davebuckley3000 · Mar 12, 2020

Hi,
I have a discovery 1 3.5 v8 efi and I've been told that the bearings need to be replaced. So pls could someone give me a step by step of how to replace the big end bearings and main bearings through the oil pan without removing the crankshaft and the engine in situ. Preferably with a bit of detail as I dont know what I'm doing. Thanks

Henry_b · Mar 12, 2020

davebuckley3000 said:
Hi,
I have a discovery 1 3.5 v8 efi and I've been told that the bearings need to be replaced. So pls could someone give me a step by step of how to replace the big end bearings and main bearings through the oil pan without removing the crankshaft and the engine in situ. Preferably with a bit of detail as I dont know what I'm doing. Thanks

My advice would be to leave it alone if you don't have a clue..

What evidence has been put forward to necessitate a bearing replacement?

You could do a bearing roll, but this depends on the condition of the crank.

jamesmartin · Mar 12, 2020

your best with engine out

davebuckley3000 · Mar 12, 2020

Henry_b said:
My advice would be to leave it alone if you don't have a clue..

What evidence has been put forward to necessitate a bearing replacement?

You could do a bearing roll, but this depends on the condition of the crank.

Thanks for the advice but I'll probably risk doing it myself as I want to as a project and if the engine breaks I'm not too bothered. I had an experienced friend have a look at it as it was seized after being run without oil for a few mins and he told me it had buggered big end bearings so I thought I'd replace the main ones too. Also I'm not confident enough to take out the engine as is way beyond my capabilities and dont have the tools so if someone could give me a tutorial I'd appreciate it thanks.

Henry_b · Mar 12, 2020

davebuckley3000 said:
Thanks for the advice but I'll probably risk doing it myself as I want to as a project and if the engine breaks I'm not too bothered. I had an experienced friend have a look at it as it was seized after being run without oil for a few mins and he told me it had buggered big end bearings so I thought I'd replace the main ones too. Also I'm not confident enough to take out the engine as is way beyond my capabilities and dont have the tools so if someone could give me a tutorial I'd appreciate it thanks.

If it was run dry of oil, chances all the Crank is also fooked.

best course of action is a rebuild..

davebuckley3000 · Mar 12, 2020

Henry_b said:
If it was run dry of oil, chances all the Crank is also fooked.

best course of action is a rebuild..

I only had it idling badly (misfiring and backfires) for abt 30 seconds abt 3 times with no oil and i dont think it seized when running as I only realised it was seized when I tried to start it and it would only turn slightly and stop. Would that be enough to bugger the crank?

discool · Mar 12, 2020

If as you say its the big end bearings have failed you wont need to be told, the noise of failed bearings will tell they are the issue.
U have the right idea to start with, that's off with the sump, then undo a few nuts and remove the bearing shells, replace shells and fit back the nuts.
A workshop manual will tell u exactly what to do step by step, but I didn't have a manual and it was in the days before internet so I just got on with the job, axle stands, a few spanners and a torque wrench is all u need, plus the parts as required

davebuckley3000 · Mar 12, 2020

Yeh it did seem to be making a slight knocking sound so I'll do that thanks

already got everything I need just need to find a workshop manual now

discool · Mar 12, 2020

davebuckley3000 said:
Yeh it did seem to be making a slight knocking sound so I'll do that thanks already got everything I need just need to find a workshop manual now

It’s not difficult even if u have limited mechanical skills but being logical in what u are doing is important.
I replace my bearings albeit on a four cylinder engine, because I had to replace the piston rings so it was of with the head then underneath remove the sump and a few nuts and lift out the pistons to fit new rings, re instal pistons and head and reconnect every thing undone underneath, it took me a Saturday & Sunday, I then drove the car to work on the Monday... perfect

davebuckley3000 · Mar 27, 2020

Also just wondering could anyone tell me how much torque to use when reinstalling the bearing caps

Shippers · Mar 27, 2020

davebuckley3000 said:
Also just wondering could anyone tell me how much torque to use when reinstalling the bearing caps

I would listen to the first advice you were given on here you sound like your out of your depth and are going to waste money...if you can ask that simple question re torque on here you could have googled it...dont personally fancy doing that job with engine insitu being a V8 to boot...

jamesmartin · Mar 27, 2020

davebuckley3000 said:
I only had it idling badly (misfiring and backfires) for abt 30 seconds abt 3 times with no oil and i dont think it seized when running as I only realised it was seized when I tried to start it and it would only turn slightly and stop. Would that be enough to bugger the crank?

youd want to look at the pistons ,rings and crank very carefully, a strip and rebuild,oil pump will need repriming

discool · Mar 29, 2020

davebuckley3000 said:
Also just wondering could anyone tell me how much torque to use when reinstalling the bearing caps

If you still awaiting an answer, here we go. Big end cap nuts 59Nm and the main bearing cap bolts 133Nm.

davebuckley3000

Member

Henry_b

Think outside, no box required.

jamesmartin

Well-Known Member

davebuckley3000

Member

Henry_b

Think outside, no box required.

davebuckley3000

Member

discool

Well-Known Member

davebuckley3000

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discool

Well-Known Member

davebuckley3000

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Shippers

Well-Known Member

jamesmartin

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discool

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