TC88 cam chain tensioner check

[banquo]

As you will have read in your 'quin, these can fail prematurely, and although the MoCo recommends a check at 40,000 miles, some have failed at 20,000 miles..

I'm trying to have a look at 27,000.
This is what they look like if they fail:

You can see that the outer (primary) one is OK, and within service limits, and the other (the secondary tensioner) has failed completely, with the shoe totally gone, and shards of metal lost from the tensioner into the motor. Not good.

Firstly, you need to take off the front exhaust, to get at the cam box.

Stuff an oily rag in the port, to prevent nesting birds, mice, etc. from taking up home there.
Next, fit a polythene sheet between the lower half of the cam box and the lower frame rails, and shape it to form a trough that will direct oil to your drain can. There is always some residual oil left in the cam box, and it's enough to make a big mess.
Slacken the cam box allen bolts a little at a time, in a diagonal sequence (to prevent distortion) then remove completely. If you leave the top two until last, it stops the cover falling off until you're ready. Congratulate yourself on your forethought, as a pint of dirty oil streams down your polythene into your Mackies ice cream box.

This is what the inside of the cam box looks like. There is a cam plate, which supports the outer shafts of the two cams, and houses the main oilways to and from the oil pump. The small gear from the crankshaft drives the rear cam, and behind the cam plate, there is a secondary chain, where the front cam is driven by the rear cam. Unless you have X-ray vision, or are a Venusian with eyes on flexible stalks, you can't see that.

The primary cam chain is tensioned with a spring-loaded shoe, bearing on the outer faces of the chain.

To inspect the shoe properly, you need to overcome the tension on the spring, and pull the shoe away from the chain. Having done that, you can fit a retention pin to hold it in place.
I bought the special tool from Jims, which comprises a special socket and the two retaining pins.

Having used it, it's an overkill for this job, but as you have to be really careful not to let the tensioner spring back on to the chain (which can take your finger off, or shatter the shoe) and it's needed if you ever do a cam or cam bearing change, I though it was worth buying (especially at dollar prices).
The instructions are not good, and it's not clear how the unloader is supposed to fit on to the shoe. It will go on two ways.
There's a bit of metal that extends out to the hexagon drive flats, and that's supposed to go below the lower right of the shoe. You need a huge 1 1/4" socket or spanner to rotate the tool. I used a 32mm socket, which is close enough.

Once you have rotated the shoe anti-clockwise, the hole in the tensioner will align with the hole in the cam plate, under the 'H'.

Push one of the pair of retaining pins in the kit through the tensioner, and into the hole in the cam plate.

Now you can inspect your shoe, which needs replaced if more than half the thickness is gone.
As you can see, mine looks pretty much OK.

It would be easy to say, "Well, the outer one's OK, so the inner one will be too." but if you wind back to the first picture, you can see why that's not a good idea.
At this time, I haven't managed to get a view of the rear tensioner. it would be easy if I took off the cam plate, but that involves removing the push rods, and a whole lot more hassle that I'm not ready for, so I've asked for help on various forums, and am off to find a small dental mirror, that hopefully will let me see enough.

More later....

Got some tips from HTT, and set to...

The other half of the inspection...
Get down to Boots, and buy yourself one of these:


I was looking for a simple, cheap mirror, but they were out of stock, and I spotted this illuminated one. Best thing since sliced bread, because it gets over the problem that most of us don't have three hands for the torch, the tool and the mirror...
The tensioner sits behind the cam plate, and its axle is shown under the yellow ring. The red ring shows the hole where the retaining pin fits.

Using the mirror, you can locate the two hooks on the tensioner. These are what the retaining pin fits through when the tensioner is disengaged, so you slip a sturdy and long flat bladed screwdriver under the rear one, lever it up, and then stick the retaining pin through until it supports the tensioner under the outer hook.

Push the pin in as far as it will go, then remove the screwdriver and push the pin through the rear hook, to secure the tensioner.

This is what it looks like inside:


With the tensioner secured, you are free to use the mirror to inspect the underside of the shoe, which looks pretty good on mine.

When you're finished, get the mirror in there again, and support the tensioner again under the rear hook. Keeping it supported, withdraw the retaining pin, and gently lower the shoe back on to the chain.
Degrease and clean the outer cam cover, remove old gasket, and clean faces. Fit new gasket, replace cam cover, and torque down the allen bolts in the sequence illustrated in your service manual.

[Tony Cross]

A job well done and very well explained. Thanks for that. Just out of interest if you had needed to replace the tensioner is there a better option than the standard H-D part?.

[banquo]

Hi Tony - I've been asking around on HTT, and the general feeling seems to be that the later hydraulic tensioner and roller chain is the way to go (don't ask me why, because it's still a shoe to wear).
The conversion brings the cam drive up to '06 standard, with a roller rather than silent chain, and a hydraulically maintained tensioner.
Might be tempted to do that if I was doing a cam change at some point, but that's not on the cards for now.
Other option would be the S&S gear-drive, but given the grief some people have had with crank run-out (it wasn't designed for the precision of gear drive) I wouldn't be going down that road...

