had a set of King low springs installed last year but ever since there's been a knocking noise from the rear. I took it back to the shop that installed it and they drove themselves nuts looking for what's causing it. They told me they'd tightened everything that could possibly be tightened and the knocking noise is still going on. They had 3 guys drive the car try to diagnose it, with 1 guy sitting in the back seat trying to discern where it's coming from. They inspected everything and can't find anything wrong with it. It's not THAT loud, but noticeable over bumps.

Car handles great. cant fault it - just an annoying knock. happens over the tiniest bumps in the road - not like it's travelling right up to the bump stops, etc...

Just before installing the low springs I took it to Mitsubishi to investigate a knocking noise from the front and they replaced the front stabiliser bar bushes (under warranty). they inspected the rears and said they were fine.

Now i'm worried if i take it back to mitsu (if they can diagnose what it is) they'll say it's because I've got lowered springs and make me pay thru the nose to get it diagnosed/fixed...

anyone else had a knocking noise over small bumps from the rear suspension setup after installing lows? tips for diagnosing?

I'm wondering if I should try putting the stock springs back on to see if the knock goes away - not sure if that's a massive job for a DIY or should I take it back to the garage/workshop and pay a coupla hundred just to go back to stocks, then possibly pay another coupla hundred to go back to lows if they find it's not due to the lowered springs....i'm concered about doing it myself coz i've heard those springs can really go boing big time dangerous...or can you get a cheapie tool that makes it safe to remove at home from supercheap/autoshop etc?

tips/advice? thanks in advance.

A knock on the small roughness cause the rack stabilizer of transverse stability. Sounds like a pencil in a glass.

A knock on the small roughness cause the rack stabilizer of transverse stability. Sounds like a pencil in a glass.

Google translation : The knock over the bumps is caused by the Rear Stabilizer bar.....
.



Top Effort Stayer, kudos....

Based on my experience I vote for the rear stabilizer bar as well.
Most likely worn out rubber D bushes. It doesn't take much wear before the bar starts knocking.
The bushes might look OK but still be worn enough to cause a knocking noise.
Once you put lowered springs on the bushes wear a lot faster than with stock springs, so just because the dealer said they were OK before you installed the lows doesn't mean they are OK now.
They are cheap as, about $12 the pair from a dealer, and easy to DIY replace, so that's where I would start.

Hi for me it was the bump stop installed incorrectly when the new springs were fitted

Based on my experience I vote for the rear stabilizer bar as well.
Most likely worn out rubber D bushes. It doesn't take much wear before the bar starts knocking.
The bushes might look OK but still be worn enough to cause a knocking noise.
Once you put lowered springs on the bushes wear a lot faster than with stock springs, so just because the dealer said they were OK before you installed the lows doesn't mean they are OK now.
They are cheap as, about $12 the pair from a dealer, and easy to DIY replace, so that's where I would start.

Sorry for the slight diversion, but would you recommend replacing these anyway if fitting any new suspension? I'm looking at replacing my stock set up (140k kms old) so anything that will save me hassles later on i'm all for, especially for 12 bucks.

Sorry for the slight diversion, but would you recommend replacing these anyway if fitting any new suspension? I'm looking at replacing my stock set up (140k kms old) so anything that will save me hassles later on i'm all for, especially for 12 bucks.

Leigh,

Yep, might as well replace them while you're at it. Especially if you install lowered springs.

That said, the rear stabiliser bar bushes should last well over 100,000k on stock springs, it's the 380 front stabiliser bar bushes that are notorious for wearing out quickly even on stock suspension, so I'd get them renewed for sure.

But they're nowhere near as easy to do as the rears coz they're really difficult to get at without putting the car up on a hoist.

KJ.

Okay - thanks for that people. I'll get onto the dealer for a set of new rear stabiliser D bushes.
For $12 plus a bit of under the car grunting hopefully i'll get it sorted!

:)
A knock on the small roughness cause the rack stabilizer of transverse stability. Sounds like a pencil in a glass.


I actually got a pencil and dropped it into a glass just to hear if it's the same! :)

See if you can get some poly bushes from Superpro or the likes, will last a lot longer than the rubber ones & won't cost much more.

