DangerManV
New member
Hey guys, signed up to get some help from the pros.
I have an 88 YJ. I6 with an automatic transmission. It's a 4.2/4.0 rebuild.
Anyhow, it does this weird thing that's hard to describe. After driving around for an hour or so when everything is warmed up, it will occasionally make this horribly loud and irritating grinding/zipping sound underneath the vehicle. It only happens when I am taking off, whether climbing up hill or whatever. Any gear, although pushing it up a steep hill on the highway triggers it more frequently. It usually does it once a day. The moment I hear the noise, I let off the gas and hit it again and the noise is gone.
I don't think there's any real loss of power when the noise starts, but it's hard to tell.
I can only describe the noise as being a solid mid to high sound like a train whistle mixed with this metallic rapid clipping/dragging sound. It is extremely loud. I can't stress that enough. The noise pitch doesn't change with the vehicle's speed. There is no wind up or wind down. It's solid, loud, and harsh. It only happens under acceleration. It does it in any gear. It is happening in 2wd. I haven't used 4wd enough to know anything there. It is not the motor. It comes from below the seats, but it's so loud that it's hard to pinpoint what direction. It's like a speaker next to your ear.
It has happened while climbing an on-ramp over 55.
It has happened while driving out of a drive-through restaurant.
Today, it happened after taking off from a full stop at a light in an intersection around 2nd gear.
I just changed the rear diff fluid and didn't see any major problems there. It does leak where the axle connects to the rear-end housing. The transfer case seems okay but it has a leak. I can't find any play in the drive shafts.
Any help? I have tried to record the sound, but it's so random that I can never catch it.
I have an 88 YJ. I6 with an automatic transmission. It's a 4.2/4.0 rebuild.
Anyhow, it does this weird thing that's hard to describe. After driving around for an hour or so when everything is warmed up, it will occasionally make this horribly loud and irritating grinding/zipping sound underneath the vehicle. It only happens when I am taking off, whether climbing up hill or whatever. Any gear, although pushing it up a steep hill on the highway triggers it more frequently. It usually does it once a day. The moment I hear the noise, I let off the gas and hit it again and the noise is gone.
I don't think there's any real loss of power when the noise starts, but it's hard to tell.
I can only describe the noise as being a solid mid to high sound like a train whistle mixed with this metallic rapid clipping/dragging sound. It is extremely loud. I can't stress that enough. The noise pitch doesn't change with the vehicle's speed. There is no wind up or wind down. It's solid, loud, and harsh. It only happens under acceleration. It does it in any gear. It is happening in 2wd. I haven't used 4wd enough to know anything there. It is not the motor. It comes from below the seats, but it's so loud that it's hard to pinpoint what direction. It's like a speaker next to your ear.
It has happened while climbing an on-ramp over 55.
It has happened while driving out of a drive-through restaurant.
Today, it happened after taking off from a full stop at a light in an intersection around 2nd gear.
I just changed the rear diff fluid and didn't see any major problems there. It does leak where the axle connects to the rear-end housing. The transfer case seems okay but it has a leak. I can't find any play in the drive shafts.
Any help? I have tried to record the sound, but it's so random that I can never catch it.
