Knocking noise form back end

[dugie]

Hey i'm a little worried about my car i've got a 325 sport and I think the LSD might be on its way out basicly it makes this knocking or donking noise when the back wheels go over bumps it seems worse when going down a hill any help anyone could give me would be greatly appriciated.

Matt, Brighton

[nickfromgills]

I'd put money on it being one of your rear suspension top mounts.... pulled through the rubber. Have a look behind the trim in the boot and at your suspension unit itself - is it flapping in the wind?

They're easy to replace and about 12 quid a piece. Apparently the ones from the later E34 (I think) are more robust. They can go often depending on how you drive I suppose.

[Pal318is]

Sounds like your top mounts tbh. Use the e46 m3 ones, they'll do the job tons better. Also you might want to invest in some z3 reinforcement plates too.

HTH

Pal

[march109]

Sounds like your top mounts tbh. Use the e46 m3 ones, they'll do the job tons better. Also you might want to invest in some z3 reinforcement plates too.

HTH

Pal

top advice, this is exactly what I'm using and its damn near bomb proof compared to standard E30 jobs.

[o22ie]

can i ask where you brought yours from march109, i wanna invest in some

[tailoutcharlie]

think the z3 mounts were sourced by zedone one here but he's not about at the mo.

for the e46 m3 mounts try asking zimmerbimmer in the dealer section, he'll give a 'zone' price

[fuzzy]

rear top mounts would be my first thought although rear subframe mounts is another option. is it only knocking when going over a bump? or does it knock when accelerating?

[dugie]

hey thanks for the tips i've looked at my rear top mounts but to be honest i don't know what i'm looking for, it all looks attached so i'm getting my mate who is a mechanic to look at it tonight and give me a diagnosis if they are gone where should i get the parts from BMW or ebay?

[march109]

BMW! can't garauntee the quality of ebay ones!

[fowler]

its sounds like rear top mounts but it also could be rear subframe bushes . worst case scenario

[kam-325i]

its sounds like rear top mounts but it also could be rear subframe bushes . worst case scenario

Knackerd Rear Sub Frame bush's usally show as axle tramp or a woobly rear end.

[fowler]

not always have seen them where it sounds like top mounts but the rubber has fallen out of the subframe bushes so metal on metal contact. it also could be the diff bush wornd and the diff is clonking.
just get mech fried to look at he will know

[dugie]

hey guys thanks for all your help i've checked the rear top mounts and the drivers side is deffinatley gone so i'm gonna go to bmw and get some e46 m3 ones.

thanks
Matt