[SJC69]

Well thanks for that Banquo.

I’m poised to undertake exactly the same task as you, we are just back from the US after visiting my brother where we had ordered a vast amount of H-D stuff.
I got the tensioner shoes and also the SE quick install push rods as I figured at nearly $2 to the £ it was never going to get any better than that & whatever the outcome of the inspection I would use them in the end.

I was thinking along the same lines as you, do I have to have the cam plate out just to check the secondary shoe? Seems a lot of fuss if you have a no action result.

So it looks like a trip off to Boots now then!

If you do need to replace the shoes then the cams do have to come out the plate & so new bearing time too.

I did think of the SE cam plate and wonder if the extra oiling would improve the situation, also if or when replacing all the bearings etc would it be just worth fitting for the upgraded oil pump?

I was pondering the hydraulic route too but the cams are expensive, then you need the stock H-D parts such as chains, wheels, cam plate, shoes and oil pump all of which mount up, but you can do it without remapping the EFI.

Of course the reality is the majority of TC88 are not cam chain tensioner eaters so we might be lucky!

A slight side track, I ordered all my parts from Zanottis in PA got the 20% off list discount and as my brother lives in Florida we paid no state tax and minimal shipping, about $12.00 by UPS, yep UPS the men in brown, not USPS!
Now if I brought them at his local dealer it would cost me nearly 25% more what with full price and state tax!

If you get the stuff shipped to another state, no state tax, so even if you going on holiday to say Florida it will save you a fortune to order your parts from someone like Zannotis and pay the postage get them shipped to your hotel!

I orderd the cam Tools from Georges Garage, cheaper than Jims, perhaps not up to full professional use but George does gives a lifetime warranty, his service was first class, again posted from California so no tax.




Thanks again I look forward to any updates.


Links

Zanotti H-D
Georges Garage
SE Cam plate 25283-07

[BaZa®]

As these mirrors are cheap as chips may I suggest that before using them make sure that the mirror is glued in well and that the end of it does not work loose if fitted to the shaft and not a moulded one piece.

[billytwobags]

What a great article and and photos, Ive read and been told to change my chain driven cams to gear driven but after reading threads and your article aim unsure and to be honest a bit confused.Ive also been told that S&S do a chain replacement kit ? When the time and money comes what do you think my bike is a FXSTI 06 model and i do ride it Ive done 11,000 miles so far.Its still got 6months warranty iam not technical minded.So could some one please give me a postman pat answer if possible.

[Limey_Dave]

Originally Posted by billytwobags

What a great article and and photos, Ive read and been told to change my chain driven cams to gear driven but after reading threads and your article aim unsure and to be honest a bit confused.Ive also been told that S&S do a chain replacement kit ? When the time and money comes what do you think my bike is a FXSTI 06 model and i do ride it Ive done 11,000 miles so far.Its still got 6months warranty iam not technical minded.So could some one please give me a postman pat answer if possible.

This explains the history of this problem.Have a read and wait for the fallout.

I have a theory,but,should I tell?


http://www.harley-davidson-hangout.c...te-result.html

[banquo]

Originally Posted by SJC69

1. Of course the reality is the majority of TC88 are not cam chain tensioner eaters so we might be lucky!


2. A slight side track, I ordered all my parts from Zanottis in PA...

3. ...order your parts from someone like Zannotis and pay the postage get them shipped to your hotel!


Zanotti H-D
Georges Garage
SE Cam plate 25283-07

1. Yes, I wonder why that is? Some say that some of the silent chains are rougher than others, and some have been polishing the outer faces to avoid wear, but to me, it looks like lack of lubrication. Maybe it's always the secondary shoe that fails prematurely (just a guess) because the primary chain's picking up oil from the base of the cam box, but the secondary chain's all up high...?

2. So did I. ...

3. i got the 20% and then picked them up from Zanotti's. They were going to hit me with a service charge for collecting, but when I said, "Just mail them to my motel then." they relented (i.e. John McI got involved and sorted it..).

[BaZa®]

Originally Posted by Limey_Dave

This explains the history of this problem.Have a read and wait for the fallout.

I have a theory,but,should I tell?


http://www.harley-davidson-hangout.c...te-result.html

Yer go one then....

[SJC69]

I do wonder about the lubrication side of the tensioner wear as the inner always seems to wear worse, that's why I was interested in the SE cam plate set up.

And by the way H-D have just released one for the hydraulic tensioner bikes with........... bronze bushes for the cams.


25282-07
Link


John at Zanottis is one helpful guy, next time I go to PA I shall make an effort to call in and see him.
I will get my parts posted to another state though!