Home » Public Forums » GMCnet » Jacking up the coach (Is there a right and wrong way to change a wheel?)
Jacking up the coach [message #360917] |
Fri, 18 December 2020 02:52 |
boybach
Messages: 566 Registered: December 2020 Location: Vancouver Island
Karma: 4
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Just watched a Jim Bounds video where he checked the rear suspension on a coach in his shop.
When he was jacking up the rear, he mentioned that you have to jack the rear first and then the front because if you jack up the front first you can "pop" a windshield (I'm guessing he was talking about putting her up on jackstands?)
So my question is, can you jack up the front without jacking up the rear, say, if you had a flat up front and needed to put the spare wheel on? Can you do that without cracking the windshield?
Just yesterday I had an enlightening conversation with Colin (CEdey), who told me you always jack the coach up from the center and I can see that making sense ...just not clear what Jim was referring to unless he meant getting the whole coach up on stands?
I might have to change the tires and/or wheels and just need to know the routine in case the tire place doesn't!
Oh and does the coach come with a jack? Where is it usually stored? I asked the previous owner's brother and even though he drove the coach about 12,000 miles - he didn't know
Larry
Larry - Victoria BC -
1977 ex-Palm Beach "Ol' Leaky" 40,000 miles, PO said everything working but forgot the word NOT. Atwood helium fridge, water heater & furnace. SS exhaust system, Onan, Iota Converter, R134A, New fuel lines & heat exchange hoses
[Updated on: Fri, 18 December 2020 02:53] Report message to a moderator
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Re: [GMCnet] Jacking up the coach [message #360918 is a reply to message #360917] |
Fri, 18 December 2020 03:03 |
Olly Schmidt
Messages: 1265 Registered: February 2014 Location: Germany and Scottsville, ...
Karma: 8
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On 18.12.20 09:52, twlldeen--- via Gmclist wrote:
> can you jack up the front without jacking up the rear
I've been jacking up my 23' from front center quite often, to reach
under for oil change or other stuff. So far, no problems (keeping my
fingers crossed)
--
Best regards
Olly Schmidt
PGP KeyID: 0x4196BF22
'76a 26' Eleganza II - Virginia, US
'73 23' Sequoia - Schleswig-Holstein, Germany
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Best regards
Olly Schmidt
PGP Key ID: 0x18a9 3a1f 4196 bf22
'76a Eleganza II, VA
'73 Sequoia, SH, Germany
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Re: Jacking up the coach [message #360921 is a reply to message #360917] |
Fri, 18 December 2020 05:55 |
Ken Burton
Messages: 10030 Registered: January 2004 Location: Hebron, Indiana
Karma: 10
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The problem with braking a windshield is jacking the coach causing too much stress on one front side vs. the other. If I want to only change a tire, I jack up that wheel to be changed under the A-frame / ball joint for that side. You only go up an inch or two to get the tire off. The front torsion bar (spring)take most of the lift and does not raise the frame of the coach. It is no different from driving over on a 2 inch rock, or a small hole in the pavement. If I want both sides up at the same time then I jack it in the middle.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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Re: Jacking up the coach [message #360933 is a reply to message #360917] |
Fri, 18 December 2020 10:50 |
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Matt Colie
Messages: 8547 Registered: March 2007 Location: S.E. Michigan
Karma: 7
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Larry,
In very simple terms, don't jack the coach with either end restrained.
So, if you need to jack the front, jack how you like, but leave the rear on its suspension. To change one front tire, you can jack under the ball joint and this is good because the rest of the coach can balance itself. If you jack under the center of the engine cross member, then the rear can still float.
If you need to do something in the rear, jack under the bogie casting (even better if you have the piece of steel to stop the arm travel) and as soon as you have load on the jack, let the air off or you can blow out the shocks.
I suggest that if you need to jack the whole coach that you raise the rear onto stands or cribbing under the bogie casting and then jack the front in the
center.
If you need to lift the rear all at once, you can do it with an 8' (2.5m) 4X6 (100x150mm) wooden beam at the all the way rear cross member. This works because you are lifting only a portion of the coach weight.
Do not ever have either end on two jack stands or cribbing a then try to jack one side of the other end, that is how to break things.
And a final note: Never put anything you value under the rear of a GMC that is not solidly blocked. Suspension failures can happen at any time, when it does fail, the rear can crush a snake.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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Re: Jacking up the coach [message #360934 is a reply to message #360917] |
Fri, 18 December 2020 11:22 |
boybach
Messages: 566 Registered: December 2020 Location: Vancouver Island
Karma: 4
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Thanks lads! all great info as usual!
Now I have to find out if she has a wheel nut spider on board ...let me tell you, buying something sight unseen 300 miles away in the middle of a Canadian winter and dealing with a storage yard that only opens on the weekend a 30 min drive away from my contact's place who has neither a camera or cel phone ... not for the faint of heart!
Oh and someone in the bringing the coach home thread mentioned having an emergency 4 x 4 and a couple of lagadags to use in an emergency if you get caught out with a blown airbag - so I can get that in my toolkit before I go up to get her, what length 4 x 4 and what size lag bolts would be good?
