Author Topic: 78 CB750K7 rear hub retaining ring woes. Salvageable? (Read 1212 times)

Mule169 · « **on:** March 29, 2015, 01:11:34 PM »

I've followed a lot of threads on this site, and gained a lot of knowledge (thanks to everyone for sharing), but this is my first time posting.

I traded a website for a bit of a beat down cb750 to have as a project. I was pulling apart the rear wheel to have the hubs/rims powdercoated. I didn't have a pin wrench or any "proper" tools to get the rear bearing retaining ring off, but I have a co-worker who "had a buddy" who has "built tons of bikes" and could probably just do it really quickly.

Against my better judgement, I figured I'd save myself the hassle of making a tool and just let "buddy" pull the retaining rings off the front and rear. This is what I got back...

I haven't talked to him directly but I'm guessing he tried using a punch on the notches, and just deformed them to the point where the threads galled because the notches on the front hub retaining ring are mushroomed a bit. Thankfully he just gave it back to me before he chowed it to pieces too.

I guess my question at this point is, is there any way to repair the damage to the retaining ring threads, or am I looking at finding a new rear hub to build a wheel off of? I'd imagine buying a tap that big, or taking to a machine shop is going to be pretty damn expensive.

Anyone have some thoughts (other than violent thoughts about co-worker and his "buddy")?

Powderman · « **Reply #1 on:** March 29, 2015, 01:16:33 PM »

The seal retainer is usually "staked" in 4 places around the ring at the threads. You have to drill these stakes out before the ring will move freely. If not you will do as you mentioned and screw up the threads dragging the stakes through them.

If you lock closely you can see the 4 stakes at the outer circumference of the seal retainer:

BobbyR · « **Reply #2 on:** March 29, 2015, 01:22:42 PM »

Powdermman is correct and the buddy is an asshat. Doing it right is easier than doing it over.

OK now to your problem. You can do a search and find a thread(s) with pics in which you can use a thread tap with the proper thread pitch to slowly push the threads back into shape. It takes some patience, but the result seems very good. It is a tap you can buy in Sears and other places.

The tool you did not want to make is so silly simple to make. I used a cheap pre drilled bracket from the hardware store and two screws and nuts. Probably $5 and 10 minutes. This tool you will use to reinstall the retainer.

Powderman · « **Reply #3 on:** March 29, 2015, 01:24:18 PM »

Upon closer look of your pics you can see 2 of the stakes and they look as though they may have been drill but not near deep enough to remove them. That's what caused the damage. I was surprised how much deeper and larger I had to go to remove the stakes where the ring would turn. It doesn't matter if you bugger the retainer because it should be replaced anyways. The outer thread , not so much.
As Bobby R mentioned, find an appropriate tap and see if you can salvage those and replace the seal and retainer with a new one. If you tap the 4 holes in the retainer you can thread bolts in to aide in turning it in and out without the expense of a tool in a pinch.

Powderman · « **Reply #4 on:** March 29, 2015, 01:29:43 PM »

When they are staked it doesn't just deform the first thread. It will deform down to the 3rd or 4 thread. So drilling is almost always deeper than you think it needs. At least that has been my experience.

Mule169 · « **Reply #5 on:** March 29, 2015, 01:31:18 PM »

Powderman,

Thanks for the response, this makes total sense, as the front that this guy just gave back before ruining it does have those "stake" areas drilled out a little but but perhaps not far enough. I'm going to hit them one more time, and use a proper tool (I have learned the hard way too many times to not shortcut things, and I'm embarrased I'm learning it again).

BobbyR,

Yes, I'm quite sure "buddy" did not quite have a handle on what he was doing, or just didn't stop and ask himself "what's wrong" soon enough. I apprecaite the insight making my own tool, I had originally thought of getting a large socket and filing down pins/notches to the correct size, which seemed like a bit of a pain (not in retrospect I guess), but I'll take your advice for sure. Seems much simpler.

I'll do the research obviously, but might you be able to save me some internet search time and know the thread pitch off the top of your head for the correct tap?

Cheers, and thanks again to you both.

Andy

Powderman · « **Reply #6 on:** March 29, 2015, 01:38:06 PM »

It doesn't hurt to heat the outer housing with a propane torch to expand it to ease the retainer out.
Never could understand the benefit of this type seal arrangement. Press a sealed bearing in and the proper spacers and you're done. Screw in seals just seem like so much extra work with no advantage. Am I missing something?

Mule169 · « **Reply #7 on:** March 29, 2015, 01:42:14 PM »

Will do Powderman.

Also sorry I should have used the "search" a bit more exhaustively. Found http://forums.sohc4.net/index.php/topic,62820.msg1262581.html#msg1262581 with regard to thread pitch using a tap to try and clean up the threads.

Andy

Powderman · « **Reply #8 on:** March 29, 2015, 01:49:51 PM »

I'll also add that this is a no brainer to me to use ANTI SEIZE on the threads. I see the other thread and the mention of using grease when installing the new retainer. Anti seize would be ideal for that situation. It seems no one wants to use anti seize until they have already messed something up.

Airborne 82nd · « **Reply #9 on:** March 29, 2015, 03:49:47 PM »

If you don't have a depth gauge then get one of those red straws that come with wd40 stick in the hole hold your thumb nail at the top then pull it out and you will see how far to you need to drill add just a little bit more maybe 2mm.

