Re: Tough technical questions

[Hairy]

"Nomen Nescio" > wrote in message
...
> 1. The application is to install a rotary shaft oil seal in an aluminum
> housing. The configuration of the seal is with a rubber coated outside
> diameter. The fit in the bored housing is a light push fit. I suspect
the
> seal will work loose on its own during service. What is the best way to
> install this seal? Options I've considered include replacing this seal
> constructed with a metal o.d., but this is not normally recommended due to
> the high coefficient of expansion. A more promising solution is to "glue"
> the seal in with Loctite 495, cyanoacrylate adhesive. Will that work?
>

Loctite 609 would be a better choice, IMO. 495 is just common super glue,
and would probably not be suitable for use on oil seals.

> 2. The problem is installing a chain sprocket onto a keyed tapered shaft
> which is then secured with a retaining nut. What is the best practice:
> Install on clean and dry taper, install on greased taper, or apply a high
> strength Loctite 272 to the taper before assembly? The idea is to make a
> good assembly but be able to disassemble with no more than a puller
without
> heat. Am I correct in assuming that the key is designed for indexing but
> the torque is taken up by the taper?

Yes

If the taper is greased, removal is
> easy, but the torque might be passed on to the key and cause localized
> stress and failure. Clean and dry I think is the standard way of
assembly,
> but Loctite application may be in common practice too.
>

I agree with the "clean and dry". If you are worried about it loosening on
the shaft, you could always heat the sprocket in a pan of water before assy,
then immediately torque the nut down. A little 242 on the threads would keep
the nut from loosening.
H

[Alex Rodriguez]

In article >,
says...

>2. The problem is installing a chain sprocket onto a keyed tapered shaft
>which is then secured with a retaining nut. What is the best practice:
>Install on clean and dry taper, install on greased taper, or apply a high
>strength Loctite 272 to the taper before assembly? The idea is to make a
>good assembly but be able to disassemble with no more than a puller without
>heat. Am I correct in assuming that the key is designed for indexing but
>the torque is taken up by the taper? If the taper is greased, removal is
>easy, but the torque might be passed on to the key and cause localized
>stress and failure. Clean and dry I think is the standard way of assembly,
>but Loctite application may be in common practice too.

I would clean the parts and then add a thin layer of grease. Then torque
the bolt to specs. Even with gease, you will need a puller to get the
sprocket off. Because it is a tapered press fit the sprocket will still
move a bit up the taper.
------------
Alex

[Alex Rodriguez]

In article >,
says...

>2. The problem is installing a chain sprocket onto a keyed tapered shaft
>which is then secured with a retaining nut. What is the best practice:
>Install on clean and dry taper, install on greased taper, or apply a high
>strength Loctite 272 to the taper before assembly? The idea is to make a
>good assembly but be able to disassemble with no more than a puller without
>heat. Am I correct in assuming that the key is designed for indexing but
>the torque is taken up by the taper? If the taper is greased, removal is
>easy, but the torque might be passed on to the key and cause localized
>stress and failure. Clean and dry I think is the standard way of assembly,
>but Loctite application may be in common practice too.

I would clean the parts and then add a thin layer of grease. Then torque
the bolt to specs. Even with gease, you will need a puller to get the
sprocket off. Because it is a tapered press fit the sprocket will still
move a bit up the taper.
------------
Alex

[Bill Putney]

Alex Rodriguez wrote:
> In article >,
> says...
>
>
>>2. The problem is installing a chain sprocket onto a keyed tapered shaft
>>which is then secured with a retaining nut. What is the best practice:
>>Install on clean and dry taper, install on greased taper, or apply a high
>>strength Loctite 272 to the taper before assembly? The idea is to make a
>>good assembly but be able to disassemble with no more than a puller without
>>heat. Am I correct in assuming that the key is designed for indexing but
>>the torque is taken up by the taper? If the taper is greased, removal is
>>easy, but the torque might be passed on to the key and cause localized
>>stress and failure. Clean and dry I think is the standard way of assembly,
>>but Loctite application may be in common practice too.
>
>
> I would clean the parts and then add a thin layer of grease. Then torque
> the bolt to specs. Even with gease, you will need a puller to get the
> sprocket off. Because it is a tapered press fit the sprocket will still
> move a bit up the taper.
> ------------
> Alex

