El Camino Central Forum banner
1 - 6 of 6 Posts

·
Registered
Joined
·
35 Posts
Discussion Starter · #1 ·
G'day guys,
I am changing the cam on my 85 305.

I bought a melling timing gear and chain set and when I went to install it, with the gear on the dowel pin on the cam located correctly and with bolts in the 3 holes in the cam finger tightened down I have slop on the gear side to side. The stock gear seats snug on the end of the cam into the recess in the back of the cam timing gear but this one has wiggle room. I haven't done this job before and don't know if thats normal or not. Seems to be that that amount of wiggle room would mean the gear isn't spinning concentric with the cam. I returned the melling gear set to the store and ordered a Cloyes heavy duty set but have the exact same issue.

It concerns me that both these sets have this movement on both the new aftermarket cam and also on the original stock cam that was in there originally. The fact the stock gear seats snug on the end of the cam makes me thing this is how it should be.

This is the Cloyes kit I am using.
Cloyes Parts

Here's a video of what I'm talking about. In the video i tighten the bolts and it does stop moving but thats only because the pressure of the bolts. It could still move around if I forced it.
gear slop
 

·
Registered
Joined
·
27 Posts
I don't see the '85 El Camino 5 liter on the Cloyes Parts application list, it stops at '84 for some reason. It looks like you just need bolts that have a shoulder that is the same diameter as the hole in the timing gear.
 

·
Registered
Joined
·
520 Posts
You need to check the depth of the screw hole in the camshaft to make sure the three bolts is not bottoming out in the hole. I use blue Loctite on the bolts and those gear sets seem to be good in the past and never had one be so loosie like what you have. Wonder if they drilled the pilot hole/centering pin to be big - is this pilot hole/centering pin the same size hole as the stock gear?
 

·
Registered
Joined
·
35 Posts
Discussion Starter · #4 ·
vctroneill43, I saw that however I think it does list 305H engines as suitable which is what mine is.

chris32, I have enough depth in the cam to run it right down so that rules that one out. It's strange, the recess ID is basically the same for both the Cloyes gear and the stock. The Cloyes gear is a recess depth of .110 vs the stock .120 I wondered if maybe the chamfer on the end of the cam and the chamfer on the recess of the gear means that it's not able to fully seat against the wall of the recess if that makes sense.

The pin hole is a snug fit on the gear as it should be and it looks like the holes for bolts are the same size and positioning on the stock gear as they are on the Cloyes. That's why I can only suspect the chamfer and depth as the issue. Strange thing is, the Melling kit and the Cloyes kit both have the exact same issue.

Have you used this exact kit before Chris?
 

·
Registered
Joined
·
520 Posts
Its been a number of years, but I believe it was. However, the cam gear was not loose like in your video. It may be the "the Melling kit and the Cloyes kit both have the exact same issue" are actually made by the same company. It does seem odd that your stock gear fits snug and both new sets are loose. May need to take a closer look at the inside hole compared to the stock as well as put some kind of contact paint to see if the gear is making good contact on the cam.
 

·
Registered
Joined
·
35 Posts
Discussion Starter · #6 ·
I've been back and forth with cloyes over the last few days about the issue. I measured the recess ID and the stock gear ID and they are the same however the Cloyes gear recess is not quite as deep and the chamfer on the edge extends further into the gear. I think with the cam chamfer and recess edge chamfer it means the gear is not actually locating itself on the cam even when torqued down. I did decide to torque it down and check the run out with a dial indicator and it had considerable runout, the high spot would also change too depending on where i clocked the gear in that slop. Considering this is the case on both stock cam and edelbrock cam I would suggest this is a manufacturing flaw. Going to try another brand and see how it fits.
 
1 - 6 of 6 Posts
Top