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  1. #1
    Legendary Lancista SubGothius's Avatar
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    Exclamation Beta timing belt change procedure & tips

    I was going to post this in reply to another thread, but decided it should occupy its own thread as an easier-to-find future reference for others. You will want to refer to this pic (click to enlarge) as a reference for changing the timing belt, and for following my descriptions/tips below:

    Numbered items in the photo are:
    1. Factory/dealer timing reference tool (which you likely will not find anywhere at any price );
    2. Nut that secures the position of the tensioner bearing (arrow shows direction to slacken the belt tension);
    3. Tensioner spring and tensioner plate anchor/pivot bolt (bolt thru the center of the spring itself is visible on the other side of the reference tool from here);
    4. Timing mark on crank pulley;
    5. Crank-timing reference pointer (you will find the equivalent of this on your belt cover or as a metal pointer bolted to the block);
    6. Aux shaft wheel timing mark.


    Timing belt replacement is easy enough for the average shadetree mechanic -- BTDT myself, in the parking lot of my apt complex at the time! The only real tricks lie in knowing how to set the tensioner bearing, and how to line up the various timing marks on the cams, crank and aux shaft. To make things easier, before removing the old belt, you may want to remove the sparkplugs and gently turn the crank until things are lined up at or near the proper reference positions.

    The cam wheels each have a small hole thru the flank, which should be aligned with a raised mark on the seal-carrier flange at the end of each cambox where the cams exit. This is easiest to spot looking from the (US) driver's side (gearbox/battery side) of the engine bay, sighting down the valley between the camboxes. In practice (thx to a tip from Haynes), I found the holes actually best lined up appearing to be tipped slightly together (towards each other and the centerline of the cylinder bores) WRT the marks on the cambox flange.

    The crank pulley should have an obvious notch on the edge or a cast-in line on the flank, which should be aligned with the TDC mark on your belt cover or crank-timing pointers. BTW, there are typically three crank-timing marks on that cover/pointer; the most-forward one is TDC and the others are -5 and -10 deg. BTDC (the latter being used for ignition advance timing-light reference).

    The aux shaft wheel has a hole like the cam wheels (actually the very same part # as the exhaust cam wheel), but this one's a bit trickier, as there's no obvious mark to align with. That hole needs to fall on a line drawn between the aux shaft center and the bolt that goes thru the center of the tensioner bearing spring. I found it easiest to stick a small screwdriver bit thru that hole, so it was sticking out in view where I could sight down from the spring-mounting bolt above and line it up.

    Now, the tensioner bearing. After you remove the old belt, be sure to test the bearing itself, see that it turns smoothly by hand with no apparent looseness nor coarseness to the motion. If you have ANY doubt that the bearing is sound, you WILL want to replace it now, but good luck finding a new one (these are not the same as a typical FIAT bearing, tho' I hear a retrofit may be possible, perhaps using a FIAT plate?). Substitute bearing cartridges of the right dimensions are available that will press into the shell and do the job, but they are not as robust as the NLA split-center-race OEM bearing, and such substitute bearings should prolly be replaced with every belt change.

    Belt tension is not actually maintained by the tensioner spring, although the spring helps get the new belt taut to set the proper tension point initially, before you lock the bearing firmly in place. There is a stud in the block that extends out thru the tensioner plate and center of the bearing, then thru a stepped-flank washer that nestles into the bearing center and has a much larger center hole than the stud diameter, then thru a smaller washer with the proper ID, all held together with a nut. The wide hole in the stepped washer allows the rotating axis of the bearing to be adjusted WRT the stud/nut when that nut is loosened.

    You may find it difficult to push the bearing back towards the slackened position while the spring is still engaged. I eventually gave up on that approach and just pried the hooked end of the spring out of the tensioner plate that carries the bearing, loosened both the spring/plate anchor bolt and bearing-center nut just enough to push the bearing back (you may want to take this opportunity to apply ample grease between those two washers on the bearing), then tightened the bearing-center nut to lock the bearing firmly in the slackened position and used a longish 13mm wrench hooked against the spring bolt to leverage the spring back into the tensioner plate. You will want to leave the spring/plate anchor nut slightly loose for now, as the plate will need to pivot on that bolt when you set tension on the new belt.

    Slipping the new belt on is fairly easy if your timing pointers are all lined up. You may need to use a 19mm wrench to jockey the intake cam ever so slightly to get the wheel and belt teeth lined up so you can slip the belt over the intake cam wheel last. Since the aux shaft turns rather freely on its own, you may need to re-align the aux shaft timing after the belt is on, but it should still be (barely!) loose enough to allow this.

