TC88 cam chain tensioner check

[Battersea]

Originally Posted by banquo

Might be better posting this on the main forum - not much traffic on here...

My limited understanding of the run-out issue is that it's the as-manufactured tolerance on the crankshaft, and nothing to do with timing side bearing wear. The crank isn't designed for gear drive, so the manufacturing tolerances will be set accordingly, for a chain drive, which will accept a lot more run-out than the gears. If you're lucky, you have a straight crank, and it's OK for gear drive. If not, you need to stick with chains, or get a straighter crank...
In other words, you can get a brand new Harley motor, whose run out will be too wide for gear drive, because it wasn't designed for that.
Does it get worse with time?
No idea, but someone else will have...

If I may just add to this comment. The crank run-out problems are largely confined to later motors (2003 up I think) when the MoCo, in their infinite wisdom, decided to increase the allowable run-out. Its generally considered that .002" TIR is the max that the run-out can be to be suitable for gear drive, although I have read in American forums that cranks with up to .004" TIR have been OK. My year 2000 was right on .002" and has been fine with gear drive for the past 13k miles.

[Matt FXDX]

Think i will be having a peep into my motor this winter having covered 9000mls, see how things are going!

Going back to the tensioner thing, i've heard plenty of scenarios as to why it's always the rear tensioner that wears, how aften the oil is changed, short trips ect!

The one thing that stands out to me is the fact that the chain is a lot shorter on the rear assembley, and so would run a lot faster causing more wear!...

[banquo]

Originally Posted by Matt FXDX

The one thing that stands out to me is the fact that the chain is a lot shorter on the rear assembly, and so would run a lot faster causing more wear!...

Length of chain doesn't change the speed it runs at Matt.... it's the RPM of the shaft, and the number of teeth on the sprocket that dictate the linear chain speed.

[Matt FXDX]

Originally Posted by banquo

Length of chain doesn't change the speed it runs at Matt.... it's the RPM of the shaft, and the number of teeth on the sprocket that dictate the linear chain speed.

Ah, thats my theory out the window Jake!

Wonder why it's always the inner shoe that wears?...

[Ukkid76]

If I’m not mistaken the run out on the gear drive is around 2 thou ish however that is to one side so if you centre the crank then check the side movement and it is 2 thou or less then is would be ok to use a gear drive set up,

But what people are doing is pushing the crank fully toone side and measuring it’s entire movement, so it the above were applicable then the read out would be 4 thou, and that person would assume there crank wouldn’t be any good,

Which is perhaps why people in the states are not having a problem with cranks that they say have a 4 thou movement!!

But anyway why change in the first place I have a 75 thousand mile 2003 Road King and have changed the timing chain’s and tensioner’s once they are up for checking now and no doubt they will need replacing but it also gives me a chance to replace the bearings and bushes at the same time, whereas with a gear drive it would be fit and forget untill something broke of course!!

I for one will keep the chains inspect every 20K or less run the motor with a good quality synthetic oil, surely that should be good enough for everyone Hu!!!!!


P.S

I do have the upgraded oil pump that allegedly pumps a load more oil to these parts than the standard pump!!!!