Hi, its been a while. Compliments of the season to the the forumites.

A bit long winded but I think importantly so to allow any reader to make sensible comment.

Fortuner 2.8 GD-6 4X4 Auto fitted with a Trapezium, towing a 2004 Penta. Towing experience, trailers, boats and vans for well over 20 years. This year it is my wife and I only (hallelujah), so we decide to go minimalistic and to greately reduce the towing weight by removing all those many items we apparently will need but used. We actually found out that we can remove even more stuff, this setting up a home away from home is starting to get a little ittitating. The motivator for removing these items was pre-empted after weighing the "stuff we take with" and realising that it does not take much to exceed the Penta's allowance, and we do.

The other thing we did was to even out the load in the van; we packed the main tent, groundsheets, 72l fridge, sparewheel (aircon in nose cone)  and camping recliners in the car. These items tended to be packed either well back or well forward in the van. The van by the way has a slightly negative attitude in front i.e. nose down.

So leave for Satara on the 17th, get to just before Witbank the front of the van roof starts lifting. Get into the van and discover the the mounting screws of the clamping device  on the one side have pulled out and there is extensive wood rot GRRRRRR. Just before this I also notice a very odd "knocking" coming from the rear of the car which to me sounds like it could be the tow hitch and that perhaps the front of the van is too light  ...... unhitch and cannot lift the front of the van. Strap a storm strap around the roof and off we go, beleiving that the knock was coming from the flapping roof, now secured. Noise is still there and is worse as the speed increases. Keep stopping to check if someting is loose, nope nothing. Also check to see if perhaps the noise is eminating from the roof of the van, it appears not. Towing stability is better but not wonderful and am a little dissapointed given the attention to load evening in the van.

Now the sound is like the cross between a muted bass drum and a fist beating on the underside of the chassis pan. Not a sharp mechanical noise bit more of a dull yet sharp thudding.

Get to Orpen Gate and notice that the bar from the Trapezium has somehow damage the nose cone and a moderately sharp turn, I remove the arm as we will be doing 30km/h from there into the camp. The fourth time the trapezium is being used?

After setting up camp I inspect the Trapezium and notice there is some play in the vertical plane and believe this could have been the the noise I was hearing, Unbolt the Trapezium and along with the bent control arm I unkindly place this at the nearest dirt bin I can locate. I have never had a good tow with the Trapezium so either way it is time for a change. If stability is a problem we can stop in Nelspruit and buy a new stabiliser. Go into Hoedspruit and buy a new tow htich and fit this. Effect a running repair to the roof which worked out remarkably well and held for the entire trip back.

So the trip back I noticed immediately that the van is significantly more stable, without any form a stabilisation. In fact I can't remember when last towing was such a pleasure ............ by the way the new Fortuner tows significanlty better than the last IMO. However the noise is still there and appears to have increased slightly in intensity. It is important to note that the noises do NOT seem related to road conditions So it cant be the Trapezium as that has gone to stabiliser heaven (and I am amazed that stability has improved), doubt if it is the hitch noise as I have never had hitch noise before.

The point of the thread is not to discuss the merits of the Trapezium, it was bought in a used condition and perhaps it was well used. The point is to get some ideas of where I can look to find this problem.

Any idea's?

Regards

Just to make Chucks' day - replace the Toyota emblem with a blue Ford one. 

That knocking sound certainly indicates that something is loose.  One my brother-in-laws' MB it was the brake caliper bolts on one wheel working loose.  The calipers had been adjusted the day before in Kimberley and not been properly tightened.

Trust you solve the mystery.

Ek hou glad nie van die Auto box nie, maaaaar vir sleep was dit nou n ander ding. Die box werk mooi daarvoor.

Ek het nie brandstof verbruik na Satara toe gemeet maar het wel vir die pad terug, moet vandag gaan volmaak, maar vir die eerste been van Satara, deur Nelspruit, deur Schoemanskloof en toe stilgehou by Shell Ultra City - Middleburg was dit 12.1l/100km, ek was verbaas want ek het gesleep teen a speedo spoed van so 115km/h wat op GPS sal seker so 105km/h wees. Dit sal die ergeste verbruik wees van na dit is dit lekeer plat Alberton toe.

Het net een of twee keer die "P" mode gebruik maar was op "S" vir die res van die tyd en vir eens kon ek baie gebruik maak van die "speed control" wat mooi uigewerk het want die paaie was nie besig en die ratkas se ratio's het ook gehulp. Ek is nie lief vir spoed beheer. 

