vibration through brake pedal and front end knock while reversing HELP!

[vr wagoon]

hey guys
just purchased a vr wagon.
my problem is when i put her into reverse and go to brake say out of my driveway, i get a vibration and knocking sound. feels like from the front end? i just replaced my front rotors and pads hopeing this would fix the problem but the issue still persists.
anyone had this problem before?

any help is greatly appreciated cheers..

[VR_Acclaim]

Vibration could be rear rotor or wheels unbalanced

[hako]

Could be the engine mounts, especially the rear one which gets soaked in oil and goes soft allowing the engine to move about. Front ones sag allowing the engine to hit the body. If they are OK, jack the front of the car up and get someone to apply the brakes firmly (engine off), then while the wheel is locked, try moving it up,down and sideways firmly to try and replicate and locate the sound you hear. Could also be a loose exhaust or many other things.
And welcome to the forum.

[The1]

didn't know they had rear engine mounts, you mean transmission mount? There's two engine mounts and one for the transmission.

[hako]

didn't know they had rear engine mounts, you mean transmission mount? There's two engine mounts and one for the transmission.

Depends on what school you went to I suppose - Gregorys manual calls it the "rear mount" - I've always called it the rear engine mount but you're probably correct - semantics?

[The1]

Yeh depends what book your i guess then, All the holden manuals call it transmission mount rather than rear engine mount as it bolts to the trans, i just bought a kit ive just replaced my engine mounts and the kit i bought was engine and trans mounts. But hey as long as we all know what you mean

[wagonman]

G'day hako,
Was it a problem B4 u re-did the brakes ? If not, go back to the rotors as you might have a sticky piston in one of the calipars, just because u hear it from the back may not mean that the problem is in the rear - the old old mans car had the same problem - sticky piston & the materials they use to make brake pads these day's is all from blended metals - "CRAP" in other words. If it's not that mate, get it up on a hoist so u can have a real good look everywhere.

Good luck with it

Cheers

[vr wagoon]

thanks for all the replys guys.
been told one of my engine mounts is gone!
would it be best to replace both engine and transmount all at once?

[The1]

i would do both engine mounts at the same time, if ones sagged and the other wont be to far off it, Trans Mount can be done anytime, engine mounts being done doesn't affect trans mount it's in a different location.

Trans Mount is on on it's own mount frame at the back of the trans, which unbolts, you have to pull off the Y frame exhaust pipes off first then you can get the trans mount frame off while supporting the trans then change the mount over.

You can do engine and trans mounts yourself but it can be a big job and a real pain to do, it's much easier on a hoist.

[hako]

I'd do all 3 - my VS just had a RWC and rear mount is soggy and split and 2 front are sagged and hitting body so they all got knocked back. I've ordered a set of 3 off Ebay for about $115 delivered. Mechanics want $220 to replace them (labour) but I figure $220 is better in my pocket so I'll probably do it myself....I'll probably regret it!

[RX25SE]

Vibration could be rear rotor or wheels unbalanced

Doubt you'd be able to pick up a out of balance wheel reversing out of a driveway.

[vr wagoon]

thanks everyone!
didnt think it would be my balance because car drives fine foward and only happens at very low speeds in reverse.
i'd say its my engine hitting the body.
just for piece of mind i will be getting the mounts replaced and new rear rotors and pads nextweek.

[nash88]

Surprised this hasn't been mentioned but the bushes in the front lower control arms, quite often wear out and cause a knock identical to what your describing, worth checking out.
Dave.