It is a myth about SLS that a WDH is not required when towing. Today we post comment on SLS and WDH from icon towing equipment maker Hayman Reese -
Self Leveling Suspension does not transfer weight from the back to front wheels of a tow vehicle.
All it does is level the vehicle. Whatever loads are on the wheels remains the same, and it requires a Weight Distribution Hitch to transfer weight from the back to front wheels.
It is a myth about SLS that a WDH is not required when towing.
We asked our friends at icon towing equipment maker Hayman Reese to give us their professional opinion. Here is what they have to say on SLS and WDH -
Simon Rodwell Product Manager CEQUENT, (Hayman Reese) a division of TriMas Corporation Pty Ltd said today -
Hayman Reese agrees with the comments above, using Self Levelling Suspension (SLS) the vehicle does appear level but the weights are the same.
Retro Toyota Excel 541 and Captiva Excel Compac swap tows
Long term users of SLS as their only towing aid may notice excess tyre wear of the rear wheels because the ball weight of the van is pushing the vehicle down behind the rear axle and the SLS is simply pumping up the rear to give a level appearance.
The critical feature of Weight Distribution Systems is to push weight onto the front wheels to ensure normal contact with the front tyres for steering and braking.
There is no reason why a vehicle equipped with SLS can't use Weight Distribution in conjunction with the SLS if, however, the vehicle is new and the SLS is standard equipment then the owner would be well advised to check with the vehicle manufacturer.
Also if anyone is looking to purchase a new vehicle that has SLS they should ask the question regarding warranty before they purchase.
With some manufacturers would-be buyers may find that the option of using the SLS and Weight Distribution together is not allowed by the manufacturer under the terms of their warranty.
Hayman Reese WDH fitted to Toyota for Coromal Excel 541 001
Editor's Note: Thanks Simon you make some worthwhile points which may not have been discussed previously
The new GoSee Captiva diesel model has SLS. We also use a Hayman Reese Weight Distribution Hitch. After testing with two Coromal caravans we find there is a significant improvement in the handling (safety) of towing with the Captiva with WDH fitted.
WDH also makes a significant improvement in the handling and braking of GoSee's 1985 restored Sahara diesel when towing.
We probably voided the Captiva warranty on day one when GoSee fitted a Hayman Reese tow bar rather than Holden approved.
We have also had to develop a work-around with the GoSee flagship Toyota Sahara diesel.
GoSee website users will find the Info Article instructive.
GSA Toyota Sahara flagship has AHC and WDH
Please use the Multi-Search box at the top of this page to read it. Click Select Search Area. Click Information Articles. Key Sahara into the white Search box and click search.
Use the same method with Captiva to find the Coromal Excel towing tests we did.
Key in Hayman Reese and the Info Articles on set-up and safety are available on GoSee.
GoSee is disappointed that despite contact with Toyotas Media Unit we have never received a response to our concerns about the Toyota's Active Height Control system.
GoSee tried to access Toyota's technical department through the service managers of two dealerships when the Media Department would not refer us or pass on our request, but unfortunately to no avail. Both service managers tried their best but Toyota "central" was not interested in assisting.
Also after initial incorrect towing capacity advice from GM we established that the new GoSee Captiva diesel is rated to 2000kg by GM, but after towing with the vehicle GoSee believes safety and comfort are better served at 1700kg max laden weight for the caravan.
Editor's Note: GoSee has provided the professional opinion of Hayman Reese on SLS and WDH to assist site visitors. As the topic is of general interest in both Australia and New Zealand we will involve engineers futher in future features.
GoSee is concerned that amatuer, speculative opinion on SLS in conjunction with WDH which is now being aired on forums has the potential to hurt people.
GoSee's position is that a professional Weight Distribution Hitch is a significant benefit to handling and braking when towing.
We base that view on practical testing on a variety of caravans which can be seen in the Information Articles available on this website.
The GoSee staff have thousands of hours of towing experience in all conditions. We know what works.
We acknowledge that vehicle makers have the responsibility to warranty their specifications.
GoSee also believes that buyers have the right to be fully informed of any limitations to the towing abilities of a vehicle before they purchase.
We recommend that the first Also See Info Article below be digested. It shows from the variations in the before and after application of a Weight Distribution Hitch that weight is transferred through the rig which gives the front wheels in particular a much better towing profile.
Also See -