Drivetrain noises

[doommachine]

Hey all,
Finally sold my other VR4, so driving the "new" one (bought from Entaran). Apparently the majority of the drivetrain is new, but I am getting some crazy clunking and sometimes if feels like the whole rear of the car bounces. Just dropped the tailshaft to replace the unis, as 2 were replaced with crappy repco ones (with the grease nipple.. eck) but I have noted there is about 10-15 degrees of play on the input of the diff, with the park brake on. When it "engages", sometimes its smooth, sometimes if I turn it backwards and then forwards it is really clunky.

The car seems to make a grinding noise on decel, in neutral, it's a low pitch noise and I can't really work out where it comes from.

The service manual is not particularly clear about this and I can't really find any useful info on this. Any suggestions as to how I can test if it's ruined without removing it?

 

[86psi]

What clutch is in it champ?

 

[JayRome]

Maroon VR4? Aus spec with Jspec font bar?

check the nut on the input shaft of the diff... I have seen a few come loose....

 

[doommachine]

What clutch is in it champ?

I believe its an exedy

Maroon VR4? Aus spec with Jspec font bar?

check the nut on the input shaft of the diff... I have seen a few come loose....

Yes, that's the one. Ex "team4g" plates.

Really? Interesting.. I'll have a look and see tomorrow. Thanks for the suggestion.

 

[JayRome]

ahhh Dans old VR4, it was immaculate when he sold it....

before Lawerence got it:

 

[doommachine]

Hah! Nice. Looks very similar but now I have the ralliart rims, bigger exhaust, intercooler... plus its been partially resprayed, it's slightly cleaner.

 

[doommachine]

OK so just noted something interesting. I made a note of how the carrier bearing bushings were installed; when I cross ref'd them with the service manual the spacer was actually installed upside down.
I have a receipt for the carrier bearings being done, I'll let everyone know which shop it was. The 2 rear unis were fairly floppy (the middle uni I actually removed with my fingers - no pressing needed) - pretty hopeful that my diff isn't ruined and the input clunking was just the tailshaft binding.

To update - the diff input bolt is fine, there is no play at all on the input flange any direction. While the diff does "clunk" when turned and it feels like there is some play when the tailshaft is turned, the wheels still turn. With the handbrake on there is still the same amount of rotational play, the axles do appear to rotate ever so slightly when the tailshaft is turned.

But at least now the tailshaft is super tight.

 

[doommachine]

More updates. The noise I was hearing when driving seems to have been coming from the front drivers side. Seems like a clicking sound when coasting, makes me think its either CV's or wheel bearings, but when I jack the car up (all other 3 wheels on the deck) and rotate the wheel I feel definite points where the wheel "lets go" - ie, I rotate it, I can feel the drivetrain resist, and then it is loose and makes a grindy clunky sort of noise. The wheel turns very freely at the "let go" point. It feels like when the chain is slipping on a bicycle.

I feel no play at all as far as the bearing, is it possible that the bearing is ruined but not have any play?

More edit :

I was getting worse drivetrain binding before, but now if I go backwards and forwards at low speeds, with the clutch partially engaged it will "clunk" very loudly, it feels like a wheel slips. I'm not sure if it will do it with the clutch fully engaged because my driveway isn't long enough. Will update later when I can drive around a car park later at night.

More edit : Had a couple guys around, put it in gear and rocked it back and forth. A lot of play, when the car is in gear it can be moved back and forth about 4cm. Dunno if that's normal.

Anyway at some point managed to find a point wherein the front of the car will make a metallic clunking/ grinding sound. I guess first (easy) point of call is taking the transfer out? What else should I check when its out?

 

[doommachine]

Okay, so I dropped the transfer case out today and ran it while on the jack stands. With the clutch out it makes a constant "chuckling" sort of noise.

It sounded like the noise was coming from the drivers side axle, so I carefully stopped that wheel turning, and the noise continues. If I push the clutch in it keeps happening while the wheels spin but tapers off in volume until they stop.

I can't make it make the noise by simply spinning the wheels when its in neutral, or in gear, but I don't think this means much.

The output shaft to the transfer has about 1mm in and out play, I believe this is acceptable?


So I'm thinking now it could either be the clutch or one of the diffs. Suggestions? How can I isolate the source of the noise?

 

[MDK87]

The play in the output shaft is normal. That's all I can help you with sorry.. Hope you get it sorted!

 

[omad]

Won't help much with the noises etc you're getting from the gearbox side, but check the output shaft and xfer case splines for wear. I'm chasing a lot of noise and chattering in the driveline myself and changing the xfer case to one that was less worn got rid of the most noise, after having tried a bunch of other things as well with little to no difference.

 

[omad]

Mate, just had another thought. The chattering noise up front may well be the clutch itself. Can be pretty common especially with some sprung-Centre clutches. Would just get louder as it travels up the driveline especially if you have play in things like the gearbox, tail shaft, transfer, output shaft, diff etc.

 

[croket]

I have a very similar noise i mine too on decel it chatters alot from drivers side front and also the tailshaft but i know thats my unis and flogged out diff. If i use my brakes on decel the chattering decreases a hell of alot. Its got me buggered as to what it is

 

[RocksolidGVR4]

Sounds like a bad CV joint to me, does the noise go away when you accelerate and return during gears changes or while cruising?

 

[4piknup]

Agree ↑ cvs.
Drive around in circles or figure 8 in culdesac. A outside observer will confirm the noise from the right front corner, or wherever.

 

[doommachine]

I did think it was a CV but it continues when the wheel is stopped from turning. It changes slightly however.

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.

Perhaps the chattering noise *is* the clutch, as its an exedy, and it is of no consequence. The binding may be another issue not related to the chattering at all. Hmm. I'll drive it around tomorrow and hope I don't blow the gearbox.

 

[chez00]

If it was spider gears in the front diff you'd be able to reproduce it by rotating a front wheel by hand I reckon. To isolate the centre diff... Maybe jack up the rear (fronts still on the ground) and rotate output shaft (if the transfer is still off)? This wouldn't necessarily point to the centre diff but would narrow it down further. I'd also be pointing a finger at the sprung clutch.

 

[doommachine]

Yes, if I get the front wheels in the right orientation relative to each other I can make it feel "grindy", but it's difficult to do. The clunking/binding happens only occasionally.
Hmm could be the clutch indeed. It makes sense to me now that I think about it, since I think the diff would be a much more repeatable thing.

Ah, thanks for the tip on isolating the centre, I didn't think of that. I'll give that a go tomorrow.

 

[omad]

Wait, audible at all times? If it was just the clutch I really doubt it would be making noise under acceleration. When you accelerate, any play in the drive train should be taken up. If it's making noise under acceleration and behaving oddly, particularly at the front/front wheels it doesn't sound like good news =/

 

[doommachine]

Yeah, that's what I thought. And the clunking/ binding as well. What say you, front diff? The centre diff is a new 4 spider, I'll be pretty annoyed if thats dead.