Guest 1949 Roadmaster Posted September 12, 2011 Share Posted September 12, 2011 Hello, my '49 Roadmaster with a Dynaflow is howling on acceleration but quiet as a mouse when coasting. I drained the rear (no sign of ATF) and re-filled with gear lube. Ring and pinion look good, no scoring or pitting. It gets louder when it heats up, can't tell if it's the trans or driveline. Not a wheel bearing, doesn't change when swerving side to side. It only happens when accelerating, and usually kicks in around 45 mph. I have a service manual on CD but can't figure if it's the rear end pinion or carrier bearings, u-joint issue in the torque tube, or rear bushing (if there is one) on the dynaflow.Anybody ever have this happen on a Buick? I could sure use some help here before digging into the wrong area.Thanks, Rick Link to comment Share on other sites More sharing options...
TxBuicks Posted September 12, 2011 Share Posted September 12, 2011 Are you sure it isn't an exhaust or muffler issue? A stopped up muffler will groan when accelerating but quiet when not. Does it howl when in neutral, either stopped or coasting? If not, it is probably not drivetrain. Put it in Park and rev it up for a few minutes and see if you still hear it. Link to comment Share on other sites More sharing options...
Guest 1949 Roadmaster Posted September 12, 2011 Share Posted September 12, 2011 No, I'm positive it's in the drive line. Let me guess, nobody makes ring and pinion gears for these anymore???????????? Link to comment Share on other sites More sharing options...
FLYER15015 Posted September 13, 2011 Share Posted September 13, 2011 No, I'm positive it's in the drive line. Let me guess, nobody makes ring and pinion gears for these anymore????????????1949,According to Dave @ Western Drivetrain in Denver, when your rear end howls upon acceleration, it's the FRONT pinion bearing, if on deceleration it's the REAR pinion bearing. Has to do with "loading" the bearings. Dave proved it to me when we tore down the Dana 60 rear end on my dodge van about a month ago. Bad front bearing. And though 1/2 of my driving in the mountains is down hill, sometimes you just have to go up, and it was driving me crazy. You can only turn the radio up so loud, before the lady of the house notices your trying to cover something up.Bearings should be easy to find for a '49.best of luck,Mike in Colorado;) Link to comment Share on other sites More sharing options...
Guest 1949 Roadmaster Posted September 13, 2011 Share Posted September 13, 2011 Thanks for the input Mike; I called trying to find a shop that would work on diagnosing and fixing the problem. They all want me to drop the car off and they'll get to it "when they can". Some shops said it would be a six month wait. I've rebuilt engines and transmissions before, but rears always scared me. I guess it's time to learn. Link to comment Share on other sites More sharing options...
Guest 1949 Roadmaster Posted September 13, 2011 Share Posted September 13, 2011 I've consulted my service manual, but can't find if there is a definitive test for pinion bearings. Do I have to pull the whole torque tube and disassemble it to check the bearings? Would it be play I'm looking for? Link to comment Share on other sites More sharing options...
Guest p foley Posted September 14, 2011 Share Posted September 14, 2011 I have a 1948 Roadmaster differential pumpkin from a low mileage 50K car. You are welcome to it but there might be a problem getting it back to Connecticut from San Diego. If someone has advertised in Hemmings they are going to Hershey from CA that might be the cheapest shipping. PauL Foley phone 619 662 6899 Link to comment Share on other sites More sharing options...
JohnD1956 Posted September 16, 2011 Share Posted September 16, 2011 1949 Roadmaster, I wanted to ask what type of tires you have on the car, and how many miles on the. Today my work vehicle started howling while driving from the front tires, which are cupped and have 65K on them, and I was reminded of when my Father in Law changed an entire rear axle in his 70 Malibu Convertible, just to find out his recapped tires made the exact same noise with the replacement rear. Link to comment Share on other sites More sharing options...
michel88 Posted September 16, 2011 Share Posted September 16, 2011 It could also be that the rear end needs an adjustment to the ring & pinion. Link to comment Share on other sites More sharing options...
Guest 1949 Roadmaster Posted September 16, 2011 Share Posted September 16, 2011 Woody, the underlying question would be why the gears would need adjustment when the car only has about 45k miles. I've had cars spin the clock and the rears are still fine. I'm thinking bearings somewhere are shot (pinion, carrier, wheel, etc.). I've checked the wheel bearings, that leaves front torque tube U-joint, carrier, or pinion bearings. Link to comment Share on other sites More sharing options...
buick5563 Posted September 16, 2011 Share Posted September 16, 2011 I just went through a very similar problem with my 55 wagon. I lubed the wheel bearings and adjusted the gears. Once adjusted, the noise was louder and sooner. I was fortunate to have a spare pumpkin with driveshaft attached. Once I pulled the rear end assembly and made this swap, the noise went away. I can only assume that it was the pinion bearing on mine.Like Old Tank said in another post, the bearings are available if necessary. You mentioned that you had done engines and transmissions so you should be able to tackle it. If you don't feel like it, at least pull the diff and take it to a rear end shop. I also have had cars that never had any rear end problems, but let it run dry and it doesn't matter how many miles are on it.Good luck and keep us posted. Link to comment Share on other sites More sharing options...
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