Wheel hub bearing removal

[Tony Press]

Just a reminder for bearings:- the moving race is usually an easy push fit while the static race is tighter fit......in the case of the hub - outer is moving so easy push fit in hub and felt carrier; whilst inner is static so a harder fit on the axle (also in this case is held by a locking nut.
If you use a bearing with seals either side, the seals can be prised off to clean out dried up/dirty grease and re-grease, they can then be pushed back in place.

Dennis

The SKF handbook recommends that the bearing rotating ring should have a tight  fit (to avoid 'creep' of the ring)   - in the case of the Austin 7 hub, in the housing, while the bearing stationary ring may have a loose or sliding fit of the inner ring, in this case on the axle. 

If the bearing is tight in the 'felt housing' -usually unlikely - then it is better to carefully press it out rather than drive it out and risk damaging the track.

Tony P.

[Dennis Nicholas]

Whilst I have your kind help on these pics, in the first pic the sharp eyed amongst you will notice that the brake backplate has rusted through slightly. This is the only point of thinning and rust, so can I ask that whilst I am aware replacement backplates are available, would you think a repair with Quck Steel apoxy after rust prevention etc would be an fairly successful, intermediate solution?

That part of the backplate is only there to keep out water and dirt and takes no stress so epoxy steel would suffice.  Presumably you do not have access to mig or gas welding?  With either a neat repair could easily be affected by cutting back the long slot of corroded plate into a regular shape and making a corresponding shape from (1 to 2 mm) steel and welding it in place.

Dennis

[Chris KC]

Whilst I have your kind help on these pics, in the first pic the sharp eyed amongst you will notice that the brake backplate has rusted through slightly. This is the only point of thinning and rust, so can I ask that whilst I am aware replacement backplates are available, would you think a repair with Quck Steel apoxy after rust prevention etc would be an fairly successful, intermediate solution?

That part of the backplate is only there to keep out water and dirt and takes no stress so epoxy steel would suffice.  Presumably you do not have access to mig or gas welding?  With either a neat repair could easily be affected by cutting back the long slot of corroded plate into a regular shape and making a corresponding shape from (1 to 2 mm) steel and welding it in place.

Dennis

This sounds like a better idea to me - easy and permanent job with a MIG and it looks like there is plenty of sound metal to weld to. Then make sure the brake drum isn't rubbing on it when re-assembled.

[Dennis Nicholas]

Ref back plate corrosion.

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When welding strips in do it in small lengths at a time...first tack in place around then fill in between tacks a little (1/4") at a time alternating from end to end and side to side.  The aim is to not heat a local area too much causing distortion.
A small tip I got from a professional welder for filling smallish holes.....clamp a piece of copper plate at the back of the hole then proceed to mig weld deposit a bit at a time building up the edge of the hole till edges join.....the copper will not get welded into place but it prevents the molten metal from forming a lump on the non weld side........only one side to tidy up and grind flush....also copper takes away the heat so less likely to just burn hole at the edge.

Dennis

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Just a reminder for bearings:- the moving race is usually an easy push fit while the static race is tighter fit......in the case of the hub - outer is moving so easy push fit in hub and felt carrier; whilst inner is static so a harder fit on the axle (also in this case is held by a locking nut.

Dennis

WRONG WRONG WRONG
Apologies to all it is as T P says the other way round.......Age addled brain and late night strike again.

"A good rule of thumb for most applications is to use a press fit on the rotating component.
That is, a shaft or inner ring rotating application like an electric motor will use a press fit on the shaft and a loose fit on the housing. A housing or outer ring rotating application like a wheel hub will employ the reverse: a loose fit on the shaft and a press fit on the housing. This will greatly reduce the chances of creep or a loosened fit during operation."  
Quoted from NTN bearings.

Dennis

[Biddlecombe]

Further. I have purchased axle/diff gasket and modern lip seal for diff end, is it a difficult job to replace these?

[Bob Culver]

For the expert and agile no. For those unfamilair with mechanical practice and machines can dvelop into a saga, esp as the diff adjustmen will likley become involved. Several previous posts.
The race should be a good fit on tubullar axle; otherwise inclined to work loose. The fit in the housing is of little consequece, except that affects seal operation and if luxury of sealed bearings are used oil can bypass..
If the axle ends are reasonable modern seals should cure. Many "moderns" rely on these alone.

[Dennis Nicholas]

Further. I have purchased axle/diff gasket and modern lip seal for diff end, is it a difficult job to replace these?

It might be best if you tell us what year your axle is?
If the inner area of the axle casing where the felt seal and its cup fit is standard the job should be strait forward to fit the lip seal.  It will depend on which axle you have and which seal you have and whether any predecessors have made any modifications.  On my heavy axle (1938 on)  there appeared to be a ring inserted in the housing.  This was the right diameter to take a lip seal.  The seal is a metal inner cup covered in rubber and with a spring around the inner diameter to hold the rubber against the shaft.  To put the seal into the housing you need to be careful not to distort the metal inner of the seal.  You need to take the spring out and insert a tube with large enough inner diameter to just go over the seal inner diameter rubber shoulder and just the right outer diameter to fit within the outer seal rubber without distorting the rubber outwards.  The ends of the tube should be square to its length, the seal can then be pressed in gently keeping it square to the housing.  GENTLE taping equally around the tube alternate side to side can do the job if no press available.  Using a drift against the seal inner part is quite likely to end in distortion and tears.
The difficult part if the seal is at all a tight fit is keeping the seal square to the housing.  The job could end up being as easy as just being able to press the seal into the felt cup carrier with your hands and fitting cup back in with its spring ring retainer.
Tip: I have found old tapered wood legs from a table/stool etc. can be useful cut down at the right diameter part for putting against the seal from the back to push it out again if it starts tipping over......also good for tapping out/pressing bearings.  Three legged furniture in house......I tell the wife I found woodworm on leg so had to cut it off 

