IP Belt Tensioner

[asavage]

Jon reached me via email, and I sent him a rebuilt tensioner.

I'm having two more welded up today. I try to keep one or two ready-to-ship.

[EZC]

Any advice on removing the crankshaft pulley when changing the IP belt? I have the 6 bolts on the pulley removed but it isn't budging. This is on a boat so there is no shortage of rust. I have been tapping on it with a hammer with no luck.

[asavage]

I think you're trying to remove the harmonic balancer ("damper"). (Ref. this post):



(Ref. this post):



What's behind it -- the crank hub -- that the six bolts thread into (Ref. this post).



On cars, for the few I've replaced, the part comes off pretty easily after removing the six bolts.

That's a lot of horizontal surface that the balancer slides over, and area for rust to form. And you can't use a puller on that damper, it'll come apart at the rubber bond and then you'll have to have it rebuilt, at a cost of around $125 -- see this thread for details.

First, I'd soak the six holes with your favorite penetrating oil, and hope that it can work its way to the outside of the crank hub.

Is the engine in running condition? If so, you can then put the six bolts back in but left untightened two turns, and run the engine for a bit. I have doubts this will work, but it's worth a shot.

[EZC]

Yes that is it, that one looks to be in a lot better shape than mine. The engine is not running. I'm trying to remove the shroud to replace the IP belt. It looks like I need to remove that balancer to remove the shroud?? I'll try putting the penetrant in the 6 holes. Also when I was reading the thread you provided one guy put a belt on to keep the engine from turning when he was removing those 6 bolts. I didn't keep the engine from turning will that be a problem?

[asavage]

If the crankshaft turns when you try to remove either the six bolts, or (if replacing the front main seal) the large center one, the best recourse is to use a rattle gun (impact wrench), but that fellow used a method involving a belt to prevent crank rotation whilst he removed the bolts.

If your bolts came out without fuss, you didn't need the help!

[In the Maxima, there is just enough room to fit a small 1/2" air impact wrench between the radiator and the large nut.]

Penetrant -- lots of it -- and then tapping hard-ish on the front face -- toward the engine, axially, not at the belt groove areas -- at alternate clock positions (6 o'clock, then 12 o'clock; 3 o'clock then 9 o'clock, etc.) and it may begin to move a smidge. To clarify: you are applying the tapping force on the center part, not the rubber-isolated belt groove part. Once it begins to move, the rest is just patience, more lubricant, and lots of tapping. I think your chances are good that you can work it loose using this method, but you're there and I'm here

Such is the way of all things marine, I'm afraid.

[EZC]

Yea I was surprised 5 of the bolts came out with an impact pretty easy but the last one I had to put some heat to. Now I'm wondering if that melted something(rubber). Anyway I'll try again tomorrow. Sure appreciate the advice, a marine mechanic is two weeks out.

[EZC]

I'm still trying to remove the shroud to get to the IP belt. I removed the six bolts do I also need to remove the large bolt in the middle on the damper. Just want to be sure.

[EZC]

Please ignore that last post I was able to remove the pulley. You were right Al, a lot of penetrant and sweat. It had a lot less rust than I expected. Belt was intact but it had a lot of cogs gone and was slipping. The smooth side of the belt was half worn on the engine side of the belt. There looks like a smooth spot on the shroud where it had been rubbing so I need to be sure there will be clearance when its all back together. Still have to line it all up for the belt to go on, I'm going to get some help with that. Well more to follow.

[asavage]

I've edited Chris' first post in this thread, with a summary of the LD28 IP Belt Tensioner situation, so folks aren't required to read four pages' worth to get the salient facts. Oh, and I'm trying to sell a few more of the rebuilt tensioners so I can recoup the cost of buying those 40 axle shafts seven years ago!

[EZC]

With some help from a friend got the IP belt on and the engine started. The first try at starting it I didn't put the cover or all the belts on. It did start but didn't run unless I kept giving it some throttle. Didn't like that so took a close look at the marks on the pulleys and the belt. The mark on the crankshaft pulley was aligned. On the IP pulley I had used a painted mark and on closer inspection I found a punch mark on the pulley that was on the other side of the cog. This time when I started it, it idled on its. It is starting better than ever now. I replaced the pulley tensioner with one I got from Al.
I really appreciate all the help definitely a wealth of knowledge available on this forum. Thanks.

[asavage]

Too many cores came back to me with bent or rusty pulleys: I am out of cores, so I can only rebuild your core.

I do still have plenty of SKF bearings and custom axles.

[asavage]

IP_Belt_Tensioner_03_Pulley_render_1b.jpg (68.21 KiB) Viewed 18842 times

IP_Belt_Tensioner_03_Pulley_render_2b.png (56.37 KiB) Viewed 18842 times

I put in a few hours today, and I got a quote to have IP belt tensioner pulleys fabricated. These would be machined from T304SS and will accept the 40mm OD SKF bearings I've been using for rebuilds.

If I get (10) fabricated, I can sell them for US$110 ea. This is a pretty hefty investment for something I'm only selling once a year

[asavage]

At this point, demand has fallen off and I have no pulleys here to supply complete rebuilt tensioners, and the original investment for the machined stub axles was never paid off. I will continue to rebuild these for folks that don't want to do it, but I have to have a good pulley as a core, it has to have a smooth surface for the belt to run on, and I'm not willing to have pulleys made at this point.

I'm now making the stub axles available free, just pay postage, sorta. Pay me $5 and I'll mail a stub axle and matching Waldes circlip to you.

You round up your own SKF 5203-2RS bearing. I use and recommend SKF for this.

You need a non-pitted pulley. Here's an example of an unusable one, after cleanup:




I will send you one stub axle and one circlip. Bearing not included.




To remove the OEM axle, you need to drill the backside end of it with a 5/8" drill. Or, use a Dremel and be careful. Or other method. I drill, then press the axle out of the backplate.

Press the new stub axle into the backplate. Weld (or have welded) the stub axle to the backplate.

Press the bearing into the sheet metal pulley. Apply Loctite green bearing mount adhesive prior to pressing. Then mount the pulley & bearing to the stub axle. It's a light fit. Install the circlip.