[JMFabrications]

I have a '01 VF2 with a 2 speed gear box that I cant seem to find a fix for this noise problem. When it first started it sounded like "marbles" in the gear box, I assumed it was a bad bearing in the gear box so I pulled the gear box out and replaced all of the bearings except the large one attached to the belt pulley. Main reason I didnt replace it was because I wasnt sure how to remove the pulley and visually it looked good.....in fact all of the other bearings looked good but I replaced them anyway. Throw everything back together and the noise is still there. After some more testing I thought for sure it was the spindle motor bearings making the noise so out comes the motor and all new bearings go on. Put the machine back together once again and the noise is still there. Ive read that some people have traced a "bad bearing" noise down to a faulty spindle encoder and that solved the noise but I dont see how the encoder can cause that and I swear it seems to be something mechanical. Ive shot a few videos of it, if anyone has any suggestions I greatly appreciate it. I will probably take the gear box out again and look over the gears even though Im pretty sure they are fine.

Noise at 7500rpm
Haas gear box noise - YouTube

Noise turning the motor by hand
Haas gear box noise - YouTube

Noise at 2500 rpm, def coming from the back side
Haas gear box noise - YouTube

[haastec]

I have a '01 VF2 with a 2 speed gear box that I cant seem to find a fix for this noise problem. When it first started it sounded like "marbles" in the gear box, I assumed it was a bad bearing in the gear box so I pulled the gear box out and replaced all of the bearings except the large one attached to the belt pulley. Main reason I didnt replace it was because I wasnt sure how to remove the pulley and visually it looked good.....in fact all of the other bearings looked good but I replaced them anyway. Throw everything back together and the noise is still there. After some more testing I thought for sure it was the spindle motor bearings making the noise so out comes the motor and all new bearings go on. Put the machine back together once again and the noise is still there. Ive read that some people have traced a "bad bearing" noise down to a faulty spindle encoder and that solved the noise but I dont see how the encoder can cause that and I swear it seems to be something mechanical. Ive shot a few videos of it, if anyone has any suggestions I greatly appreciate it. I will probably take the gear box out again and look over the gears even though Im pretty sure they are fine.

Noise at 7500rpm
Haas gear box noise - YouTube

Noise turning the motor by hand
Haas gear box noise - YouTube

Noise at 2500 rpm, def coming from the back side
Haas gear box noise - YouTube

I have heard similar noises caused by the belt. Try disconnecting the belt then command the spindle to the same rpm's you have in your videos. (spindle won't turn of course) If the noise is gone, then you know the motor bearings are good.

Next, try reconnecting the belts but at a different tension and see if the pitch changes.

Your second video of you turning by hand sounds like the teeth of the belt is rubbing on something.

Hopefully this gives you some different ideas to run with.

Good luck and be sure to post back what you find.

[JMFabrications]

I have heard similar noises caused by the belt. Try disconnecting the belt then command the spindle to the same rpm's you have in your videos. (spindle won't turn of course) If the noise is gone, then you know the motor bearings are good.

Next, try reconnecting the belts but at a different tension and see if the pitch changes.

Your second video of you turning by hand sounds like the teeth of the belt is rubbing on something.

Hopefully this gives you some different ideas to run with.

Good luck and be sure to post back what you find.

Thanks so much for your input, ill give that a shot tomorrow and see what happens.

[JMFabrications]

I have heard similar noises caused by the belt. Try disconnecting the belt then command the spindle to the same rpm's you have in your videos. (spindle won't turn of course) If the noise is gone, then you know the motor bearings are good.

Next, try reconnecting the belts but at a different tension and see if the pitch changes.

Your second video of you turning by hand sounds like the teeth of the belt is rubbing on something.

Hopefully this gives you some different ideas to run with.

Good luck and be sure to post back what you find.

I disconnected the belts and the noise is still there. I know for sure its not the spindle motor bearings as they were just replaced. Im 99% sure that its just gear slap although the video may not show that. When I turn the motor or encoder spline back and forth I hear a slap from the gears right under the encoder spline. Now if I spin the motor by hand fast enough for it to get a few revolutions the gear teeth are engaged with each other and I dont hear the slap. So I need to figure out why the gear slap is there when the machine is running. Can something electronically cause the motor to slow down and speed up for a split second causing the gears to slap like that? Im talking like milliseconds......just enough for the gear teeth to lose contact with each other then recontact causing that slap noise. The RPM display only fluctuates 1 rpm so it seems as if the encoder motor is ok but who knows. The encoder belt looks good, no missing teeth...I dont have a new one to compare it to so I cant tell how worn it is if at all.

I have a VF3 of the same model year and its so quiet you can barely hear it running. I would consider swapping the encoder motor from that machine but I cant be down both machines right now....I only have 2.

[haastec]

I disconnected the belts and the noise is still there. I know for sure its not the spindle motor bearings as they were just replaced. Im 99% sure that its just gear slap although the video may not show that. When I turn the motor or encoder spline back and forth I hear a slap from the gears right under the encoder spline. Now if I spin the motor by hand fast enough for it to get a few revolutions the gear teeth are engaged with each other and I dont hear the slap. So I need to figure out why the gear slap is there when the machine is running. Can something electronically cause the motor to slow down and speed up for a split second causing the gears to slap like that? Im talking like milliseconds......just enough for the gear teeth to lose contact with each other then recontact causing that slap noise. The RPM display only fluctuates 1 rpm so it seems as if the encoder motor is ok but who knows. The encoder belt looks good, no missing teeth...I dont have a new one to compare it to so I cant tell how worn it is if at all.