Anonymous wrote:

Suggest you check two things to start with (since you have gotten rid of the trapezium): Make sure all mounting bolts of the tow bar (to the vehicle) are properly tightened (check tighten with a powerbar and socket to make absolutely sure). Check mounting bolts and play on the van's hitch and while at it check the weld joints of the van's A-frame to the van's chassis (those A frames are basically lip channel and not very strong, and prone to rust and metal fatigue). If all of this is OK check tighten the van's axle bolts (and make sure they are all still there!)

Hi. As the towbar is a factory fitted OEM Toyota one, the one without the small step my first port of call was going to be to get the dealer to put it on a lift to check the bolts. The knocking as I pointed out would be reminisicent of someone banging on the floor pan or underneath the chassis.

Thought it coul be the entire van tow hitch and am gounf to remove the nose cone today.

Did not consider the vans axle. Need to get the wood rot sorted so will have them check at the same time.

Thanks

OOM JEEP wrote:

The tow hitch. Is this the type where the part witn the "goose neck" push into a bigger square. So that it can be removed if neccasary.
If so, it might be the problem. Send a picture of the tow hitch.
Then
Loose wheel nuts on the van.
Worn out ball or fitting on the van.
The schock on A-frame

Pse come back to us. We all will try to help.

Daar is kundige mense in Alberton wat sal help. Ek het no.s van hulle.
My no. 082 446 9323

Is nie die goose neck tiepe nie ..... klaar daardie T Hempie. Dit is die vaste towbar.

Wiele op van self sal ek vandag nagaan.

Ek sleep maar een keer n jaar omtrent so daardie fitting het maar 'n maximum van 5 000 kms op, maar sal dit ook nagaan so wel as die shock.

Dankie

Oom Jeep,

het nou vinnig gaan kyk. Hy is mooi vas en geseel. Seker daardie probleem regemaak op die nuwe modelle.

Dankie.

Daar is speeling op the towbar karavaan se kant maar min. Bietjie warm buite, sal wag vir vanmiddag an weer gaan kyk.

The more I think of this problem the less likely I think it will be on the caravan side.

The contact between the ball and socket of the tow hitch is insufficient, in my opinion, to provide sufficient mechanical coupling to transfer any noise or vibration. If the noise is from the caravan side then it will have to be real loud to overcome the road and wind noise of the car.

I am leaning towards the towbar ...... but not discounting any of the other options.

neef Herman wrote:

Andrew, van n ander hoek af. Jy noem dat jy slegs een keer per jaar sleep.
Bande kan n " flat spot" kry indien dit baie lank in dieselfde posisie staan. Dit kan vibrasies en geluide veroorsaak.

Ek hoor jou. Sal die wiele afhaal, seker volgende naweek en TWT to vat for inspeksie.

Baie gooie punt ....

Ek het Desember met my jongste seun se kar gesleep. 2010 Hyundai IX35 Diesel Auto. My Grand Vitara Pta toe gestuur sodat my oudste seun n sleep voertuig kon he en ons wou sien hoe sleep hierdie IX35 Auto. (vergeet om Yellowblade se bracket van kar af te haal)

Die IX35 het n re-moveable tipe towbar. Wel hy is LOS!!!!! jy wikkel hom heen en weer. Al wat hom vas hou is daai pen met die "splitpin" daar is geen bout moer of enige iets om hom stywer vas te maak nie. Elke keen as ek oor n hobbel ry of rowwe pad, hoor jy hoe klap daai towbar! Dit is mo@#$@ scary en veral omdat ek nou ook nie die yellowblade op gehad het nie. Is dit normaal? Glad nie! N towbar moet vas wees!!!!

Ten spyte hiervan was ek verbaas hoe goed die Koreaan gesleep het. Ons was 3 volwassenes en 2 klein kinders in die kar, die was SWAAR gelaai en teen gemiddelde spoed van 105km/h het ons n verbruik van 9.7km/ly gekry.

Andrew

Gaan dubbel check die towbar. (as hy n re-moveable unit het)

Ek het Desember met my jongste seun se kar gesleep. 2010 Hyundai IX35 Diesel Auto. My Grand Vitara Pta toe gestuur sodat my oudste seun n sleep voertuig kon he en ons wou sien hoe sleep hierdie IX35 Auto. (vergeet om Yellowblade se bracket van kar af te haal)

Die IX35 het n goosneck tipe towbar. Wel hy is LOS!!!!! jy wikkel hom heen en weer. Al wat hom vas hou is daai pen met die "splitpin" daar is geen bout moer of enige iets om hom stywer vas te maak nie. Elke keen as ek oor n hobbel ry of rowwe pad, hoor jy hoe klap daai towbar! Dit is mo@#$@ scary en veral omdat ek nou ook nie die yellowblade op gehad het nie. Is dit normaal? Glad nie! N towbar moet vas wees!!!!

