Has Anybody Changed A Grizzly G1071 OSS Spindle Bearings?

[Bill Space]

Hi all,

Yesterday I bought a G1071 OSS from a local High School for a good price (I think...) of $175. It seems to be in pretty good shape but the spindle bearings are noisy. I have done a search (actually many searches) but have not found any details regarding what changing the bearings involves. I can imagine what needs to be done but worry about stumbling blocks that I may not realize are there.

I have downloaded the parts list from Grizzly which shows an exploded parts diagram. I did find one post where the poster had to get inside his, due to a key for the oscillating mechanism falling out, and there were several pictures which were helpful, but only to a small degree as they did not relate directly to what I need to do.

I can't tell from the parts diagram if there is a splined shaft which allows the spindle to move up and down while rotating, but guess there must be one. Does anyone know? I am guessing that if I take the top of the gearbox off, that some of what is inside will come off with the top, and the rest will remain inside...and the point of separation will a splined shaft. But this is just speculation on my part at this point.

Just looking for some pointers before tearing into this thing. It does function as is, but I don't like the noisy bearing and would rather restore the unit to a quiet state when running.

Perhaps there is a thread someone that someone can point me to, that I did not stumble upon in my searches.

Any and all advice and guidance will be greatly appreciated.

Bill

[Mikail Khan]

I have a 2 year old machine. A few months ago while doing an oil change I found a screw which was supposed to retain the shaft key in place in the drain pan. I took mine apart to clean the gearbox sump and replace the screw. I should have some pics that I will try to post if I find them. I don't think the shaft in splined, it just has a key. The machine can be taken apart easily if you have a chain block and a place to hang it. MK

[Bill Space]

Thanks Mikail,

That makes a lot of sense as a key would be enough to do the job in this application and cheaper to manufacture than a splined shaft. Pictures would be great if you can post some.

Below is a link to that post I referred to above, which includes some pictures. I think the key shown is the key that transmits the power from the lower shaft to the upper shaft. The lower being stationary but rotating, and the upper both rotating and oscillating up and down. I could not see what was happening when looking at the parts disagram, but can now imagine what is going on...more or less.

So when you pull the top off the gear box, does the spindle come with it? If so, the only issue is probably aligning things so the key slides into a slot in the spindle when putting things back together I assume.

Here is that link: http://www.sawmillcreek.org/showthread.php?144571-Grizzly-g1071-oss-problem (Hope I did this right!)

Bill

[Mikail Khan]

I could not find the pics. I think they were stored on a micro sd card for my phone that got corrupted. Grizzly will send you a procedure within 2 working days if you send their tech support an email. They sent me some instructions, but they included a lot of additional steps like removing the table that were not necessary for the repair I had to do. After unplugging the machine and draining the oil. I removed the four #92V2 bolts. I positioned the sander under a chain block and attached slings to the table. I used the chain block to lift the table and the gearbox up into the air. The separation point was the coupling. I then removed the four bolts #93 which allowed me to remove the aluminum gearbox housing and input shaft complete with coupling. I was then able to clean the sludge from the bottom of the gearbox and replace the missing screw 98V2 with some Loctite to keep it in place. My gearbox housing had a large o-ring on the top face which was not shown on the drawing. I was able to use some gasket making silicone and reuse the o-ring. I did not have to go any further but this stage you will be able to remove the top half coupling grub screws and remove the coupling #23 and coupling key#121. Use circlip pliers to remove the circlip #96 which will allow you to remove the lower bearing #95 and seal #94. These bearings and seal should be available from an auto parts store. I would try to avoid removing the table and tilt assembly. To get access to the other 2 bearings you will have to remove the spindle casting #10. From the drawing you will have to remove the jam nuts#14 and cover #11. This should probably be done before lifting the table into the air. Removing nut #103 and cap screws #90 should separate the spindle casting from the housing casting #8. The spindle casting can be placed on a workbench to remove the key#13 and pin #99. Once the worm #16 is removed you can remove the nut #15. Check to see if the bearings are retained by circlips. If not you can use a rubber hammer to tap the shaft 'up' as shown in the drawing to push the upper bearing out of the spindle casting. Because of the oscillating motion, when reassembling use Loctite on any thing that can run loose that does not have a lock washer. The table and casting assembly are very heavy, if you are not familiar with slinging and using chain blocks get someone to help or take the table off with the help of a friend. I can't remember for sure, but I think I used about 6 quarts of oil (differential oil) MK

[Bill Space]

Mikail,

Thank you for such an EXCELLENT write up! Very informative and helpful. GREAT help to me.

I will contact Grizzly for a copy of their procedure for changing the bearings.

The parts diagram makes a lot more sense to me after reading your description while looking at the parts diagram. Thanks for calling out the part numbers!

When I do the bearing change I will try to take pictures and start a thread documenting how I accomplished the job, in hopes it will be helpful to others in the future.

Thanks again for taking the time to write such a detailed description! I am sure it will be helpful to others as well.

As an aside, one thing I did not expect was that apparently the worm gear, being on the spindle, is moving up and down, driven by the rotating gear that it drives. I initially did not pick this up from the drawing for whatever reason. Also, I now see the "special key" transmits power from the drive shaft to the spindle shaft, and that this key acts as a single spline type interface, allowing the spindle to move up and down within the drive shaft while both are rotating.

I greatly appreciate your help on this!

Bill

[eugene thomas]

I tore my sander apart few years ago because the threads in the sanding spindal socket got galled. came apart pretty easy. was really surprised on how simple the design on ossilating part was. good tool though.

[Bill Space]

Well, I called Grizzly Tech Support today and the guy that answered did not have a procedure. He put me on hold and apparently looked a bit, but in the end could not find anything.

I will try emailing them, but actually Mikail's write up is as good as it gets and I don't think I need anything further to do the job.

Thanks again, Mikail!