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| Did I screw up my pinion angle or is the B&T joint worn https://www.slantsix.org/forum/viewtopic.php?t=54715 |
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| Author: | SpaceFrank [ Wed Feb 26, 2014 5:45 pm ] |
| Post subject: | Did I screw up my pinion angle or is the B&T joint worn |
At least, those are the two most likely candidates I can think of. For background, I just finished swapping an 8.25" axle from a Jeep Cherokee into my '64 Dart. I got the pinion angle as close as I could, but the tolerances may not have been the best while laying on my back in the driveway. As near as I could measure, I set the rear axle so the pinion shaft was parallel to the transmission output shaft, which made the driveshaft itself point about 3 degrees down front-to-back, relative to those two shaft angles. This was with jackstands under the leaf springs, so they were under load. If I was off in any direction, it's possible the rear axle rotated forward before I welded the perches, leaving the pinion slightly farther down in the front. I replaced every piece of the rear drums. New drums, shoes, wheel cylinders, and hardware kit. I didn't manually tighten the self-adjusters, but we pumped the brakes enough times while bleeding the system that I assumed they would have adjusted themselves out. Taking the car out, the first thing I noticed at low speed was a rubbing noise that sounded like it went with tire rotation. After making a number of gentle and then heavy stops to try to bed in the new shoes, this noise went away. However, the sound would still come back while cornering, even at low speed. After a little more test driving, it seemed like the noise while cornering diminished, but it's still present. The brake pedal feels fine; it's as close to what it was before the axle swap that I can't tell the difference. Anyway, that's noise #1. Noise #2 I didn't notice until today when I drove the car to work. It seems to have a rumble when accelerated from low speed or from a stop. At cruising speed, the car doesn't seem to vibrate any more than it used to, so I'm hesitant to say that the pinion angle is off. As far as the driveshaft goes, it was shortened and balanced at a reputable shop. The rear U-joint is new and properly greased, but the ball & trunnion joint up front is old and has been driven with no boot on it for as long as I've owned the car. I've kept it relatively greased ever since we turned the car into a "racecar," but I would imagine it's pretty worn out at this point. So, any thoughts? Did I not bed the rear shoes properly? Is my B&T joint about to explode? Is it something else? |
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| Author: | kesteb [ Wed Feb 26, 2014 9:48 pm ] |
| Post subject: | |
What year of Cherokee did the axle come out of? Did you change the outer axle bearings? |
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| Author: | SpaceFrank [ Wed Feb 26, 2014 11:31 pm ] |
| Post subject: | |
It was actually a 1984 Wagoneer. No, I didn't change any of the bearings. Neither of the sounds really strike me as bad bearings, though. Noise #1 isn't a constant hum, it's more like a fast but intermittent hum. Like a rub that happens once every wheel rotation. Noise #2 is a more of a rough, deep rumble, and it goes away above a certain speed. Wouldn't an axle bearing or wheel bearing just get louder at higher speeds? |
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| Author: | gato [ Thu Feb 27, 2014 5:53 am ] |
| Post subject: | |
take the drive shaft to a "reputable" shop and get it converted to a common cross. the B & T's are expensive IF u can even find them. i never heard of "bending" the shoes as u describe. take a look inside ur drums and see if u can find any scratch marks? maybe the parking brake is dragging? |
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| Author: | hantayo13 [ Thu Feb 27, 2014 6:31 am ] |
| Post subject: | |
"take a look inside ur drums" while there also check axle bearings |
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| Author: | SpaceFrank [ Tue Mar 04, 2014 5:17 pm ] |
| Post subject: | |
I'll definitely be converting to a U-joint up front, now that I have time. The shop that shortened the shaft said they can handle it, but I was in a hurry to get ready for a LeMons road race when I made the original post. While the rumble kept up all weekend, it didn't get worse and nothing exploded. We actually placed third in class; would've possibly won if we hadn't made a few dumb mistakes. Bedding the shoes, not bending them, lol. Anyway, that noise has gone away as far as I know. I'm pretty sure it was a bit of uneven brake drag that didn't survive the first day of racing. That being said, I'm almost certain now that we didn't bed them in properly. When you'd hit the brakes hard going into a corner, the car would slow down great, but the back end would get a little wobbly even braking in a straight line. Pretty sure the rear brakes aren't doing much at all right now. I'll pop the drums off and see what there is to see. |
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