Hello. Replaced all 3 front engine seals & timing belt.

I have a very tiny oil leak at crank seal. Sure I installed it well. So question # 1 is : Since there is space can I just push back one I put in and put another in front of it ? That way there are 2 instead of just 1 .

Question 2 : Why does timing belt tensioner have to be tightened/locked down ? Isn't it's purpose to keep belt tight If left unlocked wouldn't it be free to tighten belt "automatically" ? By the way : I did not leave it untightened. After Replacinement of tensioner & belt I did tighten it. Then after driving ~ 10 miles loosened and re-tightened it. Will do so again after ~ 500 miles.

Thanks for your info/replies on these questions.

Hello,

For your question 1: That's not the usual procedure for our engine - to put two oil seals back to back. Alternatively a double-lip oil seal is better equipped for this purpose. Ours is single-lip type. I think double-lip crank seal is not available for our B230. Unless you're wiling to adopt such seal from other makes by trial. The only double-lip seal available for our cars is the replacement seal for ignition distributor shaft (optional upgrade).

For your question 2: The timing belt tensioner has to be locked down. Its the same even in other makes of car. This is to prevent 'tooth-jumping' of the belt and disrupt the timing. Not a big issue in our B230 (it is non-interference engine) but the power and fuel economy are affected nevertheless. Unlocked tensioner is normally for the accessory belt as there is no 'timing' factor involved.

Regards,

Amarin.

As belt ages & stretches wouldn't couldn't it jump a tooth ? By being not locked down tensioner would always be keeping belt tight.

Hello,

Yes the timing belt stretches a bit during its life. I think Volvo engineers had studied this aspect and found that it only does that a few times during its life - hence the need for readjustments as Spook had mentioned.

I feel that there's a bigger risk of the belt jumping a tooth during wide open throttle situations in a free tensioner setup. This is the time when the belt tension could overcome the prescribed tension force.


Regards,

Amarin.

Dear Hoola,

Hope you're well. You're correct: the timing belt may stretch with time/heat.

That's why loosening and re-torquing the timing belt tensioner nut - to 37 pound-feet - is part of routine maintenance. The rubber plug in the front of the upper timing belt case allows easy access to the tensioner nut.

Hope this helps.

Yours faithfully,

Spook

I had to do a reinstall on a crank seal once; no fun. I did find that by putting the seal in the fridge overnight, it went right in by hand and there are no leaks. Try it
--
89 240 wagon, 94 940, 200K, 94 940, 135K

Interesting. Wouldn't freezing seal make it contract and therefore make it tighter/harder to put on ? It would seem that warming it up which would cause it to expand would make it looser and easier to put on.

Hoola wrote---"Wouldn't freezing seal make it contract and therefore make it tighter/harder to put on ? It would seem that warming it up which would cause it to expand would make it looser and easier to put on." --- no--because it isn't the sealing part of the seal that offers resistance to being installed but the outer dimension which means forcing it into place either with a press or tapping -- that's where a foul-up might occur with the tiny spring jumping out of place or the sealing lip getting folded over or damaged. -- Dave

To answer your first question---I don't think there's enough room to stack two seals--but even if there is--one seal should do it if installed correctly. You may have folded the lip in one spot - or set the seal so it's riding on a grooved spot -- or the crank needs more cleaning. I know it's boring to have to do it twice but if you're contemplating taking it apart to add a second seal I'd pop out the first and try see see what the problem is.
As for the second question -- my Mom would have said---"just because". True, that some serpentine belts and maybe some timing belts have a "floating" (my term) idle/adjusting pulley, Volvo obviously wants it stationary. Reason enough to follow procedure. Re-adjust it after a few hundred miles and you'll be good to go for tens of thousands of miles. With access to the lock down nut so easy there's no reason not to do it. -- Dave

Dear Hoola,

Hope you're well. I'd not try to install two seals, because the first did not seal properly. There's a reason the seal leaks ever-so-slightly.

Before installing a seal, it is a good idea to check the shaft surface for any imperfection. If there's a micro-burr in the metal - anywhere from the end of the shaft up to the point where the seal rests - a fingertip will detect it. If there's some dirt "bonded" to the surface, a fingeritp will reveal it. These defects can be cured with some ultra-fine sandpaper (600-grit or higher).

The seal itself might be defective: there could be a tiny nick in the very edge of the seal, which is the edge that contacts the shaft. A micro-burr on the shaft could have nicked the seal's edge, as the seal was being pushed along the shaft.

There's no alternative to pulling the failed seal, and replacing it, after checking the shaft very carefully.

Inspect carefully the shaft and the seal's edge. It might be well to use a piece of PVC pipe to seat the seal. The edges of the PVC pipe should be slightly rounded (with sandpaper) so that there's no sharp edge present. Using this tool will press the seal evenly into place.

Tightening the timing belt tensioner's nut keeps the tensioner in place and so exerting a constant, even pressure on the belt. That pressure on the belt helps to keep the belt centered on the sprockets. If the belt stays centered on the sprockets, it will not cut into the front or rear timing belt cases. Because the belt does not stretch much, it does not need to be under heavy tension. If memory serves, the tensioner nut should be tightened to 37 pound-feet

Hope this helps.

Yours faithfully,

Spook