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2002 - Front/Centre/Rear diff problem?

('01-'02) 
24K views 23 replies 10 participants last post by  2.5x_sleeper 
#1 ·
The foz has a major problem!

When turning left or right on half to full lock there's a loud clunking noise and the car seems to jerk/clunk with it. Hard to explain really. It sounds like a CV joint failure but it's coming from the gearbox/rear diff area and you can actually feel the thunk through the steering and car seat/body. There is no noise or vibration when driving straight.

On the way home today I stopped at a services on the M1 and asked an RAC bloke if he'd have a listen while I slowly drove it in circles. His first words were 'Call your breakdown company'. He thought it was coming from the gearbox area. I limped home not going over 55mph.

Any thoughts?

mdg


It has been suggested that the front or centre diff may be at fault, and that the front diff has binding.

Since I originally posted this thread I have only done short journeys and there have been no more noises or clunking. The engine has been up to temp, but I would think the gearbox was still cold..

Could this therefore point the finger at the centre viscous diff thingy?

I have not yet been able to drain any fluids from the car, but I did check the gearbox levels and they were fine and the oil was clean.

Thanks in advance,
mdg :D
 
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#4 ·
Front diff I would say.same sort of thing happens on a front wheel drive when the diffs on its way out.when its noisy it will almost jurk and lurch like its popping out of gear.Fingers crossed its an inner cv shaft not a front diff.sorry I cant be more help but im not local to you to have a listen.ive had one go and ended up with a second hand gearbox.
 
#6 · (Edited)
Now this is really starting to pi55 me off.

Within 3 days of posting in the Euro section I had lots of help and suggestions as to what might be wrong.

Then the thread gets moved to the general forum and I hear nothing else.

Then I re-post in the Euro section again and I get a 2 further suggestions within 45 minutes.

Now it has moved again.

Could you PLEASE leave this thread in the Euro section as I would like quick answers to my questions.

A very annoyed,
mdg.
 
#19 ·
....
Could you PLEASE leave this thread in the Euro section as I would like quick answers to my questions.
Nope, The center diff in the MT functions the same all around the world. There is absolutely no reason this doesn't belong in the transmission and driveline forum.

Forum Rules - Please read!

General Posting Guidelines:

4. Do not crosspost, i.e. post the same thread in more than one forum. Choose the most appropriate forum for your topic and post it only once. Duplicate threads will be merged or deleted.
As for the trans troubles. I would go with the center diff if starting to bind. It is not uncommon. It can be changed out by removing the transfer section of the transmission. You don't need to split the transmission cases to gain access. IIRC there is a thread on here on how to replace them.

EDIT: http://www.subaruforester.org/vbulletin/f89/center-diffs-how-replace-them-46979/
 
#9 ·
Just read the initial post again...properly this time :biggrin:
80% I would say front diff.When the oils warm its thinner so the problems worse.When its cold and with the thick oil it lessens the problem.I personally (if you have the means) would disconnect the front driveshafts and run try to replicate the noise? A few "drifter" around here do this to imprezas so it should be possible on yours as its permanent four wheel drive so you'll still have drive.
 
#10 ·
Front/Centre/Rear diff problem...re-posted for speedy answers.

Thought I'd post this in the Euro section again as no info/suggestion as to what might be wrong was offered since it was moved from here...

The foz has a major problem.

When turning left or right on half to full lock there's a loud clunking noise and the car seems to jerk/clunk with it. Hard to explain really. It sounds like a CV joint failure but it's coming from the gearbox/rear diff area and you can actually feel the thunk through the steering and car seat/body. There is no noise or vibration when driving straight.

On the way home today I stopped at a services on the M1 and asked an RAC bloke if he'd have a listen while I slowly drove it in circles. His first words were 'Call your breakdown company'. He thought it was coming from the gearbox area. I limped home not going over 55mph.

Any thoughts?

mdg


It has been suggested that the front or centre diff may be at fault, and that the front diff has binding.

Since I originally posted this thread I have only done short journeys and there have been no more noises or clunking. The engine has been up to temp, but I would think the gearbox was still cold..

Could this therefore point the finger at the centre viscous diff thingy?

I have not yet been able to drain any fluids from the car, but I did check the gearbox levels and they were fine and the oil was clean.

Thanks in advance,
mdg


MODS...I'd like quick answers to this problem. If you feel compelled to place it in the Driveline section then why not copy it there, PLEASE don't remove it from the Euro section. Having to wait 9 hours for an answer when someone in Europe can answer within minutes is really frustrating.

