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[GMCnet] GMC Track Width [message #318132] Mon, 29 May 2017 10:18 Go to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
G'day,

On GMCMotorhome.com I found the dimensions below:

Track
Front: 75.28 in.
Rear: 85.12 in.

According to convention track is measured in the center of the tire, which
would result in the following measurements at the outside of the treads for
a LT225/75-16R (8.9 in tread width):

Track
Front: 84.18 in.
Rear: 91.02 in.

I'm on crutches and can't drive due to having my right knee replaced three
weeks ago so it is very difficult for me to get to my workshop to check
these numbers, can anybody check them for me.

The reason I'm asking is I'm investigating buying a lift to raise the GMC so
I can park cars under it in my workshop.

Regards,
Rob M.
The Pedantic Mechanic
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808




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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] GMC Track Width [message #318133 is a reply to message #318132] Mon, 29 May 2017 10:23 Go to previous messageGo to next message
James Hupy is currently offline  James Hupy   United States
Messages: 6806
Registered: May 2010
Karma: -62
Senior Member
Rob, back is wider than front. Due to combinations of front end spacers, 1
ton conversions, 16.5 vs 16 steelies, alcoa's, and other alloy wheels. If
you go with rear width, add a couple inches, you should be good.
Jim Hupy

On May 29, 2017 8:19 AM, "Rob Mueller" wrote:

G'day,

On GMCMotorhome.com I found the dimensions below:

Track
Front: 75.28 in.
Rear: 85.12 in.

According to convention track is measured in the center of the tire, which
would result in the following measurements at the outside of the treads for
a LT225/75-16R (8.9 in tread width):

Track
Front: 84.18 in.
Rear: 91.02 in.

I'm on crutches and can't drive due to having my right knee replaced three
weeks ago so it is very difficult for me to get to my workshop to check
these numbers, can anybody check them for me.

The reason I'm asking is I'm investigating buying a lift to raise the GMC so
I can park cars under it in my workshop.

Regards,
Rob M.
The Pedantic Mechanic
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808




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Re: [GMCnet] GMC Track Width [message #318140 is a reply to message #318132] Mon, 29 May 2017 11:43 Go to previous messageGo to next message
k2gkk is currently offline  k2gkk   United States
Messages: 4452
Registered: November 2009
Karma: -8
Senior Member
Rob, I believe you have miscalculated the rear tire width for the lift. You have to add one full tire width to the track to get the total width. Adding 8.9 to the 75.28 DOES result in the 84.18 you came up with for the front, but adding the 8.9 to the 85.12 would result in 94.02 inches for the rear tire width which is just a bit inside the 96" total coach width claimed (and allowed) when the coach was built.

These would be the absolute minimum to get the rear wheels totally on the lift treads/tracks. Subtract the 8.9 inches from standard front track to get the spacing between the insides of the lift treads/tracks so as ensure that all wheels will completely fit onto the lift. Needless to say that the lift treads/tracks should probably be an inch or so wider in each direction to allow some leeway when driving the coach onto that lift. I suggest that the tread/track widths be specified to be at least 4 inches wider than that of the tires to make loading the vehicle much less critical.

Nice to have the vertical space to even be able to conceive of such a capability!

Cheers!

~~ ~ D C "Mac" Macdonald ~ ~~
~ ~ USAF and FAA, Retired ~ ~
~ Member GMCMI and Classics ~
~ ~ ~ Oklahoma City, OK ~ ~ ~
~~ ~ ~ "The Money Pit" ~ ~ ~~
~ ~ ~ '76 ex-Palm Beach ~ ~ ~
~~ k2gkk + hotmail dot com ~~
______________
|[ ]~~~[][ ][]\
"--OO--[]---O-"
"--OO--[]---O-"
________________________________
From: Gmclist on behalf of James Hupy
Sent: Monday, May 29, 2017 10:23
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] GMC Track Width

Rob, back is wider than front. Due to combinations of front end spacers, 1
ton conversions, 16.5 vs 16 steelies, ALCOAs, and other alloy wheels. If
you go with rear width, add a couple inches, you should be good.
Jim Hupy

On May 29, 2017 8:19 AM, "Rob Mueller" wrote:

G'day,

On GMCMotorhome.com I found the dimensions below:

Track
Front: 75.28 in.
Rear: 85.12 in.

