Home » Public Forums » GMCnet » Replacing the final drive
| Replacing the final drive [message #93801] |
Thu, 29 July 2010 10:41  |
 |
JShot
Messages: 485
Registered: October 2006
Location: NW Ohio
Karma: 0
|
Senior Member |
|
|
Does anybody have any tips and/or tricks regarding replacing the final drive (other than the supplied instructions)? Our new 3.55 setup just arrived, and before attempting this feat, thought I would ask anyone who has already done it.
Thanks,
John
John Shotwell
Ridgeville Corners, OH
78 Royale Center Kitchen
|
|
|
|
|
|
| Re: [GMCnet] Replacing the final drive [message #93815 is a reply to message #93801] |
Thu, 29 July 2010 11:21  |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
|
Senior Member |
|
|
It isn't that much of a job, just heavy. If you can manage it at all enlist
the help of someone agile to help. A floor jack will manage the job, but the
Diff is somewhat tippy on the pad. Jack up the coach high enough to get
under it and DO NOT EVEN THINK about getting under it until it is well
supported on stands or blocking that is rated well in excess of the load.
There is one bolt or nut and stud on the top of the diff that is a bit## to
get to, but buy an end wrench and heat and bend it so it will fit. Remove
the wheels and inner fenders. I find the easiest way to break the
jackshaft/inner cv joint bolts loose is with a long 3/8 extension so that
you can get straight away from the fasteners. I have seen shallow head allen
bolts, hex head bolts, 12 point washer headed cap screws used on these
joints, so look at them carefully and don't round them off or you will make
a simple job into a difficult one very quickly. After the jackshaft is out,
make sure that the transmission dipstick tube is also out. The diff to trans
gasket is sometimes glued on by well intentioned folks, and can be a bit of
a bother to remove. Get the transmission surface completely free of all
gasket material before placing the new one. I use alignment studs screwed
finger tight into two holes to help align the diff to the trans, but tapered
alignment punches work as well. If you get frustrated while working under
the coach, roll out from under there and relax a few (minutes, hours, days)
until your perspective improves. Always work with personal safety in mind,
you can get real hurt under there. Murphy is never very far away from a GMC
being worked on. My personal policy is that I save the BEER until the job is
well done, but that is a personal choice, I ain't your mother.
On Thu, Jul 29, 2010 at 8:41 AM, John Shotwell <jshot@rtecexpress.net>wrote:
>
>
> Does anybody have any tips and/or tricks regarding replacing the final
> drive (other than the supplied instructions)? Our new 3.55 setup just
> arrived, and before attempting this feat, thought I would ask anyone who has
> already done it.
>
> Thanks,
>
> John
> --
> John Shotwell
> Archbold, OH
> 78 Royale Center Kitchen
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
|
|
|
|
| Re: [GMCnet] Replacing the final drive [message #93828 is a reply to message #93815] |
Thu, 29 July 2010 12:27 |
gmcrv1
Messages: 839
Registered: August 2007
Location: Memphis
Karma: -1
|
Senior Member |
|
|
James,
I've not ventured that far under my GMC (relative newbie) but, I was
wondering if the bottom
of the final drive is flat enough to use an old fashioned scissor lift
powered transmission jack in lieu of a floor jack. It has a webbed seat
belt type strap allowing you to strap a transmission to the top of the
jack. It also pivots in two directions.
Inquiring minds...
Thanks,
Tom Eckert N2VWN
73 Glacier
Oakland, TN
On Thu, Jul 29, 2010 at 11:21 AM, James Hupy <jamesh1296@gmail.com> wrote:
> It isn't that much of a job, just heavy. If you can manage it at all enlist
> the help of someone agile to help. A floor jack will manage the job, but
> the
> Diff is somewhat tippy on the pad. Jack up the coach high enough to get
> under it and DO NOT EVEN THINK about getting under it until it is well
> supported on stands or blocking that is rated well in excess of the load.
