Thread: Gear Drive, Gear Misalignment

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Well I didnt read all the way down so sorry for replying if your question was already answered lol.
When I put a gear drive on my SBC 350 it called for a bearing behind the gear on the cam shaft, and a button on the front. The bearing was "rounded" to a degree (0, 2, 4, 6, 8) they came in a color coded set with my gear drive.
I -believe- the degree of the cam bearing was direct with what degree before TDC you wanted the engine to run. I used 0 degrees. in a stock setup.
Then the cam gear bolted on, and when you install the timing cover a button goes right in the center and has to have a tiny amount of back pressure againt the timing cover (to much will eat a hole threw the cover)

Installing the idler gear, I can't remember which way the dog bone faces but the idler gear should have freeplay on one side and not the other. When I installed mine I but the Harmonic Damper on the end of the crank with some bolts in it so I could turn the crank slightly, allowing the idler gear to slide into place with the light tap of a hammer.

:P if you got the loud cut gear its REALLY loud for about 2k miles, after that it quiets down a bit.. but its still loud enough to wear my friends can her me coming down the street quite a ways.

Originally Posted by weylinthedirty

Well I didnt read all the way down so sorry for replying if your question was already answered lol.
When I put a gear drive on my SBC 350 it called for a bearing behind the gear on the cam shaft, and a button on the front. The bearing was "rounded" to a degree (0, 2, 4, 6, 8) they came in a color coded set with my gear drive.
I -believe- the degree of the cam bearing was direct with what degree before TDC you wanted the engine to run. I used 0 degrees. in a stock setup.
Then the cam gear bolted on, and when you install the timing cover a button goes right in the center and has to have a tiny amount of back pressure againt the timing cover (to much will eat a hole threw the cover)

Weylin, you pretty much described my installation. I also went 0-degs (well, my friend that installed it did). Did your cam and cranks gears line up perfectly? That is the crux of my problems here. How much misalignment is acceptable.

btw: I got the "quiet" grind

I bet that 32.00 timing chain is looking pretty good by now.
Blaine's Motor Supply, Inc. - Engine Parts & Services

Thank you gents for heeding my call.....my ribs are still sore from all the jabbing

Here's the thing, the engine is installed, ready to be fired up save for a set of +.050 valve keepers that I have on backorder. So, let me try to address your responses and if I have to drop the pan and pull the timing cover, then I will do so.

Denny, no pictures (read above), but it's a Pete Jackson quiet drive.

Pat, all I know is that it was a stock MkIV block, never machined. My friend actually installed the gear drive while I was working on something else so I will have to check the shipping box and see what exactly the GD came with. I dont have the old timing set either.. .I knew I should have saved it. As far as the extent of the misalignment (and to answer BigTruckDriver), I would say, to the best of my recollection, that about 65-70% of the upper and lower gear face are overlapping (at worst?) with the dual idler gear floating in between. I can draw a picture of what I mean if I am confusing you guys.

I would have to measure it to get a figure in terms of inches. Thing is, I want to say that it will work, but I dont have the experience to back that statement up. This is the only one that I have ever seen installed.

I knew you guys cared about me..

I knew you guys cared about me..[/quote] do not let every one know this . lot of people think i am a hard ass or may be just a ass

Originally Posted by pat mccarthy

I knew you guys cared about me..

do not let every one know this . lot of people think i am a hard ass or may be just a ass[/QUOTE]Wait one cotton pickin minute.
I am the ass around here and I have papers to prove it.

]Wait one cotton pickin minute.
I am the ass around here and I have papers to prove it. [/quote] ok i will relinquish that title if you have papers i do not you win. i bow to the king

the dog bone should be mark front or back and some times you need to trim it so it fits on the big pins were the gears are on the in side the of the engine block on end play for the button you can spot face the timing cover if alum or add one more timing cover gasket or face the back of the cam button or if a alum button file to fit on the nose of the button or if steel cover bump it out with a round pice of steel and hammer use a big socket on the out side of the cover as a backer when hitting it from the in side of the cover

no denny i think has as the duel idle wheel type. dog bone type that the front timing cover keeps them in

The Pete Jackson type dual idler gear drive is very forgiving. It does not need to be dialed in within mils. I ran one in my very first build '73 Monte (built in '76) with solid cammed 350 SBC. It didn't use a thrust bearing (relied on the one in the block) and no button was used. I blocked the back of the water pump to bolster the cover. I drove the bageezus outta that car. I was immature back then though . The gear drive was obnoxious to say the least.

I will never use another one

Kitz

i don't think they were ever built for the st. we used them a long time ago in round track racing motors, because(like dave said the chains wouldn't hold up.)the chains got better.

Many years ago when I still drank and partied, my friend Mike and I left his house in Watertown, SD on Friday afternoon to get some Kentucky Fried Chicken for Mike, his wife, me, and my girlfriend. Monday afternoon Mike and I called his wife from Minneapolis, Mn and asked her if she wanted regular or extra crispy!!!! Mike still has the same wife, for me, that was a lot of girlfriends ago....

My Engine builder will not use gear drives anymore either. They have shown on the dyno to cause more harmonicis in the valvetrain than a chain. Spend your money of a good double roller timing chain with torrington bearings behind the cam gear.

Another case in point, My friend built a 496 this year with a gear drive. it lasted 3 passes and caused him a huge failure.

Up to you, but i will never use one.

No, he wants a gear drive!

i have a big block in my shop came to me blown up the roller lifter were blown up cam trash it had a gear drive and the lifters that were the next to the gear drive were junk it will not have a gear drive in it when it leaves my shop the guy was thinking i was joking i told him NO way would he get that gear drive in that engine from me . they add hamonic so if it made 10 hp on the dyno i would not use one why? they break parts by adding hamonics i build stuff to say to gether i do not need a dyno for that