Bad bolt/washer or missing nut?

  • Thread starter sgvaibhav
  • Start date
In summary: This constant rubbing causes wear and tear on the splines which eventually strips them.You can try to fix it by either buying a new agitator or by re-sleeving the metal sleeve. If you don't want to take the time or money to do either then you might want to consider buying a new washing machine.In summary, you have a top loading washing machine with an issue with the drive mechanism, caused by a missing lock washer.
  • #1
sgvaibhav
68
0
Hi, I have a top loading panasonic washing machine.

It is an no agitator top loading machine – something similar like this type – http://www.automaticwasher.info/TD/AWJPEG/MODERN/2011/freewestinghous++11-19-2011-03-25-8.jpg.

So now i don't know if i have a damaged bolt, or a missing washer or a missing nut or a damaged washer.

Let me explain the problem.

The spinning motor suddenly loses contact with the screw.
The bolt/screw and the base plate then do not spin, whilst the motor spins inside.

I have added all pictures of my washing machine components.

To summarize the problem, whilst the motor is spinning, the bolt becomes lose during operation and it loses it contact and it does not spin anymore, and i keep tightening it with screw driver every few minutes to fix the problem until it occurs again.

All pictures can be found here.
https://www.dropbox.com/sh/s0b2kpk6a14tux5/m16pxyoeNd

If the problem still remains unclear let me know, i can try to record another video

I wanted to know how can i fix this problem, should i buy a new bolt (bigger??), new nut??, new washer??
 
Engineering news on Phys.org
  • #2
sgvaibhav: If you are missing a flat washer, or nut, I cannot determine that from the current pictures.

My current guess is, the splines inside the agitator disk hole might be plastic (?), and might be stripped (damaged). Perhaps a lock washer underneath the bolt head is missing (?). You might try adding a star lock washer (also called a toothed or serrated lock washer) underneath the bolt head. (But ensure the bolt would still be long enough, after adding a lock washer, to provide plenty of thread engagement length, to avoid stripping the tapped hole.)

I hope I am wrong; i.e., I hope the splines inside the agitator disk hole are not plastic. If they are plastic, there probably would be almost nothing you could do to fix the problem, and it would indicate a very poor design. But I am currently doubtful the splines are plastic.

Could you show close-up pictures of what is inside that hole on the bottom side of the agitator disk?

Another reason I guess a star lock washer underneath the bolt head is missing is because, in engineering, there is a general rule that threaded fasteners on any rotating part generally must have a mechanical locking device, not just bolt preload. If we use this rule, it indicates a star lock washer underneath the bolt head might be missing. Was there an occasion where someone could have lost this lock washer?
 
Last edited:
  • #3
Your pictures seem to be all taken from the top. Since gravity usually acts downwards, if anything has "fallen off" it it more likely to be from the bottom than the top. :smile:

The motor should be replaceable, since they sometimes burn out. If you remove it, you should be able to figure out why the drive mechanism isn't working properly.
 
  • #4
Closest I can get is perhaps this
http://www.searspartsdirect.com/partsdirect/getModelNew.pd?modelNumber=HLP23E&brandId=3126&productCategoryId=0153200&seoFormattedBrandName=Haier-Parts&seoFormattedProductTypeName=Washer-Parts&selectedDocumentId=50041385&selectedDiagramPageId=
 
  • #5
Few years ago, there was some drainage problem, and some unauthorized servicemen had repaired it, who could have been careless with the re-assembly.

Referring to 256bits diagram of Tub assy (http://www.searspartsdirect.com/partsdirect/part-model/Haier-Parts/Washer-Parts/Model-HLP23E/3126/0153200/50041385/00002?blt=06&prst=&shdMod=), I have parts 68, 70, 84, but i am missing on part 69.

Can part 69 be the source of the problem?
 
  • #6
sgvaibhav said:
Can part 69 be the source of the problem?
sgvaibhav: Yes, part 69 missing is the source of the problem. Part 69 is called an external star, toothed, or http://www.shabbari.com/product_photos/1308379827.jpg [Broken] lock washer, described in post 2. Sometimes the word "lock" is colloquially omitted. There are two categories: external tooth, as shown above, and internal tooth. Part 69 appears to be the external tooth type.

