Silly swamper wobbles

[STUMPY]

I have a set of 36" tsl sx tyres that i'm having troubles with.
I've had them balanced and was ruuning 2"wheelspacers and getting the occasional death wobble at 60km but could accelerate through the wobbles to normal driving.

I removed the wheelspacers and had no vibrations or wobbles at all.
Tyres since then hadn't been used for 2 months and were kept on my truck, then we put them on a mates truck for a run and had major death wobbles. the front end felt like it was going to explode. We couldn't drive over 40km/hour and if we did, the wobbles would come in and wouldn't stop until the car came to a complete stop.

He's truck has the IFS widetrack hubs and he normally runs 33 mtrs with no troubles at all. My rims have no damage to them and tyres were driven at 110km/h last time i drove on them.

I thought they were just flat spots and that when they warmed up they would be ok. But if there was flat spots in the tyres, we would have noticed the problem much earlier then 40km/h.

[MYTTUF]

My un balanced Q78s on 16 X 8 beadlocked rims have the wobbles at 60km, cold or hot, but I can drive out the wobble at about 80km. They do, however, have flatr spots till they warm up that shake/bump the truck.
They are grouse when off road but
Jonesy

[christover1]

possibly your steering stabilizer/damper is not up to the extra load.
Assuming you have one.
I had this problem, after fitting a new Heavy Duty one my problem was solved.
Power steer can help with this sometimes, maybe the fluid acts like a damper
Steering drag links can also be too weak for the extra load.
christover

[redzook]

maybe his caster or somthing is out of wack

and the tires really show up his problem

[Tazz]

Check both cars wheel alignments.

I had the same problem on my old cruiser when i first got it on the road.

With the swampers on it slapped its head of and you had to stop and start driving again, then would slowly start to slap again until it got that bad had to stop again.

Normal tyres back on no probs. Ended up checking wheel alignment with a tape measure and was either toeing in or out too much (don't remember which). Put back to almost neutral and drove perfectly. Unbelievable change. From shaking ya head off and forcing you to stop at 40km to doing 120+ on 39swamper with 12 beadlocked rims....

Because the swampers are much wider and also because the inner lugs so aggressive, if they are running on the inside or outside lugs they just shake the hell out of everything.

It's much more exaggerated with swampers than muddies so even slightly out of alignment can show up bigtime.

My experience any way....

[fat lux]

well thank f*ck its not just my truck that does it mine does the same thing
cant get over 40 km/h with out it slappen all over the shop
so thanks all for this info will go and have a play

[vorno_18]

also if they are not radials leaving them in the same spot, eg. parked for 2 months will put a permanent dent in the actual tire, radials dont get this but fiberglass bias tryres do so when parked for a while put the car on axle stands or remove the tyres

[Ryano]

also if they are not radials leaving them in the same spot, eg. parked for 2 months will put a permanent dent in the actual tire, radials dont get this but fiberglass bias tryres do so when parked for a while put the car on axle stands or remove the tyres

Fibreglass belted tyres are less likely of having this issue than non-belted tyres.
It also has to do with the body plies. Nylon body plies are more prone to temperature changes. They shrink and expand and develop the 'couple of day' flat spot which will work itself out once a bit of heat gets into the tyre.
Polyester Body Plies are more resistant to temperature change and maintain their sizing regardless.

Cheers,
Ryano

[STUMPY]

Thankyou to you all for the quality feedback.

I'll check the wheel allignment on both hilux's first.

Cheers

[Gwagensteve]

Do your cars have stock shackle lengths?

Longer than stock shackles (increased caster) and the effect of IFS hubs and wheelspacers (increased scrub radius) will make the wobbles far worse.

I too have run unbalanced swampers for about 6 years and they have the light wobbles at around the 70kmh mark, but I have no steering stabiliser and beadlocks.

However, I run factory backspacing.

Steve.

[Ruffy]

Stumpy, Before you go doing anything drastic... How far have you driven on these tyres????
If your swampers have been sitting and not rotating then they will develop major flat spots on the tyre and shake the crap out of the car when you go to drive it until they get some heat in them and form back into shape. I'm talking about 6 to 10 klm's of driving to get them into shape or close to it. Even if they are left standing up not on a car they still develop this in my experience. Mine do this all the time, even an overnight stand will cause bad vibrations the next morning. It's painful but if you haven't driven far on them then go for a drive and keep driving till they come good. I don't balance my swampers because they are extermely hard to balance. You think you've got them right but if you do 100k's on 'em and balance them again more often than not they will be out.
Good luck..
Oh and yes i have the 60km/h vibration nearly all the time to.. Welcome to the TSL club

Edit; I forgot to mention, TSL = They Shake Lots

[MYTTUF]

Edit; I forgot to mention, TSL = They Shake Lots

[-Richo-]

The lux in question is mine, after reading the replies here and talking to a couple of people it very well could be the dampner and the wheel alignment (tie rod is slightly bent) ill recitfy these probs first and see if it makes a difference.

