Cambelt tensioner misaligned?

MikeT · Unread post by **MikeT** » 28 Nov 2008, 18:45

Why would the tensioner not go flush against the head/block? I let my nephew try putting it on, thinking he'd be there a while figuring it out and somehow he did it first attempt. When the centre (pivot) nut was tightened (lightly) there was a gap between the back face of the tensioner and the head, which I knew wasn't right but once the top adjustment bolt was wound in, it soon brought it into line, equally when the bolt locked the tensioner "open" to assist fitting the belt, it looked good at that point.

With the belt on, the tensioner was released and it still looked ok but it was obvious, after turning the engine over by hand that the belt was being misaligned and began creeping off the top pulleys.

I assumed with the sprung plunger acting against the tensioner, it created torsion, stopping the tensioner going on straight? Either that or it's now bent

Any other ideas?

Xaccers · Unread post by **Xaccers** » 28 Nov 2008, 19:32

The screw in pin that it pivots on could be bent.
When the tensioner locking nut came off on Cassy, her's tilted causing the belt to slip away from the engine and eat it's way through the cam belt cover.
It's thanks to that event that I met Jim if memory serves

Unread post by **CitroJim** » 28 Nov 2008, 21:23

Xac wrote: It's thanks to that event that I met Jim if memory serves

No, we first met when you needed a new seal for Dex's Anti-Sink sphere Xac...

Mike, as Xac says. Bloody important to make sure the pivot is dead straight. We know what happens if it is not don't we Xac...

But yes, with it all loose, the tensioner spring will put a lateral force on it and push it out of line a tad. Also, don't forget the slot in the top of the tensioner frame is slightly proud at one end and on full retract it will pull slightly away from the head.

As long as the pivot is as straingt as an arrow and it looks ok when the belt is properly tensioned then OK.

The acid test is to spin the engine over five or six times by hand and watch the belt on the sprockets. Tghe belt normally runs toward the outside edges of the cam and pump sprockets but not right to the edge, there should be tad or so of sprocket edge visible. So long as the belt runs true and does not wander across the sprockets for those five or six rotations, all should be fine. Acid test two is to spin the engine for a few seconds on the starter and see the belt running true. If the belt wanders off the edge of the sprocket you have issues.

I'm sure you'll find it all as sweet as a nut Mike

MikeT · Unread post by **MikeT** » 29 Nov 2008, 19:11

That's the problem, it doesn't roll the belt straight. After just one engine rotation the belt had creeped from dead centre to hanging a mm or two off the edge.

Unread post by **CitroJim** » 30 Nov 2008, 19:27

Ahh, that is a problem Mike

Two things to check. Did you put the crank pulley back on when you checked the belt alignment. The pulley acts as a guide and the belt might wander if it is not in place.

Check the water pump bearings. In both my and Xac's experience, they don't like hanging around dry and you might find the bearings have failed, thus allowing the shaft to float around. This may well pull the belt off-line.

If not that, and you are sure the head is on dead-square (not cocked up at one end because the dowel is not in right or head sitting on top of it) and the camshaft is properly seated in the journals, then the tensioner or idler must be a bad 'un.

MikeT · Unread post by **MikeT** » 01 Dec 2008, 11:18

I'm hoping it's just my knack/tendency to find the wrong way to do something first time.

....

I had fitted the engine mount before my nephew fitted the tensioner while the plunger wasn't restrained. Willl remove and refit as per BOL.

Anyone got a plunger holder they can lend me?

Unread post by **CitroJim** » 01 Dec 2008, 11:26

MikeT wrote: Anyone got a plunger holder they can lend me?

A stout screwdriver works well Mike

MikeT · Unread post by **MikeT** » 01 Dec 2008, 11:40

What do you lock it against though? I can lever the plunger or I can fit the tensioner, but I can't do both without inviting muscle spasm in my back

Unread post by **CitroJim** » 01 Dec 2008, 11:44

Ahh, sorry Mike. Didn't think. Aplogies

You'll need a helper with the engine in-situ. Last time I did it the engine was sitting on an engine crane and in that situation, it's not too hard to do it solo.

Did you see my last post in your blog?

MikeT · Unread post by **MikeT** » 01 Dec 2008, 16:34

Haynes are having a laugh suggesting a DIY tool can be made to hold the plunger compressed! And why couldn't Citroen have provided two small threaded holes in the mount, each side of the plunger recess?

Anyone got a grenade spare?

G4EIY · Unread post by **G4EIY** » 01 Dec 2008, 17:06

Well I made one up some time ago now.

Can't seem to find it at the moment, as I could have added a picture.

I used a strip of mild steel about 30mm wide x 3mm thick, bent in a U form. Ground the end to a sharp edge that goes between the plunger and the lever. The other end went over the top engine mount.
It was a tight fit so held in place on it's own.

Worked very well..

MikeT · Unread post by **MikeT** » 01 Dec 2008, 17:15

If Citroen provided two tapped holes it would be even easier.

I think a hole and a pin would suffice.

MikeT · Unread post by **MikeT** » 04 Dec 2008, 12:42

Well it happened. I've lost the timing and am meeting resistance trying to rotate the engine. I don't know if I've sorted the cambelt wandering as I haven't turned the engine round.

Anyway, I tried turning the engine backwards but only succeeded in turning the bolt. Is there a known method to resolve this?

Unread post by **CitroJim** » 04 Dec 2008, 12:57

I have done it on a TU (on the garage floor) by gently turning crank and then cam in small increments until it all came right but on an XUD I'd not recommed it at all. So, slip the cam out (so all valves are closed), rotate the crank to it's timing mark with cylinders 1 and 4 on TDC and lock it.

Time and lock the fuel pump and then carefully replace the cam in the timed position (not hard if you leave the cam sprocket on, you can see the timing holes clearly enough) and then carefull tighten down the cam caps. In fact, you may be able to leave the cam in-situ with the cam caps loosened sufficiently to ensure all valves are closed whilst you are bringing the crank back to time.

You can then slip the cambelt on and the job'll be a good 'un. Hopefully you'll then see the belt running nice and true.

MikeT · Unread post by **MikeT** » 04 Dec 2008, 18:29

Of course, remove the camshaft. Cheers Jim. For some reason I thought it wouldn't possible now the manifolds are back on, I didn't fancy removing them again!

Just to be sure, the crank is near TDC when the woodruff key is around the 12 o'clock mark? I noticed there are several holes in the flywheel, some next to each other.