I had this question asked when I started this topic as one of our cars got a loose nut on the crankshaft inside the Centa.
We’ve found out by a rattling noise during driving and during idle. After taking the engine out, I discovered that the big nut was loose on the crankshaft, which give play between the crankshaft and the hub. This play did damage the splines.
The Centa rattles from left to right on the splines of the crankshaft.
As both our cars have a Phil Bleazey upgrade, Phil offered me an undersized hub for the Centa, which I installed.
This undersized hub fitted perfect at assembly, so I used that undersized hub and torqued the big nut to the advised specifications from Phil which is nearly 50% more as MMC advised.
The engine sounded all back to normal again.
But it left me with a big question: Did I make the first installation not correct? Or was the fit between the crankshaft and the hub not right? Was the big nut not tight enough torqued? Or was there another reason that the nut came loose?
From some of you, I know you’re driving with the Bleazey upgrade and using the original rubber rollers.
But these original rubbers are easily prone to breaking up.
The Bleazey rubber rollers are much stiffer or harder (depending on how you call it) and (probably) don’t break as easily.
I used the Bleazey rubbers on both cars till the nut came loose.
As the Bleazey rubbers are almost the only difference with the original Centa ( except, of course, the much easier changing of the rubber rollers when they break), I started to ask myself: “Could it be that the rollers are the reason the nut came loose”?
I investigated both different rollers.
The original has a rounder shape than the Bleazey’s; they are softer and bigger in diameter.
Could the original rollers better cope with the hammering engine in front?
As I had no proof of this, I found it wiser to return to the original rubber rollers.
Also, I’ve never heard from a loose nut with the original rollers.
After the first few meters with the original rollers, I thought the clutch felt softer when changing gears.
This is compared with the Bleazey rollers.
Don’t forget that when driving the rollers are on one side in the Centa housing pushing the car forward but when releasing the throttle the car pushes the engine and the rollers are on the other side in the Centa. This is also when shifting gears. So all the time, they move from left to right. If rubbers don’t absorb these shocks well enough, it could be in my opinion that it will undo the nut a bit of its torque. It starts with a tiny bit, but once that starts, there is no way back. The nut will get loose.
This was all in my opinion, and I wanted to find out if I was correct in my way of thinking.
But now, a few weeks later, I’m getting more and more reports from loose crankshaft nuts and all with the Bleazey rubbers.
I think it’s nessacary to put this problem on our forum as it is there for us to help and advise each other.
I hope you all understand that I don’t blame Phil for this because his solution with the Centa is ABSOLUTELY perfect.
And we all need to be thankful to him.
His solution makes it easy to change the rubbers, so we don’t have to worry if they break down.
Last edited by Laurens; 12/07/22 01:20 PM.
