No rear wheel power - is my VC dead?

I have a 1990 st185 that is effectively a FWD car. No power at all to my rear wheels. The worst thing is I think it must have been like that when I bought it and I just didn't realise.

I first noticed it because the front wheels spin from a standing start on a hill. The rear wheels do nothing and the car goes nowhere.

The mode select lever indicates the centre diff is in normal mode but it is behaving like it is in viscous free mode. When I jack up either of the front wheels with the trans in neutral they spin with barely any resistance.

My mechanic is not an AWD specialist but he has seen the diagrams of the trans in the BGB and is sure the VC is screwed and so is not transerring power to the rear wheels. From what I can work out and what I have read on here it seems like he might be right. Is there another explanation I have missed that might save me spending 100s of dollars replacing the transfer case/gearbox?

I suppose the selecter lever could have been put on wrong and it is actually in viscous free mode

Thanks in advance

Did you to change the postition of the 4WD lever?. Like you say, it might only be in the wrong position.

How much mileage does your ST185 have. Is your VC old?

If you do have to replace it, look at it as "Hey, I'm going to have a fresh new VC in my GT-Four!" I bought my All-Trac last year and I did it knowing that there was a syncro problem and wound up dropping $3200 on a rebuilt transmission and clutch, but I'm glad to know that I've got a good strong transmission for a long time!

Oh yeah and speaking from a perspective of complete ignorance on this point, being that it's "viscous"...could it be that it needs fluid?

Even if the viscous coupler was not working at all, there still is a center differential that would be splitting power front to rear. It sounds like you either have the selector lever wrong or something really broken inside the transfer case assembly.

Try swapping the position of the selector lever and see if anything changes, then go from there.

-Charlie

If the the vc is gone, the the center diff is not far behind and the car will eventually not move at all. These VCs are non service types so you do not need to add fluid, however you can have a shop cut open and weld a plug so that you can. A member is currently offering this service. If the vc/diff is gone, I would suggest finding a decent low KM gearbox over buying a new VC. It will be much cheaper, and less to take apart. You could just swap the transfers, or swap the whole gearbox. If you do the gearbox, this is also the time to consider a clutch upgrade while you are in there.

This is the time to upgrade to a st205 tranny and a new clutch while your at it :wink:

Actually reading the replies for phattyduck and CMS-GT4 made me remember the mechanic said it was definitely in the transfer case and probably due to a dead the VC.

I know I should have moved the selector lever to see what it did but the lock bolt was so stiff I couldn't get it undone. I was afraid I was gonna rock the car off the jack! I'll have another go tonight but I don't hold out much hope that the lever was somehow put on wrong.

The car's done 275000 ks so everything that hasn't been replaced is pretty tired now. The clutch was replaced a couple of years ago (don't know what with) but I think it's the original gearbox.

I read about the member doing the VC recos but yeah it'd be better all around to just get a new box or transfer. I was going to buy a gearbox from a 205 for $500 but then saw two 185 boxes on ebay for $250, one with a month waranty and one with new 2nd and 3rd synchros! I don't have plans for massive power incresases and I gather it wont help with initial acceleration so is the 205 box really worth paying double for?

It sucks having a FWD car but I am excited about what it'll be like when it's all fixed up.
Thanks heaps guys I'll let you know how it turns out.
-Robin

There are some advantages to having a st205 box but I was never personally convinced it was worth the extra money over a 185. On the other hand if you paying a mechanic to do the work and your looking at the price being 250 +giant labor bill or 500+giant labor bill. I might be more inclined to go with the nicer gearbox.

If you wanted to just replace the transfer case I have one I could sell you cheap.

Thanks for the offer mx6er2587. The new box and a new clutch went in and the car's running great (appart from the squeaking engine mount, whining wheel bearing and rattling exhaust). There was a sludge of metal shavings coming out of the transfer case so that might have had something to do with the lack of rear wheel action!