    With the new belt in place and all shafts properly aligned, loosen the tensioner bearing-center nut gently to allow the spring to pull the belt taut. Leave that nut ever-so-slightly loose for now. Turn the engine gently by hand for at least two full crank revolutions. Then fully tighten the bearing-center nut to lock the bearing's rotational axis in place, and also tighten the spring/plate anchor bolt as well.

    With any luck, you can now fire up your engine and enjoy!
    Best regards,
    -Tye (1979 Lancia Beta Zagato spider)

    "In theory there's no difference between theory and practice, but in practice there is."
    -Jan L.A. van de Snepscheut

  2. #2
    Master Lancista
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    Re: Beta timing belt change procedure & tips

    Thanks for posting this, it'll be useful since I don't have a Haynes manual yet. Anything else we should be replacing as a matter of preventive maintenance while we're in there (kinda like you should replace the water pump on V6 Alfas)?
    Chris Keen
    '77 spider veloce - since 1991
    '78 Beta Berlina - since 2008
    '79 sprint veloce - since 2005
    '97 Golf - since 1997
    Rusty But Trusty

  3. #3
    Allen Lofland
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    Re: Beta timing belt change procedure & tips

    " Leave that nut ever-so-slightly loose for now. Turn the engine gently by hand for at least two full crank revolutions. "
    Not the proper procedure This should be tightened before any movement of the belt and then loosened and retightened as you move the belt between coged pulley;s This is documented in Lancia Fiat manual. If you leave the tensioner loose as you rotate, you will not be properly tensioning the belt.
    I have this proper procedure documented at home and will post it in a few days. not presently at home.
    Other that this point the advice was sound.

  4. #4
    rossocorsa
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    Re: Beta timing belt change procedure & tips

    Quote Originally Posted by SubGothius View Post
    Numbered items in the photo are:[list=1][*]Factory/dealer timing reference tool (which you likely will not find anywhere at any price );
    I had that tool in a bunch of parts bought with a friend but he managed to some how keep most of the good bits when we had a disagreement and split the stuff up! to be honest I've never been too sure why you'd need that frame it's Lancia over doing it as usual. I do however have the tool for checking the belt tension which is so rare that I'm not even sure it's shown in the manual I'll post a pic later if I find time to dig it out of the garage

  5. #5
    Will
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    Re: Beta timing belt change procedure & tips

    Good write up, Tye!!

    I believe as long as you are going FORWARD, the tensioner being under spring tension is fine- regardless of what this or that manual says or doesn't say. If you try to back up, however, you could have issues. the manual Allen refers to may simply be trying to make things idiot-resistant.

    The tensioner bearings (original twin 14 ball races) are rebuildable. Various other sealed bearings are available which use or don't use the pressed-on shell, and the FIAT parts are widely enough available you shouldn't have to resort to making your own shell or bushing for the inside of a bearing. The trick solution would be ceramic bearings, but the balls are an odd-a$$ size.

  6. #6
    Legendary Lancista SubGothius's Avatar
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    Re: Beta timing belt change procedure & tips

    In case anyone runs across this old thread, just thought I'd mention I slightly updated the procedure today with some new tips about replacing and substituting the tensioner bearing itself. I just did this job again on my LBZ a couple weekends ago, and confirmed that a FIAT-style tensioner bearing WILL work, but only if you also use a FIAT-style tensioner bracket (bearing carrier plate). The updated procedure is here (scroll down):
    http://www.lancisti.net/forum/conten...procedure-tips
    Best regards,
    -Tye (1979 Lancia Beta Zagato spider)

    "In theory there's no difference between theory and practice, but in practice there is."
    -Jan L.A. van de Snepscheut

  7. #7
    Site Founder DJ's Avatar
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    Re: Beta timing belt change procedure & tips

    Quote Originally Posted by SubGothius View Post
    ...confirmed that a FIAT-style tensioner bearing WILL work, but only if you also use a FIAT-style tensioner bracket (bearing carrier plate).
    Correct.

