[Lion]

Hi all, I'm a Suzuki newbie and recently bought a 2002 grand vitara 2.0l 16v. It's only covered 60k miles and engine wise it runs sweet as nut. I'm really impressed with the simple layout of the engine and looking forward to at least 2-3years of trouble free motoring hopefully.

The problem I am having with it however is a loud ticking/ knocking noise coming from somewhere near the rear of vehicle . It almost sounds like something is rubbing.

It gets quicker the quicker I go and slows down as I do, even when I'm crawling at around 10-15mph it still ticks. It's not the gearbox because it still does it when I freewheel in neutral and it's nothing to do with the brakes because it doesn't change in sound or frequency when the pedal is pressed. I can only think it's coming from the rear diff somewhere?

Can anyone advise? Right now I'm considering buying a complete new axle assembly from the breakers yard as it doesn't seem that difficult a job to replace?

 

[aquanaut20]

Location, location, location.... Hmmmm!

Have you pulled and checked the driveline??

.... Philip

 

[Lion]

How do you mean pulled and checked? You'll have to forgive me as I'm only an amateur mechanic lol!

Is there a procedure to follow

 

[Max]

As in...pulled the drive-shaft and checked for smooth operating U-joints. Binding or slop can cause noise.

Raised the vehicle and spun / checked each wheel by hand looking for noise or losseness (axle bearings)?

Spun the rear differential input (pinion shaft) checking for same?

Checked the tires and rim for imbedded foreign debris or tire lumps (ply separation)?

And you can't entirely rule out the brakes even though the noise persists with application.

Drained and inspected the differential gear oil for condition and debris? Changed to seek improvement? Trans and transfer case too, if so equipped.

Lifting the vehicle, run it with the wheels spinning and listened for noise from a particular component / location is a good troubleshooting technique too.

 

[Lion]

Looking at the underside of the vehicle there appears to oil on the rear diff housing but I can't see where it's coming from. There's two plugs that I can see in the rear diff but it doesn't seem to be coming from there.

 

[Max]

Probably from the pinion (differential input shaft) seal then. You should check that gear level ASAP, for if low (or empty) that may be the source of all your problems.

 

[Lion]

Ok cheers max, is that seal a tricky repair? And I assume to refill the differential with oil I simply remove the top plug and fill up? Any particular type or brand of oil? I live in the uk so may not have access to the same brands as you guys in the US. Btw my vitara is virtually identical to the one in your avatar pic

 

[Max]

The repair is a bit tricky, needing a special (new) shaft crush washer and torque sequence. A close exam of the pinion shaft bearing and seal running surface too, assuming that the leak resides there.

Gear oil discussion here...
http://www.suzuki-forums.com/1g-199...4-differential-manual-tranny-fluid-check.html

 

[Lion]

Ok, I checked the oil in the rear diff and seeing as I was under there I decided to change it anyway. There was plenty of the old stuff in there so it certainly wasn't running dry, now it's full of fresh oil and the noise is still there.
I tried the car in 4wd hi and the noise sounded worse so could the noise be at the front of the car and travelling along the chassis making me think it's coming from the rear?
I lifted the back wheels off the ground and spun them and couldn't hear anything rattling or tapping although it wasn't exactly quiet. There was a sound of bearings turning but they didn't sound rough.
There is no oil leak on the prop shaft itself and the oil on the rear diff appeared to have come from the bottom sump plug and It looks like somebody has put some kind of sealant around it.
A friend of mine on a local farm who has several 4x4s including a grand vitara says he will change the whole rear axle for me should I choose but I'd like to try and determine what the problem is before going that far. I was trying to avoid going down the garage route but it's looking like I may need to if only to get an accurate diagnosis.

 

[Max]

Yep. You'll need a running analysis from beneath the vehicle. Don't start throwing parts at it yet.

 

[Lion]

Cheers, I'll update as soon as I know anything

 

[Lion]

Ok guys, as a follow up to this thread I removed the rear diff and found the teeth on the crown gear to be pitted and marked as if something had broken up in there at some point. There was no debris to be found and everything else looked ok.

I sourced a replacement differential from a 2003 model grand vitara fairly cheaply (top tip- it was cheaper to buy one with a full axle attached) and then fitted it in place of the old one. Obviously I counted the teeth on the crown gear to be sure it was the correct one!

I've been running it for over a month now with no problems whatsoever, the noise has gone and I'm really pleased with it.

 

[Max]

That's good news!