Oliver 70 timing gear update - (mike french)

This message is a reply to an archived post by mike french on November 09, 2013 at 03:27:20.
The original subject was "Oliver 70 timing gear update".

Mike French, are you able to share how you diagnosed the knock as timing gears? Were you able to find new gears, or did you replace with better used? I?ve got a 70 in-process that was rebuilt, but now has a knock. I?ve spent quite a bit of time listening with a stethoscope, but haven?t quite isolated problem. Looking to get a little better idea before I start tearing down, if possible. And hoping to find a gear source in case that?s the problem (haven?t checked AGCO yet).
Link to original post from 2013

FYI for you. Your best source for timing gears and I don't know if you have a 3 gear or a five gear engine is to look for gears out of an F-series continental in a forklift. A few years ago I did a story for the Oliver collectors telling of sources for 70 parts. But since then some of those sources have been sold and not be available. My e-mail should be open if you want to talk. J.

May I ask? Did that knock sound like a rod bearing? I just rebuilt my 70 and after a few minutes of running, I thought it spun a rod bearing. I could not isolate where the knock was so, I checked all the bearings and they are perfect. The gears all look to be in excellent condition so, I didn't know what to check next.

Did you put new wrist pin bushing in? What kind of bearing clearance do you have? Can you make the noise go away?

All new pin bushings. Bearing clearance .0015 with .020 under bearings. Everyt hing checks out perfect.

Thanks for the feedback J.
My engine is a 3-gear. This tractor sat for 30+ yrs and was locked up when my Gpa and I started restoration 15 yrs ago. We freed and rebuilt motor at that time (rings, rod and main bearings, I think we did wrist pin bearings, but honestly can?t recall). We ran motor for breakin and then decided it had a little knock... then life happened and it mostly sat for 15 yrs.

I?ve spent some time listening to it recently, but can?t quite pinpoint the noise. Sometimes I think it sounds like it?s at front of motor and sometimes it sounds like it?s at #2 cylinder from front. Doesn?t really seem to respond to grounding spark on any cylinder. It?s most notable at lower idle (might be why we didn?t notice it during initial break in at mid-higher rpms with very poor exhaust manifold which has now been replaced). Impression is that it doesn?t sound deep enough to be bottom end knock, but seems to be in time with crank (and doesn?t really sound like valvetrain noise). I recently added Lucas oil stabilizer to see if it had any effect - I added thru oil fill port by governor gear while engine was running and engine seemed to quite down as long as the additive was ?frothing? around gears, but noise would return as soon as additive mixed in with oil and receeded from gears. At this point I?d just like to have a little better diagnosis before I start to tear down. Any recommendations? Is there a way to inspect gear lash without pulling radiator and timing cover? Any ideas to evaluate health of wrist pins without pulling head/pistons?
I?m appreciative for any insight.

Did you check all the pistons for size? A collapsed pistonwill knock at low rpms . I have run into this a few times.

I replaced with nice used gears and replaced the govenor gear also. Yes it sounded like a rod knock and I took pan off and checked everyone. Hope you find your problem fairly easy.

Thanks for the reply. I have mine completely torn down again. Everything checks out good. The gears don't look worn and had very little backlash. Guess I will have to check them out closer.