Variomatic - low gear hold switch

[Vario Si]

I've just come back from the girlfriends, and I think I left the low gear hold switch on after being in some traffic on the M3, about 40 miles later when parking at home I realisedit was still on!

I'm unsure whether this low gear hold is functioning, as the revs seem to match normal driving! Although it does feel somewhat different to drives, I would of thought the rev difference would of been noticable?

Is there any way to test whether this is correctly working!?

Cheers

Simon

[bodejodel]

You should notice an obvious rev change when it is turned on...

[foggyjames]

Low gear hold is like NOS!!!!11

cheers

James

[bodejodel]

Indeed. It does not work very well in my Daf, but in the Daf of a friend of mine (antiekeradio on V3M) it works very well.
His Daf 55 Coupé with slightly tuned B14.4 is almost as quick as my 360...
It just keeps on pulling untill the speedo goes off the scale! (160+km/h)
With the low gear hold turned on it rips the asphalt off of the street...

[Vario Si]

Foggy, "Low gear hold is like NOS!!!" ???

Well, I don't seem to notice any difference, the bulb inside the switch illuminates (and causes the switch to get hot!)... but no affect?

No ideas how to test whether this mechanism is working, like something clicking under the bonnet - as mentioned for other tests on the vario..?

Cheers

Simon

[foggyjames]

Must be a newish bulb if it gets hot.

I was joking...it's more like VTEC y0 anyway

Try shooting Will a PM - he's unlikely to find the thread by accident. Do you have a Haynes manual....does that give any info? I can look in mine if you don't have one....but get one

cheers

James

[Vario Si]

Well I once again found the site which I remembered, that mentioned testing various tips for the CVT.

http://www.volvoclub.org.uk/66reg.shtml (last section)

As on that page, I hear a click when I press the brake pedal firmly, when the accelerator is pressed to the floor and when I switch the low ratio hold button.

Which indicates that's all working...

Hmm...

[foggyjames]

The click is presumably a relay? So let's say you're doing...30mph...on the flat, no gas, it'll normally be in a high gear ratio...ie: low revs, right? What happens if you hit the switch then....nothing? It ought to dial in at least 3000rpm I'd say.

cheers

James

[antiekeradio]

probably the click you hear is in fact two clicks at the same time. confirm that both the small black box near the EMVK (tacho relay) AND the EMVK itself are clicking when doing either of the 3 things you mentioned.

if this is OK, that only indicates the electrical part is all right.

the vacuum side of the story is not tested yet.


you can test the 'EMVK' which is the double electrical vacuum valve, located near the fusebox. (white plastic with 4 wires and a host of vacuum tubing)

by pulling off the 2 small diameter hoses that come out of the valve in parrallel.
the hoses run to the bottom of the car (to the vario)

with engine running, switch on the low-gear-hold-switch. one of the connections should be sucking now!

probably it will not... if its OK, put a hose on the other one, and put it in your ear while revving the engine just above 2000 rpm (not too much throttle) you should also hear the suction, when the engine is above 1850.


fault found; replace EMVK (keep the old one for me plz )
not found; continue...

take the 2 hoses running to the bottom of the car, blow in one of them. you should feel a building resistance, and it should sigh back at you when you release the pressure.

if the air comes out of the other hose without resistance, you should change the membranes a.s.a.p. is not só difficult.

if one hose works OK but the other has no resistance, there is a loose one under the car near the vario.


good luck, wouter

[Vario Si]

I know kick-down works - you feel the jerk as it takes affect... would that mean those hoses and EMVK are okay, or not necesarily?

If not, I'll do as you say!

Cheers

Simon

[wjp01908]

Hi Si - got your PM and in answer to your question, yes, the low hold does make quite a substantial difference on my car. If kickdown works then chances are that the low hold works too - the switch basically enegises the change down solenoid as kick down does. I would check the valve as suggested as well as the vacumm hoses as described above.

I don`t actually use the low hold much - mostly when I want to hold the speed down on engine braking, down a hill in a 30 for example - but as I say you really notice the difference when it`s on

Let me know how you get on with your checks

Will

[antiekeradio]

if kickdown really works you would notice more than just a jerk.

due to higher engine torque, the revs will go up, even without working kickdown. with kickdown in action, the revs rise a lot more
on a correctly working vehicle, you can test this by stepping the accelerator up to just before you feel a heavier resistance. notice the revs, and do it again, stepping through the heavier resistance.

on my daf I have mounted a vacuum buffer, wich provides some extra vacuum for kickdown.

fastest acceleration times can be achieved by switching on the low gear holding switch first, throttle a bit, then give full throttle (with weber; full throttle in 2 stages with small pauze) revs will be at or above redline during the entire 0-60 mph. with me and jeroen in it, 0-60 was around 12,5 sec. nothing compared to modern day fast cars, but you will easily win most 'traffic light grand prix' spurts.
normal traffic (stick shifting suckers) _never_ reaches its specified 0-60 times, on a vario you can just floor it and look at the other guy working, but still falling behind at every shift.

uh, well. most cars, that is. at least the same ones you beat with a 360.


Greetings Wouter

[Vario Si]

Driven that car the most recklessly it has ever been driven - it was great! I love the brakes and the handling... and the pulls not bad!

Anyway back to the low gear ratio hold thingy...

Putting it on at 30mph has no noticeable affect, nor does it when going at 60mph.

As that previous link says - the low hold gear light goes off when using kickdown. It may be more than a jerk, there is definately more affect than just further gas but I'm not sure...

With 27,000 miles on the clock, the low hold button has probably never been used much! I doubt my Gran who drove it from brand new - the first 18,000 miles ever got over 50mph with the car and has probably NEVER used it. And I doubt my dad and brother who owned it till I got it in March have used the switch.

I'll check those things this week when have the time!

But from no noticeable difference, something probably isn't working I have to say...

EDIT: with kickdown (or without) the revs didnt go over 4600ish I think, during that mini test run... which was floored to 65mph ish.

Cheers

Simon

[Vario Si]

Okay, tests completed this morning...

On each of the three controls (brake/accelerator/low gear switch) there is A click from the small black box...

No suction comes from either hose when revving angine with low gear hold on.

And finally, one of the hoses you can blow down without resistance, and can hear it come out - somewhere under the car!

With the lack of suction - I presume it is possible that it may due to one of the hoses being loose/broken off under the car.

So, later I will check to see if the hoses are connected onto the vario unit correctly, or find a spint in the hose.

Hopefully the hose has just come off, or needs replacing...


Simon

[antiekeradio]

No suction comes from either hose when revving angine with low gear hold on.


you were supposed to do the revving test with low gear hold OFF