Should we upgrade the rear leaf springs on our motorhome’s suspension?
QI have a 2014 Fiat Auto-Trail Tracker RB motorhome. I want to replace the rear springs, currently double leaf. I drive the motorhome fully loaded and, on researching Jones Springs, it is suggesting a three or four-leaf replacement. I would appreciate your views on this.
I have a 2018 Roller Team T-Line 590 on a Ducato X250 chassis, which has done 25,000 miles. I am generally very happy with it, having done two long trips to France and
Spain this year.
However, on a recent trip to the northeast and Yorkshire, I was disappointed with the ride of the ’van when we encountered bumpy, or poorly surfaced A and B roads, particularly from the rear end of the ’van.
There was quite a lot of wallowing, pitching and rolling, requiring a considerable reduction in speed to achieve a comfortable ride – often down to 30mph on roads with a national speed limit of 60mph – yet once on smooth roads, the ’van behaved impeccably and our dog who travels, harnessed, on the dinette forward-facing bench seat was much relieved.
I have been looking at possible suspension uprating solutions which won’t break the bank, but give more stability to the rear of the ’van on those kinds of roads in future.
These are the items under consideration and I would be grateful for your opinion on which would give the greatest benefit:
1. SumoSprings, which replace the ordinary bump stops with a firmer compound to reduce the bounce (sorry, I don’t know the technical term)
2. MAD Helper springs for single-leaf ’vans, which fit around the existing bump stop and, being progressive rate, assist with reducing the bounce
3. MAD semi-air bags, which appear to be used in conjunction with the existing bump stops, sitting alongside them, again to control the bounce
I have a friend who used to be a car mechanic and he reckons any one of them would do the same job, but at different costs, so it’s a question of which one would give the best performance gain for the money? I would appreciate your input.
AI gathered a little more information from both readers and came up with similar advice for both. I think that there is a misconception regarding the rear suspension on Sevel platforms made since 2006. Whereas the earlier vehicles often had bump stops that came into contact with the springs and this was considered normal, this is no longer the case and the two should only come into contact during serious undulations while driving and never rest there at standstill.
I pointed out that, for vehicles plated at 3,500kg, there was an option to have heavy duty springs fitted at the factory. Because it was so inexpensive (only a £75 option) I always specified this for our extra-long Maxi vans and conversions and double-leaf springs were supplied. This gave added stability and the correct attitude of ‘slightly higher at the rear’ was maintained even when fully loaded.
The suggestion of having three or even four leaves to the springs has merit, but would probably be overkill. There is a limit to how much firmness is desirable and, beyond a certain point, there would be a severe mismatch between the feel of the rear and front suspension set-ups. The angle that the vehicle sits at, even when loaded, will probably be of concern, too.
Because Ken has a vehicle that is 3,500kg, I suggest that twin leaf springs would be a huge improvement and really should have been in place from the outset. Robin’s vehicle is 4,200kg and already has twin leaves, so a third may well be the answer.
I have used Jones Springs in Birmingham several times and trust the company’s judgement so I have recommended both readers to discuss the matter with the staff there and ask for prices for the springs that they need, along with the shackle bolts, nuts and washers. The shackle bolts in particular will need to be longer than the original items and they should be replaced when springs are changed anyway.
I would not expect the franchised dealer to be able to supply these items for more than two leaves since they were not original equipment and, even for twin leaves, the prospect of getting a Fiat or Peugeot dealer to supply something different to the original spec does not bear thinking about!
It also goes without saying that the maximum axle weights should always be observed and sometimes with larger vehicles the distribution of loads within the vehicle have to be carefully considered. A trip to the weighbridge is a good idea when deciding whether changes to suspension are necessary.
This will show you how the weight is distributed and don’t forget that heavier springs also have a weight penalty.
Q Can I fix the faulty air ciculation fan in my motorhome’s heater?
