Jump to content
SAU Community

Recommended Posts

Hi guys,

Not long ago I started to hear some rear awful noises coming from the rear of my car - back left. I thought it was just the normal clunking from the welded diff I had put on there years ago.

I decided to jack up the rear left and see if any wheel studs were loose but it wasnt, what I did notice was that I was able to wobble the wheel slightly even thought it was perfectly flat against the hub. So started to trying to move parts at the subframe to see if anything was lose. I discovered that I was able to push the rear left long black column that attached itself to the diff and rear hub left and right. I tried to do the same with the right side, but it wouldnt budge.

I believe my rear left wheel's ability to rock slightly is related to that long column's freeplay.

My question is can I just change this out and replace it or does it should like something else. At first, I thought perhaps my diff was stuffed - the noise when you drive gets louder and more unbearable like bolts/nuts being crushed - ie welded diff?? Or is my wheel bearing causing this, although Ive watched clips on youtube on wheel bearings being stuffed and mine doesnt make a humming sound it makes a clunking and clanking sound that increases with speed.

Pleaes help.

Attached the the long black coluum I am referring to.

Thanks,

Nozila

post-1473-0-07150900-1418883669_thumb.jpg

  • Like 1

That "long column" is a driveshaft. Calling a "roundy-roundy bit" might have been more accurate.

See the big ends on it? With the rubber boots? Those are CV joints. One or both of them are probably rooted. You either need a new driveshaft or replace the CVs. New driveshaft may be secondhand. To remove it, simply undo the 5 bolts on the diff end flange of it and it will slide out of the hub. Take it it a CV/driveshaft specialist for fixing or take it to a wrecker to get an equivalent 2nd hand, or take it to a mechanic for a proper diagnosis in case I have mistakenly internet diagnosed it.

  • Like 1

Thanks for that. Unlikely to be rooted diff? When I move slowly, it doesnt clunk. I recall my sister's mazda 2 had bad cv joint up front and it would only make noises when turning whilst with mine it mines it moving when moving. Anyways, I will remove the driveshaft and have it looked at.

Thanks for the input

The CV is on a spline and should be able to move slightly in and out and IMO not likely your issue

Although being able to "wobble the wheel slightly" if bolted on tight would concern me ever so much

Also clunking/banging is usually a sign of dead shockies, is it worse when you drive over bumps ?

What exactly are you doing when you hear said noises ?

Hi,

Yes that's a r31 subframe I think-I was just using the pics as a reference to indicate the part that is moving. I had thought it was my coil overs as well so I checked them and they are bolted in fine. It clunks and what sounds like pots and pans banging each together which is why I'm asking if that is the sound a rooted diff makes. I'll try to go through a process of elimination by changing out the driveshaft first. Perhaps the noise is made by the wobbly rear left as when in motion, the noise increases which is understandable but I don't know why it would sound like metal-thumping and clinking yes but not sound of metal pots and pans.

Thanks for everyone's opinions so far

I think Mick is referring to the shocks internals not the fixing points to the car, having had a completely dead shock in a previous car I would have to agree, but it was only on bumps, i.e. activating the shocks. on smooth roads it was fine.

  • Like 1

Makes the noise on smooth roads, bumps or not.

So I think I can rule out the shocks? I am going to jack up the car from the diff, put it in neutral and spin the rear wheels to see if I can replicate the noise. If I cant, hopefully that can rule out the diff being shoot and allow me to focus on the freeplay I have in the rear left and movement in the driveshaft on the left that goes into the diff housing.

Going to take car down to suspension specialist on Tues.

I did jack up the car and tried to move wobbly the rear left and sure enough it did-wheel hub seems loose. Right side had no wobblys whatsoever. Put it into first and you can hear it vibrant and clunk.

thanks, I thought in my head it might be a wheel bearing but wasnt 100% sure. Going to see how much the suspension shop is going to charge otherwise I'll take it down to my family mechanic to replace for me - driving the distance there is going to create some unbearable noises.

Update guys, I just asked suspension place how much it cost to replace my wheel bearing and was quoted $625 for supply of bearing, fit and alignment. Is that quite high or within the ballpark?

It's been a while since I got anyone to serviced by anyone but myself.

