Just replacing rings and bearings and notice the number 1 piston is in with the "F" mark on top of it facing back as opposed to the number 2 and 3 which are correct facing front.
Should I put in back as it is?
Also I guess this wouldn't have been done in the factory?
Piston in Backwards
Re: Piston in Backwards
The gugeon pin might not be right in the centre of the piston for reasons of reducing side thrust on the piston....hence having a way round to install them.
I would measure each piston to make sure the offset is the same way round on each piston and it is not a piston that is installed correctly but has the 'F' stamped on the wrong side.
I would check down the sides of the piston and compare it with the other two to see if there is excessive wear. You could also maybe check the clearance between bore and piston skirt to see if it has worn differently.
If it is much the same as the others I would reinsall it. I don't have a lot of money so that is what I would do.
Edit: I would be a bit concerned about turning the piston round if the bore has a wear step in it... especially with new rings. It would be worth checking for a step in the bore as new bearings and maybe turning the piston round might have the new rings trying to run up over the step in the bore.
Rob
I would measure each piston to make sure the offset is the same way round on each piston and it is not a piston that is installed correctly but has the 'F' stamped on the wrong side.
I would check down the sides of the piston and compare it with the other two to see if there is excessive wear. You could also maybe check the clearance between bore and piston skirt to see if it has worn differently.
If it is much the same as the others I would reinsall it. I don't have a lot of money so that is what I would do.
Edit: I would be a bit concerned about turning the piston round if the bore has a wear step in it... especially with new rings. It would be worth checking for a step in the bore as new bearings and maybe turning the piston round might have the new rings trying to run up over the step in the bore.
Rob
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dexta roadless
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Re: Piston in Backwards
I would check if the numbers on the big end bearings are pointing the right way. I believe they should point towards the camshaft
6o Dexta Roadless
62 Dexta
63 Super Dexta
75 Shilter UT
62 Aebi
62 Dexta
63 Super Dexta
75 Shilter UT
62 Aebi
Re: Piston in Backwards
Great idea to check the numbers!dexta roadless wrote:I would check if the numbers on the big end bearings are pointing the right way. I believe they should point towards the camshaft
But... I think Dexta diesel big end numbers are a bit unusual and are to be facing away from the camshaft.
Les
Re: Piston in Backwards
Thanks everyone...I've checked the big end numbers and they all face the same way to the left (looking from drivers seat) so it's just the "F" mark on the piston that's different.
A mechanic has just had a look and confirms the piston is around the wrong way but due to the unknown time it's been like that and the consistent wear compared to the other two it should be put back as it came out.
A mechanic has just had a look and confirms the piston is around the wrong way but due to the unknown time it's been like that and the consistent wear compared to the other two it should be put back as it came out.