My 4wd bounces when towing van

Submitted: Monday, Sep 02, 2013 at 11:03
ThreadID: 104154 Views:10204 Replies:10 FollowUps:4
This Thread has been Archived
My 2011 Ford Ranger 4wd twin cab bounces in the back on rough roads when i'm towing my 16" Jayco Discovery single axle. I'm new at towing vans. I dont use WDS as i was told its not necessary. Any ideas how to stop this ?? The Ranger has got standard suspension. Sitting in the front seat its not bad but the passengers in the back feel it the most.
Caravan GCM 1700
Ball weight 120kg-160kg

Thanks
Bob
Back Expand Un-Read 1 Moderator

Reply By: blown4by - Monday, Sep 02, 2013 at 11:28

Monday, Sep 02, 2013 at 11:28
Assuming your ute shockies are OK, it sounds like you may have insufficient weight in the ute section of the twin cab allowing the rear of the tug to bounce or too much draw bar weight. Assuming you have the weight distributed evenly in the van with some draw bar weight for towing stability, a WDH would probably be worth a try. I assume you mean ATM 1700kg when you say Caravan GCM 1700.
AnswerID: 517512

Reply By: disco driver - Monday, Sep 02, 2013 at 11:33

Monday, Sep 02, 2013 at 11:33
Hi Bob,
My 07 Mazda extracab was doing the same thing and I put it down to the long distance between the back axle and the tow ball giving a bit of extra leverage.
Using an old rod type WDH has reduced it to an acceptable amount.

Hope this helps.

Disco.
AnswerID: 517513

Reply By: Thinkin - Monday, Sep 02, 2013 at 11:46

Monday, Sep 02, 2013 at 11:46
Hi Bob 5,

Sounds like your suspension might be bottoming out, you might need to look at a suspension upgrade and shocks. (not suggesting airbags).
You don't say how many kilo's load in the twin cab you have.
Strange ball weight figures ( 120- 160kg), have you actually weighed the ball hitch? you should have one precise number.

Check your twin cab rear spring clearance to the bump stop empty, then again fully loaded with the van. You'll find very little suspension clearance.

alpero
AnswerID: 517516

Follow Up By: Bob F5 - Monday, Sep 02, 2013 at 12:08

Monday, Sep 02, 2013 at 12:08
Im not sure on the ball weight loaded.Ill have to check it. Its 111kg on the van plate. Thats empty.
0
FollowupID: 797198

Reply By: Notso - Monday, Sep 02, 2013 at 12:08

Monday, Sep 02, 2013 at 12:08
Use a Decent WDH like Hayman Reese and you'll find it irons out most of this problem.

Also look at how much weight you are putting on the tow ball.

I do know of a few who have put spring helpers on as well.
AnswerID: 517517

Reply By: Ron N - Monday, Sep 02, 2013 at 12:47

Monday, Sep 02, 2013 at 12:47
Bob, it sounds to me like a decent set of heavy duty rear shock absorbers would be the answer.
Many standard factory shock absorbers are poor quality, and many shock absorber mounting designs are poor.

Ideally, a shock absorber should act directly at 90 degrees to the axle. However, due to design constraints, modern shock absorbers are nearly always mounted at an angle to the axle.
They can be mounted fore and aft or mounted crossways. Either way, when the springs are compressed, the shock absorbers ability to control rebound is reduced as its angle to the axle is increased.

In addition, manufacturers work on "average" loads when calculating requirements - so shock absorbers that just do the job, with little margin to spare, are factory fitted.
Yes, you might have paid $50K + for the vehicle - but the manufacturer didn't spend any more than the engineers and bean counters thought necessary, on shock absorbers!

A good quality aftermarket set of shock absorbers will more than likely provide a substantial improvement.
AnswerID: 517523

Follow Up By: Bob F5 - Monday, Sep 02, 2013 at 13:18

Monday, Sep 02, 2013 at 13:18
What brand shocky do you recommend for towing. Foam or gas filled ?
0
FollowupID: 797206

Follow Up By: Ron N - Monday, Sep 02, 2013 at 14:05

Monday, Sep 02, 2013 at 14:05
I'm not going to recommend one type or brand over another, because it's a bit like the Nissan VS Toyota VS Range Rover arguments - they all do things differently and all have different design features. What works for me, might not work for you.