According to convention track is measured in the center of the tire, which
would result in the following measurements at the outside of the treads for
a LT225/75-16R (8.9 in tread width):

Track
Front: 84.18 in.
Rear: 91.02 in.

I'm on crutches and can't drive due to having my right knee replaced three
weeks ago so it is very difficult for me to get to my workshop to check
these numbers, can anybody check them for me.

The reason I'm asking is I'm investigating buying a lift to raise the GMC so
I can park cars under it in my workshop.

Regards,
Rob M.
The Pedantic Mechanic
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Re: [GMCnet] GMC Track Width [message #318154 is a reply to message #318132] Mon, 29 May 2017 15:00 Go to previous messageGo to next message
SpookyEng is currently offline  SpookyEng   United States
Messages: 208
Registered: June 2016
Location: Navarre, FL
Karma: -5
Senior Member
Maybe those that have lifts already can suggest some models that are proven to work?

JD Lisenby- USAF Ret 1978 Royale-455 MacDash, Manny Tranny, FI-tech, 3.70 etc etc Navarre, FL
Re: [GMCnet] GMC Track Width [message #318157 is a reply to message #318132] Mon, 29 May 2017 15:43 Go to previous messageGo to next message
Bullitthead is currently offline  Bullitthead   United States
Messages: 1411
Registered: November 2013
Karma: 5
Senior Member
This is a Bend Pak BP-12 12000 lb. circa 1998
Just got it set up the other day, still need to bolt remaining posts down and connect the air system back up. The runways are set at max width, outside to outside is 94 inches. They are 20 inches wide, so there is 54 inches of space between them. The diamond plate covering is 16 feet long, the runway is actually 17 feet long and the forward stops allow the centerline of the front wheels to be almost plumb over the forward lifting crossbar. The GMC fits with about 2 inches left over outside each side of the rear wheels, but the entrance ramps catch the tire and do not flip all the way down due to the wheelbase. It's still not sitting on the entrance ramp so it's plenty safe. I had measured the total track width of mine before when comparing lifts, and remember the tire outsides to be 89 inches at the rear. Seems the math is close enough. The right side runway is adjustable so it can be used for anything less than 94 inch track width. You don't see the other posts in this pic, but they are not a problem regarding the width of the vehicle. What is important and missing from this pic is the cylinder bar that spans the front and back posts on one side(the driver side for me). For a left hand door GMC, you should put the entrance ramps on the other end, so the door is on the opposite side of that bar, like it is for me. They make the lift with the cylinder inside the runway now, eliminating that bar, and the lift uses cables instead of chains. There is one to fit the GMC in the 14000 lb. class, think it was 4100 or 4500 dollars.

http://www.gmcmhphotos.com/photos/nocat-pics/p63222-test-fit.html


Terry Kelpien ASE Master Technician 73 Glacier 260 Smithfield, Va.

[Updated on: Mon, 29 May 2017 15:45]

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Re: [GMCnet] GMC Track Width [message #318175 is a reply to message #318133] Mon, 29 May 2017 19:34 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Jim,

Unfortunately there aren't any lifts available in Australia as you describe.

Regards,
Rob M.
The Pedantic Mechanic
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808


-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of James
Hupy
Sent: Tuesday, May 30, 2017 1:23 AM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] GMC Track Width

Rob, back is wider than front. Due to combinations of front end spacers, 1
ton conversions, 16.5 vs 16 steelies, alcoa's, and other alloy wheels. If
you go with rear width, add a couple inches, you should be good.
Jim Hupy



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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] GMC Track Width [message #318178 is a reply to message #318175] Mon, 29 May 2017 19:59 Go to previous messageGo to next message
James Hupy is currently offline  James Hupy   United States
Messages: 6806
Registered: May 2010
Karma: -62
Senior Member
Rob, look under Ranger/Australia I think they have something that will do
what you want. Bend Pak also.
Jim Hupy

