thud/noise in turntable when changing direction

[tnc110]

Went and looked at a used volvo 160 excavator. noticed a bit of a thud, noise when switching direction on the turn table. feels like there is too much back lash between the pinion and ring gear. anyone ever hear of something like this. Is the backlash adjustable??? what else could it bee...swing motor appears to be tight...maybe bearings in swing motor are out?

 

[DMoline]

When I had the swing box resealed on my 325 the field mechanic did not shim the end play correctly. I had a 'clunk' when changing swing direction, it was kind of loud and echoed through the turntable hard to locate.

 

[tnc110]

When I had the swing box resealed on my 325 the field mechanic did not shim the end play correctly. I had a 'clunk' when changing swing direction, it was kind of loud and echoed through the turntable hard to locate.

how hard was it to fix? Did you do it yourself?

 

[DMoline]

tnc110. After the field mechanic installed the box with the clunk the first time I pulled the box again and took it to Cat dealer to correct. Re installed and clunk was still there. Dealer(Cashman Reno) sent number one man out twice and he determined something was still wrong in the box. He came back out, pulled the box, went back to shop and found that the shimming instructions in the repair manuel were reversed(wrong?). He put it together right, I reinstalled it and it is fine. To answer you question, Taking the box out is not bad, you need a torch for the loctite and a crane or backhoe and a bunch of the right caps. Im not much of a mechanic so I wont go inside the box. It seemed always like a worn ring gear or pinion but the problem was pinion end play due to missshimming. I always knew my problem was in the box because I knew when it started(at the reseal). Maybey this information is helpfull.

 

[tnc110]

Thanks for the reply. Volvo mechanic said it was fine...I'm still a little concerned. He advised the gears be repacked... I'm going to down load the service manual and see it the backlash is adjustable....

 

[pawoods411]

Not sure if this will be any help to you, tnc110...but I'm dealing with a similar issue with a 89' Cat E120B. Recentley had a mechanic come out and change the swivel seals, and then a thud/clunking came about for a bit of time, but has since dissapeared. Perhaps our mechanic didn't properly install the seal, and cause this. Perhaps it could've happened to this Volvo 160 you looked at. Good Luck.

 

[graderfun1]

I've had a similar experience and found it was the boom that was improperly shimmed. It's worthwhile to check all joints, boom to house, arm to boom, and bucket to arm. Sometimes a loose boom will sound like a "clunk" coming from the swing gear area. These ae easy checks and won't cost anything. Good luck.

 

[tnc110]

I've had a similar experience and found it was the boom that was improperly shimmed. It's worthwhile to check all joints, boom to house, arm to boom, and bucket to arm. Sometimes a loose boom will sound like a "clunk" coming from the swing gear area. These ae easy checks and won't cost anything. Good luck.

It was the boom to house slop left to right....thanks!!!!! This cant be easy to shim.....

 

[graderfun1]

It isn't too bad to shim. First, position the boom so the boom pin is free, or loose. Then, pry the pin away from the cab. Use the boom flag pin retainer to do this if equipped. Pull the pin only far enough to where you can insert shims between the boom and the boom mounting ears. The shims don't have to be the exact same size as the boom pin, just close enough to where they will fit around the boom pin. You can use a bunch of grease to hold the shims together. Line up the sims while someone taps the boom pin back home. This really shouldn't take much more than 45 minutes or so. Good luck.

 

[RobVG]

Nice job graderfun1

 

[graderfun1]

Thanks! Sometimes it seems complicated, but often it's the "duh" moments that get us. I've had my share!!

 

[nixs]

Just keep track of the boom so its not has drifted ever so little, its almost hopeless to put back the pin if the alignment is lost.

 

[Willis Bushogin]

back in the day, I made shims, out of flat washers and cut them like a horseshoe and drove them in there. Im sure this is not a factory fix, but when you are working in the woods and need a thick shim and a quick fix, this will work
Just a thought, for a quick fix