Oh and one more thing - bottle jack capacity/size?
Thanks again
Larry
Larry - Victoria BC -
1977 ex-Palm Beach "Ol' Leaky" 40,000 miles, PO said everything working but forgot the word NOT. Atwood helium fridge, water heater & furnace. SS exhaust system, Onan, Iota Converter, R134A, New fuel lines & heat exchange hoses
[Updated on: Fri, 18 December 2020 11:28] Report message to a moderator
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Re: [GMCnet] Jacking up the coach [message #360935 is a reply to message #360934] |
Fri, 18 December 2020 11:44 |
Rob
Messages: 651 Registered: November 2013 Location: Victoria, BC
Karma: 3
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The wheel lugs (especially for steelies) can be VERY tight. I'd recommend having a somewhat long breaker bar with you. And maybe a pipe to go with that!
I think I carry a 25" breaker bar with me when I'm on the road.
Rob
76 Royale Twin Beds, Dry Bath
Victoria, BC
> On Dec 18, 2020, at 9:22 AM, twlldeen--- via Gmclist wrote:
>
> Thanks lads! all great info as usual!
>
> Now I have to find out if she has a wheel nut spider on board ...let me tell you, buying something sight unseen 300 miles away in the middle of a
> Canadian winter and dealing with a storage yard that only opens on the weekend a 30 min drive away from my contact's place who has neither a camera or
> cel phone ... not for the faint of heart! :? :evil:
>
> Oh and someone in the bringing the coach home thread mentioned having an emergency 4 x 4 and a couple of lagadags to use in an emergency if you get
> caught out with a blown airbag - so I can get that in my toolkit before I go up to get her, what length 4 x 4 and what size lag bolts would be good?
>
> Thanks again
>
> Larry
>
>
> --
> Larry - Victoria BC -
>
> 1977 Palm Beach - 39,000 original miles so far
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Rob -
Victoria, BC -
76 Royale - Rear Twins/Dry Bath
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Re: Jacking up the coach [message #360940 is a reply to message #360934] |
Fri, 18 December 2020 16:32 |
CEdey
Messages: 10 Registered: February 2016 Location: Sidney BC
Karma: 1
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Larry, no worries. I have a 'dog bone' as temporary airbag replacement should the coach loose an airbag and original long wheel wrench. You are welcome to borrow when off to collect your coach. I'm sure I have other items you may wish to take along for your return.
Colin Edey
1978 Royale 'Rusty'
Manny Power Drive Transmission
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Re: Jacking up the coach [message #360947 is a reply to message #360940] |
Fri, 18 December 2020 18:39 |
boybach
Messages: 566 Registered: December 2020 Location: Vancouver Island
Karma: 4
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Hey thanks Colin! I will definitely take you up on that offer! What's a dog-bone BTW?
Found a place to keep her parked today, a pal in the highlands has a reasonably flat area and I might invest in a ton or two of gravel to surface her new berth.
Hoped for something closer to town, but at least it's sort of on the way Up-Island or out to Renfrew, so all good!
Larry - Victoria BC -
1977 ex-Palm Beach "Ol' Leaky" 40,000 miles, PO said everything working but forgot the word NOT. Atwood helium fridge, water heater & furnace. SS exhaust system, Onan, Iota Converter, R134A, New fuel lines & heat exchange hoses
[Updated on: Fri, 18 December 2020 18:46] Report message to a moderator
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Re: [GMCnet] Jacking up the coach [message #360948 is a reply to message #360935] |
Fri, 18 December 2020 18:45 |
boybach
Messages: 566 Registered: December 2020 Location: Vancouver Island
Karma: 4
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Hey Rob, I have a long 1/2" drive bar, but sounds like I should upgrade to a 3/4" drive AND a pipe too, no use struggling!
Too bad the Flea Markets are kaput this year, was a good place to score RV stuff (when I didn't need any)
Sounds like I'm going to ditch all my metric sockets and wrenches and start picking up SAE stuff right away!
all the best Rob
Larry
Larry - Victoria BC -
1977 ex-Palm Beach "Ol' Leaky" 40,000 miles, PO said everything working but forgot the word NOT. Atwood helium fridge, water heater & furnace. SS exhaust system, Onan, Iota Converter, R134A, New fuel lines & heat exchange hoses
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Re: Jacking up the coach [message #360961 is a reply to message #360933] |
Sat, 19 December 2020 01:22 |
boybach
Messages: 566 Registered: December 2020 Location: Vancouver Island
Karma: 4
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Matt Colie wrote on Fri, 18 December 2020 08:50
If you need to do something in the rear, jack under the bogie casting (even better if you have the piece of steel to stop the arm travel) and as soon as you have load on the jack, let the air off or you can blow out the shocks.
Matt
So Matt, being new to the whole air-bag system, I'm guessing there's a schraeder on the bag or in the line that I use to leach off the air before doing the full lift? Have to let the air off because if I leave the bag pressurized the shocks will over extend and pull apart?