On May 29, 2017 5:35 PM, "Rob Mueller" wrote:

> Jim,
>
> Unfortunately there aren't any lifts available in Australia as you
> describe.
>
> Regards,
> Rob M.
> The Pedantic Mechanic
> USAussie - Downunder
> AUS '75 Avion - The Blue Streak TZE365V100428
> USA '75 Avion - Double Trouble TZE365V100426
> USA '77 Kingsley - TZE 267V100808
>
>
> -----Original Message-----
> From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of James
> Hupy
> Sent: Tuesday, May 30, 2017 1:23 AM
> To: gmclist@list.gmcnet.org
> Subject: Re: [GMCnet] GMC Track Width
>
> Rob, back is wider than front. Due to combinations of front end spacers, 1
> ton conversions, 16.5 vs 16 steelies, alcoa's, and other alloy wheels. If
> you go with rear width, add a couple inches, you should be good.
> Jim Hupy
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
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Re: [GMCnet] GMC Track Width [message #318185 is a reply to message #318140] Mon, 29 May 2017 20:22 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
G'day,

Thanks to all that commented, below you will find detailed research I did on
this before I asked the question.

Here’s a link to Wikipedia’s definition of track measurement.

https://en.wikipedia.org/wiki/Axle_track

As you can see the track is measured from center to center of the tire
width.

http://www.gmcmotorhome.com/faq/dimensions.html

As you can see the dimensions stated are:

Track
Front: 75.28 in.
Rear: 85.12 in.

The question is how were these measurements taken?

A) From the INSIDE of the tread to the INSIDE of the tread?
B) From the CENTER of the tread to the CENTER of the tread?
C) From the OUTSIDE of the tread to the OUTSIDE of the tread?

Here's a link to the Tire Racks notes on tread width:

https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=194#treadwidth

Here's a link to the specs on specs on a LT 225/75-16R tire:

https://tiresize.com/tiresizes/225-75R16.htm

That's where I screwed up! The width of the tire is 8.9 inches NOT the tread
width!

Here's a link to the tires I have on The Blue Streak:

https://tiresize.com/tires/Nexen/Roadian-AT-Pro-RA8-225-75R16.htm

Unfortunately it does not provide the tread width only the width.

Bottom line: I'm heading down to my workshop and measure the Roadian AT
tires as installed on The Blue Streak.

Regards,
Rob M.
The Pedantic Mechanic
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808

________________________________________
From: D C _Mac_ Macdonald [mailto:k2gkk@hotmail.com]
Sent: Tuesday, May 30, 2017 2:44 AM
To: GMC Mail List; GMC Mueller, Rob
Subject: Re: [GMCnet] GMC Track Width

Rob, I believe you have miscalculated the rear tire width for the lift.  You
have to add one full tire width to the track to get the total width.  Adding
8.9 to the 75.28 DOES result in the 84.18 you came up with for the front,
but adding the 8.9 to the 85.12 would result in 94.02 inches for the rear
tire width which is just a bit inside the 96" total coach width claimed (and
allowed) when the coach was built.

These would be the absolute minimum to get the rear wheels totally on the
lift treads/tracks.  Subtract the 8.9 inches from standard front track to
get the spacing between the insides of the lift treads/tracks so as ensure
that all wheels will completely fit onto the lift.  Needless to say that the
lift treads/tracks should probably be an inch or so wider in each direction
to allow some leeway when driving the coach onto that lift.  I suggest that
the tread/track widths be specified to be at least 4 inches wider than that
of the tires to make loading the vehicle much less critical.

Nice to have the vertical space to even be able to conceive of such a
capability!

Cheers!
  
