4 x didnt lock in?
Thread Starter
|
Freshman User
Joined: Jan 2008
Posts: 47
Likes: 0
4 x didnt lock in?
Yesterday I needed 4 high going up a driveway, turned the switch but it wouldnt lock in. I put it in nuetral and went to 4 low, no problem. When I got to the top I got out and manualy locked the hubs. Then it locked into 4 high no trouble. Is this normal? Ive had a gmc for a long time with auto trac it always worked. Anyone else have this problem? Oh and my hubs on the X turn real easy so I dont think they are bound up at all. Maybe its just a one time thing? Thanks for any help.
New User
Joined: Mar 2006
Posts: 2
Likes: 0
Besure that you do not have a vacuum problem with your hubs. If your 4 wheel high and low work with you manually locking the hubs than you probably have a vacuum issue.
I had a vacuum issue that came from the rear seal on one of the front hubs. The vacuum leaks are not hard to find and are usually from the gaskets on the hub locks. You probably will have to repack the front needle bearings and replace the o ring seals. It should be done every 30,000 miles anyway.
The hubs should also be cleaned. I have seen the process but do not know where the instructins were in this forum.
I had a vacuum issue that came from the rear seal on one of the front hubs. The vacuum leaks are not hard to find and are usually from the gaskets on the hub locks. You probably will have to repack the front needle bearings and replace the o ring seals. It should be done every 30,000 miles anyway.
The hubs should also be cleaned. I have seen the process but do not know where the instructins were in this forum.
Hotshot
Joined: Oct 2005
Posts: 12,237
Likes: 22
From: Florida
Here's the hub maintenance link
http://guzzle.rbmicro.com/allube.html
I'd start with this.
To answer your question...NO IT is NOT right...when you rotate the ESOF (electronic shift on the fly) switch on the inside of the Ex to 4wheel high (or low if stopped with foot on brake in neutral) and the hubs are in 'auto'...you SHOULD engage and LOCK 4 wheel drive...
As mdb states...the vac system on these trucks are 'prone'...but also a non maintained hub (i.e. sticky) will contribute to the issue too...because if the friction of the hub is greater than the vac can overcome to 'engage' the hub...well you're left to manually 'lock' the hub (WHICH WILL WORK)...
I try and engage 4 wheel drive a few times throughout the year when I'm in campgrounds with gravel roads...to keep things 'moving'. Winter time is not a problem up here with all the snow...but many may NEVER engage the 4 wheel drive and then one day need it...and it don't work...I try and keep mine used throughout the years...I think it helps keep things moving but I have no proof of that...only a working 4 wheel system on mine I guess...
Hope this link helps.
Good luck and let us know what you find.
joe.
http://guzzle.rbmicro.com/allube.html
I'd start with this.
To answer your question...NO IT is NOT right...when you rotate the ESOF (electronic shift on the fly) switch on the inside of the Ex to 4wheel high (or low if stopped with foot on brake in neutral) and the hubs are in 'auto'...you SHOULD engage and LOCK 4 wheel drive...
As mdb states...the vac system on these trucks are 'prone'...but also a non maintained hub (i.e. sticky) will contribute to the issue too...because if the friction of the hub is greater than the vac can overcome to 'engage' the hub...well you're left to manually 'lock' the hub (WHICH WILL WORK)...
I try and engage 4 wheel drive a few times throughout the year when I'm in campgrounds with gravel roads...to keep things 'moving'. Winter time is not a problem up here with all the snow...but many may NEVER engage the 4 wheel drive and then one day need it...and it don't work...I try and keep mine used throughout the years...I think it helps keep things moving but I have no proof of that...only a working 4 wheel system on mine I guess...
Hope this link helps.
Good luck and let us know what you find.
joe.
Thread
Thread Starter
Forum
Replies
Last Post
