Gearbox noise

[Steve_H]

All,

I noticed a new noise coming from my car the other day and I'd like some pointers as to what it could be.

When slowing down and in 1st gear there's a noise from the front like something is rubbing on a tyre....then when you come to a stop the transmission clunks. The noise doesn't seem to be there when driving off, but I haven't had enough time to have a good listen.

My wife said the noise has been happening for a few weeks now.

I'm assuming it's the gearbox and I've checked the trans fluid level, which is fine. My next step is to take it into a transmission specialist for a look.

[spot01]

Are you sure its not the brakes? Try carefully slipping it into N (without pressing the button on the t-bar) when slowing with the noise to see if it stops.

[Steve_H]

Are you sure its not the brakes? Try carefully slipping it into N (without pressing the button on the t-bar) when slowing with the noise to see if it stops.

Good idea, I'll give it a try tonight.

[Hungie]

This is a super common thing with this model. It's the vacuum solenoid that controls 2-4WD failing. It's the little black thing with little hoses running to and from it located in the engine bay in front of your air box. These 4WD systems use an air system to disengage 4WD. The solenoid is about $120 on eBay and takes about 5 mins to replace. It will gradually happen more and more frequently until it won't stay in 2WD. If you don't have the cash at the moment, just select and leave it in 4H. Will use approx 1.5 litres per hundred k's more fuel. Just replace the solenoid when you can.

[Hungie]

This

[spot01]

This is a super common thing with this model. It's the vacuum solenoid that controls 2-4WD failing. It's the little black thing with little hoses running to and from it located in the engine bay in front of your air box. These 4WD systems use an air system to disengage 4WD. The solenoid is about $120 on eBay and takes about 5 mins to replace. It will gradually happen more and more frequently until it won't stay in 2WD. If you don't have the cash at the moment, just select and leave it in 4H. Will use approx 1.5 litres per hundred k's more fuel. Just replace the solenoid when you can.

I assume you could test if this is the fault by leaving it in 4H - if the noise is gone but then returns in 2H, you may be onto something.

[Hungie]

I assume you could test if this is the fault by leaving it in 4H - if the noise is gone but then returns in 2H, you may be onto something.

You could, but this part failing is so common and the symptom so specific that its 99.9% the problem.

These Pajeros are really a full time 4WD and they use a vacuum system to hold the 4WD engagement mechanism out to allow 2WD. When these solenoid start to fail they can't hold the required vacuum needed to hold the system out in 2WD.

The grinding noise you hear is 4WD trying to engage.

[spot01]

You could, but this part failing is so common and the symptom so specific that its 99.9% the problem.

These Pajeros are really a full time 4WD and they use a vacuum system to hold the 4WD engagement mechanism out to allow 2WD. When these solenoid start to fail they can't hold the required vacuum needed to hold the system out in 2WD.

The grinding noise you hear is 4WD trying to engage.

That being the case, I wouldn't be driving it much until fixed.

[gaz1]

That being the case, I wouldn't be driving it much until fixed.

Should be OK to drive in 4WD though....

[Hungie]

Yes totally fine to drive it in 4H until part is replaced.

[Steve_H]

Yup it's certainly not the brakes, its definitely drive train.

I'll test it in 4wd and see if it happens then. Thanks.

[Steve_H]

After a fair bit of testing it does appear to be the vacuum solenoid switch causing the issue. New genuine part ordered for $90, should be here before this weekend.

Thanks.

[xboxice]

After a fair bit of testing it does appear to be the vacuum solenoid switch causing the issue. New genuine part ordered for $90, should be here before this weekend.

Thanks.

Sweet i think its a good idea to engage 4H every so often

[Steve_H]

Put the new part in and everything seems fine now.

Interestingly, it went into 4wd quite often...I just think the part died of old age.

[OlWobbly]

This is a super common thing with this model. It's the vacuum solenoid that controls 2-4WD failing. It's the little black thing with little hoses running to and from it located in the engine bay in front of your air box. These 4WD systems use an air system to disengage 4WD. The solenoid is about $120 on eBay and takes about 5 mins to replace. It will gradually happen more and more frequently until it won't stay in 2WD. If you don't have the cash at the moment, just select and leave it in 4H. Will use approx 1.5 litres per hundred k's more fuel. Just replace the solenoid when you can.

I know this is an old post Hungie, but you’ve made an old mate very happy. His NM exhibited exactly the same symptoms and he was having nightmares about dropping gearboxes and thousands of $$s. Your tip was spot on.