Accuracy of maintenance manuals

[emerystora]

Seeing the postings for the torque of the front axle nut which had
some variance depending on which year manual the sender was looking
at reminds me to mention that you should not always believe
everything that you read in your manual. This is especially true if
you have the manual for the 73 or 74 models.

Over the years GM changed their mind about a few things such as
torque values and some other things.

For example the 73 manual says that the front axle is torqued to 110 ft-lb.
The 75-76 says 140-280 ft-lb. The 77-78 says 110-140 ft-lb not to
exceed 280 ft-lb.

The 75-76 manual says the front end alignment should be 0 to -1/4"
(toe out). The 77-78 says -1/16 to -3/`6" (toe out).

These are just minor differences but I have run across some others in
years past. There are also some errors in the manuals such as
misprints (I believe the firing order is shown wrong in one of the
manuals).

So, the old saying that you can't believe everything that you hear or
read also holds true with the GMC manuals.

In general, its a great tool, but just be aware that there have been
some changes over the years even when the parts did not change
between the model years.

Emery Stora
77 Kingsley
Santa Fe, NM

 

[paul bartz1]

Another inaccuracy. On page 6Y-45 of the X-7525A manual, distributor rotation is
listed as counterclockwise. On pages 6Y-33 and 6Y-34 of the X-7725 manual it is
listed as clockwise.

Dick Paterson in one of his seminars stated that distributor rotation on all
Oldsmobile engines is always counterclockwise.

Anybody have any other manual anomalies??

Gene, this would be good historical info to be included on your web site.

Paul Bartz

From: owner-gmcmotorhome
[mailtowner-gmcmotorhome]On Behalf Of Emery L. Stora
Sent: Saturday, July 01, 2000 5:44 PM

Seeing the postings for the torque of the front axle nut which had
some variance depending on which year manual the sender was looking
at reminds me to mention that you should not always believe
everything that you read in your manual. This is especially true if
you have the manual for the 73 or 74 models.

Over the years GM changed their mind about a few things such as
torque values and some other things.

For example the 73 manual says that the front axle is torqued to 110 ft-lb.
The 75-76 says 140-280 ft-lb. The 77-78 says 110-140 ft-lb not to
exceed 280 ft-lb.

The 75-76 manual says the front end alignment should be 0 to -1/4"
(toe out). The 77-78 says -1/16 to -3/`6" (toe out).

These are just minor differences but I have run across some others in
years past. There are also some errors in the manuals such as
misprints (I believe the firing order is shown wrong in one of the
manuals).

So, the old saying that you can't believe everything that you hear or
read also holds true with the GMC manuals.

In general, its a great tool, but just be aware that there have been
some changes over the years even when the parts did not change
between the model years.

 

[david l greenberg]

On Sat, 1 Jul 2000 22:19:18 -0400 "Paul Bartz"
writes:
> Another inaccuracy. On page 6Y-45 of the X-7525A manual, distributor
> rotation is
> listed as counterclockwise. On pages 6Y-33 and 6Y-34 of the X-7725
> manual it is
> listed as clockwise.
>
> Dick Paterson in one of his seminars stated that distributor
> rotation on all Oldsmobile engines is always counterclockwise.
>
> Paul Bartz

I seem to recall there is an illustration in one of the manuals that
shows an incorrect firing order.

David Lee Greenberg
The GMC Motorhome Registry
Dedicated To The Preservation of the Classic GMC Motorhome
http://www.GMCss.com/Registry.htm
http://www.Buskirk-RushRV/GMC-Registry/online-registry.htm