I don't have an answer for the specific application, but from a
design/engineering standpoint, I would follow the written procedure as
far as grease or no grease. I say that because, unless there is a
positive stop (a step), the stresses on a tapered fit will go up maybe
an order of magnitude or more for the same bolt/nut torque, possibly
stretching or breaking the sprocket if it was not designted for that
stress (i.e., if it was designed assuming no grease).

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
adddress with the letter 'x')


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[Bill Putney]

Alex Rodriguez wrote:
> In article >,
> says...
>
>
>>2. The problem is installing a chain sprocket onto a keyed tapered shaft
>>which is then secured with a retaining nut. What is the best practice:
>>Install on clean and dry taper, install on greased taper, or apply a high
>>strength Loctite 272 to the taper before assembly? The idea is to make a
>>good assembly but be able to disassemble with no more than a puller without
>>heat. Am I correct in assuming that the key is designed for indexing but
>>the torque is taken up by the taper? If the taper is greased, removal is
>>easy, but the torque might be passed on to the key and cause localized
>>stress and failure. Clean and dry I think is the standard way of assembly,
>>but Loctite application may be in common practice too.
>
>
> I would clean the parts and then add a thin layer of grease. Then torque
> the bolt to specs. Even with gease, you will need a puller to get the
> sprocket off. Because it is a tapered press fit the sprocket will still
> move a bit up the taper.
> ------------
> Alex

I don't have an answer for the specific application, but from a
design/engineering standpoint, I would follow the written procedure as
far as grease or no grease. I say that because, unless there is a
positive stop (a step), the stresses on a tapered fit will go up maybe
an order of magnitude or more for the same bolt/nut torque, possibly
stretching or breaking the sprocket if it was not designted for that
stress (i.e., if it was designed assuming no grease).

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
adddress with the letter 'x')


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[Eightupman]

FYI....."cyanoacrylate" = Super Glue. while superglue bonds a lot of low
stress applications, I do not think that the brittle properties of that
adhesive will accomplish your desired task.

As far as I know the dry taper and the keyway is all you need. As long as
the keyway fits snug into the shaft, part of it's purpose is to prevent
rotation.


"Nomen Nescio" > wrote in message
...
> 1. The application is to install a rotary shaft oil seal in an aluminum
> housing. The configuration of the seal is with a rubber coated outside
> diameter. The fit in the bored housing is a light push fit. I suspect
the
> seal will work loose on its own during service. What is the best way to
> install this seal? Options I've considered include replacing this seal
> constructed with a metal o.d., but this is not normally recommended due to
> the high coefficient of expansion. A more promising solution is to "glue"
> the seal in with Loctite 495, cyanoacrylate adhesive. Will that work?
>
> 2. The problem is installing a chain sprocket onto a keyed tapered shaft
> which is then secured with a retaining nut. What is the best practice:
> Install on clean and dry taper, install on greased taper, or apply a high
> strength Loctite 272 to the taper before assembly? The idea is to make a
> good assembly but be able to disassemble with no more than a puller
without
> heat. Am I correct in assuming that the key is designed for indexing but
> the torque is taken up by the taper? If the taper is greased, removal is
> easy, but the torque might be passed on to the key and cause localized
> stress and failure. Clean and dry I think is the standard way of
assembly,
> but Loctite application may be in common practice too.
>

[Eightupman]

FYI....."cyanoacrylate" = Super Glue. while superglue bonds a lot of low
stress applications, I do not think that the brittle properties of that
adhesive will accomplish your desired task.

As far as I know the dry taper and the keyway is all you need. As long as
the keyway fits snug into the shaft, part of it's purpose is to prevent
rotation.