Try to buy the highest quality lock washer you can find. Ensure it exactly matches your bolt size. I.e., if you have an M6 bolt, then you must buy an M6 star or serrated lock washer. It perhaps could be the external or internal tooth type; probably buy both, and see which one seems better.

By the way, the missing lock washer may have, by now, caused some partially stripped splines, as mentioned in post 2, thereby reducing their load capacity. But first, just try adding the missing lock washer, just to see if it works and how long (or if) it lasts. The evidence currently indicates it might not last long. Let us know if you want further explanation.
 
Last edited by a moderator:
  • #7
Hi there joined just to help you as I came across this question although I look forward to the site.

Yes you do have a lock washer missing but I am afraid that is the least of your problems,you require a new agitator as yours has stripped the internal splines. Notice how there is a small indent of the 6 splines in the darker grey (metal?) section in your 6th picture and a lot of grey material spread around the inside of that housing?

That material should from a splined sleeve locking the rotor (agitator) to the motor shaft with the screw/washer assy holding (not locking) it in place, instead you are trying to rely on a friction fit which will not work. Yes nvn hit on the issue in his first post but a lock washer will *not* fix your issue but will be required to prevent the screw from coming loose after the part is replaced. I would order parts 68, 69 & 70 giving you a new screw as the head on yours is damaged

BTW there would be little/nothing wrong with the design even *if* it had a plastic rather than metal spline sleeve as there is very little torque applied to the component there are machine that have just that. (Ex-washing machine engineer)
 
  • #8
Ok thanks a lot.

Time to head to the panasonic spare parts shop.
 
  • #9
siaynoq said:
Notice how there is a small indent of the 6 splines in the darker grey (metal?) section in your 6th picture and a lot of grey material spread around the inside of that housing? That material should from a splined sleeve ...
siaynoq: If you are talking here about the picture file named "Rear Screw.jpg," those approximately "six" indentations in the black greasy ring are the completely wrong size to be made by the steel shaft splines. Besides, the steel shaft has approximately twelve splines, not six splines. Therefore, I did not understand some of your description yet.

Also, the wet clothes and water have a significant mass moment of inertia. The splined steel shaft in this particular Panasonic washing machine, model NA-F60G2T, is so small, that if the internal splines were plastic, the plastic probably could not withstand the stress. We see in file "Rear Screw.jpg," there probably is a square-ish steel insert mounted into the plastic agitator. And the internal splines inside this steel insert are probably steel. But we cannot see inside the black circular hole in files "Rear Screw.jpg" nor "Rear.jpg," to give proof, because the pictures currently do not show adequate detail of the relevant parts we need to see. I think you could only perhaps get away with plastic internal splines on other designs that have a much larger-diameter splined steel shaft.

We would need better, close-up photographs, showing the relevant parts, for this specific model. And I did not understand why the first link in post 1 shows a different brand and model, instead of showing a picture of sgvaibhav's own washing machine.

Also, sgvaibhav says the agitator still works, until the bolt loosens. Therefore, it indicates the internal splines still exist, and are not totally disintegrated, unlike what your above quote implies. We do not know, however, if the splines are partially stripped, which I touched on in the last paragraph of post 6. See post 6.
 
Last edited:
  • #10
Hi nvn looking with a different opinion/from that view you may well be right and yes I was talking about 'Rear Screw.jpg' & 'Rear.jpg' more detailed photographs would help, making the grey ? as being possibly a grease soaked seal helping to prevent ingress of dirt/water down the motor shaft there is also a hex shape around the motor shaft it all looks very worn/corroded though

I would still say the internal splines are stripped at least from the views we can see as sgvaibhav tells us it stops rotating every few minutes until he re-tightens the screw leading me to believe he is relying on a friction contact, even if the screw comes loose the rotor would still be engaged with the splines with the weight of the clothes on top it would not/should not lift enough to completely disengage (especially within minutes). I imagine the last 'engineer' left off the locking washer even so the machine has worked for some time (5 years!)