I have standard shackles but with custom front leaves drilled 50mm forward, j arm steering with drag link and torque rod shortened accordingly, i dont think the caster would of been altered that drastically by moving the diff 50mm forward? ill fix the above first anyway.

It wasnt just a vibration either, it was a DEATH wobble and had to stop the rig every time it happened, very Grimace.

[Tazz]

Mine where the same, not a vibration, but a death wobble that nearly threw you out of the cab.

You had to stop cause the car was about to bounce of the road and the traffic around (on the odd occassion there was some) pulled over off the road to get out of ya way because they thought the car was gonna fall apart...

Having had the 39's sit around for a few months still on the car between drives, the warm up wobble is virtually nothing.

If you complain about the limited warm up wobble that they create then
"ya aint seen nothing".

[STUMPY]

After more thought i've come the conclusion that it's not the tyres causing the problem, only multiplying the problem.

There are no vibrations from the rear at all, only the front.
My steering stabliser is shagged and my caster is alittle out.

[christover1]

With that much tyre and offset I'd say get an after market heavy duty stabilser/damper, as OE ones didn't have Swampers in mind.
I've had a good run out of my ARB damper, and I'm sure they make them for most common cars.
No doubt there is other manufactures, too.
I'm told you can get heavy duty drag links for some cars, if needed, but I know nothing of them.
christover

[MQ080]

Joel,

Without a doubt this will be steering orientated rather than the tyres themselves and more likely caster than toe.


"The best way to visualize caster is to picture a shopping cart caster. The pivot of this type of caster, while not at an angle, intersects the ground ahead of the wheel contact patch. When the wheel is behind the pivot at the point where it contacts the ground, it is in positive caster. Picture yourself trying to push the cart and keep the wheel ahead of the pivot. The wheel will continually try to turn from straight ahead. That is what happens when a car has the caster set too far negative. Like camber, on many front-wheel-drive vehicles, caster is not adjustable. If the caster is out on these cars, it indicates that something is worn or bent, possibly from an accident, and must be repaired or replaced."

Furthermore

"If this is the case, then why did most cars have negative caster specs prior to 1975 ? There are a couple of reasons for this. In those days, people were looking for cars that steered as light as a feather, and cars back then were not equipped with radial tires. Non-radial tires had a tendency to distort at highway speed so that the contact patch moved back past the centerline of the tire (Picture a cartoon car speeding along, the tires are generally drawn as egg-shaped). The contact patch generally moves behind the caster line causing, in effect, a positive caster. This is why, when you put radial tires on this type of car, the car wanders from side to side and no longer tracks straight. To correct this condition, re-adjust the caster to positive and the car should steer like a new car."
http://www.familycar.com/Alignment.htm#Cas

Remember all the suspension mods that you have made will have affected caster and the hilux wasn't originally designed with bias tyres in mind. Take it to a truck aligners to get the current specs however your only option for a SAS lux may well be caster wedges (yuck!)

[Gwagensteve]

In theory, pulling the front axle 50mm forward on the spring will have a fairly significant effect on caster, if the springs have any arch. (i.e caster will be way more than stock)

I have experienced the death wobble of which you speak even with balanced tyres on suzukis that have too much caster (shackle reverse) or too little caster (tall springs and long shackles)

think of the wonky trolley wheel - these get a death wobble too if they are bent increasing their caster.

The offset and steering damper will help mask the problem, and might make it go away, but the caster will be what is causing the issue IMHO.

Just my 2c worth.

Steve.

[liftkit8]

death wobble = owning nissan with big lift + big rubber

[ozy1]

death wobble = owning nissan with big lift + big rubber

not always dude,

[blackmav]

The lux in question is mine, after reading the replies here and talking to a couple of people it very well could be the dampner and the wheel alignment (tie rod is slightly bent) ill recitfy these probs first and see if it makes a difference.

I have standard shackles but with custom front leaves drilled 50mm forward, j arm steering with drag link and torque rod shortened accordingly, i dont think the caster would of been altered that drastically by moving the diff 50mm forward? ill fix the above first anyway.