Concurrently with that job and casing gasket renewal you may have to re set the crown wheel and pinion mesh (side to side movement/clearance of diff carrier as well as how far the pinion teeth are meshed forward/back with the crown wheel.  Depending on which axle the methods of adjustment are different........there is a man in Cornwall who has the works setting up tool/rig which makes it easier.  Shims may well be required for setting side float of diff carrier and forward/backward mesh of teeth.
Suggest you do a lot of searching on this (where it has all been covered) and other sites to see in detail what is involved.
Also remember that whoever previously played with the axle may not have assembled properly so do not just put back what you find.....check the spares catalogue, other 7 club websites etc to see how things SHOULD be.

Where are you....there may be an expert nearby.  Good luck.

Dennis

[Terrytuned]

Axle oil leaks see BA7C technical web site for update on axle oil seals. Terry.

[Biddlecombe]

Further. I have purchased axle/diff gasket and modern lip seal for diff end, is it a difficult job to replace these?

It might be best if you tell us what year your axle is?
If the inner area of the axle casing where the felt seal and its cup fit is standard the job should be strait forward to fit the lip seal.  It will depend on which axle you have and which seal you have and whether any predecessors have made any modifications.  On my heavy axle (1938 on)  there appeared to be a ring inserted in the housing.  This was the right diameter to take a lip seal.  The seal is a metal inner cup covered in rubber and with a spring around the inner diameter to hold the rubber against the shaft.  To put the seal into the housing you need to be careful not to distort the metal inner of the seal.  You need to take the spring out and insert a tube with large enough inner diameter to just go over the seal inner diameter rubber shoulder and just the right outer diameter to fit within the outer seal rubber without distorting the rubber outwards.  The ends of the tube should be square to its length, the seal can then be pressed in gently keeping it square to the housing.  GENTLE taping equally around the tube alternate side to side can do the job if no press available.  Using a drift against the seal inner part is quite likely to end in distortion and tears.
The difficult part if the seal is at all a tight fit is keeping the seal square to the housing.  The job could end up being as easy as just being able to press the seal into the felt cup carrier with your hands and fitting cup back in with its spring ring retainer.
Tip: I have found old tapered wood legs from a table/stool etc. can be useful cut down at the right diameter part for putting against the seal from the back to push it out again if it starts tipping over......also good for tapping out/pressing bearings.  Three legged furniture in house......I tell the wife I found woodworm on leg so had to cut it off 

Concurrently with that job and casing gasket renewal you may have to re set the crown wheel and pinion mesh (side to side movement/clearance of diff carrier as well as how far the pinion teeth are meshed forward/back with the crown wheel.  Depending on which axle the methods of adjustment are different........there is a man in Cornwall who has the works setting up tool/rig which makes it easier.  Shims may well be required for setting side float of diff carrier and forward/backward mesh of teeth.
Suggest you do a lot of searching on this (where it has all been covered) and other sites to see in detail what is involved.
Also remember that whoever previously played with the axle may not have assembled properly so do not just put back what you find.....check the spares catalogue, other 7 club websites etc to see how things SHOULD be.

Where are you....there may be an expert nearby.  Good luck.

Dennis

Thank you for such a helpful post Dennis, firstly I am on East Sussex Coast and Gary Edwards is a great help but I know he is busy and I don't want to keep bothering him, and I need to learn myself!
The axle is as far as I can tell, just like all major parts of the car, original, dated 7 32. It fits with Woodrow, but I find this lacks the little nuances that you guys can give!
I am a bit slow at the moment as I had a VERY minor stroke like episode on Monday, so I will try separating the bearing and seal from the hub this afternoon after "mother" has gone to work.
Regards, Peter

[Dennis Nicholas]

Peter
google "a7ca archive" and you can look in the archive and print out the spares list (888 or 888A depending on chassis number) (a7ca = Austin7ClubsAssociation.)
That was a change year so not sure whether you have the 3 piece (banjo) axle case or the 2 piece (D type). Hope it is the 2 piece as easier to set diff carrier end float using the built in threaded serrated adjusters and no requirement for shims. All parts of the car have their part numbers stamped on or cast on in raised letters/numerals so you should find on the back axle the date, ratio and part number (part number on each part of the 2 piece axle case) It is on the housing that the diff sits in and may need a bit of paint removal if previously thickly painted over. The pinion toothed end has numbers on it...ratio and a number related to the meshing and thus shims between torque tube and casing. The crown wheel will have matching/related numbers.....something to read about.
Good websites are Cornwall A7 club; Bristol; Southampton; Dorset; London....+ others. Cornwall club has the info on setting up axle if I remember.
Don't be afraid to ask...we all had to start somewhere.....and I am still learning at 74.

Dennis