Balance shaft alignment

[97egl]

Never have kept balance shafts but on my winter beater I'm gonna use as a daily I figured I would keep them since it's not a race purpose vehicle. Anyways the sprocket for the balance shaft is off slightly when everything else is lined up dead center. I also remember there being a few degrees of play between the shaft and sprocket. Also is an ACL oil pump, maybe that's part of the issue.

Guessing it'll be fine but figured I would ask before closing it up..... may subconsciously be looking for a reason to rip them out before putting the engine back in the car because somehow it'll end up as a racecar.

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[steve]

It's not a whole tooth off so you have it on correctly assuming you have the lower balance shaft has the correct phasing.
It looks like if you were to turn the crank a tiny bit back all the lower marks would be closer to their marks.

Do you have a picture showing the TB tensioner pulley as well? It may be the angle but the tensioner looks overtightened.

 

[97egl]

Alright that makes me feel better. And yes the tensioner turned while I was tightening the bolt so the hydraulic tensioner is in a little far but its not bottomed out. I gotta pull the belt off to put the metal shield on that goes behind the mount anyways so I can get it set right when I time it then.

 

[pauleyman]

Alright that makes me feel better. And yes the tensioner turned while I was tightening the bolt so the hydraulic tensioner is in a little far but its not bottomed out. I gotta pull the belt off to put the metal shield on that goes behind the mount anyways so I can get it set right when I time it then.

There is a spec for the tensioner. If it's out of spec you should fix it.

 

[97egl]

There is a spec for the tensioner. If it's out of spec you should fix it.

Yeah I'm going to fix it when I pull the motor mount bracket to install the shield that I forgot. It'll be tonight or tomorrow. I'm not going to run the engine like that. Since the arm isn't bottomed against the housing of the hydraulic tensioner and is still on the pin it shouldn't put much more stress on the belt where it would cause issues sitting for a couple days

 

[steve]

Make sure there isn't a big divot in the arm were it rubs the pin of the tensioner. That will eat into your tensioner range. If there is have it welded up.

 

[XC92]

Make sure there isn't a big divot in the arm were it rubs the pin of the tensioner. That will eat into your tensioner range. If there is have it welded up.

How big is too big? I'm at this stage of my TB replacement myself and there was a depression around 1mm or less deep made by the tensioner pin digging into it. I reinstalled the tensioner, arm and pulleys yesterday but can easily take them off to properly measure it using a depth gauge. Is there a depth value where you really should get it filled? And is there a safe alternative to welding, say JB Weld?

 

[steve]

Will it work with a 1mm or less deep hole, yes I'm sure there are cars out there running with a bigger divot. I have to ask if there is a hole now how deep with it be in another 60k?

As far as I can tell the only answer to your question is 0. Any thing else is the same as extending the specification for the tensioner by that much. There is only a 3.8mm to 4.5mm range for the correct setting so an extra mm is significant.

If you have something harder and more wear resistant than the iron or the welding rod filler feel free to use it.

 

[XC92]

Well, my view is that if I'm going to be fixing every relatively minor issue with my car it'll be another year before I feel safe to drive it. I mean rings wear out but you don't do a ring job if compression gets below optimal numbers. You don't get out the Bondo every time you get a minor ding. And so on. You wait until a certain threshold is passed, or approached, and I was just asking if I'm there.

Well, that's true for most people. If you race or gave a high HP car or otherwise push it, or if you're a tinkerer who likes things to be in optimal shape and have the time, budget and will to keep it that way, sure, go knock yourself out. But for most people, it's just not going to happen, because life, time, money, priorities, etc.

When my 29+ year old car with still under 78k miles on it goes another 60k, I'll certainly have another look at it. In fact I can all but guarantee that I'll do so well before then, most likely next spring when I intend to take the TB covers off to see if my TB job held up or if there are issues with sagging belts, oil and coolant leaks, failing pulleys, etc., and, yes, the tensioner arm dimple.

I doubt I'll put enough miles on it before then to deepen the dimple by enough to be that worrisome, so if it's "acceptable" now then it should be then, if ever so slightly less so. If anything does go wrong in that whole area, it'll almost certainly be something else, and it'll almost certainly manifest itself well before then.

Btw the new TB is the EVO one, Kevlar, so stretching shouldn't be an issue and the main reason the brand new OEM tensioner might have pushed out more than a hair since now would be an arm dimple that's deepened.

And that's all I wanted to know, how much room there is there for dimple to deepen before it needs to be addressed. Seems to me that a rough rule of thumb would be that if it grows to around quarter of the total remaining play left in the pin (i.e. how much more the pin can extend beyond its initial 3.8mm to 4.5mm range), you probably want to do something about it, and if it's closer to half, you must do something about it (and even then you've got some margin left).

So, how much can that pin extend beyond its initial range?

 

[97egl]

This isn't a spec but every one I have ever done has had a slight dimple and I've never had an issue. The hydraulic tensioner is made to keep pressure on the belt as it wears/stretches over time. If it ends up so far out that you needed that last 1mm I'd suspect you have MUCH worse issues. I've changed timing belts with 50-105k on them and the tensioner barely had moved on any of them. On one I was able to re-install the grenade pin so it hadn't moved at all.

This is all just my opinion not a specification

 

[XC92]

Doesn't having a Kevlar belt, which I just installed for both belts, make this even less of a problem, since they don't stretch as much, if at all?

I also got a new OEM tensioner. New OEM everything, actually, except the BSB, which is Gates Racing, and the WP, which is Aisin.

 

[97egl]

Doesn't having a Kevlar belt, which I just installed for both belts, make this even less of a problem, since they don't stretch as much, if at all?

I also got a new OEM tensioner. New OEM everything, actually, except the BSB, which is Gates Racing, and the WP, which is Aisin.

I just went and measured 1mm with a caliper. 1mm is apparently a bit more than I was picturing in my head and have to say I haven't seen a diviot that deep before myself. I'd be surprised if you even had a .5mm diviot with only 60k miles. Maybe measuring the diviot in yours will but your mind at ease.

 

[XC92]

I wasn't able to do it today but I'll try tomorrow when I complete the TB job and post the depth here along with a photo. You're probably right and it's not as deep as 1mm.

 

[XC92]

So, I just removed the arm and measured the dimple with a high quality digital caliper, and it came out to around 0.25mm. So I'm not too worried.

It looks worse than it is:

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I'll just check on it from time to time. But since it's probably the original arm and I have just under 78k miles, it should be ok till the next TB replacement, especially since I got a new OEM tensioner and pulley.

 

[97egl]

Did you paint the arm? Because it looks like the dimple still has paint in it which would mean they are possibly dimpled from the factory. You are the original owner of this car if I remember correctly from another post of yours?

 

[XC92]

Yeah, that's SOP for me these days with any forged or cast metal part, removing as much rust and grime as possible, then priming and painting for both looks and rust protection. Except where it would interfere, like bushings and other rubbing parts, or where it could set off tight tolerances. It wasn't really called for here but I like knowing that things are nice and clean even where I can't see them normally.

And yes, I'm the original owner but I have no way of knowing if this is how it looked when new as I've never done a TB job on this car before. But it's odd that the dimple is not centered left-right. I wonder if the arm and tensioner were properly installed after the previous TB job? In any case it all looks good enough to go back on.

 

[steve]

Because it looks like the dimple still has paint in it which would mean they are possibly dimpled from the factory.

They are not dimpled from the factory. They are ground flat.