Cam chain tensioners were due replacement at 60,000 miles, my bike is now at 79,000 and I can't get the job done until after Christmas.
Do these things ever really fail or is this preventative?

 

they can fail. when depends on riding style, age, tensioner shoe style, oil used...

 

My 2005 were replaced at 40,000 miles.
Turned out they could had gone another 40k but we changed them along with a cam upgrade
Etc

 

They do fail.....I replaced mine at 26K and the back one was in the chest in pieces and the front one wasn't far from it. (05' Springer Classic)

 

Best upgrade done to my 2000FLSTC 32k miles. Tensioners are not seen, can't be admired and polished but can sure hand grenade a motor. Now when I ride its with confidence those orange pieces of plastic on springs are gone. My outer was passable but the inner was split down the middle but still intact.

 

Obviously, there were many Harley motorcycles produced during the spring cam tensioner years of the Twin Cam, '99-'06.... Most have not had an issue...

However, there have been enough failures, that the MoCo redesigned that part of the Twin Cam engine.... That is not an inexpensive solution...

IMHO... this is a case of the stakes being more important than the odds... By that I mean, the odds probably aren't great that the tensioners will absolutely fail happen, but what's at stake if it does happen is pretty serious... There can be a very significant difference in the cost of repairs between a preemptive changeout of the cam tensioners, and repairing an engine where they have failed... I believe with the age of these engines, the odds are increasing...

In just my limited anecdotal experience, three out of three bikes I inspected with the spring tensioners and link chains, I have felt all needed to have the tensioners replaced, because they were in jeopardy of failing.

My three observations involved low mileage bikes, but with 15+ years of service. It is my opinion, that with age and heat cycles, the OEM tensioner pads get brittle, which puts them at risk of breaking apart, even if the actual wear isn't substantial. Even if they don't break apart, those small pieces that break off from the pads could cause issues. If one comes to rest in a lifter, it could reduce and/or stop oil flow to the rockers...

The last cam chest I upgraded was just last week. It was an '04, EFI, Stage I engine with 19,900 miles on the bike. Here are the tensioners I removed and replaced. I would not have wanted to be driving around with these tensioners in any of my bikes...




I believe they are just too easy, and depending on your choice of updates, also fairly cheap to replace, rather than to ignore them or just "roll the dice"....

 

My friends '03 Ultra grenaded at 21,000 miles with oil pump failure due to this problem.
My '00 Classic had new ones installed at 40,000 during a service,they were toast 60K later at 100,000 miles and I went gera drive.

 

IMO - You're running on borrowed time..... I have had friends get 60k out of them, I had a friend who's failed totally at 22k miles...

 

At 20K, mine weren't worn bad, but they were pitting slightly.
If the TC's would have come with gear drive, they'd have been virtually bullet proof

 

That is the strange thing about the Cam shoe tensioners, I replaced mine in my 02 Heritage (which now my Son in law has) only had 15-16k on the odometer - as soon as I opened the cam chest the front shoe was ready to go, just messing with it the side of the shoe broke off as that was how deep the chain had imbedded into the shoe, the back shoe wasnt that bad.I went with the Hyd upgrade, wood`s sold the whole package and it wasnt cheap - but that bike runs very good.

I just changed the shoes on my 02 Road king - here is the thing, if you do these upgrades or change the shoes often (I do) then you already have the tools.....however, if this is your first go around changing just the shoes, its not really that cheap. By the time you buy the cam bearing tool (ebay for $60-$75) , the shoe removal tool (Vtwin Mfg - $145) & the install tool ($36 +/-) you`ll have a little money spent right there. the shoes are only like $15 - $20 dollars with shipping but after you buy the inner bearings, Orings, gaskets, lifters (should change) adjustable PS if you go that route? oil, oil filter (Id do an oil change) etc... you`ll have some money in it - but better than not doing it cause that will cost way more.