D40 auto gearbox noise

[Johnmc]

Hi,

Am a newbie to Navaras, automatic gearboxes and 4x4 in general. I have recently purchased a 2008 automatic D40 and really like it. However, In the last 10 days, I have noticed a strange intermittent sound from underneath when in drive. Sounds kinda like the sound of two knives or metal discs being rubbed together. Happens when the vehicle is static as well as moving, so I guess it's coming from the gearbox? Anyone any ideas of what it could be? If so, is it a sign of some problem I need to get sorted? This Navara only has 38k kms on it and it has had a fairly soft life from what I can see. Under a dealer warranty at present. The dealer is over 100 miles away from me. Is it ok to drive it like this or will I do damage? The noise is becoming more frequent.
Thanks in advance.

 

[Dave]

Check the radiator coolent.

Have heard of D40 auto's sucking up coolent into the gearbox. A splt in the bottom of the radiator.

Checked the fluid level in the gearbox ?

 

[Johnmc]

Hi,

Thanks for the heads up. I will check this today.

 

[Dave]

From memory to, torque converters had issues around that model too.

 

[Old.Tony]

Welcome to the forum.

Torque converters were an issue but they'd cause a vibration at around 80-90km/h as the TCC engaged/disengaged repeatedly. The only known repair was to replace the torque converter but there might be some means of repairing the TCC - I don't think we'll ever know the answer to that, but since your problem occurs at a standstill I doubt the TCC is involved.

I think checking for contamination in both places (radiator and transmission sump) is the first place to look. The gearboxes are fairly solid units but the transmission cooler lives in the bottom of the radiator and if someone's used normal water in the coolant it could cause corrosive damage to the unit.

Are you certain that it's coming from the gearbox? Have you used a stethoscope to listen to the innards? A long-shaft screwdriver with the tip placed on the gearbox and the handle placed against the ear substitutes reasonably for this.

 

[JPMC]

Are you sure it's coming from underneath?
Next time you here it pop the bonnet and check that the fan isn't touching something it shouldn't or that one of the belt pulley's isn't wobbling around excessively.