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Discussion Starter #1
My 48k Miles Leaf has developed a rumble... above 25mph it has developed a noise a bit like a straight 6 piston engine. The pitch changes with speed.
Got the wheels off the floor. No loose side to side movement. Rear drivers side wheel makes a ticking noise if I spin it by hand.

I was wondering between bearing and maybe something like a delaminated pad in the park brake. Local dealer suggested it might be a loose drive shaft! Apparently they have replaced a couple.
Anyone think that likely.
Or have another experience That could help?
Thanks
 

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To eliminate brake noises you could remove the wheel, then unbolt brake caliper and swing it clear, then rotate the hub.

A failing bearing can click when rotated and not all bearings get loose when they fail, I had a front wheel bearing fail on a Fiat 126 many years ago which started seizing, which made it quite difficult to keep the car going straight for a half mile to a local garage. The bearing was so badly seized the could not get the hub apart and fitted a second hand steering hub/knuckle instead.

Drive shafts tend to make noises like clunks or clicks when rolling slowly and accelerating/decelerating or turning on full lock.

Does a straight six makes a whining noise? That would certainly be consistent with a failing bearing.
 

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Discussion Starter #3
Drive shafts tend to make noises like clunks or clicks when rolling slowly and accelerating/decelerating or turning on full lock.

Does a straight six makes a whining noise? That would certainly be consistent with a failing bearing.
Thanks @niggle
It’s more a ticking noise when I spin by hand, not particularly loud or alarming tbh.
On the road it’s quite a deep noise. I’ve been through a few bearings in ICE cars. Usually it’s a harsh whiny noise. This noise has deeper tone and less harsh, but maybe the low frequencies are drowned out by an ICE.
 

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Discussion Starter #4
Hmmm it is indeed a bearing.
Noise is suffused with some added rattle and grind from a part corroded disc. Looks like a piston seized so inside pad was only contacting the disc in places. The rest of that inside face of the disc is a nasty corroded mess.
Nissan replacement bearing - priced at “holy shit balls how much”.
 

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Nissan replacement bearing - priced at “holy shit balls how much”.

Low miles to have a bearing fail. Did one of the front ones on my wifes leaf at about 115k, £55 for a good quality SKF unit . Wouldn't give a Nissan dealer my money, simple job for any competent garage ;)
 

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I don’t have a Leaf but bearing damage is fairly common if a swinging caliper is held under pressure against one face of the disc by a seized piston (often the piston will move forwards when brakes applied but only return to where the ring of corrosion stops it). This eccentric pressure is a bit like permanent cornering force.
 

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. This eccentric pressure is a bit like permanent cornering force.

Yeah, that might indeed have stressed the bearing. Although it seems early for a piston to seize in the bore, the sliding pins however are very prone to sticking and really need a yearly clean and lube to remain functional.
 

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Yeah, that might indeed have stressed the bearing. Although it seems early for a piston to seize in the bore, the sliding pins however are very prone to sticking and really need a yearly clean and lube to remain functional.
[/QUOTE

The main cause of piston stick is filthy black fluid. Neglecting the fluid change is a mistake. I don’t have a Leaf but especially with cars with the motorised handbrake there is debris from that mechanism (usually a glorified nut and powered bolt with the nut inside the piston) along with rubber from the seals and the fluid is noticeably discoloured after 2 years. The microscopic ‘wipe’ of this collects and hardens stopping the piston from returning - it comes off with metal polish leaving the piston serviceable with a new seal (a dealer would replace the caliper). Better to flush and avoid it though.

The numerous posts about ‘nothing to service’ on an EV are just wrong. The lesser use of the brakes means more corrosion debris gumming up too. A decent clean and lubricate takes 15-20 mins per corner and using the correct grease types for pins, the pad slide points and the back of the pad where it meets the piston is important too. The little triple toothpaste style packs make it convenient.
 

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I find that the biggest pain in the bum with the type of caliper used by the leaf is the 'rust jacking' that occurs under the shiny shims the pad ears sit on, and are supposed to slide on.
Good idea in principle but I find they seize the pads solid after a scottish winter :(
Sometimes better to leave them out I think.
 

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Discussion Starter #11
I don’t have a Leaf but bearing damage is fairly common if a swinging caliper is held under pressure against one face of the disc by a seized piston (often the piston will move forwards when brakes applied but only return to where the ring of corrosion stops it). This eccentric pressure is a bit like permanent cornering force.
Indeed that could be a cause... for clarity however I should probably add the additional details that the corroded disc is front nearside and the failing bearing is rear off side. Likely unrelated then.
I think we can reasonably say 48k is a bit early for bearing failure.
 
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