I have a 1992 Q45 with a serious vibration between 1500-2500 rpm. I have been told that the driveshaft may need balancing (can these balance weight fly off?) or perhaps one or more of the u-joints are bad causing restricted travel. Another theory is that the rear transmission mount may be breaking down causing the transmission to drop, hence putting the driveline in a bind.
What should I look for when inspecting the transmission mount? Are there any specs to investigate?
Has anyone ever had to have their driveshaft rebalanced or overhauled?
Boudreaux
92 Q45 SHIMMY 1500-2500 RPM
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elwesso
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Re: 92 Q45 SHIMMY 1500-2500 RPM (BOUDREAUX)
Does the vibration occur with the engine in park and in drive??? IE moving vs not moving?
Re: 92 Q45 SHIMMY 1500-2500 RPM (BOUDREAUX)
If it's a transmission mount, you should be able to determine it easily on a visual inspection - all pounded flat n stuff, from the shimmy. Mine was a mess. I had a nasty shake centered at about 2250 RPM. Replacing the transmission mount took care of it.
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texasoil
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A bad driveshaft will cause vibration that is road speed related, not engine speed related. Drive at the bad speed and slip it into 3rd.If the vibration changes a lot--not the driveshatf. Maybe an engine mount or exhaust system hangers hard. A sagged transmission mount seems to cause a resonant vibration at 1500 RPM and 2450 or so. Any vibration that is present when not moving is either engine mounts, transmission mount, or exhaust system mounts.
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nissanforlife
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Re: (texasoil)
WOOHOOO!! another olathe Q-man... hope you get the problem figured out.. these guyz are really helpful.. come hang out in the infiniti general forum too... its basically Q central..
Re: 92 Q45 SHIMMY 1500-2500 RPM (BOUDREAUX)
grab driveshaft at the carrier bearing and wiggle. if there is a lot of movement, there you go. look out, had to replace the whole driveshaft on a friends 90 q45, because replacement bearing was moddified and NLA. over $500 and that was with employee discount.