smart_451_front_suspension_clunk_common_issues_and_diagnosis¶

2 excerpts.

Excerpt¶

youtube.com/pb_garage/smart_451_front_suspension_clunk_common_issues_and_diagnosis · p. 1 · Applies to: 450, 451, 452, 453, 454, #1, ebike

hey guys welcome to PB garage today I'm going to show you how to diagnose that pesky clunking noise in the front of your smart 451 now if you've had a 451 for any amount of time you probably know what I'm talking about happens a lot you're driving along and over time things start to wear out and especially over like speed bumps things like that slow bumps you get a clunk clunk or over bigger potholes or anytime that the suspension is unloading you get a clunk and there's a whole bunch of different parts that can actually cause that noise so we're going to take a look at every and I'll show you guys how to pick out what the issue is and then we can talk about different ways to solve the problem all right so I've obviously got my 451 jacked up here wheel off so that we can have a look at all the suspension components now the first thing you're probably going to want to check if you haven't replaced these already is your sway bar bushings so right in here there's a bushing this is your front sway bar and these bushings often wear out and spoiler alert in the case of this car this is the issue how do I know well if we grab that sway bar and give it a little tug there's a whole bunch of play and if we look right in here you can see that sway bar is just floating in that bushing so in my case easy diagnostic there other issues that you can come across uh these sway bar end Lings can go bad so this bolt up here can get loose and that sway bar end link can start to Rattle it's got a couple of ball joints on it those can go bad as well so you'd have to replace that sway bar end link another place that can be an issue and I've had to deal with this a few times you can see on this car the bushings on the control arm on the inside here this one's starting to sneak out a little bit these are starting to go bad um I've had to replace a few of these and they cause that clunk as well here's the back one now that issue with those bushings fairly easy to solve you can buy the bushings individually take the control arm off and press the bushings out and press new ones in but I found it easier just to order a complete unit because another source of that clunk can be the ball joint at the end of the control arm here where it goes into that knuckle so if you buy a whole control arm with new bushings new um ball joint on the end replace that whole unit very easy now I have another video on the channel That goes into depth on how to disassemble the whole front suspension here so I'm not going to talk too much about that but just to know uh where the problem issues are obviously tie rod ends can be an issue too this can get loose that's typically not going to give you a clunk over bumps it'll give you a clunk as you're turning the steering wheel sometimes it'll give you a clunk in One Direction than the other uh so check those as well you can just grab the end and give it a tug there now another really common area on these guys is the springs and the spring uh bearing up in the top goes bad and the bushing on the top of that as well so this spring here obviously is intact and if we have a look up here you can see where that cup is and I can show you guys actually I have the parts right here there's a rubber bushing that sits up in the top and a little bearing cup there that sits on the top of the strge as well so they're up there in the case of this one you can see turns freely no problem what happens is that bearing seizes up up there so if you go and check this and this is seized uh what'll happen is it'll actually snap the top top of the spring off or the bottom of the spring and then you've got a broken spring and another uh source of that front end clunk now in just a second I'll go to a different car that has broken Springs and we can have a look at that but just before we do I want to go back to these bushings if we have a look on the other side of this car we can see I've replaced this control arm already so those bushings are good but the way that would show up if we had the wheel on here and you give the wheel a pull and push uh forward and back into the car on both sides at the same time you'll get a bit of a clunk in that direction so again checking that front spring check that perch everything's spinning freely so we know that that's not an issue with this one now I'll take you guys out to another car and show you some Broken Springs now this is a parts car that's been sitting here for a little bit but it does have broken front Springs now the easiest way to tell is you see how close that tire is to the front guard if it's up right close to that guard or even inside the guard good chance those Springs are broken another way to tell if you're turning the steering wheel and you hear like a clunk clunk clunk or a pop pop pop as you turn the wheel going from you know full lock to full lock another good indication that that bearing in the top of the strut has seized and now you've probably got a broken spring so I'm just going to jack this car up here real quick so that we can have a look now with that front tire just barely off the ground you can see and here pretty easy to spot I mean there's the bottom ring of the that spring you can see the Spring's shot

Excerpt¶

youtube.com/pb_garage/smart_451_front_suspension_clunk_common_issues_and_diagnosis · p. 2 · Applies to: 450, 451, 452, 453, 454, #1, ebike

past that so that bottom ring is broken off and this the Spring's kind of gone for a little uh Excursion down towards the wheel there but I'll pull this wheel off so we can actually get a closer look okay now with that wheel off you can see it's very obvious broken spring here still under compression a little bit but it's hung up on that ear where the sway bar in link attaches so this one up at the top totally seized and often I'll see them not break necessarily at the bottom here they'll break right at the top and you you'll get like a a ring just hanging out here a piece of the spring uh that broke breaks off and just kind of hangs out in here or falls down to the bottom or I've even had one get like fall down into the brakes and get wedged in there and make a hole racket while you're driving down the road so you know there's lots of ways that these fail but Broken Springs on these because of that uh bearing going bad at the top pretty common so definitely check that out if you got a clunk in the front end along with as I say the sway bar bushings and your control arm bushings and ball joint so there you go guys pretty much everything that can go wrong in the front end of your smart 451 giving you that clunk over bumps um like I say I do have a video explaining the disassembly and re reassembly of the whole front suspension on the channel so if you guys are going through and you find an issue with one of the components go check that video out I think the only thing I may not have covered in that is the sway bar bushings so I'm going to tackle those on this car right now because that's part of the issue that this car has it's a really simple process if you guys are interested in that stick around if not thanks for watching we'll see you guys the next time okay have a good one all right so to get at these bushings super simple just grab yourself an 18 mil wrench you're going to come in here get on that nut turn that guy out and once you've got that guy loose you can just pull that nut right off and with that nut off this like clam shell here should just be loose and you can flip that front half of that clam shell out lots of play in the in the control or the S bar there so you can get both sides both halves I should say of your clamshell out and then you can just pull that bushing off and then I've got a new set of bushings here from Meo Tech brand new bushing now I'll be completely honest with you guys I know that if I had polyurethane bushings you're supposed to put some dialectric grease or something on there to kind of lubricate it I'm not sure if you do that with rubber bushings or not I feel like with rubber you're supposed to just put them on dry but if you guys know better by all means please let me know in the comments so we just pop that guy on put the back half of our clam shell back in here and the front half and I'm just going to put a little dab of antise on my threads there just to make me feel better about myself put that nut back on and tighten it down now I'm going to tell you guys I don't know what the torque spec is on this I'm going to tighten it down to what feels right to me if you guys have a good feel for that go for it if you're not sure by all means the Google button will help you find the answer I am certain now if you guys remember how much play was in that bushing it was going clunk clunk clunk at the beginning of the video now it's nice and tight so I'm going to do the bushing on the other side and call it a day thanks for watching guys we'll see you in the next one