It wasnt just a vibration either, it was a DEATH wobble and had to stop the rig every time it happened, very Grimace.

No death wobbles were reported when you ran my pedes??? But they do have a few weights on them.

[Old Yella]

Edit; I forgot to mention, TSL = They Shake Lots

I found my old Iroks to be better than my TSL SX's, but they do get better after a good warm up.

I wonder If it has anything to do with weight/width or bigger lugs.

[-Richo-]

The lux in question is mine, after reading the replies here and talking to a couple of people it very well could be the dampner and the wheel alignment (tie rod is slightly bent) ill recitfy these probs first and see if it makes a difference.

I have standard shackles but with custom front leaves drilled 50mm forward, j arm steering with drag link and torque rod shortened accordingly, i dont think the caster would of been altered that drastically by moving the diff 50mm forward? ill fix the above first anyway.

It wasnt just a vibration either, it was a DEATH wobble and had to stop the rig every time it happened, very Grimace.

No death wobbles were reported when you ran my pedes??? But they do have a few weights on them.

i did 110 down the freeway on the pedes, no death wobbles only the sound of WW2 bombers flying above thats what made me think it was the swampers cos they arent that much different in size.

[Old Yella]

The lux in question is mine, after reading the replies here and talking to a couple of people it very well could be the dampner and the wheel alignment (tie rod is slightly bent) ill recitfy these probs first and see if it makes a difference.

I have standard shackles but with custom front leaves drilled 50mm forward, j arm steering with drag link and torque rod shortened accordingly, i dont think the caster would of been altered that drastically by moving the diff 50mm forward? ill fix the above first anyway.

It wasnt just a vibration either, it was a DEATH wobble and had to stop the rig every time it happened, very Grimace.

No death wobbles were reported when you ran my pedes??? But they do have a few weights on them.

i did 110 down the freeway on the pedes, no death wobbles only the sound of WW2 bombers flying above thats what made me think it was the swampers cos they arent that much different in size.

I ran 35" pedes for a couple of years before my swampers and you could drive all day at 100 kmph no problems.

One thing I have found is that you can run Swampers at a lot lower pressure without beadlocks than what you can run pedes.

I don't know the difference in make up between these 2 styles of tyres.

[STUMPY]

Joel,

Without a doubt this will be steering orientated rather than the tyres themselves and more likely caster than toe.

Remember all the suspension mods that you have made will have affected caster and the hilux wasn't originally designed with bias tyres in mind. Take it to a truck aligners to get the current specs however your only option for a SAS lux may well be caster wedges (yuck!)

It's not my car that is have the troubles we are speaking of. Yes i did have some issues but at the time i was running 2" wheel spacers on flip centered rims.

[christover1]

Anything that moves the wheel and tyre outwards, whether thats wider tyres, rim offset, or wheel spacers puts extra leverage on the steering parts. Plus the extra weight also adds to the torque thru the leverage.

This doesn't cause the issue itself, but amplifies any problems already in the steering geometry.

If the problem is design rather than worn or damaged parts, then modifying steering is only real cure.

Safety and condition of all steering gear should be inspected of course.

But a good damper, tho it won't trully fix the issue, can mask the problem, which is all most people want.

christover

[Gwagensteve]

PErsonally, I would rather not run with a damper and know what the poor front end was feeling rather than have it masked out.

It has been said many times that a well designed steering system has no need for a damper.

I have very little wheel shake with no damper, 20+ year old steering gear and unbalanced SX's.... but I have 7.5" rims with 6" of backspacing. (factory specs)

steering dampers also blot out some of the nice steering feedback that you get with bias ply tyres, (but it could just be me that thinks that bias tyres feedback is "nice")

I am sure that if I had 3" backspaced rims or spacers, I would have a death wobble too.

Steve.

[MQ080]

Joel,

Without a doubt this will be steering orientated rather than the tyres themselves and more likely caster than toe.

Remember all the suspension mods that you have made will have affected caster and the hilux wasn't originally designed with bias tyres in mind. Take it to a truck aligners to get the current specs however your only option for a SAS lux may well be caster wedges (yuck!)

It's not my car that is have the troubles we are speaking of. Yes i did have some issues but at the time i was running 2" wheel spacers on flip centered rims.

I would say Drop Bear's caster is out then

[grimbo]

also could be tread blocks that are missing or chewed out in certain spots

[bazzle]

You do need a damper . If only to save your wrists if a rut is hit on the wrong angle!
On the Hilux check the ball joint loading springs in the 1st motion arm from the steering box. They are adjustable and should have correct preloading.

Bazzle