I have a VF3 of the same model year and its so quiet you can barely hear it running. I would consider swapping the encoder motor from that machine but I cant be down both machines right now....I only have 2.

it is possible that the encoder, belts and/or pulleys for the encoder could give those kind of results. If you haven't already, I would remove the encoder. Inspect the belt good, and just as important look at both pulleys good. Most likely they are both aluminum and they will wear out. There should be a noticable flat between the encoder pulley teeth and make sure the teeth are not twisted. The pulley mounted at the transmission can be harder to inspect but look at it closely also.

If unsure, I would replace all three items for the encoder; belt, pulley @ encoder, and pulley @ gearbox FYI the pulley at the gearbox is sweat fitted onto the GB shaft, but comes on/off easily with a quick heat up with a torch. A new one should be made out of steel and will last much longer. If they havent been changed in a long time, it's still cheap insurance for future issues even if it doesn't fix your current problem.

Good luck!

[JMFabrications]

it is possible that the encoder, belts and/or pulleys for the encoder could give those kind of results. If you haven't already, I would remove the encoder. Inspect the belt good, and just as important look at both pulleys good. Most likely they are both aluminum and they will wear out. There should be a noticable flat between the encoder pulley teeth and make sure the teeth are not twisted. The pulley mounted at the transmission can be harder to inspect but look at it closely also.

If unsure, I would replace all three items for the encoder; belt, pulley @ encoder, and pulley @ gearbox FYI the pulley at the gearbox is sweat fitted onto the GB shaft, but comes on/off easily with a quick heat up with a torch. A new one should be made out of steel and will last much longer. If they havent been changed in a long time, it's still cheap insurance for future issues even if it doesn't fix your current problem.

Good luck!

Thanks again for the suggestions. Im going to order those 3 parts now and see if that solves any of the issue. If not I will probably just let it go, it doesnt seem to be hurting anything other than my ears. Im using DTE 25 gear box oil, should I consider something thicker?

[haastec]

Thanks again for the suggestions. Im going to order those 3 parts now and see if that solves any of the issue. If not I will probably just let it go, it doesnt seem to be hurting anything other than my ears. Im using DTE 25 gear box oil, should I consider something thicker?

I have never used anything but the DTE25 so I cannot comment on the success of running anything thicker.

If those parts still do not fix it, I would try to find a time to swap the encoders between machines. Shouldn't keep you down to long to test with the donor encoder but I understand time is money. Either way, just be sure to reset the spindle orientations when finished. Both machines!

Just a note, if you unplug the encoder, expect an encoder alarm when you plug it back in and command an RPM the first time, this is normal. Reset and try again, it should be good to go after that.

[JMFabrications]

I have never used anything but the DTE25 so I cannot comment on the success of running anything thicker.

If those parts still do not fix it, I would try to find a time to swap the encoders between machines. Shouldn't keep you down to long to test with the donor encoder but I understand time is money. Either way, just be sure to reset the spindle orientations when finished. Both machines!

Just a note, if you unplug the encoder, expect an encoder alarm when you plug it back in and command an RPM the first time, this is normal. Reset and try again, it should be good to go after that.

As a last resort I may try to swap the encoders. The VF3 has a SMTC and I have never removed the head cover but it looks to be 3 pcs or so....not sure if its any easier or not but I may give it a shot. Ill do it after hours so we dont lose machine time.

I greatly appreciate all your help! Ill be sure to report back.

[JMFabrications]

So I replaced both pulleys and the belt and unfortunately the noise is still there. Im not too confident that the encoder motor is the problem so I probably wont bother pulling one from another machine. I think I will just put everything back together and deal with it, this machine has been kicking my butt for 2 weeks now and Ive had enough. Too bad Haas threatens you with a $150 restocking fee on returned parts or I would just buy a new encoder to try quick and return it.

[JMFabrications]

Just curious, whats the max spindle RPM fluctuation you should see on the display screen even under a heavier load? Im seeing as much as +/- 7 RPM change when at 50%+ spindle load. Maybe that's an indication the spindle encoder is faulty?

[haastec]

Sorry the belt an pulleys did not take care of the issue.
I am not really sure what is an acceptable range for a fluctuating rpm display is because it seems that every machine is a bit different on how the display acts; 7 rpm doesn't sound unreasonable to me though.

At this point I would wait until you have time to borrow the encoder from the other machine. If that checks out okay, then the GB is about the only thing left as a source of the problem.

[JMFabrications]

Sorry the belt an pulleys did not take care of the issue.
I am not really sure what is an acceptable range for a fluctuating rpm display is because it seems that every machine is a bit different on how the display acts; 7 rpm doesn't sound unreasonable to me though.

At this point I would wait until you have time to borrow the encoder from the other machine. If that checks out okay, then the GB is about the only thing left as a source of the problem.

Yea once I get some downtime Ill try to swap the encoders but for now Ill just let it go. Thanks again for all your help!

[PRENTCO]

I see this is a pretty old post but did you ever figure out the problem? I have the exact same noise coming from my gearbox on my 1999 VF4.
Thanks!

[JMFabrications]

I see this is a pretty old post but did you ever figure out the problem? I have the exact same noise coming from my gearbox on my 1999 VF4.
Thanks!

I ended up just replacing the entire gear box as it eventually locked up on me and took out the gears. In hindsight it was most likely the 1 bearing that I could not get off to replace.

[PRENTCO]

Ok thanks appreciate the information.

[jason003]

it sounds like a bearing-related issue. What type of bearing is used here and what material is the cage made of?