"Nomen Nescio" > wrote in message
...
> 1. The application is to install a rotary shaft oil seal in an aluminum
> housing. The configuration of the seal is with a rubber coated outside
> diameter. The fit in the bored housing is a light push fit. I suspect
the
> seal will work loose on its own during service. What is the best way to
> install this seal? Options I've considered include replacing this seal
> constructed with a metal o.d., but this is not normally recommended due to
> the high coefficient of expansion. A more promising solution is to "glue"
> the seal in with Loctite 495, cyanoacrylate adhesive. Will that work?
>
> 2. The problem is installing a chain sprocket onto a keyed tapered shaft
> which is then secured with a retaining nut. What is the best practice:
> Install on clean and dry taper, install on greased taper, or apply a high
> strength Loctite 272 to the taper before assembly? The idea is to make a
> good assembly but be able to disassemble with no more than a puller
without
> heat. Am I correct in assuming that the key is designed for indexing but
> the torque is taken up by the taper? If the taper is greased, removal is
> easy, but the torque might be passed on to the key and cause localized
> stress and failure. Clean and dry I think is the standard way of
assembly,
> but Loctite application may be in common practice too.
>

[Scott M]

"Nomen Nescio" > wrote in message
...
> Thank you all for your advice.
>
> Do you think a steel cased oil seal will work satisfactorily in aluminum
> alloy if the seal is a good press fit? I would apply a light coat of
> Permatex #1 or Permatex Aviation to the outside diameter before driving it
> home.
>
> I am working on an obsolete motorcycle. The supplier has on hand
> elastomer
> coated o.d. oil seals, but the retention in the bore is problematic. I
> don't think OEM stuff is available and he is supplying generic parts. If
> that is the case, my automotive supplier can special order any seals I
> want
> by size and type specification, so the decision can be made to go with a
> conventional metal case seal. Rubber coated o.d. is supposed to be ideal
> for aluminum alloy, but I don't see any reliability in these seals if I
> can
> literally push into place by hand with essentially no mechanical
> retention.

put a little silicon on the outide of the rubber coated seal and then you
could pean it in a bit with a punch.....just another option.

[Scott M]

"Nomen Nescio" > wrote in message
...
> Thank you all for your advice.
>
> Do you think a steel cased oil seal will work satisfactorily in aluminum
> alloy if the seal is a good press fit? I would apply a light coat of
> Permatex #1 or Permatex Aviation to the outside diameter before driving it
> home.
>
> I am working on an obsolete motorcycle. The supplier has on hand
> elastomer
> coated o.d. oil seals, but the retention in the bore is problematic. I
> don't think OEM stuff is available and he is supplying generic parts. If
> that is the case, my automotive supplier can special order any seals I
> want
> by size and type specification, so the decision can be made to go with a
> conventional metal case seal. Rubber coated o.d. is supposed to be ideal
> for aluminum alloy, but I don't see any reliability in these seals if I
> can
> literally push into place by hand with essentially no mechanical
> retention.

put a little silicon on the outide of the rubber coated seal and then you
could pean it in a bit with a punch.....just another option.

[Repairman]

Use the rubber coated ones and the Permatex to help hold it.
You will get galvanic action between the steel and aluminum with the
non-coated ones. That's why the OEM ones are rubber coated to prevent that
corrosion from happening. You don't want the cases to corrode and get pitted
in the seal area after time goes by.
A 2 stroke motor has retainer plates to hold the seals in as they have
pressurized bottom ends, not a problem with a vented 4 stroke crankcase.
--
John
"anything you say can & will be misquoted & used against you"
'01 FLHR ''Red"
'04 MXZ 600ho
'99 XC700
BRC mem

