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Crankshaft half shells: Re-torque? [UPDATE 3]
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#16: Re: Crankshaft half shells: Re-torque? Author: kandlbarrett, Location: Swindon PostPosted: Fri May 17, 2013 4:35 pm
    ----
If you can get at the bolts to re-torque them then you should be able to remove the bearing caps. If you can do that and the bearing rumble is very slight I would replace the bearing shells. You should even be able to get the top half of the shells out without removing the crank. Do it like this:-

1 - Loosen and then nip back up each bearing cap.
2 - remove the first cap.
3 - using a very thin bladed screw driver use it to just rotate the top half of the bearing very slightly.
4 - use something like a 15 thou feeler gauge you should be able to push the bearing through 180 degrees where you can then take it out. (the oil film may be holding it to the crank but it will come off.)
5 - replace and push back into position using the same procedure.
6 - fit the bottom half of the bearing to the cap, refit the cap, fit new bolts, fit the bearing cap and nip up the bolts.
7 - repeat the procedure for the rest of the bearings.
8 - follow the manufacturers procedure for final tightening of the bolts.

If you don't know already the bearing halves have a small notch that will only let them turn and be refitted in one direction so check that before trying to rotate then.

Cleanliness and being very careful not to scratch the crank is essential.

Try it. Bearings are quite cheap (stretch bolts may be more expensive though) and with the sump off you don't have much to loose.

Some people will scream that this is a bodge (it is) but, when money is tight and the bearings have only just started to rumble this can work. I have done one or two where the engines were still running silently 30,000 miles later.

#17: Re: Crankshaft half shells: Re-torque? Author: V9977, Location: Athens, Greece PostPosted: Fri May 17, 2013 5:36 pm
    ----
Thanks for this, I wanted to do as exactly as above but:
The TU3 has a lower crank-case or 'bearing-case' as Peugeot seems to call it, so the caps are not accesible or even visible from underneath. The first few posts on this thread explain it with a quick diagram I knocked-up as well.

So my thought is.. since I'm in there, give'em a tighten and hope for the best.
Your excellent instructions are supreme by comparison.

I do have the torque & angle tighten values, and a good feel of what is going-on with the engine and how to go about it, so we'll see.

Cheers.

#18: Re: Crankshaft half shells: Re-torque? Author: kandlbarrett, Location: Swindon PostPosted: Fri May 17, 2013 8:53 pm
    ----
As before I wasn't sure of the internal design but assume it must be similar to others and that is that the bearing caps, whatever the design, end up with their faces tight (flat) against the main block casting. Once flush / tight no amount of extra tightening or torque on the bolts will reduce the crank / bearing clearance it will only serve to put extra tension onto the block and bolt threads with the risk of either stripped threads, weakened or even broken bolts.

#19: Re: Crankshaft half shells: Re-torque? Author: V9977, Location: Athens, Greece PostPosted: Sat May 18, 2013 6:17 am
    ----
kandlbarrett wrote:
As before I wasn't sure of the internal design but assume it must be similar to others and that is that the bearing caps, whatever the design, end up with their faces tight (flat) against the main block casting. Once flush / tight no amount of extra tightening or torque on the bolts will reduce the crank / bearing clearance it will only serve to put extra tension onto the block and bolt threads with the risk of either stripped threads, weakened or even broken bolts.

OK I strongly agree with this.
In this case there are no sepperate bearing caps, the 'lower crankcase' is a bearing ladder and is infact one large piece.

'Just checked, and genuine bolts from Peugeot are not astronomicaly expensive (1.5 EUR each) I'll see if they are a in-stock item and consider replacing them to avoid major trouble like you say.

#20: Re: Crankshaft half shells: Re-torque? Author: kandlbarrett, Location: Swindon PostPosted: Wed May 22, 2013 1:06 pm
    ----
I am still unsure what you are trying to achieve. If you are hoping that tighter bolts (new or old) will reduce the slight bearing grumble I really think that wont work. Once the main components are face-face no extra torques will reduce the bearing / crank clearance so won't reduce the rumble you are hearing.

As before I don't know how the internals go together but if bolts were loose enough to allow bearings to rumble then your engine would be trash by now.

There is a lot of technical considerations when determining the size and tightness of a bolts (stress loads it will experience, diameter of the bolt to cope with that, material it is made from, vibrations etc.) but while bolts seem cheap, if you are doing this to reduce clearances and bearing noise I really think you are wasting time and money. After the first few NM or Ft.Lb torque the component faces are flush and the rest of the torque is to preload the bolt to both cope with forces it will endure and ensure it doesn't come undone and it does not further reduce clearances.

