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Post by isuzumudman on Apr 17, 2008 19:19:43 GMT 11
I have two swb Bighorns. One is auto and the other is manual. I bought new (suspension lift) rear springs & shocks and put them on the auto one and wound up the torsion bars to suit. At about 100kph a low pitch rumble became apparent just when easing off the accelerator (not too noticible when accelerating or decelerating but really noticible when coasting). I then took it all off & fitted them to the manual one. The noise was transferred too! The auto one is now quiet at all speeds and the manual one develops the same drive train rumble at about 100kph.
Any ideas?
Dave
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Post by geeves on Apr 17, 2008 20:20:18 GMT 11
This can happen on any vehicle that has its hight changed. First make sure all your ujoints are ok and the spring bolts are tight to eliminate actual faults.
cause is most likely that the lift has changed the allinment of the driveshaft flanges. These must be perfectly parallel or vibrations can occur. It can be fixed by raisein or lowering the rear ofthe gearbox or wedges between the spring and diff. The hardest part is measureing the angle to compensate which will be less than 1 degree
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Post by isuzumudman on Apr 20, 2008 6:18:53 GMT 11
This is the conclusion I think I was coming to as well. I'll have to find a way to accurately measure the angles when I have nothing else to do.
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Post by elysian on Apr 20, 2008 8:38:04 GMT 11
This may not be related at all, but when you wound up the front torsion bars, did you get a wheel alignment too ?
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Post by geeves on Apr 20, 2008 15:24:43 GMT 11
How bad is the vibration? If not bad why worry
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Post by isuzumudman on Apr 21, 2008 22:13:07 GMT 11
Irksome is a good word! It really is only a noise in the drive train which becomes apparent somewhere above 90kph. Not a big deal really. What change would I expect if I removed the Inertia wheel from the drive train?
Dave
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Post by geeves on Apr 22, 2008 7:04:21 GMT 11
inertia wheel???
The lwb bighorns have a 2 piece driveshaft with a rubber mounted bearing in the center that is bad for causeing vibration when the rubber gets old. They are cheapest at the holden dealer. Dont know if the swb has this though
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Post by isuzumudman on Apr 24, 2008 21:22:56 GMT 11
The Inertia Wheel (inertia ring?) on the manual swb bighorn bolts on to the front end of the rear drive shaft just behind the transmission.
It is a 2kg? steel band about 200mm diameter and 25mm wide & thick. The area between the steel ring and the central mounting plate is rubber with 6 steel cylinders. It is not fitted to the auto one.
The front and rear drive shafts are both of simple construction with expansion/compression splines only.
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Post by geeves on Apr 25, 2008 16:28:11 GMT 11
never ran into one of them before. Try removing it if easy as the rubber does perrish causeing strange things. Ever heard of the dual mass flywheels on prados? They are similar in construction and last about 60000km
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