Rear End Knocking

[TMAC]

Just bought a 74 Bronco. It is mostly stock, 302 auto. It's been lifted but I could not tell you how much. I suspect 3-5". When in park I can roll the truck back and forth a few inches. When I go from park to drive or drive to reverse, there is a loud clank as it goes into gear. The slop is in the read end. The truck rides fine but I'm sure this will not get better by itself. Can this be repaired or should I just start searching for another rear end? TMAC

 

[Wildturkey]

Unless you are having vibration problems or a roaring noise in the rear I wouldn't worry too much about a clunk when the gears lock up.Mine has always done that,even when it was 3 years old.It has lasted us 31 years.Might be a good idea to keep an eye on it tho.

 

[Broncoholics]

Sounds like the rear end is wearing out. Most times its from getting stuck in a mud hole and switching from Drive to Reverse while giving too much gas. Or the ring and pinion is worn and needs to be replaced some day. This problem can last for years in a street rig. Check for metal in the gear fluid. You might also check the rear u-joints on the driveline and add traction bars so the axle doesn't twist under torc. This will help everything last longer. Duff's long link traction bars do well and don't limit travel. I can lift any of the four tires 46" off the ground with these on before another lifts. Also check to see if the pinion nut is tight.

Eric

 

[amcabbott]

( A few things to think about first if you get a used one unless its low milage it will probibly not last much more then the one you have. how ever changing the bearings and the ring & pinion and all the neet stuff inside is a real nightmare. you need a housing spredder. a plasti gauge shim kit. if you got it that far replace the wheel bearings and seals as you have to pull the axles anyway to get the spider set out. I agree with Broncoholics it could last for years that way or it could leave you sitting in the woods. try to find out where the play is by taking the drive shaft off the u joint should have no play at all. then try the yoke it should not move up down or in and out at all none zero. if it is moving the bearing is either shot or is to loose.take the yoke off and look inside if the bearing or race are shot the whole rear end needs rebuilt but if both are in good shape you can tighten the play up by removing the shims from behind the bearing only go 1 at a time as this changes how the ring and pinion mesh to tight and they will bind and start to howl. replace the seal with a new one. remember if the bearing is shot the one on the inside will be also.

 

[Wildturkey]

I Have been running fords for over 30 years and this is a design problem.Never have I been on the side of the side of the road because of this.Auto trans seem to make the noise worse.If no vibration or other noise run it till it shows other problems.IF you have a stock Bronco with the stock 9' rear please ignore all of these experts and just enjoy your Bronco.It's just a Bronco thing.Want to hear some noise?Get a detroit locker!!Sounds like steel gears breaking every corner you turn.Run It!!