Motorhome and campervan tech advice: Driving automatics
Words by Peter Rosenthal
Go back a decade and options for automatic gearboxes on vans were limited but now there is a huge range and these new systems offer improved fuel efficiency and much smoother gear changes.
Automatics are easier to drive than a manual motorhome as you only have to worry about two pedals – essentially just stop and go. Simply select ‘D’ for drive and off you go.
For older drivers with mobility or leg strength issues, this can keep them driving for longer. Even for fit and able drivers, not having to use the clutch in heavy stop/start traffic is a real boon.
An automatic can also hold the vehicle on a hillstart negating the use of the handbrake and avoiding having to be precise with the clutch.
The main benefit is that automatics are more relaxing to drive and can reduce stress.
While, traditionally, automatic gearboxes had less gears than manual gearboxes and tended to slur the gears, or jerk when changing, this isn’t the case with modern systems. The best examples change gears without you noticing and don’t use any more fuel than a manual.
An automatic partnered with a powerful engine will make a motorhome a real pleasure to pilot and an added benefit of automatics is that they’re deemed to be a safer risk than manual gearboxes by many insurance companies.
Downsides to automatic gearboxes
Other than having to adapt your driving style, the only downside to an automatic is the initial cost – both of the automatic itself and also the higher output engine they’re often partnered with.
Reliability of autos is similar to that of a manual gearbox and, given the low annual mileage of a typical motorhome, they should last just as long. Generally, they do have minimal maintenance – often just an oil change on a torque converter model, though many are sealed for life.
However, if they do have an issue you will need to visit a main dealer or an automatic gearbox specialist – few local garages have the equipment or capability to rebuild an automatic.
Robotised manual gearboxes, such as Fiat’s previous automatic gearbox on its Ducato, called Comfort-Matic, do need replacement clutches from time to time, but not as frequently as a regular manual gearbox.
Also, automatic vehicles tend to wear out front brake discs slightly more frequently than manual vehicles.
How reliable are automatic gearboxes?
We spoke to Dave Hughes, the director of Gearbox UK, based in Doncaster, to get his opinion on the reliability of automatic gearboxes. The biggest selling automatic system in motorhomes has been Fiat’s Comfort-Matic robotised manual, which has now been replaced.
Dave says the Comfort-Matic is a reliable gearbox. “It’s a pretty robust gearbox and we generally only see these for servicing work,” he says. “The modern generation of automated manuals seem pretty durable.
“We see more issues with Mercedes automatics and generally this is down to ECU failures. As these aren’t available to buy on the aftermarket, we’re now able to repair the delicate wires in the gearbox ECU.”
What are the automatics to avoid? “The early Ford PowerShift gearbox is a little under-designed and we’ve had a few issues with the earlier dual-clutch models.
“The DSG unit on the VW Transporter is much better and seems far more reliable. The only issue we see on those is that the clutch packs do wear on the campervans that tend to travel fully laden. But they can be replaced for around £1,200 so it’s not too bad.”
What about Renault’s robotised manual? “These are pretty reliable and, if we do see issues on them, nine times out of 10 it’s down to the electronic issues. The automation pack can fail and we’ve also seen the actual stalk inside the vehicle failing.”
Are there any tips to extend the life of an auto?
“Traditionally, many autos were sealed for life and didn’t have any servicing instructions – even though they have an oil filter built in. Unlike engine oil, they don’t get carbon build up in their oil though so, if the oil is contaminated, it’s usually because there’s an issue.
"For peace of mind, we’d suggest that the gearbox oil and filter is renewed on every third service. As modern vans typically have 18,000 to 20,000-mile service intervals, changing the oil and filter at 60,000 miles is about right.”
Types of automatic gearboxes
It’s helpful to understand what type of technology the automatic gearbox fitted to your motorhome uses to be able to drive it best. While the technology is constantly improving with all sorts of variations on the theme, there are only four main versions:
Torque converter automatic – These have been around since the 1930s so the technology is well developed and any issues have been ironed out. They consist of two main parts – a torque converter and a gearbox. Like a manual gearbox, an automatic does have separate sets of gears to vary the ratios, but how the unit changes gear differs.
The key component is the torque converter, which is a large drum that sits in the bellhousing and is filled with fluid and a complicated set of internal channels or vanes. At low speeds, the torque converter can spin independently of the gearbox while, at higher speeds, the fluid is forced into different channels to lock the crankshaft to the gearbox layshaft to create a solid coupling and drive.
