Chain tensioner adjustment, turned in to major failure

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DanWils
Posts: 4
Joined: Mon Oct 22, 2018 5:32 pm
Dino: Fiat Dino 2.4 Coupe

Re: Chain tensioner adjustment, turned in to major failure

Post by DanWils » Tue May 07, 2019 8:19 pm

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Last edited by DanWils on Thu Jul 11, 2019 8:27 am, edited 1 time in total.

Dario
Posts: 85
Joined: Fri Nov 29, 2013 12:18 pm
Dino: Fiat Dino 2.4 Coupe

Re: Chain tensioner adjustment, turned in to major failure

Post by Dario » Thu May 09, 2019 11:27 am

I'll be the first to express my amazement and congratulate you for the time and energy you put into getting it back on the road. You will put it back in the car knowing that no part that could fail was left behind. That is certainly worth the price.

I hope you will have the car back on the road in time to enjoy some Danish Summer!

Dario

DanWils
Posts: 4
Joined: Mon Oct 22, 2018 5:32 pm
Dino: Fiat Dino 2.4 Coupe

Re: Chain tensioner adjustment, turned in to major failure

Post by DanWils » Thu May 09, 2019 5:24 pm

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Last edited by DanWils on Thu Jul 11, 2019 8:26 am, edited 1 time in total.

Peter B
Posts: 50
Joined: Sun Dec 24, 2017 2:47 pm
Dino: Fiat Dino 2.4 Spider

Re: Chain tensioner adjustment, turned in to major failure

Post by Peter B » Thu May 09, 2019 5:44 pm

never, never, never......why....this conditions are perfect.....for years !

DanWils
Posts: 4
Joined: Mon Oct 22, 2018 5:32 pm
Dino: Fiat Dino 2.4 Coupe

Re: Chain tensioner adjustment, turned in to major failure

Post by DanWils » Thu May 09, 2019 7:08 pm

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Last edited by DanWils on Thu Jul 11, 2019 8:26 am, edited 1 time in total.

Peter B
Posts: 50
Joined: Sun Dec 24, 2017 2:47 pm
Dino: Fiat Dino 2.4 Spider

Re: Chain tensioner adjustment, turned in to major failure

Post by Peter B » Thu May 09, 2019 8:44 pm

Hello Dan,
sorry, but who tell this story ?
You spend a lot of money and you will get no better car for the money, also now as daily driver...
Other opinions ?
This car was build as a daily driver in new conditions and not for collection....
greetings
Peter

DinoTomNL
Posts: 39
Joined: Sat Dec 07, 2013 8:23 pm
Dino: Fiat Dino 2.4 Coupe
Location: The Netherlands

Re: Chain tensioner adjustment, turned in to major failure

Post by DinoTomNL » Tue Aug 13, 2019 11:37 am

Hi Stefan,

So would it be good to replace those studs as a preventive maintenance to be sure on running cars? Think that can be done quite easy with the engine in situ when adjusting valves or so? Or do you need to take out the camshafts for that?

Best Regards,
Tom
Stefan2000 wrote:
Sun Aug 19, 2018 10:11 pm
Dan,
I was there by coincidence last Friday and they were just opening up your engine when i walked in. Really sad to see the damage that occured.
But what i heard from them and what i could conclude myself was well was the following.

The studs from the camshaft bearing caps are made of 5.6 grade steel. The torque spec. for the nuts that torque down these bearings are actually to high for a 5.6 grade steel stud. Therefore if you torque these bearing down to the specified torque these studs stretch up. I have seen and measured these studs at their facility and they really are stretched, all of them at every cilinderhead from every engine. You will notice that because the tread is stretched and the nut will not get on it without resistance. So what they do over there with every Dino cilinderhead is replace all the studs with 10.9 grade studs and special notched nuts that can not come loose.
What happened in this case is that one of the studs was so stretched that the nut came completely loose, it feel off at some point and ended up falling between the teeth of the drive gears for the camshafts. This damaged the gears and because of the high force needed to sqeeze that nut between the gear it also ruined the bearing from that shaft.
This got worse rapidly until it really broke down. Probably by tensioning the chain to try to get rid of some unwanted noised the forces on the gears and the broken bearing got even higher and death penalty was declared...

Well it's in good hands now. Keep us updated because this can be informative to everyone over here.

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