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 Post subject: front wheel bearings.
PostPosted: Sun Sep 22, 2019 11:35 am 

Posts: 27
Not having done this before please can someone explain the procedure for removing the bearings from the hub. ?


 
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 Post subject: Re: front wheel bearings.
PostPosted: Sun Sep 22, 2019 4:00 pm 
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Location: Southern California
Once the split pin and nut are removed, a puller will get the hub off. There is a factory tool for this, or a generic one can be adapted to do the job.

Getting the bearings out is as simple as tapping them out with a hammer and suitable punch. The hub usually has a couple machined slots so you can get a punch in there and tap on one side and then the other, gradually working the bearing out. Be patient and try to prevent it from going crooked. The outer bearing exits outward, inner bearing inward.

Inspect all surfaces and remove burrs if you find any. The new bearings should go in tight. If they slide in easily but not by hand then you can use sleeve retainer, but if they are loose enough to go in by hand then you have a worn hub and it will need to be replaced.

When installing the new bearings (after packing with grease of course), start with the rear. You can use a hydraulic press, being careful to not let them go in crooked. Or, tap them in by hand but do not tap on the inner race of the bearing or you risk damage. Hit on the outer race only, while being careful not to ding the hub. Once the rear bearing is in, don't forget the bearing spacer before installing the outer! And might as well replace the grease seal while it's apart.

Torque spec on the hub nut is 40-70 lbs/ft which should allow you to find a torque where the split pin hole lines up with the castle nut.

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 Post subject: Re: front wheel bearings.
PostPosted: Sun Sep 22, 2019 5:47 pm 
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Location: North America
The TC front hubs are different from "modern" hubs. They have no (ultra hard steel) bearing races that are pressed into the hubs. Instead, the hub acts as the race, and the bearing is simply pressed into the hub. What seems to happen to TC front hubs is the hole where the bearing goes into gets ovaled out. The bearing may seem to be a tight fit, but it actually can wobble around in there. You have to check this very carefully to be sure the hub is not worn out. I consider the front hubs of a TC to be maintenance items, like brake pads or tires. When they are worn out, simply replace. Last front hubs I bought from Abingdon Spares were made in Britain and seemed quite good quality, and were less than a new set of tires.


 
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 Post subject: Re: front wheel bearings.
PostPosted: Sun Sep 22, 2019 5:55 pm 
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Technically speaking the ball bearings do have two races, an inner and an outer. But they come assembled and are cannot be separated. You press the assembly into place as a unit. The races are hardened steel just as modern "tapered" style are, but are simply in a different configuration.

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 Post subject: Re: front wheel bearings.
PostPosted: Sun Sep 22, 2019 8:01 pm 
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Most people with any mechanical knowledge know what a race is, but few can imagine a front hub without any race. British refer to races as cups. Steve, I was talking about races in hubs, not in bearings. Any of us that have converted our hubs to use tapered roller bearings-- have races in our hubs.

Technically speaking, the original design TC front hub did not use ball bearings, they actually use "angular contact ball bearings."


 
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 Post subject: Re: front wheel bearings.
PostPosted: Sun Sep 22, 2019 9:12 pm 
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Location: Southern California
Bearing "races" and "cups" are completely interchangeable terms. Ray is in the UK but he calls them races, so that's how I responded. I usually call them races as well, as it's just what I'm used to.

The actual ball bearings are the same in the various "cartridge" type ball bearing assemblies. It's the design of the races that make it an angular bearing.

Side note: For those reading this who don't know, angular bearings are designed to take both radial and axial loads, which is obviously important for a vehicle that goes both straight and also rounds corners!

Whether or not you have tapered bearings doesn't really matter, any wheel bearing uses a pair of races. They're just different in design. Tapered bearings have a separate outer race which is pressed in first, then the roller bearings and inner race slide in together afterward. With a ball bearing, all three parts go in as a unit.

Tapered bearings, while not essential, are a smart upgrade. They allow precise adjustment of end float while retaining the desired spindle tension. More precision and more strength. Some will also say better longevity. I also highly recommend Bob G's upgraded spindles for even greater strength. The TC spindles were never meant to last 70 years. But I digress...

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 Post subject: Re: front wheel bearings.
PostPosted: Mon Sep 23, 2019 12:29 am 
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Location: North America
Probably bad adjustment or not exact spindle/bearing spacer length lends to the ovaling out of the hubs. Needless to say, bearings that are not perfectly centered (or moving around slightly) in the hub are going to make it quite impossible to ever set up the steering in a satisfactory way, whether using either angular contact ball bearings or tapered roller bearings. It is good to have someone with good eyesight to spot the bad fit caused by wear in the centers of the hub. This is one place I would not rely on special bearing retainer "glue."

The only trouble with converting to tapered bearings is the spacer needs to be slightly longer than standard. A proper one-piece shim should be hand fitted and sized to give zero end float. Once all set up for tapered, the spindle nut still must be torqued to 65 lbs or so, which is much more than most are used to when tightening down tapered bearings on applications with no spindle/bearing spacer.