The automatic gearbox can then shift gears using a variety of electro-hydraulic systems. As the gearbox is connected to the engine via the fluid-filled torque converter, it’s much gentler to the drivetrain and can shift gears almost imperceptibly.
CVT – Continuously variable transmissions can trace their roots back to the late nineteenth century when they were used on sawmills and they were also used on motorbikes from the 1910s onwards. They were popularised by DAF in the 1950s, which used them on its cars.
Since then they have been used on aircraft power generators and twist-and-go scooters, as well as on many modern vehicles. Rather than using gears, CVT use two pairs of cones linked together by either a rubber or chain belt.
Each pair of cones can either move closer together, which causes the belt to lift up towards the outer edge of the cone, lowering the gearing, or can move further apart, which raises the gearing as the belt travels closer to the centre of the shaft. This means that the gear ratios are infinitely variable and this allows the gearbox to keep the engine revs constant for maximum engine economy and longevity.
In use, CVT-equipped vehicles can feel strange to drive as the engine revs are not directly related to the speed of the vehicle. This can make them seem like they’re revving as if the clutch is slipping. Currently, there are no vans sold in the UK with a CVT gearbox, but some imported models, such as the 2010-onwards Nissan Elgrand, do use this system.
Automated manual – There are lots of confusing acronyms for this type of gearbox – DSG, SMG, ASG, ETG, etc – as well as a variety of different names such as semi-automatic, electro-hydraulic shifting, power shift, etc.
The key point is that they all use clutch friction plates that are shifted either using a hydraulic or electronic actuator. Some also use a twin-clutch system that allows them to preselect the next gear for smoother and faster shifts – these are often referred to as dual-clutch automatics, but are a sub-set of the main automated manual category.
The dual-clutch versions can give fast gear shifts and are just as efficient on fuel as a manual gearbox. The downside is that they will require replacement clutch plates and they can be more expensive to maintain. So, if the vehicle is out of manufacturer warranty, buy with care or take out an extended warranty.
Robotised manual – Although this is an automated manual gearbox, the key point to make about it is that it’s a converted manual gearbox, rather than a gearbox that was designed from the outset to operate automatically. Instead of a human actuating the clutch and gearshift, electro-hydraulic controls integrate with a computer to take over these functions.
As with a manual gearbox, they use gears and a regular single clutch plate. Examples include Fiat’s previous Comfort-Matic system and the Renault QuickShift.
Pluses to a robotised manual are that they can be just as fuel efficient as a manual gearbox and don’t weigh much more than a manual.
The downside is that they can require a slightly different driving technique to get the most out of them. Single-clutch versions can be jerky if this isn’t appreciated.
Torque converter automatics are engineered to ‘creep’. With your feet off both pedals on flat ground the vehicle will slowly creep forward. Why? Because it makes parking and traffic a doddle. To park, simply let the vehicle creep at idle and vary the speed by gently braking. No clutch slipping is needed and you don’t have to dance between three pedals.
In traffic, you simply need to ease off the brake to move forward.Torque converter automatics are also much safer on hillstarts and will generally hold the vehicle in place – sometimes needing a little throttle on steeper slopes – to prevent roll backs.
Some modern CVT and automated manual gearboxes mimic the action of a torque converter gearbox and do feature a level of creep and can also hold the vehicle on a hill start (sometimes in conjunction with a hill-hold braking systems) but it’s always worth asking the salesman if the automatic you’re interested in has a hill start function.
Fiat ZF automatic
Given that the Fiat Ducato base vehicle dominates the motorhome market, the new torque converter automatic gearbox option is big news and dealers predict it will be a popular option, especially as it is quite keenly priced. It costs around £4,500 as an option on the 140bhp, 160bhp and 180bhp engines. It’s not offered on the 120bhp base engine so you’d also need to add on the additional £900 cost of upgrading to the 140bhp engine.
The gearbox itself is made by the German gearbox manufacturer, ZF, which is renowned for its smooth shifting and reliable automatics.
It is a compact transverse unit that offers nine forward gears and three driving modes – Normal, Power (designed for fully laden vehicles or when ascending a hill) and Eco. You can also shift manually or hold it in a certain gear, which can be useful in slippery conditions or when descending hills.
Tips for driving an automated manual
As automatics only use two pedals, it is best to only use your right leg on the brake pedal and the throttle pedal – stop and go. If it’s your first automatic, tuck your left leg well out of the way – this avoids you absentmindedly trying to press the clutch down and instead hitting the brake pedal!
Modern motorhomes tend to use a fly-by-wire throttle system, which means that they are precise in how the throttle pedal works (and can also vary the linearity of the pedal by using different electronic modes – like an ‘Eco’ button).
