Comformatic , again

[Casper46]

We have had a couple of MHs with Comformatic boxes, I usually drive them in manual, but after reading a lot of different opinions I am trying to use automatic, I do forget sometimes.
Maybe it's me ( only driven for a living for 50 years) but I do find problems when sometimes not being able to get a run to serious hills I can't get it to change down from 4th to 3rd when it starts labouring. Is there a knack other than getting slower and slower until it decides to comply to my swearing.

 

[icantremember]

Just knock it down with the gear selector.

 

[Casper46]

That's what I try but it won't change down.

 

[icantremember]

It probably won't change down if your speed is too high, otherwise you may have a fault.

 

[hymerman]

I have a merc sprintshift, I don't know if they are in any way similar, but when I had a problem it was the sender on the rear wheel giving the gearbox incorrect speed info. Very simple fix .

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[Happy1]

Have you tried the up button?
The one just north of the gear selector looks like a giant gas bottle on back of van with arrows going through it.

 

[Casper46]

Have you tried the up button?
The one just north of the gear selector looks like a giant gas bottle on back of van with arrows going through it.

i have never used it, I'll try it next journey,Thank you.

 

[Pausim]

I think the symbol on the UP button is meant to be a heavy weight going uphill (but it does look like a gas bottle). Bearing in mind that most motorhomes are heavily laden to start with makes this button more important. I have only been driving a Comformatic for just over 1 year but quickly decided that this button is best used most of the time. I usually find that a change down can be prompted by flooring the accelerator in what used to be known as “kick down”. The Comformatic manual says automatic gear changing depends on engine speed, road speed and pressure on the accelerator. The only time I find it might occasionally be in the wrong gear is when using cruise control, which is when it is not getting accelerator pressure messages. The simple solution to this seems to be to shove the accelerator down and override cruise control.

 

[Steve and Denise]

We had a tag comfort matic for 3 years and pressed the up button when we bought it and never took it off drove fine, holds the gear longer and changes down a bit sooner which is the idea of it, and we were 5 ton.

 

[Mark and Mindy]

I don't see how it could cause the engine to make more power so what does the up button really do?

Mark

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[Pausim]

I don't see how it could cause the engine to make more power so what does the up button really do?

Mark

It doesn’t make more power, it holds lower gears for longer.

 

[IanRJ]

I don't see how it could cause the engine to make more power so what does the up button really do?

Mark

It allows the gearbox to hang on to specific gears longer. So instead of changing up at say 2500 revs it might hold the gear until either the load reduces(say topping a hill) or the revs reach 3000 as an example.

Works great for me uphill, but I find it interferes with the downhill breaking assist and often drops too many gears when breaking downhill so too high a rev range. I turn it off unless hill climbing

 

[pandas]

Have you tried the up button?
The one just north of the gear selector looks like a giant gas bottle on back of van with arrows going through it.

The magic up button does it for me. Don’t need to worry about anything.

 

[cornish boy]

Must admit I have never used the hill assist button, just tend to give the gearlever a quick nudge when I want it to down-change going up-hill and pop it back into auto when reaching the crest.

Must try the hill assist button next time out.

 

[Lenny HB]

What year is your van?
Our first Comfomatic was 2014, current one is 2017, its far better than the 2014 one.
Also what engine do you have as a Comfomatic will never work very well with the 130 due to the standard turbo.

Also how many miles as your van done as the Comfomatic is at its best after 15,000 miles.

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[RobbyMClark]

Hit the up button on mine during the summer in Cornwall for the first time and the bloody think fell through the dash. Had to take the gaiter off and find it!!
Will be a bit more sympathetic with it next time

 

[DBK]

We have had a couple of MHs with Comformatic boxes, I usually drive them in manual, but after reading a lot of different opinions I am trying to use automatic, I do forget sometimes.
Maybe it's me ( only driven for a living for 50 years) but I do find problems when sometimes not being able to get a run to serious hills I can't get it to change down from 4th to 3rd when it starts labouring. Is there a knack other than getting slower and slower until it decides to comply to my swearing.

Its possible the gearbox does know what it is doing. Depending what engine you have maximum torque is generated at quite low revs and what you think is a "labouring" engine might be one actually running at exactly the right speed for the load. If it is genuinely not changing down early enough then as suggested it sounds as if there is a fault.