> There is one bolt or nut and stud on the top of the diff that is a bit## to
> get to, but buy an end wrench and heat and bend it so it will fit. Remove
> the wheels and inner fenders. I find the easiest way to break the
> jackshaft/inner cv joint bolts loose is with a long 3/8 extension so that
> you can get straight away from the fasteners. I have seen shallow head
> allen
> bolts, hex head bolts, 12 point washer headed cap screws used on these
> joints, so look at them carefully and don't round them off or you will make
> a simple job into a difficult one very quickly. After the jackshaft is out,
> make sure that the transmission dipstick tube is also out. The diff to
> trans
> gasket is sometimes glued on by well intentioned folks, and can be a bit of
> a bother to remove. Get the transmission surface completely free of all
> gasket material before placing the new one. I use alignment studs screwed
> finger tight into two holes to help align the diff to the trans, but
> tapered
> alignment punches work as well. If you get frustrated while working under
> the coach, roll out from under there and relax a few (minutes, hours, days)
> until your perspective improves. Always work with personal safety in mind,
> you can get real hurt under there. Murphy is never very far away from a GMC
> being worked on. My personal policy is that I save the BEER until the job
> is
> well done, but that is a personal choice, I ain't your mother.
>
> On Thu, Jul 29, 2010 at 8:41 AM, John Shotwell <jshot@rtecexpress.net
> >wrote:
>
> >
> >
> > Does anybody have any tips and/or tricks regarding replacing the final
> > drive (other than the supplied instructions)? Our new 3.55 setup just
> > arrived, and before attempting this feat, thought I would ask anyone who
> has
> > already done it.
> >
> > Thanks,
> >
> > John
> > --
> > John Shotwell
> > Archbold, OH
> > 78 Royale Center Kitchen
> > _______________________________________________
> > GMCnet mailing list
> > List Information and Subscription Options:
> > http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
> >
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
|
|
|
|
| Re: [GMCnet] Replacing the final drive [message #93850 is a reply to message #93828] |
Thu, 29 July 2010 14:56 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
|
Senior Member |
|
|
Those jacks work well on a fairly flat bottom, and it you get the strap(s)
secure. they balance the load pretty well. I would estimate the final drive
to weigh 70-85 lbs. What they don't do well is rock the drive cw & ccw. That
is kinda the trick if there is one because the splines don't have much of a
chamfer on the lead edge that would help get the meshing started. What
sometimes helps is to remove the cover on the diff so you can rock the ring
gear back & forth. If you do this, be very careful with the gasket and the
top cover capscrew and shield for the vent hole. That vent hole & the maze
type gasket that is actually two gaskets stapled together is very important
to vent the diff case. Some of the gaskets I have seen do not have a hole
that matches the hole in the cover. If that is how yours is, after you have
installed the cover and before you put that shield on, take a small drill
bit that matches the hole in the cover and twirling it with your finger and
thumb, make sure there is a hole in the gasket that matches the one in the
cover, Don't overlook this step, if you do when the diff lube gets hot, it
will leak somewhere because the case is sealed except for that tiny vent
hole. These GMC's aren't very high tech but they are robust. That 3:50 will
make you think that you just added 75 HP to that Olds eng. If you get into
any problems, contact me off line at jamesh1296@gmail.com and I will guide
you through the process. Glad to help a fellow GMCer.
Jim Hupy
Salem, Or
78 Royale 403
On Thu, Jul 29, 2010 at 10:27 AM, Tom Eckert <gmcrv1@gmail.com> wrote:
> James,
>
> I've not ventured that far under my GMC (relative newbie) but, I was
> wondering if the bottom
> of the final drive is flat enough to use an old fashioned scissor lift
> powered transmission jack in lieu of a floor jack. It has a webbed seat
> belt type strap allowing you to strap a transmission to the top of the
> jack. It also pivots in two directions.
>
> Inquiring minds...
>
> Thanks,
>
> Tom Eckert N2VWN
> 73 Glacier
> Oakland, TN
>
> On Thu, Jul 29, 2010 at 11:21 AM, James Hupy <jamesh1296@gmail.com> wrote:
>
> > It isn't that much of a job, just heavy. If you can manage it at all
> enlist
> > the help of someone agile to help. A floor jack will manage the job, but
> > the
> > Diff is somewhat tippy on the pad. Jack up the coach high enough to get
> > under it and DO NOT EVEN THINK about getting under it until it is well
> > supported on stands or blocking that is rated well in excess of the load.