Ten spyte hiervan was ek verbaas hoe goed die Koreaan gesleep het. Ons was 3 volwassenes en 2 klein kinders in die kar, die was SWAAR gelaai en teen gemiddelde spoed van 105km/h het ons n verbruik van 9.7km/ly gekry.

Andrew

Gaan dubbel check die towbar. (as hy n re-moveable unit het)

Andrew wrote:

Hi. As the towbar is a factory fitted OEM Toyota one, the one without the small step my first port of call was going to be to get the dealer to put it on a lift to check the bolts. The knocking as I pointed out would be reminisicent of someone banging on the floor pan or underneath the chassis.

Thought it coul be the entire van tow hitch and am gounf to remove the nose cone today.

Did not consider the vans axle. Need to get the wood rot sorted so will have them check at the same time.

Thanks

The knocking as you describe ........................... does it increase when driving faster? In other words does the beating change when the speed changes?  Is it linked to road coditions, like only present when the road is uneven.

If rhythm increase while speed increase my less knowledgable experience tells me its with the turming of the wheels of the vehicle.

Only present with speeds exceeding 40-50km/h  probably loose shock absorber.

Hi Andrew I had an identical experience with a metalic knocking sound .I checked the tow bar mountings twice on a KIA Sorento (this is a factory bar and fitting) and could find no fault.

I use a Trapezium for many years and did not suspect it .Anyway took it to the trapizium  factory in Roodepoort and  it  was replaced, and  he presto the noise is gone and has been gone for the last 2 years.

What I do on entering the KNP is remove the trapezium arm and fit the lock screw ,this makes for better reversing,less change of damage  etc. Re attach when leaving.

Not sure if this will help you in any way??

@Chuck Norris

Het toe die tweede helfde van the reis se brandstof verbruik gereken, n bietjie erger as die eerste helfde, 12.24l/100km? Die gemiddeld was toe n heel ordentelik 12.16l/100km.

As ek mooi dink, die eerste skof af verby Bushbuskridge, Hazyview ens. het vir a lang deel n spoed beperking van 80km/h. Dit is seker hoekom verbruik vir die eerste deel van die rit n bietjie beter was.

Andrew, ek wil ook na 'n potensiele oorsaak wys op grond van persoonlike ondervinding. 

Daardie skokbrekertjie op die karavaan se inloopremstelsel - ek het een gehad waar die bout aan die een kant van die skokbreker stelselmatig losgewikkel het totdat dit verloor (op 'n baie ongelee plek).  Ek het toe eers besef waar die geluid vandaan gekom het.

Oom Jeep, Wat my pla is die speling by so n "re-moveable towbar"

My wiskunde se vir my (en ekt nie by Zuma wiskunde gekry nie) as daar 1mm speling op daardie "re-moveable towbar" is, en jy trek n streep na enige hoek toe agter op die karavaan, links of regs. Dan kan jy maklik n beweging van meer as n meter kry. Sit nou nog "bodyroll" van die voertuig by, dan kan dit groter wees. Dus beweer ek jy kan geweldige "sway" kry op die wa. (die klop geluide is net n waarskuwing)

Buiten dit, die swakste plek op die sleepstang is daardie "pen" wat alles moet vashou. Daardie pen moet ten minste 2 Ton kan hanteer, wat wel moontlik is, maar die "splitpin" twyfel ek.

Wat my hoendervleis gee (nee nie KFC nie)...... die VW Tiguan het n sleepstang wat jy trek n "lever" in die kattebak dan val daar n "gooseneck" ding onder uit waarmee jy sleep? Hoe sterk kan die koppeling wees?

Jou sleepstang is DIE belangrikste punt op enige kombinasie. Hier was al fotos op die forum van of n Isuzu of Colt bakkie wat die hele sleepstang afgekom het terwyl die persoon se wa gehak was!

Maar net my 2c

Ok so a bit of feedback.

I have not been able to look at the problem since reported. However I have an 18'5" boat that I towed last weekend and the knocking was not evident? Now the boat trailer has the axle set well to the back and the nose weight although unmeasured is significant.

That leaves me with two possibilities;

- that my nose weight in the caravan was too light causing the hitch to bounce on the ball.

- that the tyres could have introduced excessive vibration. Will take a tyre in this weekend to check for concentricity.

Cheers

Toyota confirmed having to tighten bolts on the towbar .............. which they fitted.

Indeed. But there were loose bolts so there is progress.

I am back at Toyota next week to have the front discs replaced. I want the tecbnician to point out exactly which bolts he can remember tightening, this is important for my piece of mind. I want to make sure that they are not ovecompressing the chassis.

Still probably a combo of the two, some loose bolts and a very ligh nose.

I need to tow the caravan again, it is the only way to check.