One of my steering knuckles (on the left in the attached picture) can be wobbled up and down a little on the hub and bearing assembly and can rotate in two places
The other doesn't wobble and can only rotate in one place.
Which one of these is normal? I am guessing the one on the left and that once the drive shaft is bolted on, there won't be any play(?). If so, is there a way to free the other one up, or does it need to be replaced, or can it be left alone?
Video showing the movement: https://youtu.be/pnAtWO6Bego
Is the movement there when the Axle is bolted up tight?
The movement you are showing could be simply the bearing just loosely sitting in the spindle.
If there is wobbling with the axle bolted up, then you do have a problem.
I recently checked my '72, and found that there was a definite wobble in the left front wheel. I had to replace the spindle (I had a spare) complete, as I was heading off in two days time. (Should have got a wheel alignment done before I went, but that is another story).
I pulled the old one down to see if the bearing was at fault, but alas, the bearings were perfect. But, it looked like they had been replaced without being properly set-up. The etching on the central solid spacer didn't match the etching on the bearing (Size) and therefore, even though the bearings were tight around the axle, were loose in the spindle.
I went to purchase replacements so I could rebuild the spindle, and have a ready replacement for the future, but I found that these bearings are SPECIAL, and the cups are standard. PLUS, they are tremendously expensive when compared to the "normal" bearing. The X at the end of the part number is the killer.
Bruce. >:D
I didn't notice any problems when they were on the car. They have been off the car for months. I just got them out to clean them up and replace the inner seals when I noticed the difference.
So, it sounds like from what you are saying that the one that wobbles is likely OK. What about the other one? Is it a problem that it is not loose enough to do that?
By spindle, do you mean the splined part that the axle goes through?
The looseness of the bearing could be a number of things like a non-fitting seal, or simply coming loose when the axle is pulled out.
The Spindle I was referring to is the actual upright that attaches to the top and bottom ball joints. I call it a Spindle, and you call it a Knuckle. Each Country calls things differently.
Bruce. >:D
Ah, ok....I think of the spindle as the thing the wheel bearings ride around on the front wheels of my rear wheel drive car.
The shop manual's procedure for replacing the hub and bearings is to remove the entire assembly, including the knuckle, but I found another procedure in the Haynes manual to pull the hub and bearing assembly off of the knuckle using a slide hammer while the knuckle is still on the car, so I feel better about the prospect of putting it back together and verifying everything is working without having to worry about pulling the entire thing off again should one of them need to be replaced.
My opinion is the loose one is shot. If its not loose with the wheel and axle on it will be soon.
There used to be a series of videos on youtube that looked like it was shot in the 80's showing and older at the time guy replacing the wheel bearings on a GMC RV which basically had a Toronado front end in it. I just looked and I can't find them anymore. Looking at the shop manual I was going to try and improvise something myself but after seeing that video I just took it to a drive line shop and had them do it. The guy in the video showed several tools he made himself and even with those fairly complex tools he pointed out a lot of critical details that have to be done right to even have a chance of them lasting. The shop I called had the tools and said they used to do a lot of em. I think it cost $50 labor to have them do it. I think the bearings were $150.
Seems like on one of the GMC RV sites they mention that they no longer sell the tool because the man that made them had passed away. I remember thinking it was likely the guy in the video.
The best way to check the bearing is to put the upright in a vise, and install the axle, and hub, and tighten up the nut, thereby compressing the bearings together. That is if you have the upright off the car.
You cannot replace the bearings and seals whilst the upright is in position. As the axle has to be removed to access the inner bearing and seal.
Bruce. >:D
PS. Those bearings down here are AU$165, and the seals are unobtainium except from USA.
I forgot to add they have to be pretty horrible before you really notice a problem. Every time I have had a bad one I thought it was a brake issue. When I jacked it up to look at the brakes was when I noticed the wheel would wobble maybe 3 inches side to side. Each time I was amazed there were not more symptoms. I think the brake issue was just the wobble making the pads rub and get hot so you would get a pull. Had em go on 3 different Eldos and this winter on my 4x4 Suburban which has almost the same setup except on those the hub and bearing are a bolt on assembly.
If the loose one is shot, does that mean the other one is probably OK?
Quite possibly.
Mine was loose only on the one side, but as I found out, it wasn't the fault of the bearings, but the person who did the repair some time ago, before I purchased the car from New York.
Bruce. >:D
Since the loose one is on the easy side as far as the axle goes, I'm thinking what I will do is put that side back together and see if there is play before deciding whether to buy a new bearing. If I have to take it back apart, it isn't much more work than the test you suggested.
Thanks, Bruce and TJ for your thoughts!
If the other one is tight and smooth then it may be alright. The bad one could be just wear or like Bruce experienced it was not properly installed and is now damaged.
I looked again for the videos but didn't find them. IF you search "GMC motorhome wheel bearing" you should get several hits including this PDF procedure with photos.
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&uact=8&ved=0ahUKEwiK_fm1zuPMAhXGxYMKHYRoDxEQFggpMAI&url=http%3A%2F%2Fwww.gmcmi.com%2Fwp-content%2Fuploads%2F2014%2F05%2FFront-Wheel-Bearing.pdf&usg=AFQjCNGGi_n-sPlwDy0ryuTJNY_7Y8fP6w
Maybe I had better take some pictures of the disassembled hub?
Bruce. >:D
Thanks for the link, TJ...will check it out. Bruce, can you clarify what happened with yours? You said you found it loose, but it ended up being OK...or did I misread something? yes, pics of yours disassembled would be great!
The problem with mine was that whoever replaced the bearing/s, failed to set up the bearing pre-load to specifications, which means that he didn't use Factory parts.
There is a solid spacer between the inner and outer cones, (the part that is holding the tapered rollers) and in my case, it was too thick, and spaced the bearings too far apart, hence the slop when the axle was tightened.
The shop Manuals always give the specifications when rebuilding a differential, that being the pinion pre-load, but nothing in the Cadillac Manual. The Front hubs are virtually the same as a construction as a Diff Pinion. Most Diffs use Crush Washers, which are "crushed as the nut is tightened, to achieve a rotating pre-load in the bearings, but performance cars use solid spacers. Here the pre-load is obtained by using shims till there is no play, and then shims are removed to obtain the required pre-load. Once the correct thickness has been obtained, then the stack of shims is replaced with a solid spacer of the same width. This final assembly is also the time that the seals are installed, as putting in the seals prior to this would interfere with the pre-load measurement.
The Cadillac uses a Solid Spacer, but there is no mention made of the pre-load required as the replacement bearings and solid spacer are supplied as a matched set. I am not sure if Cadillac still supplies these parts, but they aren't available down here. Just the bearings.
Bruce. >:D
The last set I bought the spacer came in the box with the pair of bearings so my assumption was the spacer was sized to go with the pair of bearings.
This is one of the parts I found...a complete set, I think.
http://www.summitracing.com/parts/ntl-a23?seid=srese1&gclid=CjwKEAjwyPW5BRCC3JaM7qfW_FwSJACM3jz995rzUPeiS6oUilrKyA9IG5q84huF2awGwApzq5ttlhoC6dnw_wcB
Be great if it does fit, as it will make fitting a replacement simpler, as there will be no pre-loading setting required.
Bruce. >:D
That is the way my last ones came. Did you catch the ship date?
When I see dates that far out I don't hold my breath that the part will actually be available.