andywrxppp

Hi, I've got a problem with my 2003 WRX PPP, when I come on and off the power (no matter how smoothly) I get a hefty bounce through the drivetrain, its more pronounced in the lower gears. Its like there is a load of slack somewhere.
I have replaced the engine mounts and gearbox mount for group n items, I originally thought they were the problem. It is improved in some repsects but almost undriveable around town, coming on or off the thriottle in a slow speed bend/roundabout is horrible. I have noticed the rear diff front outrigger bushes are very slack (moveable by hand easily), is this a likely culprit?
Anyone experienced this, what are the usual culprits, any advice appreciated. Its ruining a pretty sound car!

328isport

iTrader: (6)

Doesn't sound nice, especially as you've already done the engine mounts, did you uprate the pitch mount also? Sounds like the diff is the next thing to mount properly and then go from there, It could just be that the bushes are completely shot. Easiest option would be to have a read through this post

https://www.scoobynet.com/drivetrain...iff-brace.html

And go for either the one 2pot posted a link for or a Beatrush one (I posted the details of someone who's doing them at a good price on the thread also). Either will bolt the diff to the subframe bypassing the bushes

JDM_Stig

iTrader: (3)

Where is the noise ?
If in the rear area where these are then yes as they are a pita,
But as you have changed the engine and gearbox mounts is the noise at the front ?

andywrxppp

I didn't change the pitch stop mount, I wasn't really sure how much it actually does, its on my list, do you think that in itself would cause a major problem? I can't see the engine moving at all if I put in gear and lift the clutch to take up drive whilst watching.

Thanks for the link to the brace, I would rather keep things standard ish if possible, I imagine that brace adding a lot of NVH? Has anyone changed their outrigger bushes for standard ones? I've seen the supplementary washer type bush inserts, I don't really like the idea of those when the bush is so tired.

andywrxppp

I don't have a noise as such, just a load of slack, its difficult to tell where its originating from. I assume the back end as I 've replaced the bushes at the front (all except the pitch stopper), also I've seen how slack the outrigger bushes are. I assume the actual diff mounts are in a similar state. I can't believe how many bits of rubber are worn out on a ten year old car!

andywrxppp

Update on this, I've replaced the main diff bishes with superpro items (what an easy job) the old ones were slack as hell. It's definately better but not quite there yet. I've still not done the outrigger ones. I'm thinking maybe just the superpro supplement washers for that.
I think my pitch stop mount should be done too. Any reccomendations for a make? I don't want loads of harshness and I don't care what it looks like, its a functional thing for me?

matt-c

iTrader: (5)

Did you fully resolve this in the end?

andywrxppp

No! Its a total pain, the new mounts here and there have tightened things in some respects but in other ways its made the overall problem worse. Having the engine, gearbox and diff with group n mounts has made that all nice and solid but the slack within is now more obvious, if that makes sense. In all honesty I suspect one of the diffs (front or centre) has some slack in it. I've read how much fun it is getting the gearbox out of one of these and am just putting up with it for now, I've done 20k miles like it! Has yours got the same problem?

matt-c

iTrader: (5)

I notice it sometimes yes.

Mostly you can drive round it and it causes no issue, just need to put more throttle or dip the clutch, it's annoying though overall.
I think you are right, there is some play somewhere which is causing this.

Am getting gear and diff oil changed at the weekend, but not really expecting it to help.

Looking on web it seems a common problem with different types of vehicles too.
I'll get to the bottom of it eventually.

andywrxppp

Mine sounds a fair bit worse than yours to be fair, the first thing i did was change the gearbox and diff oil, it quitened things down a bit, but then i put group n mounts on which brought the noise right back!
It does indeed seem quite a common problem, look at any bmw forums in particular... The trouble with awd is that there are so many more places for a problem to occur!

Good luck, keep us posted!