, then the transmission
has to shift before disengaging and engaging the clutches, which takes a
little longer.

--
Mike F.
Thornhill (near Toronto), Ont.

NOTE: new address!!
Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)
 
Stewart said:
My grandfather used to tell me about a car he had with CVT. Would
probably have been in the 20s or 30s.

My recollection of how he described its workings involved two friction
wheels at right angles to each other, with one able to move radially
in relation to the other, thus effecting continuously variable ratios.
A little different to the DAF version, but still employing the device
of picking up the drive from an ever changing output diameter. Thus
the invention of CVT pre dates the 60s by a considerable margin.

Any motoring historians able to say what car that would have been? It
*may* have been a Jowett.

--

Stewart Hargrave

I run on beans - laser beans

For email, replace 'SpamOnlyToHere' with my name
Click to expand...

That's exactly how the "transmission" on my neighbour's snowblower works
- although of course it's not automatic - there's a shift gate with 6
discreet positions. Moving the driven wheel over the center to the
other side of the driving wheel turns turns the driven wheel the other
way - thus giving you reverse.

--
Mike F.
Thornhill (near Toronto), Ont.

NOTE: new address!!
Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)
 
Because there's more to the internet than hits alone, Mike F wrote:

This Audi transmission is a manual style transmission with 2 clutches
and 2 input shafts.
Click to expand...

Right. For some reason I got the idea we were talking about autoboxes.
Must have been the word 'auto' in the subject.
One set does the odd gears, the other the even
ones. The computer "thinks" about which way you're likely to shift, and
engages that (higher or lower) gear, with that clutch disengaged. When
you hit the shift lever, the one clutch disengages, the other engages,
and off you go. If you go the other direction, then the transmission
has to shift before disengaging and engaging the clutches, which takes a
little longer.
Click to expand...

Very clever. I'm put in mind of the pre-selector gearboxes first found
on Lanchesters and then Daimlers. I once briefly drove a Daimler bus
that had one. At the time I'm sure it was the hight of sophistication
(and later developed into the fully automatic box), but I never could
figure out what the point of it was.

For those who are not familiar with it, you selected the gear you
wanted to change to *before* you needed it by moving a lever. Then at
the appropriate time you depressed the 'clutch pedal' and the change
was completed.

But why??



--

Stewart Hargrave

I run on beans - laser beans


For email, replace 'SpamOnlyToHere' with my name
 
Today's class in Auto History and Practice 101:

I'm not personally familiar with any of the European pre-selector
transmissions but have driven '30's American cars fitted with the Bendix
"Electric Hand" version of pre-selection. The users that I know of were
Cord, Hudson and Packard. Doubtless there were others - all now known
to the Encyclopedia readers only.

These cars featured a column mounted miniature "barrel" with a stubby
gear selector that could be moved to the now conventional gates. The
lever could be moved to any gear at any time, with the actual shift made
by a vacuum cylinder for the long axial throw and electro magnets for
the shorter lateral throws. Not super fast, but convenient and
effective.

Unfortunately, the system was prone to electrical problems which weren't
the flash and smoke variety, but tended to run the battery down when the
car sat for 8-10 hours. GM had introduced hydramatic in the Oldsmobile
('38? '39?) at a point where Bendix might have made further
improvements. Obviously, there was no reason to continue in the face of
a real automatic. Cord, with the transmission in the nose of the car,
was the only marque that really benefited from a "shift by wire" box, so
their death was likely a contributor to the death of the electric hand.

bob noble
Reno, NV, USA
 
Because there's more to the internet than hits alone, Bob Noble
wrote:

These cars featured a column mounted miniature "barrel" with a stubby
gear selector that could be moved to the now conventional gates. The
lever could be moved to any gear at any time, with the actual shift made
by a vacuum cylinder for the long axial throw and electro magnets for
the shorter lateral throws. Not super fast, but convenient and
effective.
Click to expand...

This sounds remarkably similar to a system on use on public buses here
in the UK until very recently - may still be used on some.



The most unlikley auto box system I heard of (never encountered first
hand, but read about in a workshop manual) was by Renault, sometime in
the 60s. IIRC the box was a normal gate-shift, operated by servos of
some sort (though I can't remember how these were governed). But the
'clutch' was a piece of science friction (geddit?!?); it was a drum
stuffed with iron filings with a big electromagnet wrapped around it,
bolted to the flywheel. The output shaft (which may have had vanes or
splines) came out of the back of it as per usual. When the
electromagnet was turned off the drum could rotate without
transmitting drive to the output shaft; turn the magnet on and the
iron filings apparently locked together, resulting in drive.

It's unlikely that a car of that era would have had an alternator so I
bet it put a strain on the charging system.


--

Stewart Hargrave

I run on beans - laser beans


For email, replace 'SpamOnlyToHere' with my name
 
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