As it’s so sensitive, you can influence the point at which gears are changed by varying the pedal pressure by an infinitesimal amount.
So, when you can see that the road ahead of you is flat, if you ease back on the throttle pedal you can get the gearbox to change up to a higher gear earlier. This reduces the engine revs and can save fuel.
It’s particularly useful on Fiat Ducatos fitted with the Comfort-Matic gearbox, which is highly sensitive to throttle angle.
All automatic gearboxes do require you to be more sensitive with the throttle than you would be with a manual gearbox.
Don’t worry about the vehicle ‘running away with you’ though – motorhomes have such low power-to-weight ratios that this isn’t likely to be an issue.
A feature of all automatic gearboxes is that they all have some form of kickdown. This is when the driver’s foot is presssed hard down on the throttle. The gearbox will change down a gear (or two) to provide a burst of acceleration. This is useful if the vehicle is slowing down while climbing a hill or when it is overtaking.
Many CVT and automated-manual gearboxes mimic this kickdown action – either electronically, hydraulically or by using mechanical gears.
Manual gear selection
All automatics tend to have some method of manual gear selection – either by manually moving the gearlever to a set position or by activating flappy paddles behind the steering wheel.
This can be useful when descending a steep hill so you can control the speed by using engine braking (some autos do this automatically, some don’t) or when pulling away on a slippery surface when a higher gear to reduce torque and wheelspin is needed.
Some drivers just like to control the gears manually without having to press the clutch.
Maximise automatic life
Most automatic gearboxes tend to require little servicing work and many torque converter models do not need regular oil changes. However, some do need to have their oil renewed and their oil filter changed periodically – check with the main dealer for this.
To get the most out of an automatic gearbox, there are a few golden rules. First is to only shift from drive ‘D’ to park ‘P’ or reverse ‘R’ when the vehicle is stationary. Shifting between these gears even at the lowest of speeds can cause wear to the clutch bands.
Equally, don’t start off by revving the vehicle and selecting a gear – always select ‘D’ before applying power.
In traffic, leave the vehicle in ‘D’ – you won’t save any fuel or wear by shifting it to neutral.
Finally, if your vehicle ever needs to be towed, make sure you follow the procedure in the owner’s manual. Not all automatic vehicles can be towed and gearbox damage will occur if they’re flat towed.
One automatic gearbox that MMM used to receive more letters for in Tech Help than any other was the Mercedes Sprintshift gearbox, used on the Sprinter from 2001 to 2006. This semi-automatic used a clutch and a complex hydraulic and relay system to change gears. Its slow shifts were a problem as the revs often dropped to a level that the engine couldn’t pull that particular gear, causing the unit to hesitate and fumble for another gear.
At the time, Mercedes also offered an excellent torque converter gearbox but, as this was more expensive, many buyers chose the cheaper Sprintshift model. Happily, most of these models have now left the mainstream used motorhome market.
Towing with an automatic
Not all automatic gearboxes offer the same towing capability as their equivalent manual gearbox so check with the converter (not the van manufacturer) or check your handbook to see what the maximum towing limit is. Motorhome makers may decrease the maximum towing limit due to other design considerations, such as the increased weight of an automatic gearbox.
That said, on the new nine-speed torque converter auto on the Ducato, the towing weight is identical to the manual gearbox. As the automatic version delivers extra torque (thanks to the greater range of gears) it should be well suited to towing.
You can fit an automatic to any vehicle but it’s a bad idea – to do it properly on a modern vehicle would need the wiring loom and ECU replacing, as well as the dashboard, gear-lever and all the associated linkages and cables. It’s complicated and expensive.
Plus, as it would now be a ‘modified’ vehicle it may carry an increased insurance premium and could be difficult to sell.
On an older vehicle it may be more practical to do an automatic swap, but you’ll struggle to find the parts as autos in vans were a rare option.
Other than trading the vehicle in for an auto, with a modern vehicle another option is to have an automatic clutch pedal system fitted. Various firms offer this service and one of the most well known is the Auto-Clutch system - vehvac.com
This costs around £2,000 fully fitted and converts the clutch to operate using an electronic actuator that is triggered via a button on the gear knob. While it won’t change gears for you automatically, not having to press the clutch pedal with your leg can be a big help for those with mobility issues. The manual clutch pedal is retained in this system so other drivers can use it like a normal manual gearbox.
The verdict on automatic gearboxes
While robotised manuals can be an acquired taste, most people who try a torque converter automatic fall in love with them. If you’re not sure, we suggest trying before buying your next motorhome to see if it is for you.