"Nomen Nescio" > wrote in message
...
> Thank you all for your advice.
>
> Do you think a steel cased oil seal will work satisfactorily in aluminum
> alloy if the seal is a good press fit? I would apply a light coat of
> Permatex #1 or Permatex Aviation to the outside diameter before driving it
> home.
>
> I am working on an obsolete motorcycle. The supplier has on hand
> elastomer
> coated o.d. oil seals, but the retention in the bore is problematic. I
> don't think OEM stuff is available and he is supplying generic parts. If
> that is the case, my automotive supplier can special order any seals I
> want
> by size and type specification, so the decision can be made to go with a
> conventional metal case seal. Rubber coated o.d. is supposed to be ideal
> for aluminum alloy, but I don't see any reliability in these seals if I
> can
> literally push into place by hand with essentially no mechanical
> retention.
>

[Repairman]

Use the rubber coated ones and the Permatex to help hold it.
You will get galvanic action between the steel and aluminum with the
non-coated ones. That's why the OEM ones are rubber coated to prevent that
corrosion from happening. You don't want the cases to corrode and get pitted
in the seal area after time goes by.
A 2 stroke motor has retainer plates to hold the seals in as they have
pressurized bottom ends, not a problem with a vented 4 stroke crankcase.
--
John
"anything you say can & will be misquoted & used against you"
'01 FLHR ''Red"
'04 MXZ 600ho
'99 XC700
BRC mem

"Nomen Nescio" > wrote in message
...
> Thank you all for your advice.
>
> Do you think a steel cased oil seal will work satisfactorily in aluminum
> alloy if the seal is a good press fit? I would apply a light coat of
> Permatex #1 or Permatex Aviation to the outside diameter before driving it
> home.
>
> I am working on an obsolete motorcycle. The supplier has on hand
> elastomer
> coated o.d. oil seals, but the retention in the bore is problematic. I
> don't think OEM stuff is available and he is supplying generic parts. If
> that is the case, my automotive supplier can special order any seals I
> want
> by size and type specification, so the decision can be made to go with a
> conventional metal case seal. Rubber coated o.d. is supposed to be ideal
> for aluminum alloy, but I don't see any reliability in these seals if I
> can
> literally push into place by hand with essentially no mechanical
> retention.
>

[Nate Nagel]

Nomen Nescio > wrote in message >...
> 1. The application is to install a rotary shaft oil seal in an aluminum
> housing. The configuration of the seal is with a rubber coated outside
> diameter. The fit in the bored housing is a light push fit. I suspect the
> seal will work loose on its own during service. What is the best way to
> install this seal? Options I've considered include replacing this seal
> constructed with a metal o.d., but this is not normally recommended due to
> the high coefficient of expansion. A more promising solution is to "glue"
> the seal in with Loctite 495, cyanoacrylate adhesive. Will that work?

I suppose a seal with a slightly larger o.d. is not available? that
would be the ideal option. The seal ought to need to be pressed or
lightly hammered in to have any hope of reliable retention.

>
> 2. The problem is installing a chain sprocket onto a keyed tapered shaft
> which is then secured with a retaining nut. What is the best practice:
> Install on clean and dry taper, install on greased taper, or apply a high
> strength Loctite 272 to the taper before assembly? The idea is to make a
> good assembly but be able to disassemble with no more than a puller without
> heat. Am I correct in assuming that the key is designed for indexing but
> the torque is taken up by the taper? If the taper is greased, removal is
> easy, but the torque might be passed on to the key and cause localized
> stress and failure. Clean and dry I think is the standard way of assembly,
> but Loctite application may be in common practice too.

FWIW the standard practice for dealing with tapered-end rear axles
with separate hubs (commonly used on Studebaker, AMC and others) is to
install them clean and dry. They require a lot of force to separate
when torqued to spec, so no worries there. I have heard tell of
people lubing the tapers and subsequently splitting the cast iron
hubs.

nate

[Nate Nagel]

Nomen Nescio > wrote in message >...
> 1. The application is to install a rotary shaft oil seal in an aluminum
> housing. The configuration of the seal is with a rubber coated outside
> diameter. The fit in the bored housing is a light push fit. I suspect the
> seal will work loose on its own during service. What is the best way to
> install this seal? Options I've considered include replacing this seal
> constructed with a metal o.d., but this is not normally recommended due to
> the high coefficient of expansion. A more promising solution is to "glue"
> the seal in with Loctite 495, cyanoacrylate adhesive. Will that work?