I have just noticed something else of concern, there is distinct circular scoring of the 3 round nylon?? shapes matching the inner circular ring on the underside of the rotor. Is this due to the metal insert in the rotor being damaged/worn or has the motor shaft dropped? Possible motor gearbox housing loose (sounds terrible) that much friction on the rotor could be another reason for the splines stripping if indeed they have, can you lift the motor shaft at all (although maybe a friction fit through its top bearing not enabling you to)

More detailed photographs would help for sure.
 
  • #11
siaynoq: Good points. That perhaps helps shed a little more light on the issues. Another mystery to me is, how all that black grease could stay inside a washing machine. I thought detergent soap, mixed with moving hot water, would fairly quickly dissolve grease. This implies the grease exists in an air pocket, such that no water touches the grease; and I guess this implies that the greasy black ring is a water-tight and air-tight synthetic rubber seal.

But with the bolt loosening (due to the missing lock washer), I do not understand how the rubber seal did not leak. I think it would leak, thereby eliminating part of the air pocket, up to the plastic fins above the rubber seal. Therefore, it seems this should have washed off most of the grease (?), up to just above the bottom of the plastic radial fins. Instead, we see lots of grease still remaining below this level.

And if the rubber seal was leaking, perhaps water also leaked down the steel shaft, toward the motor, causing corrosion.

I think the three, round, white, teflon or nylon bumps (bumpers), and six outer bumpers, are intended to be bearings, limiting the agitator tilt; therefore, some scoring might be normal.

Anyway, with the motor also being old, worn, and noisy, as I mentioned in the last paragraph of post 6, I would "first, just try adding the missing lock washer, just to see if it works, and [just to see] how long (or if) it lasts."

Adding the missing lock washer is such an easy thing to try first, just to see if it works, and just to see how long it lasts. Therefore, I would not recommend buying a 30 euro agitator before even trying this simple lock washer installation.

sgvaibhav: I would first try an internal lock washer. If it does not work well, I would then try an external lock washer. If it does not work well, then I might buy a new agitator (and parts 68, 69, and 84), but only if I think the washing machine motor has a long life span remaining.
 
Last edited:

1. What are the signs of a bad bolt/washer or missing nut?

Some common signs of a bad bolt/washer or missing nut include a loose or wobbly connection, visible wear or damage to the bolt or washer, and difficulty tightening or securing the bolt.

2. How can I tell if a bolt/washer is the correct size?

The best way to determine if a bolt/washer is the correct size is to consult the manufacturer's specifications or use a bolt gauge tool. The bolt should fit snugly and securely into the hole without being too loose or too tight.

3. What can happen if I use a bad bolt/washer or a missing nut?

Using a bad bolt/washer or a missing nut can result in a weak or unstable connection, which can lead to equipment failure, safety hazards, and potential injuries. It is important to always replace any damaged or missing hardware to ensure proper functioning and safety.

4. How often should I check the bolts/washers and nuts on my equipment?

It is recommended to regularly check the bolts/washers and nuts on equipment, especially those that are subject to vibration or heavy use. It is also important to inspect them after any significant impacts or changes in temperature.

5. What is the best way to prevent issues with bolts/washers and nuts?

The best way to prevent issues with bolts/washers and nuts is to regularly inspect and maintain equipment, use the correct size and type of hardware, and replace any damaged or worn hardware immediately. It is also important to follow proper installation procedures and torque specifications.

Similar threads

Replies
10
Views
1K
  • Mechanical Engineering
Replies
3
Views
2K
Replies
17
Views
3K
  • Mechanical Engineering
Replies
3
Views
5K
Replies
1
Views
2K
  • Mechanical Engineering
Replies
1
Views
3K
Replies
6
Views
1K
Replies
3
Views
935
Replies
3
Views
1K
  • Electrical Engineering
Replies
3
Views
1K
Back
Top