Cruzzar 22 Report post Posted January 30, 2012 (edited) Ever since I put my '70 together I have had what I think is gear whine from the rear end. Makes noise while at a constant speed above 45 mph in 3rd, 4th, and 5th gear. This was a completely new rear end when I first installed it. New bearings, ring and pinion, traction lock. At about 100 miles I pulled it out and had a new ring and pinion put in by another person and it still makes the same noise. Measured axles and I have about 1/4" clearance between end and spider gear pinion. Axles have brand new bearings and spin smoothly. Drive shaft has about 3/4" freeplay into the trans when rearend of car is at ride height. Pinion angle is within a .5 degree of being parallel (trans down at 2 deg. rear up at 1.5 deg). Noise goes away when you ascend or decend a mountain grade. I can't believe the noise is comming from the trans (it was new TKO 500 when installed) but I'm open to anyones suggestions or experiences. I don't know what it could be in the trans that would make that noise, that is, what is common to all three gears (3rd, 4th, 5th)? If it was a bearing then it would make the noise all of the time. I suspect something was amiss when the rearend was first assembled and the second person didn't pick up on it when he set up the second set of gears. Both people are quit knowledgeable and completent mechanics and are baffled. This thing is draving me bananas! Any suggestions, ideas, recommendations of a transmission shop that is quite knowledgeable regarding TKOs, location of a large cliff that I can drive it off of will be appreciated. Edited January 30, 2012 by Cruzzar Quote Share this post Link to post Share on other sites
Mike65 476 Report post Posted January 30, 2012 Does the noise go away when you step off the gas?. When I replaced the ring & pinion in the rear of my (sold) 68 GT Coupe, when I would accelerate or hold a steady speed there was a whine from the rear end, if I would step off the gas the noise went away. I was told the pinion pre load was not set correctly causing the noise. Hope that helps. Quote Share this post Link to post Share on other sites
sportsroof69 13 Report post Posted January 30, 2012 What's the gear ratio? Do you know what the backlash was set at? Quote Share this post Link to post Share on other sites
Cruzzar 22 Report post Posted January 31, 2012 The ratio is a 3:70 with 31 spline. Back lash is at .010, runout on ring gear is about .002 both radially and side to side. The only think I can visually see is the bearing that is on the end of the pinion gear ( held in by the circlip) appears loose. This bearing has no inner race but the cage that holds the bearings in place appears to be very loose. I can take my finger and spin the race and bearings around without having to move the pinion gear. I know this is not a press fit onto the pinion but I would think that it should have very little clearance. I will take it back to the last guy that set it up and see what he thinks. Quote Share this post Link to post Share on other sites
sportsroof69 13 Report post Posted January 31, 2012 Yeah that doesn't seem right. All the other specs seem good. I usually try to get my lash around .008, but .010 is acceptable as well. Quote Share this post Link to post Share on other sites
Lemon Owner 11 Report post Posted February 1, 2012 I'm with Mike65 on this as I think it has something to do with pinion bearing preload. I had a whine in my diff so I adjusted the backlash to .010" with no change. So I tightened the pinion nut ever so slightly and it is a little quieter. Could probably do with a little more when I get around to it. Quote Share this post Link to post Share on other sites