BobbyR · « **Reply #10 on:** March 29, 2015, 04:08:40 PM »

Quote from: ace1969 on March 29, 2015, 01:31:18 PM

Powderman,

Thanks for the response, this makes total sense, as the front that this guy just gave back before ruining it does have those "stake" areas drilled out a little but but perhaps not far enough. I'm going to hit them one more time, and use a proper tool (I have learned the hard way too many times to not shortcut things, and I'm embarrased I'm learning it again).

BobbyR,

Yes, I'm quite sure "buddy" did not quite have a handle on what he was doing, or just didn't stop and ask himself "what's wrong" soon enough. I apprecaite the insight making my own tool, I had originally thought of getting a large socket and filing down pins/notches to the correct size, which seemed like a bit of a pain (not in retrospect I guess), but I'll take your advice for sure. Seems much simpler.

I'll do the research obviously, but might you be able to save me some internet search time and know the thread pitch off the top of your head for the correct tap?

Cheers, and thanks again to you both.

Andy

Andy,
I literally went to the hardware store and bought a flat steel brace or bracket made by Stanley for 3 bucks. I cam e home found out two of the pre drilled holes line up with the stakes. I found two screws that fit into the stake holes, put a nut on each screw to hold it. I drilled out the stakes and spun out the retainer.

Put the bearings and races in the freezer. Heat the hub a bit, pull the races out of the freezer and if you use enough heat, they practically fall into place which allows you to tap them in gently rather than smash them. I reused the retainer by using loctite on the threads and restaking the retainer.

Good Luck

Powderman · « **Reply #11 on:** March 29, 2015, 04:12:51 PM »

LocTite is a bit of overkill IMHO. The staking is more than enough to hold the retainers which is obvious by hard they are to remove without unstaking. I would do the opposite as mentioned before and use anti seize before staking them. The tool BobbyR made is simple and effective.

BobbyR · « **Reply #12 on:** March 29, 2015, 04:26:53 PM »

Quote from: Powderman on March 29, 2015, 04:12:51 PM

LocTite is a bit of overkill IMHO. The staking is more than enough to hold the retainers which is obvious by hard they are to remove without unstaking. I would do the opposite as mentioned before and use anti seize before staking them. The tool BobbyR made is simple and effective.

Yeah that is true. I teach railcar maintenance. We torque, loctite and sometimes safety wire. I used some sissy loctite.

Mule169 · « **Reply #13 on:** March 29, 2015, 06:30:14 PM »

*sigh*

Well I just drove over to "buddy's" house to have a chat about my hub, and its state. Once again, embarrassingly drove home the lesson. Take your time, don't be in a rush, and when in doubt do it yourself. This is the retaining ring...

$:-\$

Thanks again to everyone who responded. Anti-Seize, flat bar and nuts for home made tool, measure with WD40 straw, stake the new ring with locktite (if I want to impress the railcar maintainence instructor).

Hopefully I can revive the hub with some TLC to the threads, and not have to fork over lots of $$ for a replacement.

Andy

BobbyR · « **Reply #14 on:** March 29, 2015, 06:51:02 PM »

Others may disagree, I think that retainer is not reusable.

Mule169 · « **Reply #15 on:** March 29, 2015, 08:42:37 PM »

guess that's all you can do is laugh.

martin_uk · « **Reply #16 on:** March 30, 2015, 02:44:28 AM »

Running a tap round of same pitch worked well for me, so you have a good chance.

I didnt risk Loctite on mine, not sure how critical this is as bearings are held in by axle bolt retaining force in any event.

calj737 · « **Reply #17 on:** March 30, 2015, 04:44:54 AM »

Blue LocTite is a good recommendation as it lubes the threads and creates a bond.

martin_uk · « **Reply #18 on:** March 30, 2015, 06:20:52 AM »

Quote from: calj737 on March 30, 2015, 04:44:54 AM

Blue LocTite is a good recommendation as it lubes the threads and creates a bond.

Have you tried removing after in case it bonds too well?

calj737 · « **Reply #19 on:** March 30, 2015, 06:52:40 AM »

Blue is pretty forgiving stuff. In lieu of re-staking the retainer, it holds it well yet still yields to a proper tool. If not Blue, then definitely anti-sieze is a requirement. But then you need to stake it. Take your pick-

BobbyR · « **Reply #20 on:** March 30, 2015, 07:43:59 AM »

Quote from: ace1969 on March 29, 2015, 06:30:14 PM

Thanks again to everyone who responded. Anti-Seize, flat bar and nuts for home made tool, measure with WD40 straw, stake the new ring with locktite (if I want to impress the railcar maintainence instructor).

Hopefully I can revive the hub with some TLC to the threads, and not have to fork over lots of $$ for a replacement.

Andy

I used a drop of Blue thread locker as a matter of habit on my part. As pointed out the retainer is captured and not likely to go anywhere.

The two nuts that hold the front axle supports I Blue Loctite since there is a lot of vibration down there and I think I want them to stay in place

.

Other may have their own favorites. One thing people do is put way too much on figuring more is more.

Bodi · « **Reply #21 on:** March 30, 2015, 08:44:42 AM »

"Never could understand the benefit of this type seal arrangement. Press a sealed bearing in and the proper spacers and you're done. Screw in seals just seem like so much extra work with no advantage. Am I missing something?"
I think the seal is just to keep water and dirt out of the hub. With OEM single seal bearings those could be a severe problem. Using double sealed bearings is an improvement in keeping the bearings themselves dry and clean but water inside the hub could rust up the bearing races, axle, and spacer pretty badly. There's a large cavity inside the hub and temperature changes would suck in any water sitting around the bearing, I suppose.

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Author Topic: 78 CB750K7 rear hub retaining ring woes. Salvageable? (Read 1212 times)