~~ ~ D C "Mac" Macdonald ~ ~~
~ ~ USAF and FAA, Retired ~ ~
~ Member GMCMI and Classics ~
~ ~ ~ Oklahoma City, OK ~ ~ ~
~~ ~ ~ "The Money Pit" ~ ~ ~~
~ ~ ~ '76 ex-Palm Beach ~ ~ ~
~~ k2gkk + hotmail dot com ~~
______________
|[ ]~~~[][ ][]\
"--OO--[]---O-" 
________________________________________
From: Gmclist on behalf of James Hupy

Sent: Monday, May 29, 2017 10:23
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] GMC Track Width
 
Rob, back is wider than front. Due to combinations of front end spacers, 1
ton conversions, 16.5 vs 16 steelies, ALCOAs, and other alloy wheels. If
you go with rear width, add a couple inches, you should be good.
Jim Hupy

On May 29, 2017 8:19 AM, "Rob Mueller" wrote:

G'day,

On GMCMotorhome.com I found the dimensions below:

Track
Front: 75.28 in.
Rear: 85.12 in.

According to convention track is measured in the center of the tire, which
would result in the following measurements at the outside of the treads for
a LT225/75-16R (8.9 in tread width):

Track
Front: 84.18 in.
Rear: 91.02 in.

I'm on crutches and can't drive due to having my right knee replaced three
weeks ago so it is very difficult for me to get to my workshop to check
these numbers, can anybody check them for me.

The reason I'm asking is I'm investigating buying a lift to raise the GMC so
I can park cars under it in my workshop.

Regards,
Rob M.
The Pedantic Mechanic



_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org



Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] GMC Track Width [message #318186 is a reply to message #318185] Mon, 29 May 2017 20:35 Go to previous messageGo to next message
k2gkk is currently offline  k2gkk   United States
Messages: 4452
Registered: November 2009
Karma: -8
Senior Member
Accurate measurement of tread could be done from left side of left tire to left side of right tire OR right side of left side of right tire.

Mac in OKC, OK

Sent from my iPhone

On May 29, 2017, at 20:23, Rob Mueller wrote:

G'day,

Thanks to all that commented, below you will find detailed research I did on
this before I asked the question.

Here's a link to Wikipedia's definition of track measurement.

https://en.wikipedia.org/wiki/Axle_track

As you can see the track is measured from center to center of the tire
width.

http://www.gmcmotorhome.com/faq/dimensions.html

As you can see the dimensions stated are:

Track
Front: 75.28 in.
Rear: 85.12 in.

The question is how were these measurements taken?

A) From the INSIDE of the tread to the INSIDE of the tread?
B) From the CENTER of the tread to the CENTER of the tread?
C) From the OUTSIDE of the tread to the OUTSIDE of the tread?

Here's a link to the Tire Racks notes on tread width:

https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=194#treadwidth

Here's a link to the specs on specs on a LT 225/75-16R tire:

https://tiresize.com/tiresizes/225-75R16.htm

That's where I screwed up! The width of the tire is 8.9 inches NOT the tread
width!

Here's a link to the tires I have on The Blue Streak:

https://tiresize.com/tires/Nexen/Roadian-AT-Pro-RA8-225-75R16.htm

Unfortunately it does not provide the tread width only the width.

Bottom line: I'm heading down to my workshop and measure the Roadian AT
tires as installed on The Blue Streak.

Regards,
Rob M.
The Pedantic Mechanic
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808

________________________________________
From: D C _Mac_ Macdonald [mailto:k2gkk@hotmail.com]
Sent: Tuesday, May 30, 2017 2:44 AM
To: GMC Mail List; GMC Mueller, Rob
Subject: Re: [GMCnet] GMC Track Width

Rob, I believe you have miscalculated the rear tire width for the lift. You
have to add one full tire width to the track to get the total width. Adding
8.9 to the 75.28 DOES result in the 84.18 you came up with for the front,
but adding the 8.9 to the 85.12 would result in 94.02 inches for the rear
tire width which is just a bit inside the 96" total coach width claimed (and
allowed) when the coach was built.

