[shark]

Hey guys,

Tried my first RUF today.
I ended up using factory rear springs and 1 inch extended shackles.

I got it all welded up and when I went for a drive at about 60kms per hour it got crazy shakes and had to pull over.

I repeated this a few times and all with the same results.

I was given the shackles and there seems to be a bit of slop in them and I'm not sure if that's causing the issue.

Any help would be greatly appreciated

[alien]

"slop" in the shackles will definitely do that... as will the extended shackle and possibly longer leaves changing your caster angle....

try putting stock shackles back on just for a test drive to see...

[shark]

Okay the slop is just me not paying enough attention I think.

Won't the shackle angle be screwed if I put the factory ones back on?

[JrZook]

When was the last time you did your wheel bearings and kingpins?

[shark]

I haven't looked at the since I first bought the car.
I had zero problems yesterday and since doing RUF today I can't drive past 60kph.

Shakes are so bad I have to pull straight over

[Matthew]

If you have changed the caster angle it may exacerbate any underlying kingpin or wheel bearing issues.

You will also want to remove that load leaf from the pack, it's going to act as an anchor.

[shark]

Okay the more I think about it I do get a very slight shake at about 70km per hour.
So would they be the obvious culprits??

Or should I still try the factory shackles?

I'm going to triple check all my measures tomorrow too. Make sure I haven't done anything silly.

[alien]

factory shackles will be a bad angle, but at least you can use them to see if its the shackles causing it - then diagnose if its the castor angle or the shackle needs bigger bushes to make it more snug... actually, looking at the pics (could be the camera lens) but the shackles are hell bowed... the middle bracing bit might be too wide hence not being able to tighten them to the bushes properly.

the ideal solution would be to shift the hanger forward and run a stock shackle though (full ruf) - search for moph's build thread - he did a bolt on full RUF which turned out pretty tidy for a home DIY job!

[rick1970]

How are your shackle bushes? It mite just be the pic, but things seem a little wonky there.

Mine is set up with std rear main leaves, and a mix of Sierra and LJ leaves from there (used what i had lying around), front hanger moved 30mm forward and 90mm (+20mm) shackles with std Suzuki rubber bushes. Its a tad soft in the front, but dosn't get the shakes.

Suzuki shackle pins are 13mm, so if using bolts (assume 1/2"), its the same as having a bit of wear before you start.

[shark]

Shackle bushes still seem okay.

Your right the shackles are bending in and i can tighten alot more.
I did consider what I have done as a full ruf??

[SierraDan]

My ruf look exactly the same. Id check bearings.

[alien]

shark wrote:

I did consider what I have done as a full ruf??

yeah, you moved the hanger... but IMO it should be about 30mm further forward so you could run a stock shackle. shorter means less side to side movement, which means less chance of wobbles and less effect on castor angle cos you're not rotating the diff as much.

[SierraDan]

I have zero wobbles. Ive never driven a sierra that drives as nice. As mine does.

[JrZook]

Must have not driven many sierras then

[SierraDan]

Apparently.

[shark]

Hey guys,

Okay i got a progress report..

So far i have done the following.

Double checked all the bushes and made sure they were all in good condition.

Reverted back to factory shackles. Looks nice and firm and straight.

Moved shackle mount to the 60mm point (60mm from original position)

Re-torqued the wheel bearings and removed any slop.

Its still shaking, it drives past 60 kmph now but starts at 70 kmph.

It feels very very dodgy driving it on the roads..

Please help i need to get this sorted before work tomorrow.. What have i missed??

I'm starting to regret tackling something like this with no experience.

[shark]

I also remade the spring pack with some leaf's out of the the front pack (removing those "anchors")

[shark]

Some pics

[jono165]

I think your kingpin bearings need adjustment/replacement. They need to be shimmed so that a certain amount of force is required to move the steering knuckle.
Its likely that they were ok before you did the RUF but now that the castor has changed the wear on them is accentuated.
Attached is the section of the FSM relating to kingpin shimming.

[JrZook]

King pins and wheelbearings!

As SierraDan said he had a similar setup as what your started off with and had no issues

[alien]

i went for a ride in it just before... when it gets its wobble on the front rims are moving 50mm each way! its a crazy big wobble!!!

looking underneath, the front pinion angle is too steep by a fair bit, so that wouldnt be helping the caster angle, and would definitely accentuate worn kingpins... that said though there is no play in the kingpins or wheel bearings.

Would also explain why fitting the shorter shackles has helped the wobble a little, as it would have pointed the pinion down a bit more, just not enough to bring it back to factory.

[Daves4wd]

Suzukikid had the same problem turns out it was worn spring bushes... I'm not saying it could be that but make sure it's all nice and tight... Just saying

[want33s]

Wheel alignment to check actual caster and then caster wedges.

[shark]

Hey guys,

Mick came over and we went over a few things.
I went and tightened all the u bolts again. Without knowing the torque settings I didn't want to break them as I have done on my patrol in the past.
Tightened the shackles too.
Mick sorted out the slop in the steering.

We then went for a drive and the shakes had gone. I won't feel very confident about it till I have driven to work and back tomorrow.

It is definitely due for a wheel alignment

[shark]

Okay results are in.

Used the car to get to and from work today and slight trip to training racking up about 100kms

Not one sniff of a shake, in fact it would have to be the best its driven in ages. Seems to soak up the bumps alot better than before.

So it seems strange that it was either the play in the steering box or the torque of the u bolt nuts. Now i went and torqued them up properly tonight and they still needed quite a bit to get them up to spec. IM surprised as i really did tighten them up nice and firm.

I will put the king pins and wheel bearings on teh shopping list but i have now had 3 people have a quick feel and reckon they feel okay..

Cheers for all your help fellas, will update if anything changes