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Jimny wobbles are back
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Author:  Wanderer [ Fri May 23, 2014 4:11 pm ]
Post subject:  Jimny wobbles are back
Can anyone advise me.
The dreaded Jimny steering wobble is coming back , have previously changed all King pin bearings and fitted shims, and replaced the knuckle joint seals about 25K kl ago and car was wobble free.
This time around have checked KP bearings for condition and smoothness and found OK. Seals also appear OK.
Question is how much preload is required to reduce shimmy.
I have added shims to give approx 5 to 5.5 lb tension using spring balance at tie rod fitting on L & R knuckle joints, with the seals removed.
Is this enough? :?:
I am concerned adding too many shims will actually distort the KP bearings and housing.
Also car has 40mm OME lift will the change in castor amplify the wobble?
Author:  tanshi [ Fri May 23, 2014 4:15 pm ]
Post subject:  Re: Jimny wobbles are back
yes castor can effect wobbles. can also be worn control arm bushes and a shit load of other things
Author:  Jezza86 [ Fri May 23, 2014 5:19 pm ]
Post subject:  Re: Jimny wobbles are back
Question is how much preload is required to reduce shimmy.
4kg initial torque applied to the holethe tie rod goes in. normally measured without scraper seals. but you can test with the scraper seals on. if you have less then 4kg with scraper seals on you know you have troubble.
so 8.8lb with the tie and drag links removed and no tyre on the hub.

after 25000km balancing tyres may be a good idea.
Author:  Wanderer [ Fri May 23, 2014 6:34 pm ]
Post subject:  Re: Jimny wobbles are back
Thanks for the feed back.
Will re-shim the hubs and see how it goes, the tyres are standard 205/70/15 and very old , i thought the problem was just the tyres and balance
so went and got a set of Maxxis 753 M/T's on ranger 7" rims , (205/75/15's) car looks great but drives like shit .
So put the originals back on to do the trouble shooting.
Have put in .010" shims in both upper KP,s will re-shim and give it another go.
Have also visually checked most bushes around the front end cannot see any obvious defects car does mostly back road touring not extreme off road. 120K on the clock.
Once again thanks for the feed back.
Author:  zukenutter [ Fri May 23, 2014 9:12 pm ]
Post subject:  Re: Jimny wobbles are back
Wobbles while braking or just random driving?

Heavy pre-loading will cause rapid crushing of the KP bearings. Make sure you check the bearings before adding more shims.

I've been finding tyre rotation front to rear to be beneficial when a shimmy starts happening but not helpful to you this time I guess. Have you fitted any caster correction? If not that would be the first thing I'd suggest. IMO Jimnys need +caster at stock height so I think any lift would benefit with it
Author:  Wanderer [ Sat May 24, 2014 11:20 am ]
Post subject:  Re: Jimny wobbles are back
Wobbles are present under acceleration rather than braking.
Will shim again and test with old tyres. Then new wheels if improvement noted, KP bearings are well lubed and smooth
Any recommendations for castor correction bushes / supplier?
I see Suzistore have some.
Author:  zukenutter [ Sat May 24, 2014 2:22 pm ]
Post subject:  Re: Jimny wobbles are back
Can't help you with caster bush brands. I get a little shimmy under hard acceleration at the moment too but not enough to be an issue.
Author:  Mike57 [ Sat May 24, 2014 2:55 pm ]
Post subject:  Re: Jimny wobbles are back
I got my castor correction bushes from Ebay but the Suzistore ones would be good. I expect they are pretty much all the same. Adding castor did help with my slight wobble but later it came back and the KP shims fixed it. Only problem with these correction bushes is are they are all poly so they don't flex at all.