Thank you,
mdg.
__________________
Less than 123BHP/Even less lb.ft
FOTM May 2010
 
#11 ·
Front diff I would say.same sort of thing happens on a front wheel drive when the diffs on its way out.when its noisy it will almost jurk and lurch like its popping out of gear.Fingers crossed its an inner cv shaft not a front diff.sorry I cant be more help but im not local to you to have a listen.ive had one go and ended up with a second hand gearbox.
Ok thanks.

So what breaks on them? And why only when the box is warm?
 
#12 ·
Just read the initial post again...properly this time
80% I would say front diff.When the oils warm its thinner so the problems worse.When its cold and with the thick oil it lessens the problem.I personally (if you have the means) would disconnect the front driveshafts and run try to replicate the noise? A few "drifter" around here do this to imprezas so it should be possible on yours as its permanent four wheel drive so you'll still have drive.
 
#18 ·
My browser is set up to take me straight to the Europe section...i rarely visit the 'whole' forum......we all get along really well in this section and most want to discuss 'ALL' our comments/faults etc under the same roof.

I appreciate the format of Forester.org and like all forums it has specific sections for specific discussions, i have no wish to rock the boat but the Europe section has been running like a Swiss watch until the recent sudden displacement of some of our threads!...Hence MDG having to re-thread his initial thread.
 
#17 ·
removing 1 front shaft might help as the diff wont get wound up.Removing a rear shaft would rule out a rear diff yes.Im worried about running the front without a shaft in it as it would bit a great strain on the wheel bearing.If possible separate the cv cup/boot and leave it in the hub.I think it has a surclip that needs removed then chapped off the shaft.(please check that though)
I did this shaft trick on my bugeye when i suspected my diff was knacked but it was the box :chair:
While running the car in the car park at very low speed the wheel bearing collapsed.Now this maybe just coincidence but just thought id say.
There is a very friendly knowledgeable guy on scottishscoobies.net with username Braveheart aka John who could talk you through everything should you need it.
Or i have his mob number if you prefer.
 
#21 · (Edited)
To add to the center diff trouble shooting.

Other possible items to look at that may fit the bill from your description.

CV - Typically makes a click, pop, crunch during turns or hard acceleration. You may be able to rule these out by getting all 4 wheels in the air, turning the front wheels full lock( this will be the most extreme angle you can put the CV joints into) and spin each wheel by hand feeling and listening for any noises.

Axle shaft - Some have had the axle shafts pop/pull out of the transmission(non-roll pin type). When they do this drivers report a pop/grinding on hard throttle, heavy loads, turns. The noise happens when the splines of the shaft walk out of the diff the last few mm and the diff basically freewheels rubbing on the axle stub. This is usually accompanied with not being able to get up to speed as the power is going the path of least resistance, taking power away from the other 3 wheels.

U-joints - easy enough to check by eye/hand getting under the car while it is up in the air. Look for excessive free play.

The most common diagnosis process for the center diff is to drive in circles as you have done and listen for where the noise is coming from. If from the transmission area most of the time you have your culprit.

A failed spider/cross gear in a front/rear diff would be much like a popped out axle. Power will go the path of least resistance. Typically a broken spider gear in the diff doesn't give much warning before totally failing. There really isn't that much to them, once they break a little they lose almost all of their strength and break up totally.

EDIT:

did some clean up and moved offtopic posts out to the helpdesk forum.
 
#22 ·
Subaru forester transmision wind up

sorry to drag up an older thread but maybe you could help me with an urgent question?

Similar to the above my 2001 UK Forester 2.0 non turbo manual drives fine but after a decent run (say half an hour) when you then try to do a 90 degree parking manouvre or reverse into a space the transmission winds itself up on full lock.

You can feel the resistance in the transmission build to the point where it feels lumpy, there is a slight knocking noise, and the only thing to do is straighten up the steering and go forwards and back a couple of times.

This feels like a problem with the centre diff not doing its job.
All 4 tyres are the same brand, size, and almost new so the wear is equal across all 4.

Anyone with the same model, 2.0 UK manual forester had this issue, what was the answer?

Can you jack it up and unwind the the strain is so how?
(my dad used to have an early Subaru XT turbo with no centre diff and sometimes we had to jack it up and wind the wheels back to release the wind up when we parked it i 4wd by mistake and when it was run with unevenly worn tyres front to rear).
 
#24 ·
@wertanphilip welcome to the forum!

Please complete your "Public Profile" ► add your vehicle details! ◄
Bobby...

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