These would be the absolute minimum to get the rear wheels totally on the
lift treads/tracks. Subtract the 8.9 inches from standard front track to
get the spacing between the insides of the lift treads/tracks so as ensure
that all wheels will completely fit onto the lift. Needless to say that the
lift treads/tracks should probably be an inch or so wider in each direction
to allow some leeway when driving the coach onto that lift. I suggest that
the tread/track widths be specified to be at least 4 inches wider than that
of the tires to make loading the vehicle much less critical.

Nice to have the vertical space to even be able to conceive of such a
capability!

Cheers!

~~ ~ D C "Mac" Macdonald ~ ~~
~ ~ USAF and FAA, Retired ~ ~
~ Member GMCMI and Classics ~
~ ~ ~ Oklahoma City, OK ~ ~ ~
~~ ~ ~ "The Money Pit" ~ ~ ~~
~ ~ ~ '76 ex-Palm Beach ~ ~ ~
~~ k2gkk + hotmail dot com ~~
______________
|[ ]~~~[][ ][]\
"--OO--[]---O-"
________________________________________
From: Gmclist on behalf of James Hupy

Sent: Monday, May 29, 2017 10:23
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] GMC Track Width

Rob, back is wider than front. Due to combinations of front end spacers, 1
ton conversions, 16.5 vs 16 steelies, ALCOAs, and other alloy wheels. If
you go with rear width, add a couple inches, you should be good.
Jim Hupy

On May 29, 2017 8:19 AM, "Rob Mueller" wrote:

G'day,

On GMCMotorhome.com I found the dimensions below:

Track
Front: 75.28 in.
Rear: 85.12 in.

According to convention track is measured in the center of the tire, which
would result in the following measurements at the outside of the treads for
a LT225/75-16R (8.9 in tread width):

Track
Front: 84.18 in.
Rear: 91.02 in.

I'm on crutches and can't drive due to having my right knee replaced three
weeks ago so it is very difficult for me to get to my workshop to check
these numbers, can anybody check them for me.

The reason I'm asking is I'm investigating buying a lift to raise the GMC so
I can park cars under it in my workshop.

Regards,
Rob M.
The Pedantic Mechanic



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Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

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GMCnet mailing list
Unsubscribe or Change List Options:
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Re: [GMCnet] GMC Track Width [message #318193 is a reply to message #318186] Mon, 29 May 2017 21:01 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Since The Blue Streak is up on jack stands I am going to measure:

1) From OUTSIDE of front tread to OUTSIDE of front tread
2) From INSIDE of front tread to INSIDE of front tread
3) From OUTSIDE of rear tread to OUTSIDE of rear tread
4) From INSIDE of rear tread to INSIDE of rear tread

With those measurements I will be able accurately place the wheels on the
ramps.

Regards,
Rob M.
The Pedantic Mechanic
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808


-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of D C
_Mac_ Macdonald
Sent: Tuesday, May 30, 2017 11:35 AM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] GMC Track Width

Accurate measurement of tread could be done from left side of left tire to
left side of right tire OR right side of left side of right tire.

Mac in OKC, OK



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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] GMC Track Width [message #318223 is a reply to message #318132] Tue, 30 May 2017 09:54 Go to previous messageGo to next message
midlf is currently offline  midlf   United States
Messages: 2212
Registered: July 2007
Location: SE Wisc. (Palmyra)
Karma: 1
Senior Member
There is a difference between track width and overall width. Overall outside tire dimension is what rob needs and his method as stated in his first post will get him that.

Track witdth is a different measurement. When LL & I played around with SCCA as licensed tech inspectors we did track width inspections as part of post race tech inspection on the winners. We measured track from the inside of one wheel to the outside of the other. Note I said Wheel not tire. We had a very simple gauge we used to do this.

Here is SCCA's definition of this proceedure:

4. MEASURING TRACK
Track is the distance between the centerlines of the wheels as raced, without driver, measured at a horizontal plane through the wheel hub centerline. Alternatively, it may be measured from the inside of one wheel at the hub centerline height to the outside of the other wheel, then conversely from the outside of the first wheel at hub centerline to the inside of the second wheel. The 2 dimensions obtained are to be added together and divided by 2 to obtain the average. Measurements are to be taken at both front and rear of the wheels and averaged to compen- sate for toe-in/out. Under certain circumstances it may be preferable to measure from the outside of one wheel to the outside of another and from this dimension deduct the thickness of one wheel. This should be repeated 180° opposite to the first measurement and the two dimensions averaged.

