Re: Clearance bewteen hub and half shaft

[Wim Jetten]

I just pressed a brand new half shaftinto a brand new rear hub. I am
referring to a TC.
After having done so I noticed that with the half sahft in its final
position there was some clearance between the half shaft and the hub.
Looking at the splines both on the shaft as well as in the hub one could
talk about a a large and small diameter.
On the shaft the large diameter being the actual diameter of the shaft and
the small diameter where the additional has been machined away to form the
splines.
When talking about the hub the small diameter is the bore of the hub and
the large diameter is the diameter where the additional has been machined
away to form the splines.material I hope I am clear.
It appears that the large diameter of the hub is ca. 0.4 to 0.5 mm larger
than the large diameter of the shaft.
When holding the assenmbly aginst the light one clearly sees (the same)
clearance between each of the outer splines of the shaft and each of the
innner splines of the hub.

Is this normal? It will ceratianly cause rear axle oil to seep through into
the space behind the spinner. But I am more concerned the strength of the
connection between shaft and hub.

Best regards,

Wim Jetten

[Dave A]

Hi Wim,

I think there is a measurement of the final length of the axel sticking out
from the hub, and if you use the Grunau axel nuts with seals you will not
have a leak problem. I am not sure of the measurment, but I am certian
someone on the list will know it.

Cheers, Dave 48" TC

-----Original Message-----
From: mg-tabc@yahoogroups.com [mailto:mg-tabc@yahoogroups.com]On Behalf
Of Wim Jetten
Sent: Monday, September 12, 2005 11:56 AM
To: mg-tabc@yahoogroups.com
Subject: [mg-tabc] Clearance bewteen hub and half shaft


I just pressed a brand new half shaftinto a brand new rear hub. I am
referring to a TC.
After having done so I noticed that with the half sahft in its final
position there was some clearance between the half shaft and the hub.
Looking at the splines both on the shaft as well as in the hub one could
talk about a a large and small diameter.
On the shaft the large diameter being the actual diameter of the shaft and
the small diameter where the additional has been machined away to form the
splines.
When talking about the hub the small diameter is the bore of the hub and
the large diameter is the diameter where the additional has been machined
away to form the splines.material I hope I am clear.
It appears that the large diameter of the hub is ca. 0.4 to 0.5 mm larger
than the large diameter of the shaft.
When holding the assenmbly aginst the light one clearly sees (the same)
clearance between each of the outer splines of the shaft and each of the
innner splines of the hub.

Is this normal? It will ceratianly cause rear axle oil to seep through into
the space behind the spinner. But I am more concerned the strength of the
connection between shaft and hub.

Best regards,

Wim Jetten





Yahoo! Groups Links

[Donald Wilkinson]

Hey Wim:

digitaldon thinks you have a problem. This joint is supposed to be an
interference fit, requiring a minimum of six tons to press these parts
together, and certainly shouldn't show any light through it. How much
force did you use? Sounds as if you used some bogus repro parts, and if it
is as you describe, it'll likely fail. Hate to be the bearer of bad
tidings.....................................

Don
TC 7993

[Terry Horlick]

It is easy to say "use more than 6 tons when you press the axle into
the hub. But how do you know how much that is? I have a 12 ton press
(Chinese import) so I thought that you just pull it down kinda hard
and you are there. I figured that pulling down with all your might
would get you 12 tons.

That was until I put a gauge onto my press.
http://pages.sbcglobal.net/thorlick/Press/press.htm
Here's what I found:

Pull down firmly any you get one, maybe two tons. Pull down with all
you are worth (I come off the floor when pulling 170 lbs.) and you get
maybe 5 tons.

When I converted my press I added a 12 ton air jack and found that
the "12 ton press" starts to smash at around 6 tons. It really
deforms at about 11 tons. I had replaced my press bolts with grade 8
hardware. I have a friend whose press blew apart and sent the grade 1
bolts it came with through the sheetrock ceiling!

So if you are hammering that axle into the hub, it will fail. If you
are using an import 12 ton press and pumping by hand and it goes
together, it will fail. If you are using a cheap press and it creaks
and the top cross member starts to smash you are probably at about 6
tons. If that is the case, get someone you really don't like to
finish pressing that axle on that press.

