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Prop Shaft Hydraulicing

G

Guest

Guest
Morning All,
Have any of you come across a good solution to problem of hydraulicing
(spelling?) in the prop shafts?
Just to explain - the front and rear prop shafts comprise two halves
that slide in and out of each other when you go over bumps. You keep
the join lubricated via a grease nipple on the proshaft that forces
grease between the splined shaft that links the two halves.
The hydraulicing problem comes in when you pump the grease into the
axle - it effectively acts like a hydrualic ram forcing the two halves
apart and putting pressure on the transfer case and the diff. This
would explain the problem of worn output shaft bearings I have seen on
some people's transfer cases.
I have just removed my rear propshaft to replace a worn UJ and am quite
staggered at how much pressure is require to move the two halves back
and forth. Which is worrying when you think of the forces being
applied to the transfer case and the diff everytime the axle moves
(shortening or extending the propshaft).
I guess a lot of the problem could be down to old grease so will be
giving both halves a thorough clean out, but would be interested to
know if any of you have come across any clever solutions.
Certainly in the future I will be adding a strip down, degrease and
then regrease of prop shafts to any vehicles I'm prepping.
--
Regards,
Julian Voelcker
Mobile: 07971 540362
Cirencester, United Kingdom
1994 HDJ80, 2.5" OME Lift
 
Morning All,
Have any of you come across a good solution to problem of hydraulicing
(spelling?) in the prop shafts?
Just to explain - the front and rear prop shafts comprise two halves
that slide in and out of each other when you go over bumps. You keep
the join lubricated via a grease nipple on the proshaft that forces
grease between the splined shaft that links the two halves.
The hydraulicing problem comes in when you pump the grease into the
axle - it effectively acts like a hydrualic ram forcing the two halves
apart and putting pressure on the transfer case and the diff. This
would explain the problem of worn output shaft bearings I have seen on
some people's transfer cases.
I have just removed my rear propshaft to replace a worn UJ and am quite
staggered at how much pressure is require to move the two halves back
and forth. Which is worrying when you think of the forces being
applied to the transfer case and the diff everytime the axle moves
(shortening or extending the propshaft).
I guess a lot of the problem could be down to old grease so will be
giving both halves a thorough clean out, but would be interested to
know if any of you have come across any clever solutions.
Certainly in the future I will be adding a strip down, degrease and
then regrease of prop shafts to any vehicles I'm prepping.
--
Regards,
Julian Voelcker
Mobile: 07971 540362
Cirencester, United Kingdom
1994 HDJ80, 2.5" OME Lift
 
Sounds like your splines are a bit dry Julian! Gravity should be enough
to slide the two halves apart!
I tend to take the prop off to grease it which I do manually (pull it
apart and apply grease) and I leave the grease nipple off until the prop
is back on the truck so the pressures are minimized.
You could grease it via nipple as usual and then undo the nipple a few
turns to let pressure out but I'm not convinced the grease gets to where
you need it most, a bit like the problem with CV's IMHO.
Best regards,
Jon.
-----Original Message-----
From: [Email address removed] [mailto:[Email address removed]]
On Behalf Of Julian Voelcker
Sent: 02 November 2005 12:37
To: [Email address removed]
Subject: [ELCO] Prop Shaft Hydraulicing
Morning All,
Have any of you come across a good solution to problem of hydraulicing
(spelling?) in the prop shafts?
Just to explain - the front and rear prop shafts comprise two halves
that slide in and out of each other when you go over bumps. You keep
the join lubricated via a grease nipple on the proshaft that forces
grease between the splined shaft that links the two halves.
The hydraulicing problem comes in when you pump the grease into the
axle - it effectively acts like a hydrualic ram forcing the two halves
apart and putting pressure on the transfer case and the diff. This
would explain the problem of worn output shaft bearings I have seen on
some people's transfer cases.
I have just removed my rear propshaft to replace a worn UJ and am quite
staggered at how much pressure is require to move the two halves back
and forth. Which is worrying when you think of the forces being
applied to the transfer case and the diff everytime the axle moves
(shortening or extending the propshaft).
I guess a lot of the problem could be down to old grease so will be
giving both halves a thorough clean out, but would be interested to
know if any of you have come across any clever solutions.
Certainly in the future I will be adding a strip down, degrease and
then regrease of prop shafts to any vehicles I'm prepping.
--
Regards,
Julian Voelcker
Mobile: 07971 540362
Cirencester, United Kingdom
1994 HDJ80, 2.5" OME Lift
 
Hi Jon,
That's the thing, they are packed with grease.
I do agree that stipping down and degreasing and then manually greasing
the splines should be done reasonably often. Some recommend doing this
every couple of services.
One of the key issues seems to be the thickness of the grease - if it is
too thick/dry when you fill via the nipple it doesn't push past the
splines and out at the join causing the hydraulicing problem.
Cleaning it all out and then using a light CV style grease is probably the
best option.
--
Regards,
Julian Voelcker
Mobile: 07971 540362
Cirencester, United Kingdom
1994 HDJ80, 2.5" OME Lift
 
Hi Jon,
That's the thing, they are packed with grease.
I do agree that stipping down and degreasing and then manually greasing
the splines should be done reasonably often. Some recommend doing this
every couple of services.
One of the key issues seems to be the thickness of the grease - if it is
too thick/dry when you fill via the nipple it doesn't push past the
splines and out at the join causing the hydraulicing problem.
Cleaning it all out and then using a light CV style grease is probably the
best option.
--
Regards,
Julian Voelcker
Mobile: 07971 540362
Cirencester, United Kingdom
1994 HDJ80, 2.5" OME Lift
 
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