Last edited by kandlbarrett on Wed May 22, 2013 1:12 pm; edited 1 time in total

#21: Re: Crankshaft half shells: Re-torque? Author: macj, Location: Essex PostPosted: Wed May 22, 2013 1:12 pm
    ----
What He Said

Nothing to be gained by changing bolts. The shell carrier wont allow the shells to nip tighter... bite the bullet and replace the shells before the crank needs doing

#22: Re: Crankshaft half shells: Re-torque? Author: V9977, Location: Athens, Greece PostPosted: Wed May 22, 2013 4:20 pm
    ----
Many thanks for additional thoughts,
I think there's quite likely nothing wrong with the shells themselves.

These aluminium castings are all over the place, much like a cylinder head.

'Will update soon.

#23: Re: Crankshaft half shells: Re-torque? [UPDATE 1] Author: V9977, Location: Athens, Greece PostPosted: Sat Jun 15, 2013 8:44 pm
    ----
OK, finaly did the work today and results are so far, good - to quite good.

Work carried:

1) Cleaned all the 'stuff' accumilated in the bottom of the sump for the past 12 years.
2) Cleaned & re-built the oil pump and replaced pressure spring and piston inside it. (pain)
3) Re-torqued bearing ladder bolts as follows:

a) Locked the V-belt tensioner to remove one-sided upward force on the crank pulley.
b) Used a jack under the bearing-ladder block to push it up (cancel weight) with a piece of wood wedged in between.
c) Turned crank pulley bolt to turn over the engine and help neutralise forces (theoreticaly).
d) With a torque wrench, slowly worked-up it's scale to find point at which each bolt 'snaped-loose' (tightening).
This turned-out to be around 50N/m, gradualy and slightly increasing towards the fly-wheel end bolts.
e) Decided NOT to use the new bolts but instead re-torque the existing ones in-place in a spiral order as recomended. As each bolt was loose, I would take it to around 70N/m with 'give' being more at the crank pulley end. Decided NOT to angle-tighten, as recomended (44 deg) for when fitting new bolts on a 'naked' engine.
f) Kept continualy turning the crank pulley AND flywheel end (fourth gear engaged) to help neutralise forces, and made 2 more 'rounds' to get them all even.

4) Re-fitted everything, oil-pump, sump etc but used the oiled-paper TU1/TU3 gasket (Elring 984.451) instead of gasket paste. It works fine so far and I'll be keeping an eye on it to report how it holds-up.
5) Also made sure the oil-pump cog wheel was engaged exactly as before on the chain by marking both of them and lining up again. (ultimate pain)
6) New oil added (Shell Helix Ultra 5W40 syn), and oil filter.

First results:

1) The car still works.
2) Crank-pulley now spins straight (camber angle) and a lot less wobbly, with much reduced action of the V-belt tensioner absorbing the tension variations as it turned.
3) Less vibrations and reduced 'whiring' noise which I felt was from the way the crankshaft was sitting in the shells (might not have been).
4) Much less V-belt noise (hardly none) due to correct sitting on the crank pulley and no rubbing on the flange.
5) It appears for now that the crankshaft has not been 'pinched' and it turns as well as before. I hope it stays that way.

6) The valves are out now! I never considered that the miniscule change of the crankshaft position with respect to the camshaft parallel above it, would cause an effect on the highly sensitive valve timing. The position of the pistons is slightly different (relative to each-other) compared to before.
It is a tiny amount, but just enough to percieve it and I estimate at least 300 miles needed for them to settle back down. Then, re-adjust and a further 300 miles to get to the state I had them before. We'll see.

I'll update when needed regarding all of this, for long-term effects and how it's going etc.

Cheers for everyone's help so far. Smile

#24: Re: Crankshaft half shells: Re-torque? [UPDATE] Author: V9977, Location: Athens, Greece PostPosted: Mon Jun 17, 2013 4:20 am
    ----
1) Another update, a previous problem with clutch noise has now completely disappeared ( www.206info.co.uk/Foru...tml#596203 ).

2) Valves will need to be re-adjusted ASAP and then as per above.

3) At some point in the car's life someone had fitted 1560 V-belt instead of the required 1564. This meant incredibly tight fit (until it stretched and somewhat settled) but still putting a massive upward tension on the crank pulley and hence crankshaft, and ultimately causing this 'tilt'.

I stress that obviously it's not suddenly all perfect, but absolutely worth the improvement from this counter-bodge so far...

#25: Re: Crankshaft half shells: Re-torque? [UPDATE 2] Author: V9977, Location: Athens, Greece PostPosted: Sun Jun 30, 2013 11:40 am
    ----
Still good, oil is breaking-in nicely now as well.



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