However, the vehicle doesn't know what lies ahead so when approaching a steep hill I often change down manually and don't wait for the gearbox to decide when to do it. This is particularly useful on alpine passes when the inside of a sharp bend can be very steep and automatic changes down in the middle of the bend can be a bit rough. Doing it in advance makes for a much smoother and less stressed progress.

 

[SpeedyDux]

Mine romps up hills in Auto 5th or 6th. If it is a very hilly road I use the UP button. That also provides more engine braking on the down slope (you need to disregard the high revs, it won't harm the engine).

It is easy to flick the lever forward to override the Auto program and change down a gear, if you feel the need to. I use full Auto all the time. That's what Comfortmatic is designed for.

 

[Happy1]

Hit the up button on mine during the summer in Cornwall for the first time and the bloody think fell through the dash. Had to take the gaiter off and find it!!
Will be a bit more sympathetic with it next time

Mine did exactly that! fished it out but it wouldn't stay put so the fiat garage "fixed" it probably with some super glue!

 

[Lenny HB]

Must admit I have never used the hill assist button, just tend to give the gearlever a quick nudge when I want it to down-change going up-hill and pop it back into auto when reaching the crest.

Must try the hill assist button next time out.

The hill asist is for very steep decent only works up to 25kph.

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[Happy1]

Must admit I have never used the hill assist button, just tend to give the gearlever a quick nudge when I want it to down-change going up-hill and pop it back into auto when reaching the crest.

Must try the hill assist button next time out.

By hill assist do you mean the button next to the traction plus button?
I’ve got this on a 4x4 where it maintains a set speed irrespective of how steep the slope is going downhill, combination of abs, diff locks and the 4 wheel drive system but doubt it will be much use on a 3+ton van with none of the gizmos but never tried it so no idea if it works.
We’re in lockdown so if you get out before me let us know how you got on!

 

[G7UXG]

I use Comfort-matic mostly in auto but not with the ‘UP’ button engaged. I find it changes down too early and too low at roundabouts for example. I’d rather use auto in normal mode and give it a ‘nudge‘ when it’s needed. Even in a 5 ton tag axle, I don’t think it needs the UP button. 2.3 litre Euro 6 180 pulls very well, with peak torque from around 1500rpm through to 3000rpm.

 

[Casper46]

Thanks everyone, I will have to have a play with it next time it happens.
It’s a 2 year old 2.3 180 Euro 6. It drives well most of the time and usually sails up hills fine. It’s just if I have been slowed down by someone in front and I’m in 4th gear, that’s when it won’t change down.

 

[cornish boy]

The hill asist is for very steep decent only works up to 25kph.

By hill assist do you mean the button next to the traction plus button?

Ah, I actually meant the UP button not hill assist.

 

[Happy1]

So has anyone actually had a situation where they have tried the hill descent and lived to tell the tale?

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[Abacist]

I am sure that the Comformatic gearbox also uses some form of inclinometer as it can't otherwise know when its going downhill or know when you start climbing a hill before the revs start to drop. My reasoning for this is that it won't go back to 6th gear until it is on the flat again after a decent.

The uphill button works for me but tend to use it only for going up and not down hills.

Take care also to put the gear lever in neutral at traffic lights and other temporary stops as its easy to overheat the clutch. Uphill in slow/stopped traffic is a problem for this so use the handbrake and neutral unless able to move with the clutch fully engaged - otherwise the auto box rides the clutch and it overheats! Also possible to do this trying tight, hard lock on, reversing especially in my tag axle as the resistance is too great.

Trying to make some helpful points for those with Comformatic boxes based on my experience with my 2014 3 litre tag axle N + B.

 

[Mark and Mindy]

So has anyone actually had a situation where they have tried the hill descent and lived to tell the tale?

I have tried using the down button a few times. I don't remember exactly what the warnings are but most of the time although going slow and being on the brakes I have been going too fast and it complains that it can't be used. Even if I'm going slow enough the van then speeds up under engine braking and the function starts flashing on the dashboard.

I don't know how it's supposed to work and whether it reduces power or uses more engine braking or applies the brakes.

Mark