Hi, While my car was being repaired I had to replace the diff cradle / rear sub frame (which ever you want to call it) and I decided to fit the rest of my "Energy Suspension HYPER-FLEX SYSTEM Bush Set" I bought years ago. So sub frame bushes, diff mounting bushes etc. Now that I have the car back I have noticed (well there is no missing it actually) a loud thumping noise coming from the back of the car. The thumping is only when: First put your foot on the clutch while moving Take your foot off the clutch while moving Take your foot off the accelerator, coast and then put your foot back on the accelerator. General rule is you will hear either 2 or 3 loud thumps. There is no missing the sound, it?s very loud and noticeable. Problem is, I don?t know if the diff was damaged in the accident and the sound is from within the diff or the problem is what the mechanic has diagnosed. The mechanic has just called and said they can?t find anything wrong with the car at all. He believes that the noise is because of the replaced bushes. When the drive shaft kicks in (so in the above conditions) the thump/vibration of the diff being engaged (he did describe it more technical than that, but I forget the exact wording) is being transferred into the body of the car. Previously the factory gel filled bushes would have soaked up the vibration that is causing the noise. They had the car up on the hoist and one person sat in the car while the other just turned the drive shaft (he said even gently turning it) and as soon as the slack is picked up the exact same noise is heard in the car. Has anyone else who has replaced bushes in the rear had the same problem? If this is indeed the problem, do you think it?s because of the diff cradle bushes or the actual diff mounting bushes? I?m guessing it?s the main cradle bushes, simply because they are the most expensive, and hardest to fit/remove of the lot I really can?t put up with the noises, so they are going to have come out again...I just don?t want to remove the lot if it?s only a couple that are the problem. Hope you can help. Cheers Mark
I didn't fit them, but a mechanic did I also have more confidence in him then probably any other mechanic/trade person I've ever come across. But I guess anyone can make a mistake. He has just gone over it and checked it all again with the same conclusion. I'm not sure if you can even put the bushes on the wrong way around can you? Thanks for the reply. Cheers Mark
Similiar I've got the exact same problem with my car at the moment also... I have not replaced any of the bushes yet, but have been told that it is part of the Diff mount bushes. It's quite a solid thudd whenever you go to accellorate. That would be my only suggestion, and as I said I have not replaced mine so that may or may not be the problem. Thats just the direction i've been told to go in. Fate
I'll ask him to check again as he was pretty sure it wouldn't be possible to mount them incorrectly....subframe bushes that is...or you talking about the diff mount bushes? Cheers Mark
Talking about the diff bushes. There are 4 of them. Two at the back that the diff bolts slot into and two at the front that the diff sits on and a bolt goes through. May have been possible to put them in upsidedown, which may cause the diff to be sitting at an angle its not me to be at. Not sure but may be good to check
Mechanic is going to get sick of me I get ringing him every 5 minutes with a suggestion. He said he has already checked the diff mounting bushes and they are in correctly. He insists the noise is just the backlash from the driveshaft being transferred to the car body.... Maybe slight differences in firmness between different brands of bushes??? Cheers Mark
I have the same noises in my car(and the same bushes) so I think we may be on to something here. I have been half convinced that the noise was from the fitting of the tailshaft, but I remember it happening before I got my one-piece shaft, so that can't be the reason, can it? :bash:
Feeling a bit better Hi Chili, Well that makes me feel a little better, knowing I'm not the only one. I use to sometimes get the thump when reversing on my driveway....if I sometimes went a bit quick and jumped on the clutch it ..coasted and then hit released the clutch again. But now I get 2 or 3 of the thumps everytime I change gears etc. Same as you I hope? I'm not sure if the noise is very noticable from outside the car (I hope note) but I'm not going to be able to put up with it for long. Really wrecks the mood when giving the car a bootfull Cheers Mark
Good point. The online Z32 manual does not show how the bushes go either, I had to look at a S15 manual.
Yeah, I only new cause I made a point of looking when I pulled the subframe down and dissembled it. Man these cars are fun :zlove: :zlove: :biggrin:
S15 Manual. Hi Don't happen to have an electronic copy of the S15 manual? More specifically the pages relating to the bush positioning? Cheers Mark
I have this as well and I reckon its the front diff bushes. I went over the instructions again and again and even looked it up on the internet but came to the same conclusion. I reckon its the diff knocking in its mount so to speak, it wont move but because there is no give in the bush the noise will transmit through the car, but then thinking about it I don't hear it anymore so it might just have settled in or I have the stereo too load.:biggrin:
Excellent another person with the problem Not good for you....but makes me a little happier. The mechanic was leaning towards the main bushes where the frame mounts to the car as the problem. I think mostly because these are the Gel filled ones from the factory. As he said, Nissan wouldn't use something like that if it wasn't for a reason. I might look at changing just the ones you mentioned first (because they should be easier/cheaper to do first). And if they don't fix the problem I should be able to reuse them. Although, I too was wondering if they would settle down over time, but I thought the whole point of these new bushes is that they don't wear.... I guess I'll just have to turn the stereo up as well for now Cheers Mark
Its on the hard drive but I don't know how to send it. Originally just did a Google to find it, used 's15 service manual' I think, S14 would do too. Or try here http://www.nissansilvia.com/
So my car is doing this now.. I haven't touched the bushes from when I bought it. I get just one loud thump whenever there is a decent change from acceleration or deceleration. My concern is that I can FEEL the rear subframe moving... I am planning on driving to zedfest and then down to Bega.. about 5000km round trip! Any chance something bad can happen? My understanding is the bush is likely collapsed / broken and the subframe and or diff is just moving? Nothing can come off or cause my car to break down?