Note this proceedure is set up to compensate for any discrepancies that could be caused by alignment. Wow it's been a few years since I gave this any serious thought.


Steve Southworth
1974 Glacier TZE064V100150 (for workin on)
1975 Transmode TZE365V100394 (parts & spares)
Palmyra WI
Re: [GMCnet] GMC Track Width [message #318232 is a reply to message #318223] Tue, 30 May 2017 16:38 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Steve,

I think I should have asked for the distance from the outside of the tire
contact patch on the driver side to the outside of the tire contact patch on
the passenger side for the front and rear wheels.

With that information I can make a drawing that will show where the tires
will contact the ramps.

Regards,
Rob M.
The Pedantic Mechanic
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808


-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of Steve
Southworth
Sent: Wednesday, May 31, 2017 12:54 AM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] GMC Track Width

There is a difference between track width and overall width. Overall
outside tire dimension is what rob needs and his method as stated in his
first
post will get him that.

Track witdth is a different measurement. When LL & I played around with
SCCA as licensed tech inspectors we did track width inspections as part of
post race tech inspection on the winners. We measured track from the inside
of one wheel to the outside of the other. Note I said Wheel not tire.
We had a very simple gauge we used to do this.

Here is SCCA's definition of this proceedure:

4. MEASURING TRACK
Track is the distance between the centerlines of the wheels as raced,
without driver, measured at a horizontal plane through the wheel hub
centerline.
Alternatively, it may be measured from the inside of one wheel at the hub
centerline height to the outside of the other wheel, then conversely from
the outside of the first wheel at hub centerline to the inside of the second
wheel. The 2 dimensions obtained are to be added together and divided by
2 to obtain the average. Measurements are to be taken at both front and rear
of the wheels and averaged to compen- sate for toe-in/out. Under certain
circumstances it may be preferable to measure from the outside of one wheel
to the outside of another and from this dimension deduct the thickness of
one wheel. This should be repeated 180° opposite to the first measurement
and the two dimensions averaged.

Note this proceedure is set up to compensate for any discrepancies that
could be caused by alignment. Wow it's been a few years since I gave this
any serious thought.
--
Steve Southworth
1974 Glacier TZE064V100150 (for workin on)
1975 Transmode TZE365V100394 (parts & spares)
Palmyra WI

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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] GMC Track Width [message #318233 is a reply to message #318232] Tue, 30 May 2017 16:55 Go to previous messageGo to next message
Justin Brady is currently offline  Justin Brady   United States
Messages: 769
Registered: April 2015
Location: Bell Buckle, TN
Karma: 11
Senior Member
How does this even happen?
Someone walk outside with a tape measure and measure the damn tires, mind blowing how everything turns into a theoretical argument around here hahaha. I would do it but my GMC is 500 miles away.

If I asked what color the tires were I bet there'd be 34 people arguing about how GM went with an odd colored tire and then it would dissolve into an argument about tread wear.


Justin Brady http://www.thegmcrv.com/ 1976 Palm Beach 455
Re: [GMCnet] GMC Track Width [message #318235 is a reply to message #318233] Tue, 30 May 2017 17:33 Go to previous messageGo to next message
Ken Henderson is currently offline  Ken Henderson   United States
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
Senior Member
But at least we don't fight and flame about it. :-)

Ken H.

On Tue, May 30, 2017 at 5:55 PM, Justin Brady wrote:

> How does this even happen?
> Someone walk outside with a tape measure and measure the damn tires, mind
> blowing how everything turns into a theoretical argument around here hahaha.
> I would do it but my GMC is 500 miles away.
>
> If I asked what color the tires were I bet there'd be 34 people arguing
> about how GM went with an odd colored tire and then it would dissolve into
> an
> argument about tread wear.
> --
>
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
Re: [GMCnet] GMC Track Width [message #318237 is a reply to message #318235] Tue, 30 May 2017 18:06 Go to previous messageGo to next message
Justin Brady is currently offline  Justin Brady   United States
Messages: 769
Registered: April 2015
Location: Bell Buckle, TN
Karma: 11
Senior Member
Haha Ken this is very true!

