Suspension systems for towing

Submitted: Friday, Jan 22, 2010 at 13:32
ThreadID: 75403 Views:2343 Replies:3 FollowUps:5
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First off, thanks to all who replied to my previous queries on tow vehicles. We ended up with an 01 Troopy (non turbo).

We've had it kitted up to the trailer, have done around 8000k with it on so far, tows very nicely despite the size (30ft and 3.5T). Need to get some assistance with the rear suspension on the troopy. The weight of the trailer is dragging down the rear a noticable amount (not enough to affect steering or contact with the road, but can definitely see the body of the vehicle is far from flat).

We do use the car a fair bit as well when not towing, but rarely carry more than myself, the husband, and the dog + gear so not overly worried about ride in the back for passengers.

Can anyone suggest what would be possible solutions? The father in law has suggested assistance leaf's on the current suspension, and also had an airbag system suggested. Just wanting to know what is out there.

thanks in advance
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Reply By: Member - Tour Boy ( Bundy QLD) - Friday, Jan 22, 2010 at 14:07

Friday, Jan 22, 2010 at 14:07
I had a 78 series troopie with 12 leaf mine spec springs at std height in the rear and it handled the loads well and still rode well as the 78 series have a very long leaf pack (about 175mm longer then the 75 series), this also allowed for great wheel articulation from such a heavy pack.

Kermit the troopie

I don't particularly like air bags as they put too much localised load on areas that weren't designed for it ( see patrol chassis cracking and cruiser spring mounts bending). Those 1/2 leaf bolt on load helpers put a lot of strain on the leaf pack and weren't really designed for vehicles that leave the blacktop.

Change the leaf pack once and forget about it knowing it is the right thing first time. It doesn't have to have a lift you can get std height like mine was.

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AnswerID: 400605

Reply By: Tenpounder (SA) - Friday, Jan 22, 2010 at 14:22

Friday, Jan 22, 2010 at 14:22
Hi Manda. The first thing I was told to do was to find out how much download there was on the towbar. If there's too much, then common sense says lighten the load!! First option to do this is to fit a WDH (Weight Distribution Hitch) aka Hayman Reese to transfer some weight from the Troopy's back end to the front. From what you say, you don't need/want more than say 350-400 kg on the ball.
I was told there's no point in trying to jack up the Troopy with springs if the problem is too much weight on the ball.
And, and you fit stronger springs, then presumably you'll have a back end like a go cart (sorry, I meant the Troopy) when the van isn't hitched.
Just my thoughts.
AnswerID: 400607

Follow Up By: Tenpounder (SA) - Friday, Jan 22, 2010 at 15:06

Friday, Jan 22, 2010 at 15:06
Hi Just seen your previous thread. Since you are owing a trailer with kayaks plus gear, isn't it OK to consider packing the trailer so that the drawbar weight is under 400kg? That's a heap cheaper than buying new springs, WDHs or airbags!!
Of course, some would even consider moving the axles forward a bit, but that's getting complicated. Hope this helps.
FollowupID: 669794

Follow Up By: Tenpounder (SA) - Friday, Jan 22, 2010 at 15:07

Friday, Jan 22, 2010 at 15:07
Oops! 'Towing' not 'owing'
FollowupID: 669795

Follow Up By: Mooze - Friday, Jan 22, 2010 at 15:40

Friday, Jan 22, 2010 at 15:40
Thanks for the suggestion Chris. We're a bit limited in how we can pack the trailer due to number (51) of kayaks and their dimensions. Also the current undercarriage is positioned as far forward as legally possible (originally when it came from manufacturers had an illegal rear overhang length of 4m rather than 3.6m which is legally allowed).
Already running a WDH to assist (wouldn't dream of towing without one (or at least not something this size).

So unfortunately gotta go the suspension improvement route.
FollowupID: 669799

Follow Up By: Tenpounder (SA) - Friday, Jan 22, 2010 at 17:06

Friday, Jan 22, 2010 at 17:06
Sorry for stating the obvious! You've already covered the points I made, but I thought, well, just in case, I'll start from square one. I don't think one should ask what the GCM of your rig may add up to!!, but I hope you can work out a fix.
Kind regards
FollowupID: 669809

Follow Up By: Mooze - Saturday, Jan 23, 2010 at 13:45

Saturday, Jan 23, 2010 at 13:45
Obvious is always best place to start :) especially if you don't know someones current rig :)

Not sure I want to know either - it's been gone over (when fully loaded) by an engineer and ok'd - beyond that I don't want to know. It tows well even through middle of Sydney's skinny roads, it gets there.
FollowupID: 669947

Reply By: Member - Mfewster(SA) - Saturday, Jan 23, 2010 at 13:32

Saturday, Jan 23, 2010 at 13:32
Check out Aussie Super Springs. Also do a search on this forum for others who have used them. A better alternative than just boosting up the rear springs.
AnswerID: 400720

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