I would not use poly bushes in a pink fit, if they were so great Mits would use them on all production cars as they are also cheaper to make. Is a reason new cars dont use them plus they actually wear faster and will squeak as soon as the lube dries out.

Rubber will compress over time and will deteriorate where poly wont but the poly bush will eat itself away.

For the cost, get a couple of sets, put a set away and you will still be out in front. Even on my Rally Car I am keeping all rubber bushes

I would not use poly bushes in a pink fit

Fair enough. I've not heard many positives about poly bushes. Even Todd Selby said rubber is the way to go. For some reason tho he supplies non rubber bushes if u buy a swaybar from signature swaybars...
I'll get a couple of sets.

Sorry to dig up an old thread but it sounds like I have the exact same issue!

BlackWhite, did you ever figure out what this problem was? I'm a bit skeptical that it could be the rear stabilizer bushes considering the noise appeared the day after lowering it. Checked all the bolts today, everything's done up tight. Will maybe take the entire strut out tomorrow and see if it could possibly be the top strut bolt.

Hi for me it was the bump stop installed incorrectly when the new springs were fitted

My money's on this.
The bump stop has a small metal ring in the middle of it, which if not seated properly would cause just the noise you're hearing Dan.

KJ.

Ive driven kifs 380 and it's always made that noise at the back and his car is on superlows

I've had this problem since fitting Kings Lows. I only hear it slowly turning left into a driveway or over a rise or dip in the road, Have never been able to track it down but will check the bump stop centering.

Ive driven kifs 380 and it's always made that noise at the back and his car is on superlows

My car did it before I lowered it. My ex's 380 did it also, also stock.

Just a heads up for people who go the King Low route, over the weekend TreeAdeyMan, my old man and I may have found what was causing this. We took the rear struts out, and after some banging around it seemed the noise was actually coil knock. On the top end of the King spring, the coils are closer together than the stock spring, and the noise seemed to be those few coils knocking together upon compression. We solved the problem by sliding some foam tubing around the spring and on to the second coil where the knocking would have occurred. This seems to have reduced the noise by 90%. May not be a permanent solution though as the tubing will eventually wear through.

I haven't seen the Dobinson springs, but hopefully they may be a bit different and not have this issue. I only put the Kings in as I picked them up cheaply second hand. I'll look at replacing them with a set of new Dobinsons at some stage in the future, possibly when I need new shocks.

Sorry to dig up an old thread but it sounds like I have the exact same issue!

BlackWhite, did you ever figure out what this problem was? I'm a bit skeptical that it could be the rear stabilizer bushes considering the noise appeared the day after lowering it. Checked all the bolts today, everything's done up tight. Will maybe take the entire strut out tomorrow and see if it could possibly be the top strut bolt.

Sorry for late reply...i havent found the cause...took it for the 90k service last wk and they (mitsu)said it's the modded suspension...so i dpnt know what to do...the knock is still there...

For some of u with the knocking occurring from new have u had a look for the seatbelt guides? I found both my rear seatbelt guides tucked away behind the back seat and cos theyre hangin on strings they sway about and knock against the metal behind the seats..fwiw...but i will try kj's suggestion...if i can get the original installer of the king lows to agree to look at it without charging too much.....

I have fitted a few sets of Dobinsons to 380's with no issues, only issue is that Dobinsons only make the low, although they list the super low they have no intention of actually making them for some reason, I think they feel the demand is too low, may be an oppertunity for me to chat to them to see how many orders would need to be placed to get them to produce them. Given that they are listed would infer that the specs for them are there.

I have also fitted Kings to a few 380's, on these I have used the old Pedders trick and put the garden hose over the top 2 coils, this is what Pedders used to do to stop the coil slap in their sprung paper clips they pass off as springs

I have fitted a few sets of Dobinsons to 380's with no issues, only issue is that Dobinsons only make the low, although they list the super low they have no intention of actually making them for some reason, I think they feel the demand is too low, may be an oppertunity for me to chat to them to see how many orders would need to be placed to get them to produce them. Given that they are listed would infer that the specs for them are there.

I have also fitted Kings to a few 380's, on these I have used the old Pedders trick and put the garden hose over the top 2 coils, this is what Pedders used to do to stop the coil slap in their sprung paper clips they pass off as springs

Sounds like king super lows front, Dobinson lows rear may be the way to go!