cam shaft fibre timing cog

[philby26]

Hi all
Can any one tell me what the best way to go about removing and replacing the fibre cog on the the cam shaft for the grey motor
as mine has striped some teeth.?
thanks Phil

[Rusty_T]

Phil,

The gear needs to be pressed off and the new one pressed on, which means the engine may have to come out and the sideplate,rocker gear, pushrods, cam followers etc will have to be removed(and maybe the sump to allow you to guide the cam back in) It's not a hard job but you may also need help to remove the motor. Hope this helps.

Cheers Rusty

[EffCee]

The easiest way to take the old gear off is to use a small grinder and cut through the metal insert that presses onto the cam. This allows the insert to spread. You must pack the sump and surrounding area with rags so that they catch all the dust from the fibre gear and grinding matter. I cannot stress enough to use sufficient rags to catch all the debris and to ensure that you dont cut through the insert to the cam. As you come close to the cam the cut line will quickly turn blue. Have it like this from the front of the insert to the rear, give it a sharp tap with a cold chisel to give the insert a final "crack" and the insert (and what is left of the gear) will be easy to remove.Take care not to damage the cam. Then simply align the teeth ensuring that the cam marking is correct and tap the gear back on.

I know that this sounds quite rough and I suppose it is to a degree, but it does work and will save you having to remove the engine.

Having said that the disclaimer is this; if the grinding matter gets into the sump and the sump isn't taken off and cleaned, it will in due course pass through the oil pump into the engine and do severe damage.

If you are unsure of your skill with what I have outlined then the safest method is to do what Rusty T said.

Regards

Keith
F4+
 

[colt]

We used Keith's method on the weekend to change the gear on our FJ. A fairly easy job for the experienced, I wouldn't attempt it otherwise. If your not sure I would be taking the motor out & doing it properly. you should also change the crank gear as they come as a matched set. (I presume your putting a steel or alloy gear on)
Colin.

[philby26]

Thanks guys its now off "peace of cake"
I have a new fibre gear to go on i was told that the steel or alloy was noisy (not sure about that though)
I just hope it hasn't bent any valves i was just turning a corner and i heard a few taps and she stopped dead.
 
thanks again
Phil   

[colt]

We used a steel 1 on our stock FJ & I can't hear it. Be careful putting the new gear on, don't hit it without wedging something in the fuel pump hole ( this isn't the way we did mine) because of the welsh plug at the back of the cam.
Colin.

[crashbox]

g'day

i was in a "kidney kaper" bash, in a ej with a worked grey. when i rebuilt the motor prior the rally i couldnt get a alloy timing gear in time ,so a fibre one was installed and yep in the middle of nowhere , about 100km from Rankin Springs it let go. ....so it was flat towed be hind a hq holden with a 427 big block chev 4 wheel discs, a verrrrrry scarrrry tow! in  rankin springs i found a 2nd hand cam, pressed(bashed off) the timming gear off the old cam complete stuffed the ol  spare cam,then used a cold chiesel to take the ol one off(no other tools avaliable!) in the ej, then bashed it back on with a xtension socket wedged in the fuel pump slot so the cam wouldnt pop the welsch plug g out, anyway with heeeeps of silicon the motor ran fine, and completed the ralley!

mr crashbox

[gp]

The original GMH fibre gears were (generally speaking) usually good for about 100,000 miles. From more recent experience with some of our club members, the fibre gears that were sold through rare spares in canberra (not sure where they got them from?) have proven to last about 1000 to 4000 miles. Even if the alloy/steel gears were noisy (Which they don't seem to be), they would have to be a better repalcement than a short lived fibre gear.

As Colt said, make sure if you tap the new gear on (while the cam is still in the engine), ensure you don't push the welch plug out of the back of the block.

Cheers,

Graham

[EffCee]

The only "noisy gears that I have heard has been the steel or alloy gears that have been straight cut. they are definately noisy but wmost people that have fitted them have sought the "blower type whine" that they emit

Keith
F4+
 

[Rod]

Hi Phil and All,

I have replace gear both in and out of the car. The beauty of being out of the car you can press the new gear on very well get the end float correct.

However, doing it in the car is just as easy. As outlined above use a die grinder and carefully take all precautions mentioned. Getting the gear on this way is difficult as its difficult to get much leverage when hammering it on at the same time holding a tyre lever in the fuel pump opening to stop the cam moving back and knocking out the welch plug. Not to mention its hard to get the correct end float.

A way I has taught by an old mechanic was to tap the end of the cam and make up a puller with a large washer. It pulls on the gear a treat and you can get the end float correct as well. I have been fortunate in that I have come across cams that have already been tapped. Saves so much time. Hope this approach is of help.

Cheers

Rod

[philby26]

thanks guys
i will put these ideas to use and let yous know how i go
thanks again Phil

[southside]

who sells the steel gears apart from american autos?

[philby26]

thanks guys
for your help she is now running again  it wasn't to bad of a job at all
thanks again
phil

[Paul In Ireland]

Which method Phil?

[colt]

The makers of the steel gears are Master Engineering in Adelaide. I can't find his contact details at the moment.
He made up 200 sets last year, so should have plenty left.
Colin.

[philby26]

I first cut of the old one with the thin blade grinding wheel  above the key way (the thinest peace) then tapped it with a sharp coldchisel which split it open slightly and then levered it off . i then took out the fuel pump put a bar behind a cam lobe and held it while my mate tapped the new one on with a soft copper hammer we only had a few inches of swing but that is all you need it didn't
need to be bashed on with great force
I have never done it before but if ya really put your mind to it and take care its not that bad at all    

[Rod]

Great to see that you got it on Phil. I forgot to mention in my post that you can either place the gear in the sun or if you have an oven close by in it. I found when I used the oven trick to heat the gear up, it goes on very easy indeed without a lot of force.

Cheers

Rod

[Johns]

Graham, having just rebuilt a grey for my wagon with a fibre timing gear I am concerned to read your post. The engine is not yet in the car, so I can change it.

Can you confirm there is definitely a problem with the Rares gears, can anyone else comment?

Cheers
John

[colt]

John, even though i haven't had 1 go myself, There is no way I would use a fibre gear, new or otherwise. There was a stage not long ago where we would just about take bets as to whose gear would go today. They seem to last a few thousand miles if you're lucky. And this is with a good oil supply. I'm for changing it.
Colin.

[Rod]

Don't be fooled that steel gears can't "go" either. I had one go on me after about 7-10 thousand miles. It totally shocked me when it happened out in the middle of no where. It had good oil supply also. I suspect I may have damaged it trying to hit it on cold while the motor was still in the car.

I wonder if there are any others out there who have had a steel gear go??

Cheers

Rod