> > There is one bolt or nut and stud on the top of the diff that is a bit##
> to
> > get to, but buy an end wrench and heat and bend it so it will fit. Remove
> > the wheels and inner fenders. I find the easiest way to break the
> > jackshaft/inner cv joint bolts loose is with a long 3/8 extension so that
> > you can get straight away from the fasteners. I have seen shallow head
> > allen
> > bolts, hex head bolts, 12 point washer headed cap screws used on these
> > joints, so look at them carefully and don't round them off or you will
> make
> > a simple job into a difficult one very quickly. After the jackshaft is
> out,
> > make sure that the transmission dipstick tube is also out. The diff to
> > trans
> > gasket is sometimes glued on by well intentioned folks, and can be a bit
> of
> > a bother to remove. Get the transmission surface completely free of all
> > gasket material before placing the new one. I use alignment studs screwed
> > finger tight into two holes to help align the diff to the trans, but
> > tapered
> > alignment punches work as well. If you get frustrated while working under
> > the coach, roll out from under there and relax a few (minutes, hours,
> days)
> > until your perspective improves. Always work with personal safety in
> mind,
> > you can get real hurt under there. Murphy is never very far away from a
> GMC
> > being worked on. My personal policy is that I save the BEER until the job
> > is
> > well done, but that is a personal choice, I ain't your mother.
> >
> > On Thu, Jul 29, 2010 at 8:41 AM, John Shotwell <jshot@rtecexpress.net
> > >wrote:
> >
> > >
> > >
> > > Does anybody have any tips and/or tricks regarding replacing the final
> > > drive (other than the supplied instructions)? Our new 3.55 setup just
> > > arrived, and before attempting this feat, thought I would ask anyone
> who
> > has
> > > already done it.
> > >
> > > Thanks,
> > >
> > > John
> > > --
> > > John Shotwell
> > > Archbold, OH
> > > 78 Royale Center Kitchen
> > > _______________________________________________
> > > GMCnet mailing list
> > > List Information and Subscription Options:
> > > http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
> > >
> > _______________________________________________
> > GMCnet mailing list
> > List Information and Subscription Options:
> > http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
> >
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
|
|
|
|
| Re: [GMCnet] Replacing the final drive [message #93856 is a reply to message #93850] |
Thu, 29 July 2010 15:11 |
gmcrv1
Messages: 839
Registered: August 2007
Location: Memphis
Karma: -1
|
Senior Member |
|
|
Thanks Jim,
Yes the jack does work well on the older flat pan transmissions. Thanks
also on the vent tip. I hate not having the tools to do the job...
Not looking to do this anytime soon, just trying to get this coach on the
road.
Thanks Again,
Tom Eckert N2VWN
73 Glacier
Oakland, TN
On Thu, Jul 29, 2010 at 2:56 PM, James Hupy <jamesh1296@gmail.com> wrote:
> Those jacks work well on a fairly flat bottom, and it you get the strap(s)
> secure. they balance the load pretty well. I would estimate the final drive
> to weigh 70-85 lbs. What they don't do well is rock the drive cw & ccw.
> That
> is kinda the trick if there is one because the splines don't have much of a
> chamfer on the lead edge that would help get the meshing started. What
> sometimes helps is to remove the cover on the diff so you can rock the ring
> gear back & forth. If you do this, be very careful with the gasket and the
> top cover capscrew and shield for the vent hole. That vent hole & the maze
> type gasket that is actually two gaskets stapled together is very important
> to vent the diff case. Some of the gaskets I have seen do not have a hole
> that matches the hole in the cover. If that is how yours is, after you have
> installed the cover and before you put that shield on, take a small drill
> bit that matches the hole in the cover and twirling it with your finger and
> thumb, make sure there is a hole in the gasket that matches the one in the
> cover, Don't overlook this step, if you do when the diff lube gets hot, it
> will leak somewhere because the case is sealed except for that tiny vent
> hole. These GMC's aren't very high tech but they are robust. That 3:50 will
> make you think that you just added 75 HP to that Olds eng. If you get into
> any problems, contact me off line at jamesh1296@gmail.com and I will guide
> you through the process. Glad to help a fellow GMCer.
