Prado steering wandering

[HeathNZ Junior Member Find all posts View Profile Close HeathNZ]

Am considering selling my 96 SWB Prado but have an issue with the steering wandering and want to get it sorted before selling (and if it doesn't sell for a while I want to be safe while using it).

My steering rack failed at last Warrant of fitness (6mths ago - buggered beyond repair - didn't notice seemed fine to me) so was replaced with second hand unit (in good condition I was told) and all was good for 6 mths. Went in for a Wof last week and the steering rack was buggered again, but repairable this time. Also got failed on rear tyres (one had a slash down to the steel belts - didn't see it) so I replaced the rears with some near new tyres (Nangkang Mudstars 265/75/16 - fronts are same size but khumo kl71 almost worn out and need replacing soon). A Wheel align was done and all good.

The steering feels like it is wandering all over the place now when driving and I am having to make constant corrections to steering to keep going straight. It's like I am driving down train tracks and the wheels are diving left and right incrementally.

Could this be the difference in the tyres causing a problem (rears fighting the fronts due to slightly smaller rolling diameter.) or should I look more at the steering rack area? Tyre pressures are all good (actually since I set them all up at 41psi it is worse/ more noticeable) and where I always had them with the original set of kl71's.

If I had just done the rack or the tyres then it might be easier to pin down but now I am confused as to which is the cause of the wander.

I have tried to get the rack to move (wiggle on its mounts) but it feels tight. I assume that when the rack was out the rack mounts were checked and all was tightened back up to spec.

Might see if I can grab another pair of tyres to replace the front ones so I have near new tyres all round.

Heath.

[Bear63 Senior Member Find all posts View Profile Close Bear63]

So the new tyres are on the rear ? Is that right? If so that is your problem I have come across this lots of tiimes

[HeathNZ Junior Member Find all posts View Profile Close HeathNZ]

Dropped some new ones on the front too (so all the same type and tread depth), adjusted pressures to 36psi all round and its better but still wandering. Next step is to drop it off again at the mechanic so they can check the new rack mounts are tight etc. Better not be something else wrong (just dropped $2.5K to fix this up for sale and cant afford anymore).

Could it just be the new tyres are MT's (the old ones were so worn they may as well have been road tyres) and they are wobbling around on the tread blocks (Nangkang mudstars - copy of old BFG mud terrain pattern - not the new km2 pattern).

[Guest Close Guest]

Maybe you need more caster angle ???

[SWR Banned Find all posts View Profile Close SWR]

Gday HeathNZ

Without going too deep into the wheel alignment as i will assume it is ok!.. for now!... (Either that or your wheel alignment guy is not good? ... Lol

I would get the rear axle bushes & rear panard rod checked because if these are torn/ Worn the rear axle will steer the rig!... Especially when putting power through the drive train (Accelerating) or when you suddenly back off on the power.

Normally "NEW" tyres go on the front?... Especially when doing a wheel alignment?...

Cheers

[fridayman Senior Member Find all posts View Profile Close fridayman]

Maybe you need more caster angle ???

I'm also thinking that it sounds like the caster isn't right.

[glen_ep Addicted PP Member Find all posts View Profile Close glen_ep]

The symptoms sound like the alignment is not correct. How much faith do you have in the shop who performed the alignment? Workers may not make the necessary adjustments if they think the existing settings appear "good enough". They especially don't enjoy moving the lower arms around if they are seized up - too much work.

Is the vehicles direction being changed by groves in the road (following grooves) or is it just wandering left/right aimlessly, depending on a slight steering adjustments? Also, does it occur whilst accelerating, coasting or braking?

[HeathNZ Junior Member Find all posts View Profile Close HeathNZ]

New tyres fitted both ends now (second hand near new that is).

Going to get them to redo the alignment (they have done the last few and it was all good).

Car wanders slightly (its like tramlining when you hit grooves on the road) The wander is only small and only needs tiny corrections but its constant. It almost feels like something is loose, but its all good and tight in the steering components.

I am picking the alignment is just not quite right and will have it done again now the new tyres are on both ends. Also the tyre pressures are all consistent now (one front tyre was 47psi and the others were 38psi - not happy as I paid for a service which includes checking tyre pressures) and I wonder if the pressure differential on the front would affect things enough to make a difference.

No work was done on the rear end other than tyres and it drove sweet as a nut before the work was done.

Heath

[HeathNZ Junior Member Find all posts View Profile Close HeathNZ]

Alignment rechecked and is good (within specs).

Align guy went for a drive and commented that the truck drives well but has no feel in the steering. put it on the hoist and found the newly refurbished rack is very tight and is restricting movement (killing any road feedback and the steering isn't returning to centre).

Suggested I drive it for a while to see if the rack frees up a little but if it doesn't in a week or so to go back to the guys who rebuilt the rack for them to sort.

Anyone else had similar issues with rebuilt racks ?

[Bear63 Senior Member Find all posts View Profile Close Bear63]

I have struck this issue with rebuilt racks , pretty rare though , sometimes there is to much preload on the rack , also the valve body has been damaged but not picked up during the rebuild
Tramlining is nearly always caused buy insufficient toe in or the design of the tyre treads ie different tread designs front and rear or say light truck rated tyres on one end and passenger rated on the other

[HeathNZ Junior Member Find all posts View Profile Close HeathNZ]

Getting better with driving. Perhaps a few bubbles are being worked out of the system with driving.

[croozza Avid PP Poster! Find all posts View Profile Close croozza]

Getting better with driving. Perhaps a few bubbles are being worked out of the system with driving.

How bad was the old rack, maybe the new one is more direct and you are now just starting to get use to it.

[Beast2h Member Find all posts View Profile Close Beast2h]

check the ball joint's between the rack and hub's and also the bushings in the steering rack.

[ken2m Junior Member Find all posts View Profile Close ken2m]

the bushings in the steering rack.

2nd on the rack bushes, identical problem $75 on ebay for nolothane. fixed my problems. Ken.