Birty Dastards Jeep Club
Tech Forum => Workshop => Topic started by: akabigm on December 31, 2009, 11:46:18 AM
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I've booked it in for a mechanic to have a look, but just wonder if anyone has any ideas.
Grand Cherokee WJ 99 4.7V8, at 60mph steering goes very light and truck feels unstable at front end, but ok when under power but when lift foot off gas ie downhill, approaching obstacle/bend etc starts, but will be happy at 70mph plus when powered and OK at all times under 50mph.
Has nearly new BFG all-terrians, and Old Man Emu shocks and springs new, so don't think tyres or shocks ????? didn't have the problem until recently
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if its lifted check the caster angle, also worth rechecking the tyre balance
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Definatley re-check the balance of all wheels, very easy to loose a weight & the balance can change when new tyres have bedded in :icon_winkle:
Its a cheap & easy 1st check
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castor angle,
fucked ball joint on the trackbar
tracking will need to be corrected if lifted
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totaly shot damper
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I'm +1 for steering ball joint (maybe a axle knuckle joint too), been here before with mine & it was the drag arm ball joint, OME lift is sub 2" so wont affect the geometry that much, & I have driven my grand without a steering damper and get no wobble
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Not saying this is it and it might all be different for RHD trucks but seems to be a prob for WJs and not such and issue for ZJs and XJs.
this and Iceland offroad are a good resource. Look here.... http://www.kevinsoffroad.com/wj/wj_dualsssetup.html (http://www.kevinsoffroad.com/wj/wj_dualsssetup.html)
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i am with fatso. steerin damper.
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i am with fatso. steerin damper.
yeah but they only mask an issue, WJs can run without them
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agreed but still better to have one than not i think.
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Mechanic is puzzled, :icon_rolleyes: he can feel the problem but checked ball joints etc etc no play, nothing worn, he doesn't know what it is ! Only suggestion was the EMU shocks and springs are to blame....... thanks for all the suggestions, will have to wait until my jeep expert gets back from his holidays in sunny parts, and in the meantime don't drive above 60........
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Are you sure your BFG's are genuine ones, a few years ago there was a large shipment of copies( poorly made in china, un even tread/sidewall thickness) that appeared over here, why not try swapping wheels front to rear to see if there is a problem with a tyre.
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Slighty off topic I had death wobble & it went after I got smaller rims bigger tyres & a lift :banghead:
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with tracking and wheel alignment the vehicle should run correct. steering wobble or death wobble as the yanks prefer to call it is normally caused by the lack of a suitable or working steering damper or worn track rod ends/ loose joints. this is a result from a bump from the road on the tyre which then sends the input to the steering wheel and with a bit of play in the steering causes the vehicle to veer either to the left or right. normally called bump steer in the UK.
Large tyres can add to the factor due to the play in the sidewalls but not to the extent that is being compained about here.
Is there any play in the steering ? do you have to turn the steering wheel more than normal to make the jeep corner or do you have to keep correcting the steering wheel to travel in a striaght line. If so the steering box might need looking into (yes this steering issue is almost std on the cj series, now ducks for cover)
(thinking out load, could there be a problem with the transfer box in regards to the torque split front to rear if running in perm 4wd)
one other option is to swap back to the std dampers on all corners and see what happens. what you could have is a defective set on the front that cant cope with the road input in the situations you describe causing the front wheels to patter as they cant cope with the wheel road input. I have seen this in the past but this is normal in damper development not on a road vehicle.
As for OME springs these are just set at a PSI loading (how much weight for the spring to move 1" in compression) so aren't an issue as they are the same as any other maker.
let us know the outcome
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So many answers !! Thanks for thinking, the BFGs are I think totally genuine from Event Tyres, but swapping might be worth a try, I thought steering damper but its not when you hit a bump just when lift the power off at speed.
Steering seems oK at all other times, will have tracking checked
The transfer box idea seems to me uneducated brain to have some merit, its permanent 4WD and I think the quadra trac ii system splits 40/60 in high range, maybe its taking the drive away from the front for some reason best know to its self? in low range of course can't replicate as can't do 60mph then !
As said I know a man who might know, in some senses if its something major like transfer box that might be OK as I still have a warranty on major bits :icon_winkle: will go and read the small print as to what is covered.
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obviously you can apreciate it is had to diagnose a solution across an internet forum, the best answer is to find a stretch of road where you can replicated the problem every time so that your mechanic can actually feel and see the problem so that he then can go and find the solution.
i think this is a case of throwing ideas at you no matter what and quite a few can be dismissed easily
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On the TJ you can adjust the castor when you lift it. It is adjusted by the excentric bush arrangement in the front lower control arm bushes. Do you have you these on yours and have you adjusted them?
(https://birtydastards.com/frm/proxy.php?request=http%3A%2F%2Fi82.photobucket.com%2Falbums%2Fj272%2Fmmore514%2FDSCN3286.jpg&hash=71b738c46d9c010174d8f46af177a3ebdbe73557)
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Thanks for all the suggestions, it turned out to be steering damper, lack of oil therein, now replaced and can go faster than 60mph !, but they found some other things at rear but also fixed and got new MoT, only left with noisy front diff........
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So the Dangerous Brothers were on the money then......
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The steering damper wasn't the cause of your problem. The new one is simply hiding the fact that there is something wrong with your front end.
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The steering damper wasn't the cause of your problem. The new one is simply hiding the fact that there is something wrong with your front end.
Not necessarily.
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they dont fit dampers as standard for nothing
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they normally fit them to reduce the effect of a problem the manufacturer can't resolve.
4x4's with bump steer
motorbikes with lively light steering (suzuki jumps to mind)