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Car jerking when switching engine off

('03-'05) 
13K views 13 replies 5 participants last post by  dave5358 
#1 ·
I have a Forester 2002 SG5 Automatic. When I switch the engine off after putting the gear in P (Park) position, it jerks as though the gear was engaged and I tried switching the engine off. It happens the same when switching off in Neutral position. However, I also does not happen always. at times it is ok. But it happens on most occasions. What could be the problem?
 
#4 ·
Not figured out yet

I had my mechanic check the solenoids inside the gearbox. he says they are fine. Still the problem is there. As I have another same model. I noticed that when driving, while accelerating or applying brake, I feel a click sound on the gear level. I need to hold it to feel it. It is also not always.

Can I get a guidance on which solenoids or connectors to check for around that area and also some guidance on the two wheel drive by using a fuse. I can then test myself and try to figure it out.

and yes, the cause is definitely the rear diff being engaged while switching off. Sometimes when I want to reverse, I do feel some resistance in moving reverse. I can engage the reverse gear and when I lift my foot from the brakes, the car does not move reverse. At times it does!
 
#5 · (Edited)
The issue is the AWD transfer clutch is fully engaged, you are driving with a 50/50 front to rear torque split. This puts the gearbox under tremendous strain. When You turn off the car, the engine stops turning, so the gearbox oil pump stops turning, hence the hydraulic oil pressure, which is used to lockup the AWD transfer clutch, disappears, and you feel the car lurch when this happens. Car can be in any gear and this will happen.


There is a solenoid control valve, all on its own in the rear section of the gearbox (in the extension housing) that controls this transfer clutch. It is not houses with the other control solenoids. The transfer clutch solenoid control valve is either sticky or intermittently faulty. Insert the FWD fuse. In the engine bay fuse box (going by memory here sorry, anyone else?)

Is the AT Oil temp light flashing when you turn the ignition to position II ?

To get to this solenoid control valve, mid section of the exhaust has to be removed, the propeller shaft removed, and the gearbox's rear extension housing removed. It is CRITICAL the gasket for the rear housing is replaced and RTV gasket maker is not used. The gasket sets the preload on the thrust bearing. Older gaskets were paper, newer were a crush steel. Neither can be reused.

There are four different solenoid control valve part numbers, correct part number selection is going to be a challenge.

Here are links to opposed forces, the spare parts identification web site.

Opposed forces. Solenoid Control valves


Opposed forces. Extension housing


I've searched the web, but can't find a picture of the March 2001 to November 2004 extension housing, only earlier variants. This photo shows the gearbox out of the car. The extension housing has been removed. The solenoid control valve is the part the wire runs to. See below:

 
#7 ·
I placed the fuse for the FWD. When starting the car, the dashboard showed the FWD light. Car moved ok but when switching off, the jerk occurred.

The oil temp light show when ignition on but goes off when the engine starts. Has not shown when running.

Then, with mechanic, dismantled the propeller and gearbox and checked on the transfer clutch solenoid valve and tested ok. cleaned though. Put back the whole thing and with new oil. Clutch showed some wearing on the edges.

The jerking when switching off still remained.

While I drive, and when I hold my hand on the gear lever, while slowing or pressing the accelerator, I feel some solenoid clicking. That is not normal as I have another same car and it does not behave the same. Could it be to do with some solenoid near or around or underneath the gear lever?

What else can I try?
 
#8 ·
The solenoid must be closed, with 12 volts applied to the solenoid, blocking the oil flow to the multi plate transfer clutch, to disengage the rear wheels, putting 100% drive to the front wheels.

The MPT's clutch basket's wear has to be VERY severe to cause any issues, I have one with 1.5mm deep grooves that works fine.

I suspect an obstruction in the solenoid valve assembly, preventing the cutoff of fluid. With the FWD fuse in, on loose gravel, do the front wheels spin?


Anyone else care to comment?
 
#9 ·
Just to amuse the heck out of you guys, this started happening to me when I replaced the 4eat in my '03 with a trans from an '04.

Turns out between '03 and '04 they reversed the signal to the transfer duty solenoid, so at idle in park it was at max lock, and went to min lock when I needed lockup.
 
#10 ·
Very interesting. I now note that the previous owner had changed the gearbox. However, at times, it works well and at times it does not. I have now noted that when driving. while accelerating or decelerating using the brake I feel a solenoid click sound in the gear lever. It is the one that engages and disengages the rear clutch. I can be assure that the gear box and the rear clutch solenoids are ok. (This is also after check-up) It does seem that a certain solenoid that you can feel while holding the gear lever is send ding the wrong signals for the release and engaging of rear clutch.

Does the above give some idea to anyone who can assist me on what to check next? I am also able to shift gear from neutral to reverse without pressing the brake.

Would it be that when the new gearbox was fitted, some connections or alignments were not done properly?

Can I get some pictures to guide on checking under the gearbox lever?
 
#11 ·
more info

Further to above, I went for a long drive of totally 1100km and the car was very good. I also realised that I can shift the gears from neutral to reverse without pressing the brake. Can this help in sorting out the problem of rear clutch locking while switching off but not always?
 
#14 ·
You go to a repair shop that has a 'power flush' machine. They attach hoses to your transmission and basically flush all the fluid and alien lifeforms out. Compare this to draining about 1/3rd of the fluid each time you drain the auto transmission at home. On the downside, the power flush might cost $100+.

There are several threads regarding power flushing and even recommendations as to whose 'system' or machine does good/better jobs. And, there are some experienced users who suggest that the drain/dilute/repeat method is just as effective.

I've never had a power flush done. But if your transmission valve is really functioning properly but a line or bleed to the valve is obstructed, a power flush might do more good than a drain/dilute/repeat.

I guess you have to decide if it's worth the $100+ gamble before you tear down the transmission to attack the valve. If it works, it might be a bargain. If not, the transmission you tear down will have clean(er) innards.
 
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