 
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 Post subject: Re: front wheel bearings.
PostPosted: Mon Sep 23, 2019 7:21 am 
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Location: Southern California
I agree. I've never been entirely happy with bearing retainer compounds either. They do work in this situation, since all they have to do is fill the microscopic gap, not actually glue the bearing in place, but they don't give me a warm, fuzzy feeling. And eventually the hub will have to be replaced anyway.

Making a one-piece shim is fancy, but time-consuming and not really necessary. Generally the spacer is within a few thousandths of the needed gap, and shims of varying thicknesses are used to set the clearance to approximately 2-3 thou end float at full torque. You will want this adjustability to account for variances in replacement parts down the road. MGBs for example typically require about 45 thou of shims to achieve the desired end float.

Another side note for anyone else reading... no matter which type of bearing your TC is running, the spacer MUST be installed and the nut fully torqued. TCs are known to crack spindles and the spacer/shim stack will greatly increase the strength of the assembly. All cars with ball bearings use a spacer. There are cars that use tapered bearings and no spacer which have zero torque on the nut (tighten, then back off to the closest hole), but the TC isn't one of them!

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 Post subject: Re: front wheel bearings.
PostPosted: Mon Sep 23, 2019 8:34 am 
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Thanks for the end float correction, Steve. I used the Jim Buell article http://www.mg-tabc.org/library/Buell-TC ... 3rd-ed.pdf as a guide when I converted my new hubs. Last page. It calls for 0.002" - 0.005" end float with tapered bearings. Easiest if checked on a dry (no grease yet) assembly. When converting to tapered bearings, the additional length needed for spindle/bearing spacer is in the neighborhood of 1/8 inch.


 
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 Post subject: Re: front wheel bearings.
PostPosted: Mon Sep 23, 2019 2:51 pm 

Posts: 27
The reason I asked about how to remove the bearings is because I am faced with a specific problem. I think the bearings have been replaced by the previous owner and have not seen any use. Unfortunately, the hub will not tighten without binding; indeed any tightening causes it to lockup solid so I assume the fault lies with the spacer; it is loose and may be incorrect.

The problem is that I suspect the bearings have been treated to a good dose of Loctite and are well and truly stuck. As has been pointed out if you impact the inner race the bearings will be damaged but I can't see any other way of removing them. I have an internal bearing puller but I can't fit it because of the spacer. I have a 12 ton press but can't apply an even pressure.

I guess I will have to sacrifice these (original) hubs and bearings and purchase new hubs. Fortunately I already have a set of taper roller bearings ready to fit. I may have to turn up some new spacers on the lathe or add shims as required.


 
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 Post subject: Re: front wheel bearings.
PostPosted: Mon Sep 23, 2019 3:01 pm 
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Location: Southern California
If the hub is good, I'm sure you can get the bearings safely out The presence of locktite is not a good sign, but doesn't necessarily mean the bearings were loose. Some people just like to go overkill. I'd get a punch in there and beat them out with a large hammer. Might want to protect the spinner threads with a block of wood. Heat also helps to break locktite loose.

As far as the binding, I think you're on the right track with the spacer being too short. For ball bearings, the spacer length should measure the same as the distance between the shoulders inside the hub that the bearings sit on. It's also possible that one or more bearings are either not fully seated, or are in crooked, which would also cause binding.

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 Post subject: Re: front wheel bearings.
PostPosted: Mon Sep 23, 2019 8:18 pm 
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Location: North America
Sounds like the hub "races" are ovaled out as described above, and the bearings got glued in off center.


 
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 Post subject: Re: front wheel bearings.
PostPosted: Tue Sep 24, 2019 11:00 am 

Posts: 27
In the end I drifted the bearings out and discarded them. When I have cleaned up the hub and removed any burrs or evidence of adhesive, I will hopefully be able to fit my new taper roller bearings. I understand how important it is to achieve the correct pre load so they are in the Goldilocks zone. I have also read that the spacer needs to be placed under sufficient load to reinforce the spindle. I have crack tested them and all appears well. I just hope I get it right.

Thanks to everyone for their input.

Ray.


 
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 Post subject: Re: front wheel bearings.
PostPosted: Sat Oct 05, 2019 1:38 am 

Posts: 27
It has become apparent that the outer race (of the outer of the two bearings) was stuck in place with Loctite; or similar. My attempts at fitting the new taper roller bearings have received a set back because the new outer race is a slack fit on it's seat. I imagine the bearing has 'spun' as it can easily be rotated by hand.

Is it the opinion of the forum that I should replace the hub ...or can I simply repeat the Loctite remedy?


 
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 Post subject: Re: front wheel bearings.
PostPosted: Sun Oct 06, 2019 7:52 am 
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Location: Southern California
So the outer race is spinning inside the hub? If it's spinning with no resistance then I would replace the hub. If it takes a bit of effort to spin it then most people would use locktite but of course it depends on your own comfort level. The main thing is that you want zero play. If it's super loose or you can feel any play at all then the hub is trash, unfortunately.

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 Post subject: Re: front wheel bearings.
PostPosted: Sun Oct 06, 2019 11:07 am 

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Yes Steve. I am sure the hub is finished. I am trying to do the best I can with the rebuild so new hubs to go with the new bearings seems sensible.

There is no way I shall be spoiling the ship for a ha'peth of tar. !


 
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