This archived thread below touches on many points - but at the end of the day, a good brand aftermarket shock absorber with increased size and damping ability over the originals, is going to provide you with better damping than what you have now.

http://www.exploroz.com/Forum/Topic/58778/Foam_Cell_or_Gas_Filled_shockies.aspx

One has to keep in mind, that although you have around 150kgs on the towbar - when your ute hits a bump, the ute is effectively lifting and lowering another 850kgs (approx half the van weight) each time.

This places a vastly-increased load on the shock absorbers. You no doubt also have around 350 kgs of passengers and 100-200kgs of cargo in the ute as well. Coupled with the van, this all adds up, to place a heavy loading on shock absorbers as they try to control the rebound of a lot of weight that is moving up and down.

Yes, a good WDH will also make a difference - because the WDH does a similar job to shock absorbers, in that it dampens any excesssive up and down movement of the ute and the van, after a bump has been hit.
However, an investment in a set of good quality heavy duty aftermarket shock absorbers will also be an investment in roll stability as well.

Have a talk to several suspension shops and see if you can sort the sales BS from useful advice. You need to talk to at least a couple of shops to see what's on offer, and to see what might appear to suit your budget and your vehicle requirements.
1
FollowupID: 797208

Reply By: MEMBER - Darian, SA - Monday, Sep 02, 2013 at 13:22

Monday, Sep 02, 2013 at 13:22
Uprated shocks might be worthwhile, but don't discount a WDH - my rig (though heavier than yours) can be driven safely without WDH but when used (pretty much full time for me), the WDH significantly reduces the tendency of the car to pitch fore and aft on undulating surfaces....a modest spring tension is all it takes, because the big lunges go past my setting and the resistance gets greater anyway.
AnswerID: 517528

Reply By: Rockape - Monday, Sep 02, 2013 at 13:52

Monday, Sep 02, 2013 at 13:52
Bob,
if you check your manual it states not to use a WDH.

I tow a single axle van with a 2012 Ranger and it tows with ease. No pitching or bucking.
The suspension however is upgraded for an extra 300kg. I also know my ball weight is 180kg.
AnswerID: 517529

Reply By: Member - Greg H (NT) - Monday, Sep 02, 2013 at 16:08

Monday, Sep 02, 2013 at 16:08
Bob

I had a similar problem to yours in that I have a current model Ranger and 16ft Jayco Freedom. The back end bounced like a pogo stick.

This is working for me.

I have put airbags in the back to assist the springs and new EFS shocks. I run 8-10 psi when empty or lightly loaded with 20 psi when I have the van on. No WDH. This has taken the bounce out of the back by a large amount with the complete unit behaving better.

Cheers

Greg
AnswerID: 517536

Reply By: Shaker - Monday, Sep 02, 2013 at 17:49

Monday, Sep 02, 2013 at 17:49
Hope it's not chassis flex, saw one last month at Hells Gate with a broken chassis!

AnswerID: 517540

Reply By: Roughasguts - Tuesday, Sep 03, 2013 at 11:27

Tuesday, Sep 03, 2013 at 11:27
I would have thought you need more forward weight in the Van.
Any type of rearward weight would make the van bounce, is my thoughts.

Cheers.
AnswerID: 517566

Follow Up By: KevinE - Wednesday, Sep 04, 2013 at 19:36

Wednesday, Sep 04, 2013 at 19:36
Hi Roughasguts,

That's the 1st thing I thought as well!

I'm wondering Bob F5 if you have a water tank in your van?

If so, is it baffled? If not, all that water is just sloshing around in your tank. I'm sure that you know that water weighs around 1KG per litre - the amount of water in your tank x 1KG = an awful lot of weight sloshing around! = bouncing in your tug.

I'm also wondering if the water tank is rear of the axle/s? If so, then you will also get lots of bouncing in the tug.

Cheers,

Kevin.



0
FollowupID: 797350

Sponsored Links

Popular Products (13)