    AND the Beta-specific bearing is identical to the bearing used in the driveshaft center support bearing on the FIAT 124 such as the one at the link below.

    https://autoricambi.us/collections/d...center-bearing
    DJ Richards
    eBay ID: classic-ricambi
    1978 Beta Coupe, Nero

  8. #8
    Legendary Lancista SubGothius's Avatar
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    Re: Beta timing belt change procedure & tips

    Quote Originally Posted by DJ View Post
    AND the Beta-specific bearing is identical to the bearing used in the driveshaft center support bearing on the FIAT 124 such as the one at the link below.
    https://autoricambi.us/collections/d...center-bearing
    Identical in size, so it will fit and work, but not identical interior construction; that's the substitute bearing I mentioned, and suggested replacing with every belt as a precaution, when I originally wrote this up. The proper Lancia bearing has a split inner race for assembly of its double row of slightly smaller BBs; Midwest-Bayless appears to carry it now:
    http://midwest-bayless.com/LANCIA-BE...a-all-new.aspx

    I'd got a bearing from Vick that their site said would replace the out-of-stock Lancia type, but I failed to notice it was also listed for FIAT applications and thus wouldn't work with the Lancia bracket as-is, so rather than go thru the return rigamarole I decided to test and confirm conclusively that the FIAT tensioner bearing would work with a FIAT bracket, and sure enough, it does.
    Best regards,
    -Tye (1979 Lancia Beta Zagato spider)

    "In theory there's no difference between theory and practice, but in practice there is."
    -Jan L.A. van de Snepscheut

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    Site Founder DJ's Avatar
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    Re: Beta timing belt change procedure & tips

    Quote Originally Posted by SubGothius View Post
    ...confirm conclusively that the FIAT tensioner bearing would work with a FIAT bracket, and sure enough, it does.
    AND a Scorpion/Montecarlo bracket, which is the same as the FIAT.
    DJ Richards
    eBay ID: classic-ricambi
    1978 Beta Coupe, Nero

  10. #10
    Master Lancista LanciaPaul's Avatar
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    Re: Beta timing belt change procedure & tips

    So just to add to this discussion on the idler bearing....I can't speak to the appropriateness of either substitute bearing in this application because I don't know what the loading conditions are. It probably is a function of the amount of torque it takes to turn the cams and how far from perfect alignment the pulleys are.

    It look like there are three candidates:
    1. The OEM SKF 617546A bearing. I've seem the suffix HT22 added on. The HT refers to "High Temperature" grease and the "22" specifies the grease. This is a sealed, two-row angular contact ball bearing with a split inner race. There are 14 balls per row. The contact angle is unknown. It is 25x52x20.6mm
    2. The popular substitute that is sold by vendors is 5205-2RS. "2RS" means two rubber seals. This is also a sealed, two-row angular contact ball bearing BUT it has a solid inner race. What does this mean from a practical standpoint? It means it has less balls in it. If you think about it, to assemble a bearing with a one piece inner race, you have to push it off-center, load in as many balls as you can, push it back on-center and rivet a cage around the balls. This rather dramatically limits the number of balls that you can have compared to the split inner race design in which the only limiting factor to the number of balls is keeping them from touch each other. In looking at some pictures of unsealed 5205 bearings on-line. It looks like they have about 8 to 10 rollers per row. The contact angle is listed at 25°.
    3. A straight-up deep groove 62205 2RS ball bearing. This bearing is 2.6mm thinner than the two-row bearings at 25x52x18mm. Fundamentally, a deep groove bearing is not typically interchangeable with two-row angular contact bearing. The principle reason is that the deep groove bearing has limited ability to take axial loads. It appears to have 9 balls.

    So, all that being said, the basic dynamic load rating for a bearing is given by:
    Click image for larger version. 

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    Which says that the number of rows of elements is a factor to the .7 power and the number of balls is a factor to the .666 power so these are important factors. Since we don't know the contact angle of the OEM bearing, it is hard to say how EXACTLY it compares to the 5205 bearing, but if we are pessimistic and assume it is 45° vs the 25° of the 5205, it would be about a 28% difference which would partly make-up for the fact that it has a lot less balls. The negative would be that it is less able to handle axial loads which really doesn't seem all that bad. How much axial load can the smooth rubber belt exert on the idler shell? I don't know the answer. The deep groove bearing would clearly be inferior to the other two in most regards, but not knowing the load makes it impossible to say if it would be adequate or not.

    Anyhow, my recommendation would be use the OEM if you can find it, which is rather difficult. If not, use the 5205-2RS which is available everywhere (Amazon, for example) and cheaper than dirt, as bearings go. It is probably less capable than the OEM bearing, but if choosing between a used OEM bearing and a new 5205, I'd go with a name brand (SKF, NTN, FAG, Koyo, etc) 5205. I would really have a hard time feeling good about the 62205 bearing. If anything, it is more expensive and less available than the 5205-2RS bearing and is inferior in most regards (less life and not the same width as the stock bearing).
    1974 Fiat X1/9
    1981 Lancia Zagato

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