1996 Subaru Legacy with bad rear wheel wobble

[subyworkshard]

I am a new forum participant with a serious problem. My 1996 Subaru Legacy has a bad wobble from the rear wheels when accelerating (not when coasting). The car has low mileage (156,000 km) and the engine runs well and I need the vehicle but can't afford an expensive fix. I typically do my own mechanical repairs and maintenance. I tried to switch to front wheel drive only but it appears the power control solenoid is malfunctioning. When the correct fuse is installed the dash indicator FWD light comes on but the rear wheels still get power to them and so the wobble continues.

Is there anything I can do to disengage the rear power to the rear wheels? I can't find a correct power solenoid for such an old vehicle. Is there some ghetto-rigging I can do that would enable more car use without quickly damaging the transmission or other essential component? Is there any way of resolving my problem short of replacing the rear drive train components by the trial and error method?

[el_freddo]

When you say rear wheel wobble do you mean vibration? 

This could be caused by many things as noted - start with the basics:

- check mounting bushes of gearbox, diff and tail/propshaft; check centre bearing of the tailshaft for movement.
- check uni joints for any play. ANY movement in one of these (where you can move one bearing cap closer to the other without the other one moving) means you need to replace it. Which means mods or a new tailshaft. 
- check rear CVs for any unexpected movement. 

Also realise that putting the 2wd fuse in will still see the rear drive shafts, diff and tailshaft spinning when the car moves. It just won’t receive power from the gearbox - assuming you have the auto from your description. 

What speeds do these vibrations occur? Is there a specific gear it happens in? Can you induce it by driving “manually” by selecting the gear the auto is to be in? 

If it occurs in all gears when accelerating my thoughts are it will be an issue with the auto.

[ocei77]

If your sure your lug nuts are tight , then likely your bearings are shot .

To replace the complete hub is not that hard. Just time and jack stands.

Go here for fsm:Index of /Auto/Japan/Subaru

 

 

 

 

 

[forester2002s]

If it's a vibration (rather than a visual wobble) coming from 'somewhere' in the rear of the car, then it could be the main drive-shaft vibrating under load. The centre bearing of the drive-shaft (located forward of the rear-diff) could be loose, or beginning to get loose.

[subyworkshard]

Thanks for your response. It feels like a wobble from the rear wheels but it could be a strong vibration. I can't see any wobble when I ride my bicycle beside or behind the car. It starts wobbling at bicycle speed and continues getting worst as I continue to slowly accelerate and stops as soon as I take my foot of the accelerator. After my process of elimination I have concluded it's either centre drive shaft rubber bushing, the transfer box, or the transmission. As there is no vibration coming from the front wheels and the auto transmission seems to functioning fine in all respect, good fluid, no leaks, and changes gears nicely, I tend to think its the drive shaft. I can not fine a new replacement for the centre bushing/bearing so I would have to buy a new shaft to eliminate that possibility, and the work to re & re. I was hoping I could easily and cheaply turn it into a FWD vehicle only. BUT, I also can't locate a new power transfer solenoid to re & re and not sure of what can of worms I may be opening up to replace it. The car has low mileage and motor runs well but it's been used like a work horse and has been beat up other wise, kind of like me at my old age and abused by hard physical work, so I'm hoping to get some more use to enable a big clean out of the salvaged construction materials around my home so my kids won't have to deal with my junk.

So I'm looking for a simple, cheap fix to get a little more life and abuse out of it.

Any future suggestions would be very much appreciated. My car has been a good work horse so I hate to put it out to the pasture yet while I still have a need for a beater.

Thanks again.