Member Since: 24 Dec 2020
Location: Norway
Posts: 107
I am not sure about using that 2 meter breaker bar to tighten the pulley bolt with all the stresses put through the crankshaft with its history of snapping the crankshafts on these engines 😳
1st Jan 2021 9:56 pm
Motolab
Member Since: 18 Oct 2019
Location: Sleen
Posts: 1820
Pete K wrote:
Thought this was the official tool.
Still goes at the gearbox end
you are right Pete.... responded too quick Best regards
Harold
Always looking for Pre '55's & Pre war British Motorcycles! knowing or having one for sale? PM please. I visit the UK 6 times a year
Ps. I edit my texts quite often, english is not my native language, so I will edit My “typo’s” etc.
2nd Jan 2021 8:34 am
Motolab
Member Since: 18 Oct 2019
Location: Sleen
Posts: 1820
Kviasen wrote:
I am not sure about using that 2 meter breaker bar to tighten the pulley bolt with all the stresses put through the crankshaft with its history of snapping the crankshafts on these engines 😳
2.7 has no real excessive “history” regarding snapping...
That is “more” a 3.0 “thing” (Same tool though)Best regards
Harold
Always looking for Pre '55's & Pre war British Motorcycles! knowing or having one for sale? PM please. I visit the UK 6 times a year
Ps. I edit my texts quite often, english is not my native language, so I will edit My “typo’s” etc.
2nd Jan 2021 8:44 am
Kviasen
Member Since: 24 Dec 2020
Location: Norway
Posts: 107
Hm there are loads and loads of 2,7 snapping the crank, the diference berween the 2,7 and the 3,0 are that the 3,0 also spinn the crankshaft and main bearings probably due to the low saps oil C1 speck that is especialy formulated so the particle filter should not block.
My D3 2,7 that was running her whole life on the A5 for 205000 km dident have any signs whatsoever on the conrod and main bearings and you could hardly tell it was even used.
My D4 2012 3,0 that had run her whole life on C1 spun a conrod bearing on 210000 km and all conrod and main bearing was showing bad wear especialy on the top half of the conrod bearings where most pressure from pistons is transmitted.
In the C1 oil aperantly an important additive is removed that probably have to do with high wear.
i cant document it further but i have eywitnesed this so at least i will change to A5 oil and rather change my particle filter prematurely than change the whole engine.
2nd Jan 2021 9:12 am
aja4x4
Member Since: 14 Apr 2019
Location: Westbury
Posts: 2463
Its the other way normally, the 2.7 rarely snaps a crank but engines fail due to spun bearings and oil pump failures.
The 3.0 engines have a higher failure rate due to higher engine output and weaker design, early engines can spin bearings but later ones 2016 on fitted bearings with tabs on to prevent this happening.
The 3.0 engine also tends to overheat the rear two pistons i personally think that this is caused by low oil pressure to cooling nozzles.
2nd Jan 2021 11:17 am
Kviasen
Member Since: 24 Dec 2020
Location: Norway
Posts: 107
I guess it all about where you gather your information from.
Overheating the rear 2 piston caused by low oil flow to the cooling spray nozzles is the first time i hear but of course i cant say that this cant happen.
The 2,7 and 3,0 are identical exept stroke and bore and a different oil sump so how the 3,0 l engine is weaker must be realy down to casting, steel quality level
2nd Jan 2021 11:35 am
aja4x4
Member Since: 14 Apr 2019
Location: Westbury
Posts: 2463
I think the cranks only started to fail when they started making them in Korea from what i have read.
LR were very fussy over the steel quality on the D2 engine and they all came from one foundry so i have been told because of the quality of there castings.
But the D3 engine was French so i guess quality wasnt even a consideration
2nd Jan 2021 11:44 am
Motolab
Member Since: 18 Oct 2019
Location: Sleen
Posts: 1820
I recon a UK forum like this one is a rather good source.... 8)
Regarding different/weaker “design”. Well different stroke on a crankshaft is a different design isn’t it? so different production and since Ford uses in the same engine a different, stronger crankshaft who do not have a record for snapping... it seems clear to me that there is a design/production flaw somewere
The crank is the issue.. not the crankcase...
Not all go though... % wise maybe even less than we “think”, it is normal to hear/read more stories about defects than good running gear..Best regards
Harold
Always looking for Pre '55's & Pre war British Motorcycles! knowing or having one for sale? PM please. I visit the UK 6 times a year
Ps. I edit my texts quite often, english is not my native language, so I will edit My “typo’s” etc.
2nd Jan 2021 11:55 am
Kviasen
Member Since: 24 Dec 2020
Location: Norway
Posts: 107
Aja4x4 gives impression that 2,7 dosent snap the cranks but loads of these engines does exactly that.
And you can actually take the broken crank pieces from 2 different engines and its a more or less perfect match.
Yes we might be on a metalurgic level on causes why this happens but it happens.
Alloy used, casting procedure, hardening methods can all be factors and of course the quality inspection after its finished and ready to go in the engine is also an important factor maybe x ray control would have reavealed some internal hairline craks and the crank would have been scrapped.
Some cranks fail and some last untill the car is scrapped.
Anyway when you change stroke and bore you of course change the construction but to say it is a weaker
construction will require massive gadhering of info.
Last edited by Kviasen on 2nd Jan 2021 12:59 pm. Edited 1 time in total
2nd Jan 2021 12:26 pm
Pete K
Member Since: 15 Jan 2016
Location: GL
Posts: 10735
As they all go in the same place, I would say design weak point (maybe caused trying to get a short engine )
I don’t think it’s true to say the ford ones don’t fail. Our Aus and USA friends can tell us if this is true or not.
2nd Jan 2021 12:49 pm
Kviasen
Member Since: 24 Dec 2020
Location: Norway
Posts: 107
The short construction with partly overlapping conrods is one thougt and even how the oilways inside are drilled can be faktors that could cause micro fractures.
2nd Jan 2021 1:08 pm
aja4x4
Member Since: 14 Apr 2019
Location: Westbury
Posts: 2463
If you look at a broken crank they are so thin at that point and has a hole machined into the web, its a pity that nobody has designed an uprated crank they would sell like hot cakes
2nd Jan 2021 2:00 pm
aja4x4
Member Since: 14 Apr 2019
Location: Westbury
Posts: 2463
Just looking at the snapped crank survey in the general section both D3 and D4 are showing a 9% failure but it doesnt define wether this due to failed bearings or snapped cranks. It would be nice to know what the failure rates are on both.
If the D3 is a lot less and you rebuilt an engine with tabbed bearings and uprated oil pump it should be a reliable engine.
2nd Jan 2021 2:15 pm
Kviasen
Member Since: 24 Dec 2020
Location: Norway
Posts: 107
There are billet cranks but of course the prices are out of reach for a used Discovery 3 or 4 owner.
2nd Jan 2021 2:15 pm
M3DPO
Member Since: 22 Sep 2010
Location: Notts.
Posts: 8243
Sorry to change the subject chaps;
Has anyone done a cam belt change on a Stop Start D4?- I've hit a problem with mine on the rear belt, there is a 30mm steel pipe (appears to be water) behind the cam belt cover bolted to a bracket that appears to be bolted to the rear of the engine(see photo). Has anyone taken this off to access the belt?- if so how, more importantly how did you split it and put it back.
The rear cover will not come off without it being moved.
Can the bracket marked in red be taken off?- I don't think it supports the pipe.
Click image to enlarge
It can when others can't,
It will when others won't,
It goes where others don't.
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you are right Pete.... responded too quick 