Hope you are sure it's the bearing!

I'm not certain for 33 gtst, but for 32 gtr they are available from Nissan only ~350 trade price. So 300 to R & R is reasonable considering the work involved.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • I agree with everything else, except (and I'm rethinking this as it wasn't setup how my brain first though) if the sensor is at the end of a hose which is how it has been recommended to isolate it from vibrations, then if that line had a small hole in, I could foresee potentially (not a fluid dynamic specialist) the ability for it to see a lower pressure at the sensor. But thinking through, said sensor was in the actual block, HOWEVER it was also the sensor itself that broke, so oil pressure may not have been fully reaching the sensor still. So I'm still in my same theory.   However, I 100% would be saying COOL THE OIL DOWN if it's at 125c. That would be an epic concern of mine.   Im now thinking as you did Brad that the knock detection is likely due to the bearings giving a bit more noise as pressure dropped away. Kinkstah, drop your oil, and get a sample of it (as you're draining it) and send it off for analysis.
    • I myself AM TOTALLY UNPREPARED TO BELIEVE that the load is higher on the track than on the dyno. If it is not happening on the dyno, I cannot see it happening on the track. The difference you are seeing is because it is hot on the track, and I am pretty sure your tuner is not belting the crap out of it on teh dyno when it starts to get hot. The only way that being hot on the track can lead to real ping, that I can think of, is if you are getting more oil (from mist in the inlet tract, or going up past the oil control rings) reducing the effective octane rating of the fuel and causing ping that way. Yeah, nah. Look at this graph which I will helpfully show you zoomed back in. As an engineer, I look at the difference in viscocity at (in your case, 125°C) and say "they're all the same number". Even though those lines are not completely collapsed down onto each other, the oil grades you are talking about (40, 50 and 60) are teh top three lines (150, 220 and 320) and as far as I am concerned, there is not enough difference between them at that temperature to be meaningful. The viscosity of 60 at 125°C is teh same as 40 at 100°C. You should not operate it under high load at high temperature. That is purely because the only way they can achieve their emissions numbers is with thin-arse oil in it, so they have to tell you to put thin oil in it for the street. They know that no-one can drive the car & engine hard enough on the street to reach the operating regime that demands the actual correct oil that the engine needs on the track. And so they tell you to put that oil in for the track. Find a way to get more air into it, or, more likely, out of it. Or add a water spray for when it's hot. Or something.   As to the leak --- a small leak that cannot cause near catastrophic volume loss in a few seconds cannot cause a low pressure condition in the engine. If the leak is large enough to drop oil pressure, then you will only get one or two shots at it before the sump is drained.
    • So..... it's going to be a heater hose or other coolant hose at the rear of the head/plenum. Or it's going to be one of the welch plugs on the back of the motor, which is a motor out thing to fix.
    • The oil pressure sensor for logging, does it happen to be the one that was slowly breaking out of the oil block? If it is,I would be ignoring your logs. You had a leak at the sensor which would mean it can't read accurately. It's a small hole at the sensor, and you had a small hole just before it, meaning you could have lost significant pressure reading.   As for brakes, if it's just fluid getting old, you won't necessarily end up with air sitting in the line. Bleed a shit tonne of fluid through so you effectively replace it and go again. Oh and, pay close attention to the pressure gauge while on track!
    • I don't know it is due to that. It could just be due to load on track being more than a dyno. But it would be nice to rule it out. We're talking a fraction of a second of pulling ~1 degree of timing. So it's not a lot, but I'd rather it be 0... Thicker oil isn't really a "bandaid" if it's oil that is going to run at 125C, is it? It will be thicker at 100 and thus at 125, where the 40 weight may not be as thick as one may like for that use. I already have a big pump that has been ported. They (They in this instance being the guy that built my heads) port them so they flow more at lower RPM but have a bypass spring that I believe is ~70psi. I have seen 70psi of oil pressure up top in the past, before I knew I had this leak. I have a 25 row oil cooler that takes up all the space in the driver side guard. It is interesting that GM themselves recommend 0-30 oil for their Vette applications. Unless you take it to the track where the official word is to put 20-50w oil in there, then take that back out after your track day is done and return to 0-30.
×
×
  • Create New...