Justin Brady http://www.thegmcrv.com/ 1976 Palm Beach 455
Re: [GMCnet] GMC Track Width [message #318252 is a reply to message #318237] Tue, 30 May 2017 22:22 Go to previous messageGo to next message
Carl S. is currently offline  Carl S.   United States
Messages: 4186
Registered: January 2009
Location: Tucson, AZ.
Karma: 13
Senior Member

Outside to outside of the tires (rear) measures approximately 93 inches with Eagle wheels and 225/75 tires.

Carl Stouffer '75 ex Palm Beach Tucson, AZ. Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles, Solar battery charging. GMCSJ and GMCMI member
Re: [GMCnet] GMC Track Width [message #318257 is a reply to message #318252] Wed, 31 May 2017 02:12 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Carl,

Thanks! Not really as you have confirmed my problem the lift I am looking at
Rotary SM14EL and the max width of the ramps is 86 inches! BUGGER!

I have contacted the local distributor and asked him to check with the
Rotary factory to see if they can be placed further apart.

I have checked Bendpack and their lift did not go high enough to park my T&C
under it, HOWEVER, I could mount it on steel plates to increase the height,
but the drive on ramps would be at a higher angle and that might create a
problem.

Justin,

I agree with you, you can ask how much is 2 + 2 and get all kinds of answers
here. However, that's the charm of the place; I have noted MANY TIMES this
place is like a bunch of guys sitting around a pot bellied stove in an old
country store trading stories (and lies). However, every is trying to help
and therein lies the magic; you won't find many places like this now-a-days
:-)

Regards,
Rob M.
The Pedantic Mechanic
USAussie - Downunder
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808


-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of Carl
Stouffer
Sent: Wednesday, May 31, 2017 1:22 PM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] GMC Track Width

Outside to outside of the tires (rear) measures approximately 93 inches with
Eagle wheels and 225/75 tires.
--
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive,
Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American
Eagles,
Solar battery charging. GMCSJ and GMCMI member

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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] GMC Track Width [message #318260 is a reply to message #318132] Wed, 31 May 2017 08:11 Go to previous messageGo to next message
JohnL455 is currently offline  JohnL455   United States
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
Senior Member
77 w Alcoas and 225s
This is at widest outer point of contact patch to ramp
REAR. 7'6"
FRONT 6'10"
My Cooper tread width is 7" so minus 14 for front minimum
Keep in mind if the ramp spec is measured at widest point you loose about 1" of flat (1/2" inner and outer) due to the radiused rounded over edges of the diamond plate-- like standing on the roof of a TZE.


John Lebetski
Woodstock, IL
77 Eleganza II
Re: [GMCnet] GMC Track Width [message #318264 is a reply to message #318154] Wed, 31 May 2017 08:33 Go to previous messageGo to next message
Ken Burton is currently offline  Ken Burton   United States
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Registered: January 2004
Location: Hebron, Indiana
Karma: 10
Senior Member
I'm not quite sure what you are doing, but I guess at this point that I should mention if you are using a post type lift, you will need wider that 96" to clear the body (96") plus the mirrors when you drive on. Send a note to Blaine Merrell and ask how wide his is. You can drive on his carefully and just clear both side mirrors by about 3" per side.

I'm guessing his is around 104" between posts.


Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
Re: [GMCnet] GMC Track Width [message #318268 is a reply to message #318264] Wed, 31 May 2017 09:42 Go to previous messageGo to previous message
Bullitthead is currently offline  Bullitthead   United States
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Registered: November 2013
Karma: 5
Senior Member
The lift I just set up has almost 118 inches between the posts. Just finished anchoring them down last night.

Terry Kelpien ASE Master Technician 73 Glacier 260 Smithfield, Va.
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