Fitted in my motorhome is a Trumatic S 3002 P heater and the air circulation fan has stopped working. Can anyone tell me how to gain access to this fan as I have inspected the area fully and just can’t see a way to get at it to replace it.
AThere are a few reasons why the fan may not be working and a failure of the fan motor would not be at the top of my list. More likely it will be a bad connection or a fuse. Perhaps the fan control knob is faulty?
However, you will need to remove the heater cover to get at the motor and check out if any voltage is applied to the fan motor as part of basic fault finding.
Unplug the mains hook-up lead from the motorhome first. Ensure that the heater is cold before attempting to remove the cover.
The cover is unlocked by pushing the two locking levers (shown as 1 on the diagram) outwards simultaneously. It can be swivelled out and lifted from the lower bearings. Refitting is a reversal of this procedure, bottom in first, the ease the top in until you hear the catches click.
Q Can you tell me more about Fiat’s Comfort-Matic gearbox?
I thoroughly enjoyed reading the recent article (Dec 2023, p166) about the servicing of the Fiat-based motorhomes. It was a very practical article and explained many questions that I come up with.
One thing that I would like your views on, is the Fiat Comfort-Matic gearbox. I have a 2017 Hymer motorhome on a Fiat with the Comfort-Matic. It has only covered 12,000 miles and is always serviced annually regardless of the mileage.
Touch wood, the gearbox has always worked exactly as it should and has never been serviced, ie, oil changed. I have read some horror stories about this gearbox when it does go wrong, and the costs involved.
Your thoughts, comments and experience with this gearbox would be interesting.
Alan Robbins
AThe Comfort-Matic is a difficult subject. Yes, there is guidance in the handbooks that stipulates that the clutch operation fluid should be changed regularly, but experience has led me to believe that is not a good idea. It is a difficult job, even for Fiat dealers, and can cause other problems.
It is also true to say that some of the horrific repair estimates that have been circulating are the result of negligence and/or incompetence by the workshops guilty of misdiagnosing problems.
Major items of the control unit are very expensive, but I have not heard a case yet that I believed had been diagnosed correctly.
I am not oversimplifying this when I say that you have a normal clutch and gearbox, to which has been attached a set of hydraulic actuators and a computer to control it. With inputs from you (accelerator, brake and gear selector) and information regarding the engine output, the computer controls the clutch and which gear to select.
The difficulties arise when the clutch wears, or the fluid becomes contaminated over time.
If the fluid is changed, or the clutch is replaced, the settings for the position of the clutch and the actuators change.
These have to be calibrated in a very specific order, by a Fiat Examiner diagnostic device. Words are used such as ‘clearance’, ‘purge’ and, well, you get it... it is not for anyone untrained or without the correct procedures and diagnostic unit to attempt.
On the whole, I say leave it alone unless it shows signs of malfunctioning. Any anomalies more than an isolated, random warning light or a reluctance to move into drive or reverse (the typical trait of hanging onto first gear for too long when cold is annoying but a ‘feature’) and it needs to get looked at without delay. Preventative maintenance in this case is not advised.
The next thing to consider is who will work on it, should the need arise?
In the UK, many of our ambulances are Fiat Ducatos and most of them are Comfort-Matics. They are normally serviced and repaired by Fiat Professional dealers that are also Iveco Truck dealers.
There is, therefore, a fairly sparse, but at least an existing network of experienced workshops that do this stuff regularly. They have the space, the equipment and the expertise along with the backup of the factory to call upon if things get complicated.
This may be the case in the ROI. I don’t know. If it is, then it would be a good idea to locate your nearest dealer and have a chat with the service manager. It may offer different advice to mine! The choice is always yours, of course.
What you tend to find, though, is that dealers are more sympathetic and helpful if you have followed their advice. If they were to recommend that you get the fluid replaced without delay, let them do it!
If you do ever need a replacement clutch, the parts for that will be a similar cost to a manual gearbox, but the time that it will take to remove and replace the hydraulic control, then calibrate it and test it, will add considerably to the cost.
Nick Fisher