Drivetrain noises

4GTuner

Help Support 4GTuner:

doommachine said:
And like I said, the entire car feels like it "grabs" sometimes.

It's audible at all times, including when coasting in neutral. The grabbing happens on occasion from standstill, and my dad said that when he was driving on the highway at some point it felt that there was a flat tyre, he pulled over and it was fine after that. At low speeds when it happens it feels like a wheel is bouncing on the road.
Click to expand...
It's hard to piece together everything you've said but this ^ sounds similar to what happened with my friends VR4 when the transfer seized (no oil).
You said you've replaced the yoke. Was the old one leaking? If so is there a possibility the transfer was run dry?
 
Transfer is fine, I've pulled it out, theres no play, and the car makes the same noise with the wheels off the ground with the transfer out as in.

The transfer was replaced recently, and theres grey sealant around it which indicates it was at least inspected; the oil that came out of it looked brand new as well. I believe it blew at some point before, but what would take the transfer out within the gearbox? Centre diff? Front diff?
 
Just been reading through your posts trying to figure out what going on, hmmmm

So. You have had the transfer case off, front jacked up and it still makes the cluncking noise. Is this
with the car running, off or both?

With the transfer case off you have eliminated your rear drive line and so the noise has to be coming from
the gearbox/axles front drive line.

Is the noise coming from both front wheels or just the driver's side?
Has the gearbox been rebuilt lately?
Have you checked the gearbox oil, any signs of metal?

Can you video the fault and post it, this will help diagnosing it. My thoughts are that something has come
adrift in the gearbox but I hope that im wrong.
 
When the transfer case is off it makes a constant clicking sound (I thought it was a CV but when the wheel is stopped from spinning it still makes the noise).

The clunking occurs under load, on occasion. Yes, the box is recently rebuilt and it has (at least) a 4 spider centre diff, in addition to a bunch of other later model parts (various evo3 bits, not sure on the gear set).

The clunk and the noise - I can't help but feel they are somehow related, but separate issues.

The car has made the grinding noise continually but nothing has broken since my dad literally drove it 400 kays a couple of weeks ago, and was using the car as a daily for a while as well. Possibly the grinding noise is just due to the clutch/ upgraded components, but the binding really worries me and it definitely feels like a wheel stopping briefly. I haven't been able to replicate the binding in any way with the car on jack stands.

I will attempt to take a video of it but it will probably be difficult to hear on video, the car is of course rather loud.

OK So I thought about this as well..
What if the VCU was on its way out, or funky? It feels like the rear wheel binds the majority of the time (which is why I thought initially that the rear diff was gone).
If the VCU was a little ruined would it explain the sudden binding? Would this happen even at highway speeds, suddenly the rear wheels are just not travelling at the correct speed? My dad said that it felt like he had a flat tyre.



The grinding noise doesn't sound bad per se, it's just a noise my other car never made.


I jacked up all but one wheel today to see what it feels like - I thought there was some play in the front diff but it feels like the same amount of play that the rear diff has.

Regardless of which wheel is off the ground, I can feel that the VCU has some pull, but it seems slightly variable. If I turn a wheel back and forth, on some occasions I can feel a very slight increase in drag, I hear no noise associated with it but I assume this is due to the lack of load.
 
I had a real bad clattering in the Eterna when on deceleration but quiet on acceleration, you could hear it even with the window up when going past concrete barriers. Ended up being the DOJ joint in the tailshaft, I pulled it apart and the remains of grease had turned into a solid dry mass. Cleaned it up repacked it with grease and it has been silent for the last 12months.
I also had a vibration on what felt like the rear left wheel under hard acceleration, but that was just my centre bearings as they had sagged quite a lot.
 
Definitely not tailshaft. Centre bearings new, as are unis. Lobro was repacked when centre bearings done.

Today I backed it up and down the driveway until I heard the "clunk", then jacked it up and tried to rotate any given corner wheel. No rotation.

With both rear wheels up, both wheels rotate, no noise. One rear wheel - play only, I can see the tailshaft move though. With both front wheels up there is a definite "clicky" feeling but they rotate smoothly, with just one front wheel off the ground there is about 20 degrees of rotational play and the tailshaft moves. So definitely a diff, but which?

How can I test the front and centre diffs independently of each other?

It rolls in neutral no problem, although if it gets rolling fast enough I still hear a clicking.
 
I'm starting to think the centre diff may be the cause. I recently rebuilt one and you can shim them too tight and cause the spiders to bind. The side gear thrust was much happier in my experience at the top end of the thrust range (0.25mm). I initially set it to 0.05mm, the lower end of the range and it grabbed and bound up, very much like you are describing. This was all tested on the bench by hand, just to clarify. I haven't played with a 4 spider - who machined it? Maybe get their opinion?

I can't think of a way to isolate the two diffs due to the common shaft. I don't think it can be done without disassembly now that I think of it.
 
