New Auto Trannies

I don't think they (like most manufacturers) actually design any auto gearboxes - aren't they all bought in?

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?

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.

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

Cheers,

AJ

Reply to
AJ MacLeod
Loading thread data ...

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!

Reply to
LiFe

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.

Reply to
James Sweet

Reply to
Rob Guenther

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

Rob Guenther wrote:

Reply to
Marc Brack

Reply to
Rob Guenther

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.

Reply to
Marcel van der Stok

"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.

Reply to
LiFe

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

R. LiFe.

Reply to
LiFe

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.
Reply to
Stewart Hargrav

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

Reply to
Stewart Hargrav

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

Reply to
Bob Noble

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

formatting link

LiFe.

Reply to
LiFe

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.

Reply to
Stewart Hargrav

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.

Reply to
Mike F

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.

Reply to
Mike F

Right. For some reason I got the idea we were talking about autoboxes. Must have been the word 'auto' in the subject.

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??

Reply to
Stewart Hargrav

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

Reply to
Bob Noble

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.

Reply to
Stewart Hargrav

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.