Trying to visualize what would happen and having a bit of trouble getting it clear - sorry if I'm being a bit thick!
Larry
Larry - Victoria BC -
1977 ex-Palm Beach "Ol' Leaky" 40,000 miles, PO said everything working but forgot the word NOT. Atwood helium fridge, water heater & furnace. SS exhaust system, Onan, Iota Converter, R134A, New fuel lines & heat exchange hoses
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Re: Jacking up the coach [message #360966 is a reply to message #360961] |
Sat, 19 December 2020 07:19 |
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Matt Colie
Messages: 8547 Registered: March 2007 Location: S.E. Michigan
Karma: 7
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boybach wrote on Sat, 19 December 2020 02:22Matt Colie wrote on Fri, 18 December 2020 08:50 If you need to do something in the rear, jack under the bogie casting (even better if you have the piece of steel to stop the arm travel) and as soon as you have load on the jack, let the air off or you can blow out the shocks.
Matt
So Matt, being new to the whole air-bag system, I'm guessing there's a schraeder on the bag or in the line that I use to leach off the air before doing the full lift? Have to let the air off because if I leave the bag pressurized the shocks will over extend and pull apart?
Trying to visualize what would happen and having a bit of trouble getting it clear - sorry if I'm being a bit thick!
Larry
Larry,
I don't have any of that stuff. I just go up to the cab and set that side to "Lower". That vents the side airspring to the cab.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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Re: [GMCnet] Jacking up the coach [message #360976 is a reply to message #360966] |
Sat, 19 December 2020 11:49 |
sgltrac
Messages: 2797 Registered: April 2011
Karma: 1
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Or loosen the air line nut at the bag.
Sully
Bellevue wa
On Sat, Dec 19, 2020 at 5:20 AM Matt Colie via Gmclist <
gmclist@list.gmcnet.org> wrote:
> boybach wrote on Sat, 19 December 2020 02:22
>> Matt Colie wrote on Fri, 18 December 2020 08:50
>>> If you need to do something in the rear, jack under the bogie casting
> (even better if you have the piece of steel to stop the arm travel) and
>>> as soon as you have load on the jack, let the air off or you can blow
> out the shocks.
>>> Matt
>>
>> So Matt, being new to the whole air-bag system, I'm guessing there's a
> schraeder on the bag or in the line that I use to leach off the air before
>> doing the full lift? Have to let the air off because if I leave the bag
> pressurized the shocks will over extend and pull apart?
>>
>> Trying to visualize what would happen and having a bit of trouble
> getting it clear - sorry if I'm being a bit thick!
>>
>> Larry
>
> Larry,
>
> I don't have any of that stuff. I just go up to the cab and set that side
> to "Lower". That vents the side airspring to the cab.
>
> Matt
> --
> Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL,
> GMCES
> Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum
> Brakes with Applied Control Arms
> SE Michigan - Near DTW - Twixt A2 and Detroit
>
> _______________________________________________
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> Unsubscribe or Change List Options:
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Sully
77 Royale basket case.
Future motorhome land speed record holder(bucket list)
Seattle, Wa.
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Re: [GMCnet] Jacking up the coach [message #360987 is a reply to message #360976] |
Sat, 19 December 2020 18:21 |
Ken Burton
Messages: 10030 Registered: January 2004 Location: Hebron, Indiana
Karma: 10
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sgltrac wrote on Sat, 19 December 2020 11:49Or loosen the air line nut at the bag.
Sully
Bellevue wa
That is what I do. 9/16" open end
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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Re: Jacking up the coach [message #360990 is a reply to message #360917] |
Sat, 19 December 2020 20:18 |
boybach
Messages: 566 Registered: December 2020 Location: Vancouver Island
Karma: 4
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So why do the shocks break if you don't let out the air one way or another?
Larry
Larry - Victoria BC -
1977 ex-Palm Beach "Ol' Leaky" 40,000 miles, PO said everything working but forgot the word NOT. Atwood helium fridge, water heater & furnace. SS exhaust system, Onan, Iota Converter, R134A, New fuel lines & heat exchange hoses
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Re: [GMCnet] Jacking up the coach [message #360991 is a reply to message #360990] |
Sat, 19 December 2020 20:35 |
James Hupy
Messages: 6806 Registered: May 2010
Karma: -62
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They do not all break. The Bilsteins are the most prone to breakage. The
KYB's are physically stronger, and they rarely break but they do
hyperextend and the results are a failure of the seals, a subsequent loss
of the gasses they are filled with, and sometimes fluid as well. What
lowering the air pressure does is to prevent or lessen the effects of
hyperextension. The addition of a short piece of leaf spring between the
bogie box and bogie arm before you jack the coach is all that is needed,
usually.
Jim Hupy
Salem, Oregon
On Sat, Dec 19, 2020, 6:19 PM twlldeen--- via Gmclist <
gmclist@list.gmcnet.org> wrote:
> So why do the shocks break if you don't let out the air one way or another?
>
> Larry
> --
> Larry - Victoria BC -
>
> 1977 Palm Beach - 39,000 original miles so far
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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