|
|
|
Subaru Forester Tranny Problem
My 2002 Forester has been a great all around car. I bought it with 30K miles a couple of years ago. The only problem I have is that, when driving in snow or extreme rain and I go from good traction to absolute spinning of front wheels, the 4 wheel drive engages in the rear about a 1/2 second later with a loud bang. This is not just a clunk. It is a bang which shocks you and the car. My daughter has the same car and it does not have this problem.
I have an extended warranty which lasts until August 2007. I have taken the car to 2 dealers who cannot reproduce the problem. It is never bad weather when I bring it in or they have driven it in gravel which does not reproduce the problem. The last dealer (last week) told me that a clunk in the rear end is normal as when the front loses traction more power is shifted to the rear wheels. They said that I should bring it in in bad weather and try to reproduce the problem for them. This is difficult since usually in bad weather people just want to get home.
So it appears my options are a) get ready for some bad weather driving to the dealer, or b) tie this car to a tree and kill the damn transmission before August next year  . Anyone ever have a problem like this? Any hints on what the problem could be?
|
|
 Add Photo
Bookmarks: |
|
|
|
|
Subaru Forester Tranny Problem
Give "Click and Clack the Tappet Brothers" a call on National Public Radio. The link shows their website.
It sounds like a road water-related (do they use road salt where you are?) issue either delaying, preventing or shorting the signal to the computer telling it to lock up gradually. Not sure but there may be a "limp home" mode that is causing it to engage so rapidly that tells a sensor to "do it anyway" even though a signal is not 100%. I'm only guessing--going on my experiences with other systems.
Link:
|
|
Add Photo
Bookmarks: |
|
|
|
|
Subaru Forester Tranny Problem
Have you checked for play in the universals and rear end? A lot of the old trucks we used in the woods would have worn rear ends and then near new front ends, as you seldom turned them in. If you placed them in 4 wheel they would bang and hop down the road. It could just be taking out the slack in the drive train as it engages. I would roll underneath and wiggle the drive shafts to determine how much slack is there.
Second, I don't really know this system. My Uncle's Forester is AWD and manual. If it is an electric clutch like the overdrive systems on the Volvo's, Triumphs etc then it is like you drop the clutch with a bang if you do not retard the accelerator. Some of the GM products use this sensing technology and only engage the rears or front electrically or hydraulically when needed. If the rear engages with the front spinning then you may very well get a bang as the clutch pulls the other set of wheels in.
|
|
Add Photo
Bookmarks: |
|
|
|
|
Subaru Forester Tranny Problem
Thanks guys. Interesting site EW, I will have to check it out. Peters, I haven't got up under there - the first dealer said universals, etc were tight. But maybe I should look for myself. I can minimize the problem by laying off the gas when in snow. It is maximized when revving and gunning through the snow. Fortunately with this car there is usually no need to gun through the snow. One the traction does take hold it can go pretty much anywhere.
|
|
Add Photo
Bookmarks: |
|
|
|
|
Subaru Forester Tranny Problem
They advertise these systems as "seamless" and "you never know it is engaging". Not having owned one I can not say how they should work. I thought all the Subaru were now all wheel drive. I rented an Outback in South Dakota one snowy night and I know it was.
|
|
Add Photo
Bookmarks: |
|
|
|
|
Subaru Forester Tranny Problem
Just for the fun of it, I'd say that it would be the coupler for the two axles. Don't know why but there is an error factor built into it and I think that it isn't engaging properly. You might be able to get it to act up by jacking the front of the car and leaving the rear on the ground without moving the car.
|
|
Add Photo
Bookmarks: |
|
|
|
|
Subaru Forester Tranny Problem
Interesting thought Art, it may be worth a try. I guess I would just manually spin the front wheels and see what is going on underneath.
|
|
Add Photo
Bookmarks: |
|
|
|
|
Subaru Forester Tranny Problem
NC: Somewhere in my mental archives I recall something about these systems that uses a viscous coupling like a torque convertor, versus a purely mechnanical lock-up. If so, you may not be able to replicate the lock-up condition jacked up.
And, I Googled your vehicle and a result came back as being able to buy a new rear axle---interesting, huh?. The site/my computer locked up twice (of course) so I wasn't able to find out more. But having had 3 imports over the years---and replacing a rear axle on one--that pounding sound may be a bad axle and what you are hearing is momentary pinion and/or bearing backlash/wind-up as the front drives the rear and plays catch up. This is fairly easy to detect jacked up, but you'd have to know the specs first. You might be able to hand-rotate the drive shaft hard and fast enough to get it to make noise. Dunno.
|
|
Add Photo
Bookmarks: |
|
|
|
|
Subaru Forester Tranny Problem
The Subaru drives predominately from the fronts, they do differ from one to the other but my memory tells me from a sales pitch that they are 80% front and twenty percent rear. If the coupler was losing it's ability to function it very well could be slaming into it's work instead of nicely beginning to function. My thoughts for what they might be worth is to raise the front so they would be able to spin and see what the rear is doing might tell where the clunk is coming from. Is this a standard or auto transmission?
|
|
Add Photo
Bookmarks: |
|
|
|
|
Subaru Forester Tranny Problem
Art is it a viscous coupling system or a continuously variable system like the newer transmissions. My only experience with owning a AWD was an old Jeep full size Cherokee,74. It used an expensive system like the Range Rovers which is a linked chain that moves like the newer continuously variable transmissions from what I know. For the era the system was quite economical as with a 360 ci I got about 16 mpg.
What I read there are 2 different systems on the Subaru.
Active AWD: Subaru's automatic transmission use Active AWD, mostly front wheel drive and uses traction sensing computer input to electronically vary the front to rear power split via a hydraulic multi-plate transfer clutch.
and
VTD AWD (variable torque distribution). New in 2001, VTD transfers powers front to back electronically. The power split is 45/55 front/rear and the rear wheel bias is designed for a more luxury car feel as opposed to the front bias of the Active AWD system. Usually 45/55 front to back split but that varies according to wheel slippage.
My guess is the system in this Forester is the first one an there is slack in the drive train or mechanical or electronic problem with the rate of engagement. Did you check is there were any recalls on this model? It might be as simple as reflashing the control memory. I found a site once that you placed model numbers and VIN in and told you all the recalls on the vehicle. I will see if I can find it again.
|
|
Add Photo
Bookmarks: |
|
|
|
Gas Generator Weather Protecti
11-19-2006, 08:29 
Digg It 
Del.icio.us 