My real suggestion: Take it to a shop with a real 50 ton press with a
gauge on it which is calibrated. Then ask the shop to measure how
much force it took to press the axle in. If it was less than 6 tons
return the axle to the maker and have them make you a proper sized
part. This is certainly not going to make the axle man happy and will
probably end with you having a sub-standard axle, less money and going
to Bob Gruneau and get a proper axle and hub done up. I can do the
pressing in my shop now, but I chose to buy from Bob... it is a real
deal to do it that way.

IMHO Terry TC2285

--- In mg-tabc@yahoogroups.com, "Donald Wilkinson"
wrote:

> Hey Wim:
>
> digitaldon thinks you have a problem. This joint is supposed to be

an

> interference fit, requiring a minimum of six tons to press these

parts

> together, and certainly shouldn't show any light through it. How

much

> force did you use? Sounds as if you used some bogus repro parts,

and if it

> is as you describe, it'll likely fail. Hate to be the bearer of bad
> tidings.....................................
>
> Don
> TC 7993

[Jorolibb@aol.com]

Dear Wim & Don,

Having some clearance between both major and minor diameters isn't
necessarily a bad thing. If you have a side fit spline with enough of an interference
fit I feel that you should be OK. About 13 years ago I replaced the rear hubs
(splines for the road wheels were worn out) on my MGA, pressing out the original
shaft and reinstalling it in a new hub. The was some clearance between both
diameters but it took quite a bit of force with my 20 ton press and a bit of
heat, but not to much heat to get the shaft into the hub. A bit of sealant and a
core plug have kept everything dry all this time and some 20,000 miles later
the axles and hubs are still tight. I know MGA's have a cobore for a core plug
but I can't remember if there is one in a TC hub and I'm to tired to go out
into the shop to look at one right now.

Having spent 17 years in the custom gear and gearbox industry I have learned
various ways to assemble shafts and gears including tapers without any keys
but not having my TC together yet I don't make any claims at being a TC expert.
As Don commented in his email, " How much force did you use?". It is my
opinion that a good press fit between the original type of hub and axle is a very
satisfactory practice.

I will suggest to contact either Bob Grunau or Roger Furneaux of this list,
who both have vast experience with rear axles and hubs for their opinions.

John Libbert
Milford,OH
TC 2138
J2 3118
MGA 70528


[Non-text portions of this message have been removed]

[1939mgtb]

Don't you have a pressure guage on the top of your press? Oops. Sorry, I
read down further....
My press is an old WW2 model made of serious stuff. I paid next to nothing
for it, and it works like a charm.....no creaking or other scary noise.
The Navy probably was using it to press propellors on shafts or some such!!
Frankly, I used Bob G's shafts and hubs, and have had no problem of any
kind. Try them, you'll like 'em. Terry is right!
Best,
Ray
"Spes mea in Deo est"

----- Original Message -----
From: "Terry Horlick"
To:
Sent: Monday, September 12, 2005 8:16 PM
Subject: [mg-tabc] Re: Clearance bewteen hub and half shaft