I suppose a seal with a slightly larger o.d. is not available? that
would be the ideal option. The seal ought to need to be pressed or
lightly hammered in to have any hope of reliable retention.

>
> 2. The problem is installing a chain sprocket onto a keyed tapered shaft
> which is then secured with a retaining nut. What is the best practice:
> Install on clean and dry taper, install on greased taper, or apply a high
> strength Loctite 272 to the taper before assembly? The idea is to make a
> good assembly but be able to disassemble with no more than a puller without
> heat. Am I correct in assuming that the key is designed for indexing but
> the torque is taken up by the taper? If the taper is greased, removal is
> easy, but the torque might be passed on to the key and cause localized
> stress and failure. Clean and dry I think is the standard way of assembly,
> but Loctite application may be in common practice too.

FWIW the standard practice for dealing with tapered-end rear axles
with separate hubs (commonly used on Studebaker, AMC and others) is to
install them clean and dry. They require a lot of force to separate
when torqued to spec, so no worries there. I have heard tell of
people lubing the tapers and subsequently splitting the cast iron
hubs.

nate

[Bill Putney]

Nate Nagel wrote:

> ...I have heard tell of
> people lubing the tapers and subsequently splitting the cast iron
> hubs.
>
> nate

Precisely the point I was making.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
adddress with the letter 'x')


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[Bill Putney]

Nate Nagel wrote:

> ...I have heard tell of
> people lubing the tapers and subsequently splitting the cast iron
> hubs.
>
> nate

Precisely the point I was making.

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
adddress with the letter 'x')


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[Refinish_King1]

Use a thin coat of Permatex clear silicone sealer/adhesive:

It would hold bananas to ice-cream and seal them as well. I use it on cars
with problematic intake manifold front and rear seal leaks. A trick from
drag racing days, with angle cut heads, and no way to use the manifold
sealing strips.

I hope this helps?

Refinish King


"Nomen Nescio" > wrote in message
...
> Thank you all for your advice.
>
> Do you think a steel cased oil seal will work satisfactorily in aluminum
> alloy if the seal is a good press fit? I would apply a light coat of
> Permatex #1 or Permatex Aviation to the outside diameter before driving it
> home.
>
> I am working on an obsolete motorcycle. The supplier has on hand
> elastomer
> coated o.d. oil seals, but the retention in the bore is problematic. I
> don't think OEM stuff is available and he is supplying generic parts. If
> that is the case, my automotive supplier can special order any seals I
> want
> by size and type specification, so the decision can be made to go with a
> conventional metal case seal. Rubber coated o.d. is supposed to be ideal
> for aluminum alloy, but I don't see any reliability in these seals if I
> can
> literally push into place by hand with essentially no mechanical
> retention.
>

[Refinish_King1]

Use a thin coat of Permatex clear silicone sealer/adhesive:

It would hold bananas to ice-cream and seal them as well. I use it on cars
with problematic intake manifold front and rear seal leaks. A trick from
drag racing days, with angle cut heads, and no way to use the manifold
sealing strips.

I hope this helps?

Refinish King


"Nomen Nescio" > wrote in message
...
> Thank you all for your advice.
>
> Do you think a steel cased oil seal will work satisfactorily in aluminum
> alloy if the seal is a good press fit? I would apply a light coat of
> Permatex #1 or Permatex Aviation to the outside diameter before driving it
> home.
>
> I am working on an obsolete motorcycle. The supplier has on hand
> elastomer
> coated o.d. oil seals, but the retention in the bore is problematic. I
> don't think OEM stuff is available and he is supplying generic parts. If
> that is the case, my automotive supplier can special order any seals I
> want
> by size and type specification, so the decision can be made to go with a
> conventional metal case seal. Rubber coated o.d. is supposed to be ideal
> for aluminum alloy, but I don't see any reliability in these seals if I
> can
> literally push into place by hand with essentially no mechanical
> retention.
>