Mike
Author:  Wanderer [ Sat May 24, 2014 5:46 pm ]
Post subject:  Re: Jimny wobbles are back
Re-shimmed to 4./4.5 kg as Jezza86 suggested. With old tyres wobble eliminated, with new tyres wobble is still present @ 70/80 kph.
I think the extra mass/diameter has a lot to do with it. Very nice to drive at 110kph on the freeway and car is much smoother to drive.
Thanks to all for the info, next is a trip out to Lerderderg
Author:  Rustyray13 [ Sat May 24, 2014 7:12 pm ]
Post subject:  Re: Jimny wobbles are back
So adding shims decreases preload by moving the inner race away from the out or.cup bearing fitted to the knuckle shimming should only be done evenly top and bottom to maintain driveshaft to stay centrally through the axle seal guide bush diff
Author:  zukenutter [ Sat May 24, 2014 7:51 pm ]
Post subject:  Re: Jimny wobbles are back
The shimming talked about regarding Jimnys is opposite to shimming a Sierra KP. Adds pre-load
Author:  Jezza86 [ Sat May 24, 2014 8:08 pm ]
Post subject:  Re: Jimny wobbles are back
adding shims increases pre load in a jimny.
IMO shims go between the upper king pin and the upper bearing race, pre loading the bearing race into the bearing cup on the knuckle.
the mass of the car at rest is on the lower kp. adding shims to the lowerkp and bearing race therefore raises the knuckle, de centralising the CV.
Author:  Rustyray13 [ Sun May 25, 2014 7:00 am ]
Post subject:  Re: Jimny wobbles are back
Ok the roger that cheers for the info
Author:  Wanderer [ Fri May 30, 2014 8:01 pm ]
Post subject:  Re: Jimny wobbles are back
For info:
After much trouble shooting, put new rubber (maxxis 753: 205/75r15) on to original stock rims.
Wobble eliminated.
Original standard rims are +5/+6 offset.
CSA steel rims (sunrasia style) as listed in the Mullins wheels catalogue for all Jimny models are -6 offset.
This was a match up made in hell, I do not recommend the CSA rims, the Jimny wobble was most severe at 60 thru to 80 kph.
All standard procedures were carried out.
Front wheel alignment carried out.
Shim KP,s and check smoothness and lube.
All linkages and bushes visually and physically checked.
Swivel hub seals checked for condition cleaned and lubed.
Shockers checked all round.
Original springs reinstalled front and rear to restore castor angles.
All wheels and tyres were correctly balanced and inflated.

Wobble was only eliminated by installing new tyres to standard rims.
On re-installing rear OME springs test drive had no wobble.
On re-installing front OME springs a very slight trace of wobble could be sensed at 78kph. possibly due to the slight change in caster angle.
If wobble returns in the future i will fit caster correction bushes only after the above procedures have been carried out again.
Hope this may be of help to others.
Author:  atari4x4 [ Fri May 30, 2014 8:11 pm ]
Post subject:  Re: Jimny wobbles are back
wonder how out of round & how much run out the sunny's have? should get them to spin one up bare on the balancer.

my tyre guy has had some shockers over the years. the 10mm extra wheel track from the offset probably isn't helping but plenty of people are running similar spec wheels with no drama's.
Author:  zukenutter [ Fri May 30, 2014 8:25 pm ]
Post subject:  Re: Jimny wobbles are back
I'll say again that caster fix would be the first thing that should be addressed, then go from there.
Author:  Jezza86 [ Fri May 30, 2014 9:54 pm ]
Post subject:  Re: Jimny wobbles are back
Check your front panhard bushes are ok and the bolts are tight. Like really really tight
Author:  zukenutter [ Sat May 31, 2014 7:10 am ]
Post subject:  Re: Jimny wobbles are back
^^ x2 also good advice
Author:  Mike57 [ Sun Jun 01, 2014 11:15 am ]
Post subject:  Re: Jimny wobbles are back
atari4x4 wrote:
wonder how out of round & how much run out the sunny's have? should get them to spin one up bare on the balancer.

my tyre guy has had some shockers over the years. the 10mm extra wheel track from the offset probably isn't helping but plenty of people are running similar spec wheels with no drama's.


It might be that the sunnies are out of round (slight buckle) but balance up OK but it could also just be the extra weight that is triggering the wobble. I never had any real problems with the wobble until I fitted manual hubs. That extra weight on the end of the axle triggered it.

I also has a new rim that balanced OK but was slightly off centre and that caused a vibration naturally.

Mike
Author:  Jezza86 [ Sun Jun 01, 2014 2:40 pm ]
Post subject:  Re: Jimny wobbles are back
Mike, If your freewheeling hubs are a problem you can get a on vehicle wheel balance done. This will allow you to rotate the fwh to one of 6 positions in which the wheel hub and fwh are most balanced even befor mounting a tyre and rim
Author:  zukenutter [ Sun Jun 01, 2014 2:57 pm ]
Post subject:  Re: Jimny wobbles are back
Did you take the wheels off while fitting the manual hubs?
I have found that even an uneven hub face or wheel going back on at different lug position can affect it.
Author:  Mike57 [ Sun Jun 01, 2014 6:21 pm ]
Post subject:  Re: Jimny wobbles are back
Jezza86 wrote:
Mike, If your freewheeling hubs are a problem you can get a on vehicle wheel balance done. This will allow you to rotate the fwh to one of 6 positions in which the wheel hub and fwh are most balanced even befor mounting a tyre and rim


This was quite a while back now. I just needed to shim the king pins and it was fixed. The lesson I learned here was it is adding weight to the end of the axles that sends it into wobble mode. I think the same issue occurs when adding bigger tyres or heavier rims.

I did remove the wheels when I fitted them.

My wobble is all fixed now after shimming.
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