> It is easy to say "use more than 6 tons when you press the axle into
> the hub. But how do you know how much that is? I have a 12 ton press
> (Chinese import) so I thought that you just pull it down kinda hard
> and you are there. I figured that pulling down with all your might
> would get you 12 tons.
>
> That was until I put a gauge onto my press.
> http://pages.sbcglobal.net/thorlick/Press/press.htm
> Here's what I found:
>
> Pull down firmly any you get one, maybe two tons. Pull down with all
> you are worth (I come off the floor when pulling 170 lbs.) and you get
> maybe 5 tons.
>
> When I converted my press I added a 12 ton air jack and found that
> the "12 ton press" starts to smash at around 6 tons. It really
> deforms at about 11 tons. I had replaced my press bolts with grade 8
> hardware. I have a friend whose press blew apart and sent the grade 1
> bolts it came with through the sheetrock ceiling!
>
> So if you are hammering that axle into the hub, it will fail. If you
> are using an import 12 ton press and pumping by hand and it goes
> together, it will fail. If you are using a cheap press and it creaks
> and the top cross member starts to smash you are probably at about 6
> tons. If that is the case, get someone you really don't like to
> finish pressing that axle on that press.
>
> My real suggestion: Take it to a shop with a real 50 ton press with a
> gauge on it which is calibrated. Then ask the shop to measure how
> much force it took to press the axle in. If it was less than 6 tons
> return the axle to the maker and have them make you a proper sized
> part. This is certainly not going to make the axle man happy and will
> probably end with you having a sub-standard axle, less money and going
> to Bob Gruneau and get a proper axle and hub done up. I can do the
> pressing in my shop now, but I chose to buy from Bob... it is a real
> deal to do it that way.
>
> IMHO Terry TC2285
>
> --- In mg-tabc@yahoogroups.com, "Donald Wilkinson"
> wrote:
>> Hey Wim:
>>
>> digitaldon thinks you have a problem. This joint is supposed to be
> an
>> interference fit, requiring a minimum of six tons to press these
> parts
>> together, and certainly shouldn't show any light through it. How
> much
>> force did you use? Sounds as if you used some bogus repro parts,
> and if it
>> is as you describe, it'll likely fail. Hate to be the bearer of bad
>> tidings.....................................
>>
>> Don
>> TC 7993
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>

[Roger Furneaux]

Digital Don wrote:

>digitaldon thinks you have a problem. This joint is supposed to be an
>interference fit, requiring a minimum of six tons to press these parts
>together, and certainly shouldn't show any light through it. How much
>force did you use? Sounds as if you used some bogus repro parts, and if it
>is as you describe, it'll likely fail.

NOT SO! The only interference fit is between the inner diameter of the hub
splines and the root diam. of the shaft splines. You SHOULD see a gap, hence
light, between the outer diam. of hub splines and the outer diam. (1") of
the shaft. This tightness should indeed need up to 6 tons to press in, but
due to manufacturing tolerances is often a bit less. I use a 15 ton floor
press with gauge made in Italy, and sold here in the UK by Machine Mart.

The sides of the splines do not actually do the driving if the interference
is correct: if shaft splines are cut too wide, then small slivers of metal
appear on pressing in! Of course, when the interference is lost, then the
shaft moves, and the sides of the splines in both hub & shaft rapidly wear
away.

All this is eliminated by taper-fit shafts, as pioneered by Phil Marino and
made by me for over ten years (and more recently by Bob G). I started out
using keys, but as with the spline sides, they don't actually transmit the
drive, so now I leave them out. I have supplied shafts for MMM cars as well
as Ta/B/C, even specials for a K3, which enabled the continued use of the
clapped-out original hub.

ocTagonally

TCRoger, Devon, Olde England


[Non-text portions of this message have been removed]

[Donald Wilkinson]

digitaldon, now corrected, will gratefully file the below away in his
archive...............................

Don
TC 7993


Digital Don wrote:

>digitaldon thinks you have a problem. This joint is supposed to be an
>interference fit, requiring a minimum of six tons to press these parts
>together, and certainly shouldn't show any light through it. How much
>force did you use? Sounds as if you used some bogus repro parts, and if it
>is as you describe, it'll likely fail.

NOT SO! The only interference fit is between the inner diameter of the hub
splines and the root diam. of the shaft splines. You SHOULD see a gap, hence
light, between the outer diam. of hub splines and the outer diam. (1") of
the shaft. This tightness should indeed need up to 6 tons to press in, but
due to manufacturing tolerances is often a bit less. I use a 15 ton floor
press with gauge made in Italy, and sold here in the UK by Machine Mart.

The sides of the splines do not actually do the driving if the interference
is correct: if shaft splines are cut too wide, then small slivers of metal
appear on pressing in! Of course, when the interference is lost, then the
shaft moves, and the sides of the splines in both hub & shaft rapidly wear
away.

All this is eliminated by taper-fit shafts, as pioneered by Phil Marino and
made by me for over ten years (and more recently by Bob G). I started out
using keys, but as with the spline sides, they don't actually transmit the
drive, so now I leave them out. I have supplied shafts for MMM cars as well
as Ta/B/C, even specials for a K3, which enabled the continued use of the
clapped-out original hub.

ocTagonally

TCRoger, Devon, Olde England