Bugger. It's a shepherd transmissions 4 spider. It rolls just perfectly in neutral, and without any noise. If it was the front diff it would make a noise, I think, Oh well, guess it has to get pulled apart. What a pain in the arse.Thanks for the help, all.
 
To test if the spider gears are binding, could you - remove the VCU and transfer case, tie up the tail shaft and try driving forward and reverse to see if they grab?
With the VCU out, the car shouldn't move but if it does (via the front wheels) then the spiders are too tight yeah? Idk just a thought.

A bit of effort though, you'd need to drain and refill the box a couple times.
 
With two wheels on the same side of the car off the ground there is no feeling of clunkiness or play, and both front and rear wheel spin. With the front two off the ground, still feel some clunkiness, and there is actually a fair amount of play in the front diff. Pretty sure now that its the front diff. I'm just going to send it to Catfords.
 
Doesn't sound too good

I remember driving it to Mt Gambier once and just out of Penola I heard a noise as if something was wrapped around the tailshaft.
Drove it slowly back to a servo in Penola and had a look under it and saw ... nothing.

It was OK after that, but since then I was always delicate with the loud pedal and as smooth as I could be changing gears.
I was never aware of any clunking at low speed so whatever it is is probably failing.

I had hoped the loss of power and vibration coming through the hills was that spark plug??
 
So just as an epilogue. I think the slop in the tailshaft, possibly the broken transfer case broke the centre diff at some point. The box felt very tight to shift into gear from the moment I got it, which I attributed to it being new, I suspect that the centre diff had been broken for at least as long as my dad had the car.

Eventually driving the car caused total failure of the centre diff, filling the gearbox with metal shavings and ruining it entirely. $4k + gearbox build; less than 10,000 kms completely destroyed.

Thanks to Catfords and 465T for helping me out as well.
 
THREAD NECROMANCY:

So after thousands of years of just riding motorcycles everywhere I've decided to pull my finger out and tune/ drive the car.

Now, I have just been considering what happened with the car and before I blow yet another centre diff and gearbox I thought I would check everything.



Anyway, in hindsight - When I bought the car Entaran mentioned that there was drivetrain binding and the centre diff exploded, which is why he rebuilt the gearbox - installing a sheptrains and a 4 spider diff. After 10,000 k's - same thing happened.


My current gearbox is a w5m332NQBK (so 3.54)

I am in the middle of checking the ratios of the rear diff (its a 3.5 housing and I cant see why anyone in their right mind would swap 3.9 crownwheel and pinion into a stock VR4 diff.. but I'll check).

Will an evo 3 transfer case bolt up to a VR4 transmission? As far as I can tell it will. I can't find any reasonable pictures of an evo3 transfer case but from what I can tell theyre 23 spline with an iron head.

I remember (way back) reading about Entaran putting an evo box into his car. The blown up box wasn't an evo box but all other things considered I can't think of any other reason for consistent and destructive drivetrain destruction outside of the transfer being wrong.

I am not sure how the drivetrain should behave. If I lift the drivers side wheels off the ground and spin one, the front wheel completes one revolution for about 4/5 of a revolution for the rear. Is this what I should expect? I presume there would be some slip as far as the VC etc?

Anyone have a clue what would destroy a centre diff?
 
Have you got another vcu? Might be worth removing it see if you can rotate the wheels and any noise. I have popped a centre diff and the vcu took up the drive enough to limp to the pits, felt like a slipping clutch. Also there is a slight ratio difference in transfer case ratios for e3.
 
No, I don't. The gearbox as far as I know has been rebuilt. When I have just two wheels from the same side of the car off the ground and turn either the front or rear wheel, the other wheel turns immediately so I assume the VCU is pretty tight.

It doesn't drive badly or make any horrible noises now I am just wanting to make absolute sure I don't smash another centre diff. (Although I forgot just how noisy the thing was in the cabin! )

If the front and rear diff ratios were different there would be a significant problem almost immediately, correct? I can't see that it would last 6000 km.
 
Yeah an e3 transfer is only slightly different. Off the top of my head I couldn't tell you. But your vcu may be taking up the difference.
 
Evo 3 has a 1.074 transfer ratio.

So yeah, VCU takes up the slight difference but surely this would effectively change the ratio of the rear diff relative to the front slightly enough to put a little bit of extra pressure on the centre diff?

I gotta pull this bloody transfer case out, don't I.
 
I think...
Mark both the flanges on the tailshaft. Split the flange and support the rear section with some cable ties so it can spin in its support.
Push the car 10m, check to see the flange marks still align. Push it 50m more. Check alignment marks again.
If they are turning at the same rate, your ratios are matched.
 

Similar threads

mathew_colville
how to bleed clutch?
2
Replies
24
Views
2K
evo-gsr
evo-gsr
D
grinding noise up front in my magna..
Replies
6
Views
1K
4piknup
4piknup

Latest posts

Back
Top