Technical Cambelt tensioner nut help needed

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Technical Cambelt tensioner nut help needed

dx90

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The nut on the cambelt tensioner has rounded off. I had to put so much force to try and undo it it rounded off.

What is the best way to get the tensioner off now?

I am afraid that the stud part that the nut goes onto might snap.

Is there any way possible to install the new belt without taking the tensioner off?
 
The nut on the cambelt tensioner has rounded off. I had to put so much force to try and undo it it rounded off.

What is the best way to get the tensioner off now?

I am afraid that the stud part that the nut goes onto might snap.

Is there any way possible to install the new belt without taking the tensioner off?

Ooh thats frustrating.. badly mangled before you start is always a worry :(

Ok: what are you changing..?

Whole kit.. belt. Tensioner . Water pump..?

Belt and tensioner.. ?

Just belt .. ???

Its just a bearing running on an eccentric mount..

So grind 2 vertical flats on the remnants of the nut.. get a decent adjustable on it.. the heat will help ;)

Then flush the grinding dust off all moving parts..

New ..or flushed.. bearing

New nut

You are good to go :)

Full hex sockets exist for a reason ;)
 
Last edited:
Ooh thats frustrating.. badly mangled before you start is always a worry :(

Ok: what are you changing..?

Whole kit.. belt. Tensioner . Water pump..?

Belt and tensioner.. ?

Just belt .. ???

Its just a bearing running on an eccentric mount..

So grind 2 vertical flats on the remnants of the nut.. get a decent adjustable on it.. the heat will help ;)

Then flush the grinding dust off all moving parts..

New ..or flushed.. bearing

New nut

You are good to go :)

Full hex sockets exist for a reason ;)

I'm changing the belt, pump and tensioner bearing. Unfortunately there is very little space in the Seicento to get a blow lamp or cutting tool in there.
 
Will a Dremel get in there to grind off the nut? Will need a lot of time, much swearing, and quite a few mini cutting discs, but likelihood of doing damage is reduced. Failing that, it might need the engine lifting.

You cannot fit a new belt without moving the adjuster. A new belt will need a different setting, and either too loose or too tight can lead to slippage or breakage. Whilst the engine is 'safe', you'd be doing the whole job again, with the same hassle. Sadly, have to persevere and do it this time.

The nut is possibly special. I think all the ones I've had have had a thread insert, that makes it tight on the stud. This is a self-locking system to prevent it from falling off, so get a new one from Fiat. With swarf floating around, fit a new bearing, no point risking it.
 
As Charlie says try a single hex socket
Ie one with 6 points not 12
 
Will a Dremel get in there to grind off the nut? Will need a lot of time, much swearing, and quite a few mini cutting discs, but likelihood of doing damage is reduced. Failing that, it might need the engine lifting.

You cannot fit a new belt without moving the adjuster. A new belt will need a different setting, and either too loose or too tight can lead to slippage or breakage. Whilst the engine is 'safe', you'd be doing the whole job again, with the same hassle. Sadly, have to persevere and do it this time.

The nut is possibly special. I think all the ones I've had have had a thread insert, that makes it tight on the stud. This is a self-locking system to prevent it from falling off, so get a new one from Fiat. With swarf floating around, fit a new bearing, no point risking it.

Do you have the part number for the nut?

I will have a good think about what you have suggested.

Thanks
 
Nut 16102211

If you need the washer behind it, 11193874 This could be special, or just a normal flat washer. Memory suggests it is a bit thicker than a normal washer. Do not replace with more than one washer to make up the thickness as they can be prone to slip.

Thanks for the part numbers.

I'll get them ordered today.
 
I've managed to get the nut off without breaking the stud.


Using the Irwin Bolt Fastener Remover set size 13mm with a spanner to turn the bolt Fastener. Not cheap but what a tool. Well worth every penny.

Thanks all for your help.


 
Nut 16102211

If you need the washer behind it, 11193874 This could be special, or just a normal flat washer. Memory suggests it is a bit thicker than a normal washer. Do not replace with more than one washer to make up the thickness as they can be prone to slip.

New washer and nut came today.


My old one was a nut only with a built in flange. (Different)


The washer that came is not a flat washer but is dish shaped. What way round does the washer go, towards the bearing?

Thanks
 
If the dish gives effectively a smaller and larger contact surfaces, you will need to match them if possible to the contact faces on the nut and bearing. If this seems to make no difference, it won't matter which way around it goes.
 
If the dish gives effectively a smaller and larger contact surfaces, you will need to match them if possible to the contact faces on the nut and bearing. If this seems to make no difference, it won't matter which way around it goes.

Thanks for the info. I will do the timing belt later. (y)
 
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