> Jim Hupy
> Salem, Or
> 78 Royale 403
>
> On Thu, Jul 29, 2010 at 10:27 AM, Tom Eckert <gmcrv1@gmail.com> wrote:
>
> > James,
> >
> > I've not ventured that far under my GMC (relative newbie) but, I was
> > wondering if the bottom
> > of the final drive is flat enough to use an old fashioned scissor lift
> > powered transmission jack in lieu of a floor jack. It has a webbed seat
> > belt type strap allowing you to strap a transmission to the top of the
> > jack. It also pivots in two directions.
> >
> > Inquiring minds...
> >
> > Thanks,
> >
> > Tom Eckert N2VWN
> > 73 Glacier
> > Oakland, TN
> >
> > On Thu, Jul 29, 2010 at 11:21 AM, James Hupy <jamesh1296@gmail.com>
> wrote:
> >
> > > It isn't that much of a job, just heavy. If you can manage it at all
> > enlist
> > > the help of someone agile to help. A floor jack will manage the job,
> but
> > > the
> > > Diff is somewhat tippy on the pad. Jack up the coach high enough to get
> > > under it and DO NOT EVEN THINK about getting under it until it is well
> > > supported on stands or blocking that is rated well in excess of the
> load.
> > > There is one bolt or nut and stud on the top of the diff that is a
> bit##
> > to
> > > get to, but buy an end wrench and heat and bend it so it will fit.
> Remove
> > > the wheels and inner fenders. I find the easiest way to break the
> > > jackshaft/inner cv joint bolts loose is with a long 3/8 extension so
> that
> > > you can get straight away from the fasteners. I have seen shallow head
> > > allen
> > > bolts, hex head bolts, 12 point washer headed cap screws used on these
> > > joints, so look at them carefully and don't round them off or you will
> > make
> > > a simple job into a difficult one very quickly. After the jackshaft is
> > out,
> > > make sure that the transmission dipstick tube is also out. The diff to
> > > trans
> > > gasket is sometimes glued on by well intentioned folks, and can be a
> bit
> > of
> > > a bother to remove. Get the transmission surface completely free of all
> > > gasket material before placing the new one. I use alignment studs
> screwed
> > > finger tight into two holes to help align the diff to the trans, but
> > > tapered
> > > alignment punches work as well. If you get frustrated while working
> under
> > > the coach, roll out from under there and relax a few (minutes, hours,
> > days)
> > > until your perspective improves. Always work with personal safety in
> > mind,
> > > you can get real hurt under there. Murphy is never very far away from a
> > GMC
> > > being worked on. My personal policy is that I save the BEER until the
> job
> > > is
> > > well done, but that is a personal choice, I ain't your mother.
> > >
> > > On Thu, Jul 29, 2010 at 8:41 AM, John Shotwell <jshot@rtecexpress.net
> > > >wrote:
> > >
> > > >
> > > >
> > > > Does anybody have any tips and/or tricks regarding replacing the
> final
> > > > drive (other than the supplied instructions)? Our new 3.55 setup just
> > > > arrived, and before attempting this feat, thought I would ask anyone
> > who
> > > has
> > > > already done it.
> > > >
> > > > Thanks,
> > > >
> > > > John
> > > > --
> > > > John Shotwell
> > > > Archbold, OH
> > > > 78 Royale Center Kitchen
> > > > _______________________________________________
> > > > GMCnet mailing list
> > > > List Information and Subscription Options:
> > > > http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
> > > >
> > > _______________________________________________
> > > GMCnet mailing list
> > > List Information and Subscription Options:
> > > http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
> > >
> > _______________________________________________
> > GMCnet mailing list
> > List Information and Subscription Options:
> > http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
> >
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
|
|
|
|
Goto Forum:
Current Time: Wed Sep 25 14:31:46 CDT 2024
Total time taken to generate the page: 0.04596 seconds
|
GMCforum
Search
Help
Register
Login
Home
