| [GMCnet] 1 Ton Front End [message #282412] |
Sat, 18 July 2015 18:58 |
glwgmc
Messages: 1014
Registered: June 2004
Karma: 10
|
Senior Member |
|
|
Now I am told it is too long by a bit so will shorten and send for a third time. JW
Hi Mark,
Thanks for adding info to this otherwise somewhat anecdotal conversation.
We have two coaches, one with the 1 Ton front end and one bone stock. Both have the same tires, 16” wheels, shocks, stock air bags with lifters, etc. The Royale with the one ton is set right at factory ride height while the Clasco with the stock front end is ride height low in front and rear. Both drive really well and other than the Clasco missing a steering damper I really can’t tell any difference going down the road.
The Royale does have a tendency towards torque steer when starting up turning going up hill. It goes away quickly but is there in the beginning. When we go on long trips we generally take the Royale because it has a larger bed, kitchen and refer. On shorter or social trips we prefer the Clasco because there is more socialization space up front. In neither case do we make that decision based on ride or drive quality so from our anecdotal experience there really is no difference. If/when the Clasco needs major front end work I will likely opt for the one ton simply because it is more cost effective than a full redo of the stock front end and brings along no downside that I know of.
I will be giving a presentation at GMCMI in So. Dakota that may shed some light on some of the ride and drive questions many owners have, including some of the perceived ride and drive issues some associate with the one ton front end. The long and the short of the story is our coaches were designed around bias ply tires. When radial ply tires became available the alignment specs did not change because GM still sold our coaches with either bias ply or radial tires even those those two tires differ significantly in how they perform going down the road. The radial ply tires need more static caster in order to go straight and not rut wander whether you use the stock or the one ton front end. They also need to be camber neutral in front and just a bit tire at the top in at the rear to keep the front and rear ends in place in a hard corner. Toe with radials needs to be zero if the front end components are tight. All of this presupposes the ride height front and rear is set bang dead on factory spec as measured from the slots in the frame front and rear after it has been driven for a few miles. If alignment is set after jacking up the front, as most commercial shops do, then all the camber and the zero caster and toe will be gone by the time you get home as the front will settle while you drive. If you just had the one ton installed and it starts to wander once you drive it home from the commercial alignment shop you would naturally “blame” the one ton geometry when you should “blame" the alignment shop for not setting the correct-for-radial-ply-tires caster, camber, toe and rear wheel frame parallel stance after the coach was driven for a few miles.
Jerry
Jerry & Sharon Work
Kerby, OR
glwork@mac.com
http://jerrywork.com
78 Royale
77/94 Clasco
============
Message: 4
Date: Sat, 18 Jul 2015 10:38:46 -0600
From: A.
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] 1 Ton Front End
Message-ID:
Content-Type: text/plain; charset="utf-8"
LarryInSanDiego wrote on Sat, 18 July 2015 10:21
> Does it have a taller spindle and would that make for a more aggressive negative camber gain curve? Just curious what you found when you modeled
> it.
The spacing between the top of the knuckle (where the top ball joint attaches) is 2" farther from the bottom of the knuckle (where the bottom ball
joint attaches) on the one-ton than on the GMC knuckle.
Looking at the AutoCAD renderings, almost all of that is accounted for by the distance from the centerline of the axle to the point where the top ball
joint attaches. In other words, if you want to try to correct for the difference by moving A-arm attachment points to the frame, you would cut the top
ones off and move them up 2 inches and leave the bottom alone. That wouldn't give you OEM geometry exactly, but it would behave more like it.
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
Jerry & Sharon Work
78 Royale
Kerby, OR
|
|
|
|
GMCforum
Search
Help
Register
Login
Home
