Need help with 4 wheel drive
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Need help with 4 wheel drive
I'm new here and I need some help. I purchased a used 2003 Excursion in November. We got snow today where I live and needed to use the 4 wheel drive. So this is a 2 part question. 1. What is the purpose of manual and auto on the hubs? I have only used auto-locking hubs, as was on my Tacoma. Are they supposed to be very hard to turn? 2. It seemed as though the 4 wheel drive only worked when I turned the hubs to manual, certainly did not while it was in the auto position. Any help would be great!
Junior User
Joined: Sep 2005
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Well here I go diving in with limited knowledge. I'm sure others will be along with better answers but I'll get the ball rolling.
The locking hubs are there in case you are in a situation where you can't move the truck just a bit to engage 4 wheel drive. My understanding is that 4 wheel drive won't engage without a small amount of vehicle movement. So with your Ford you can get out and manually lock the hubs to engage 4 wheel drive. Paying attention to the small details is what keeps Ford selling the most truck year after year.
Your dash switch is there to automatically lock the hubs, provided there is vacuum that can be applied to the hub. If you have a vacuum leak somewhere in the system, your dash switch won't do anything. First place I'd check would be the vacuum line running down to the hubs. Look for a cracked or broken line. When I had my ball joints, rotors and brakes replaced at my dealer, they automatically just replaced this vacuum line for me. As a side note, I think my dealer is great. Of course it doesn't hurt that I'm on a first name basis with the owner and always ask if Tim is in when I drop off my truck for my more extensive service needs beyond the just the basics. That's just something I learned from my old boss from 40 years ago - "All business is personal, all business is a people business". Thanks Marty.
Ok back to 4wd. Again with my limited knowledge, your front differential is, well - a differential, meaning each wheel can turn at different speeds. You need this when going around a corner as the outside wheel will be going faster than the inside wheel. Same think on the rear differential. When 4wd is engaged, everything is fine as long as your going in a straight line. But because there is no center differential to account for different drive line speeds coming from both the front and rear differential you can have drive line bind if you try and turn the vehicle while in 4wd on dry pavement. Of course your owners manual says don't use 4wd on dry pavement. The reason is that slippery conditions give our system just enough slip when going around a corner to minimize binding. If I'm driving on snowy roads in 4wd and I'm coming up to a sharp turn, I'll actually slow for the turn and turn 4wd off at the dash switch and re-engage it once I'm around the corner provided there's no other traffic around while I'm working the switch. But that's just because I'm rather particular about my vehicle, I don't recommend you do the same and it's certainly not necessary during slippery conditions.
Finally, your hubs can be hard to turn because of dirt and a lack of lubrication. Take a look at Guzzle's diesel site for more information on maintaining your hubs.
Welcome to guzzle's 4x4 Needle Bearing Maintenance Web Page
Hope this helps and I hope you get the problem diagnosed and fixed soon. These are great trucks, but do require a bit of maintenance to keep everything in top shape.
The locking hubs are there in case you are in a situation where you can't move the truck just a bit to engage 4 wheel drive. My understanding is that 4 wheel drive won't engage without a small amount of vehicle movement. So with your Ford you can get out and manually lock the hubs to engage 4 wheel drive. Paying attention to the small details is what keeps Ford selling the most truck year after year.
Your dash switch is there to automatically lock the hubs, provided there is vacuum that can be applied to the hub. If you have a vacuum leak somewhere in the system, your dash switch won't do anything. First place I'd check would be the vacuum line running down to the hubs. Look for a cracked or broken line. When I had my ball joints, rotors and brakes replaced at my dealer, they automatically just replaced this vacuum line for me. As a side note, I think my dealer is great. Of course it doesn't hurt that I'm on a first name basis with the owner and always ask if Tim is in when I drop off my truck for my more extensive service needs beyond the just the basics. That's just something I learned from my old boss from 40 years ago - "All business is personal, all business is a people business". Thanks Marty.
Ok back to 4wd. Again with my limited knowledge, your front differential is, well - a differential, meaning each wheel can turn at different speeds. You need this when going around a corner as the outside wheel will be going faster than the inside wheel. Same think on the rear differential. When 4wd is engaged, everything is fine as long as your going in a straight line. But because there is no center differential to account for different drive line speeds coming from both the front and rear differential you can have drive line bind if you try and turn the vehicle while in 4wd on dry pavement. Of course your owners manual says don't use 4wd on dry pavement. The reason is that slippery conditions give our system just enough slip when going around a corner to minimize binding. If I'm driving on snowy roads in 4wd and I'm coming up to a sharp turn, I'll actually slow for the turn and turn 4wd off at the dash switch and re-engage it once I'm around the corner provided there's no other traffic around while I'm working the switch. But that's just because I'm rather particular about my vehicle, I don't recommend you do the same and it's certainly not necessary during slippery conditions.
Finally, your hubs can be hard to turn because of dirt and a lack of lubrication. Take a look at Guzzle's diesel site for more information on maintaining your hubs.
Welcome to guzzle's 4x4 Needle Bearing Maintenance Web Page
Hope this helps and I hope you get the problem diagnosed and fixed soon. These are great trucks, but do require a bit of maintenance to keep everything in top shape.
Lead Driver
Joined: Jan 2008
Posts: 6,180
Likes: 83
From: Georgia
If your hubs are very hard to turn, please don't turn them with a pair of pliers. You can crack the hub making them useless. I suggest you spend about $3 from Home Depot and make you a 'wrench' that easily turn the hubs. It is a 2foot long piece of white pvc that is 2" in diameter. They already have these precut in the plumbing section. Then make you a notch on each side about 5/8 of an inch wide. It will fit the hubs perfectly. Some people then put a T handle on the other end to make it easier to turn. Then lubricate your hubs, let them set for a minute and turn. The more you turn them the easier they will turn. I kkep this with me at all times in case I need it.
Post Fiend
Joined: Oct 2002
Posts: 11,314
Likes: 4
great answers above ! spot on...
but being a used vehicle, who knows if the hubs were taken care of...
Since it takes forever and a day to fill up with 44 gallons, I typically go around the truck every few fill ups and turn the hubs to make sure they rotate freely....
good luck on the repairs...
but being a used vehicle, who knows if the hubs were taken care of...
Since it takes forever and a day to fill up with 44 gallons, I typically go around the truck every few fill ups and turn the hubs to make sure they rotate freely....
good luck on the repairs...
Fleet Mechanic
Joined: Jun 2006
Posts: 1,589
Likes: 20
I'm new here and I need some help. I purchased a used 2003 Excursion in November. We got snow today where I live and needed to use the 4 wheel drive. So this is a 2 part question. 1. What is the purpose of manual and auto on the hubs? I have only used auto-locking hubs, as was on my Tacoma. Are they supposed to be very hard to turn? 2. It seemed as though the 4 wheel drive only worked when I turned the hubs to manual, certainly did not while it was in the auto position. Any help would be great!
Welcome to guzzle's Ford PSD Maintenance Web Page
DSMMH
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