D40 Alternator pully gone missing

[paddyjacka]

Hi gurus we have had our d40 2.5 since new in 2013 and have had no trouble until 3 days ago. Coming home from a weekend away there was a loud bang and then the battery and brake lights came on the dash. I turned aircon etc off and continued the drive home - another 45 minutes. Got home and found the battery was dead. Long story short the alternator pully had decided to leave the car, also destroyed the alternator in the process. It is currently at my mechanic for repairs but my question is - how was it possible for me to drive for 45 minutes with the serpentine belt loose due to the missing pully and the engine did not overheat ?

 

[tweak'e]

i'm guessing you must have been using very light throttle. diesels actually run pretty cold under light throttle. thats probably also why your battery lasted so long. either that or the belt/pulley was still there giving some charge and didn't fall right off until closer to home.
however there is still the risk that the heads cracked. you won't know until its fixed and you drive it.

 

[MANNING]

..the alternator pully had decided to leave the car..

you may or may not have read that this same thing happened to me only back in may.. the crack from when that pulley decided to go AWOL was scary. In my case, the pulley wheel went but the internal spline connecting it to the alternator remained keeping the belt with enough tension that it didn't slip off.. when the two lights came on maybe 30 seconds after the bang, i immediately pulled over to the roadside and was towed to a plane where i had a new alternator waiting.

that belt does power steering and the water pump along with a couple other things i believe.

 

[Pat]

Snap (pun intended), it also happened to me. I was pulling a loaded horse trailer up hills at the time, but thankfully only 5 minutes from home. Needle was well into the red by the time I stopped, but no damage thankfully. Clearly a crap design.

 

[BarneyB]

I know the answer has prolly been covered in similar threads, but....

When this happens is the repair generally a whole new alternator?....or just a new pulley+bearing?
I s'pose it depends on how big the punch-up was when the pulley wanted to leave the island?

My cynical side says no-one makes/supplies pulley only....and Nissan makes more coin selling the whole alternator?

 

[Pat]

I was able to just screw a new pulley on (with a rattle gun). Both Nissan and aftermarket pulleys are available.

I think others have had the thread on the shaft stuffed when the pulley exits so new alternator time. Depends how lucky you are.

 

[MANNING]

When this happens is the repair generally a whole new alternator?....or just a new pulley+bearing?
I s'pose it depends on how big the punch-up was when the pulley wanted to leave the island?

My cynical side says no-one makes/supplies pulley

I did have a feeling the alternator was on the way out.. it had started a very loud clicking noise. Apparantly its the internal one way clutch that starts playing up and getting noisy.

Ringing around i found out there is two types of replacement alternator for the Navara. I ended up finding a replacement to suit at a Repco outlet in Maryborough. Staff in there were second to none - went beyond their job description to help out.

Was told that if i didn't think the Alternator was buggered and it was just the pulley, they sold the replacement kit to suit and could have saved $400

 

[BarneyB]

Noice.
I've heard about that pulley clutch on the FB groups. It's always nice when you can just replace individual failed parts, where possible.

My local Repco are great with spares too. Usually have what I need & don't rip me off.
The other day I replaced the serpentine belt on the wife's Honda.
There was 2 part numbers in the system with no guidance on difference or application. I took a punt on the shorter one... and of course it didn't fit.
Repco were cool cats when I asked to swap it for the other one, and they refunded me the price diff. All sorted in 10 mins.

 

[paddyjacka]

i'm guessing you must have been using very light throttle. diesels actually run pretty cold under light throttle. thats probably also why your battery lasted so long. either that or the belt/pulley was still there giving some charge and didn't fall right off until closer to home.
however there is still the risk that the heads cracked. you won't know until its fixed and you drive it.

It ended up that the mechanic had to replace the alternator as the shaft was flogged out. I was able to drive for some time as the serpentine belt had enough tension around the water pump even though the alternator pully was gone, the mechanic said I was just lucky the belt did not throw off

 

[GunMentalGrey]

Did you not stop and have a good look under the bonnet before continuing for 45min not knowing the belt was loose?

 

[paddyjacka]

Did you not stop and have a good look under the bonnet before continuing for 45min not knowing the belt was loose?

No I did not want to stop and take the chance of a flat battery, I watched the temp gauge and continued as it did not rise. Battery was flat when I got home

 

[Phunk]

So now I have to worry about a Timing Chain letting go or an Alternator Pulley crumbling itself to pieces.

lovely.

 

[MANNING]

So now I have to worry about a Timing Chain letting go or an Alternator Pulley crumbling itself to pieces.

lovely.

I think i had more than enough warning on the alternator.. The clicking noise was heard at lower speeds and especially when in confined spaces..
I kept pushing the limit and it would stop clicking so it went to the back of the list again.
i had planned to replace it at the end of a 3600 kay round trip - it let me down 400 from home