Need Some Opinions On Clunking Noise In Drivetrain

[jeffl1107]

Hey guys,

I need your opinions on what you think is the problem here but I think I already convinced myself what it is. The mechanic cant look at it till Friday. Last Thursday, in my 97 RD688S Tri Axle Dump Truck I was pulling out of the quarry with my last load of dirt for the day. As soon as I got to 3rd gear, I hear this real fast "Clunk" noise. I thought, maybe a fluke thing where I never got it all the way in gear or something. Got down the road about 1/2 mile, made a turn and started going back up threw the gears. Again, in 3rd it made the noise, then also in 5th. I decided to turn around and go dump my load back at quarry and take it home. It happened again about 4 times on my way home of about 10 miles unloaded in all different gears. My tranny was low on oil so filled it up and went for a ride. It happened 2 more times while out. Got home and had oil coming out of back of TRTXL1070B 12 speed tranny. But I was told by a mechanic that it is common for the rear tranny seals to go in these. But, because the tranny never once popped out of gear or the gear shift even jumped at all, I was second guessing whether it is the tranny that is the problem. Everytime I heard a clunk noise it never missed a beat in continuing to drive. So after thinking that it could be coming from another place and I just felt the vibration threw the drivetrain threw the gear shifter, I went to the one place I knew I have been having a leaking problem. That was my back rear. I noticed that the plate on the back that holds the torque arm was again loose and had about a 1/4 inch seperation, and was noticeably leaking worse, I decided to pull the bottom plug in it. When I drained it, I found metal shaving all over the plug and a good amount of small chunks of metal in the oil.

So, from what you have heard, do you think it is the rear that is the problem here. I think it is. I know some of you will probably say, "DUH", metal chunks, ya think. LOL. But I am very tight on money and just want to make sure I repair what the problem is. Just dont want to put a rear in it and find out that I still have the problem and only to find it was the tranny. I have had a leaking problem with the rear for a while and have found metal shavings on the plug before, but this is the first time I have seen small metal chunks in the oil. Here is just a few of the chunks I found in the oil.

[Rob]

Hey guys,

I need your opinions on what you think is the problem here but I think I already convinced myself what it is. The mechanic cant look at it till Friday. Last Thursday, in my 97 RD688S Tri Axle Dump Truck I was pulling out of the quarry with my last load of dirt for the day. As soon as I got to 3rd gear, I hear this real fast "Clunk" noise. I thought, maybe a fluke thing where I never got it all the way in gear or something. Got down the road about 1/2 mile, made a turn and started going back up threw the gears. Again, in 3rd it made the noise, then also in 5th. I decided to turn around and go dump my load back at quarry and take it home. It happened again about 4 times on my way home of about 10 miles unloaded in all different gears. My tranny was low on oil so filled it up and went for a ride. It happened 2 more times while out. Got home and had oil coming out of back of TRTXL1070B 12 speed tranny. But I was told by a mechanic that it is common for the rear tranny seals to go in these. But, because the tranny never once popped out of gear or the gear shift even jumped at all, I was second guessing whether it is the tranny that is the problem. Everytime I heard a clunk noise it never missed a beat in continuing to drive. So after thinking that it could be coming from another place and I just felt the vibration threw the drivetrain threw the gear shifter, I went to the one place I knew I have been having a leaking problem. That was my back rear. I noticed that the plate on the back that holds the torque arm was again loose and had about a 1/4 inch seperation, and was noticeably leaking worse, I decided to pull the bottom plug in it. When I drained it, I found metal shaving all over the plug and a good amount of small chunks of metal in the oil.

So, from what you have heard, do you think it is the rear that is the problem here. I think it is. I know some of you will probably say, "DUH", metal chunks, ya think. LOL. But I am very tight on money and just want to make sure I repair what the problem is. Just dont want to put a rear in it and find out that I still have the problem and only to find it was the tranny. I have had a leaking problem with the rear for a while and have found metal shavings on the plug before, but this is the first time I have seen small metal chunks in the oil. Here is just a few of the chunks I found in the oil.

If those chunks are lying on a piece of notebook paper I'd go with pulling the rear drive unit out of the housing for closer evaluation. Grit is normal from gear burnish as they wear, (most noticeable after a rebuild of components) but chunks the size you show are not acceptable.

Rob

[jeffl1107]

Yep there on a piece of notebook paper and those are just a few of several I found.