4wd hub question
Thread Starter
|
Hotshot
Joined: Jul 2002
Posts: 14,285
Likes: 12
From: Bend,OR
4wd hub question
Hey guys, wife had the truck to drive home during yesterdays snow storm. I thought the truck hubs were in Auto, she was calling me often complaining of getting stuck on the road. Finally a good Samaritan walked up and said she wasnt in 4wd and turned the hub and she was in good shape the rest of the time. So i get home and asked her what hub he turned and went and looked at the truck and found both hubs in the Lock position. So i guess my question is with one hub in the lock position and one hub in the auto would it cause the driving symptoms she was getting or do i have a hub issue. I will be taking the truck out today to troubleshoot a little.
Truck has electric Tcase as well. my Bronco has normal hubs with no auto setting so i am not familiar with the behavior.
Truck has electric Tcase as well. my Bronco has normal hubs with no auto setting so i am not familiar with the behavior.
Posting Guru
Joined: Dec 2016
Posts: 1,284
Likes: 2
From: Bozeman MT
Think about the inverse....
If the truck has ESOF then your auto is supposed to be vacuum activated, by design the vacuum will pull in the hub and the hub will rotate to achieve lock. Most trucks with any age or miles have a bad seal, the yellow seals fail frequently preventing the hub from being able to pull vacuum, then the hub does not engage with the half shaft automatically.
Walking up and manually turning the hub to LOCK engages that hub with the half shaft.
On a stock EOM truck the front axle differential is an OPEN Differential. Locking the drivers side hub to engage the half shaft is the best you can hope for.
If the truck has ESOF then your auto is supposed to be vacuum activated, by design the vacuum will pull in the hub and the hub will rotate to achieve lock. Most trucks with any age or miles have a bad seal, the yellow seals fail frequently preventing the hub from being able to pull vacuum, then the hub does not engage with the half shaft automatically.
Walking up and manually turning the hub to LOCK engages that hub with the half shaft.
On a stock EOM truck the front axle differential is an OPEN Differential. Locking the drivers side hub to engage the half shaft is the best you can hope for.
Tuned
Joined: Oct 2015
Posts: 392
Likes: 86
From: Roebuck, SC
Yep, dieseltech Ron (RIP) has a good youtube video about it.
You can check vacuum at the hubs by disconnecting the tubing, pulling a vacuum with a mighty vac tool and watching the vacuum. Check each side. If the vacuum holds on both tests, at least you won't have to dig into the hub(s).
Inside the truck put your climate system on vent, turn on the fan so you'll be able to tell you have air flow, then put it into 4wd high (being parked is ok). If the system goes from vent to defrost, you definitely have a vacuum leak.
There is also a relay that the front hub hoses connect to that could be bad.
All of this is in the video. Here's the link:
You can check vacuum at the hubs by disconnecting the tubing, pulling a vacuum with a mighty vac tool and watching the vacuum. Check each side. If the vacuum holds on both tests, at least you won't have to dig into the hub(s).
Inside the truck put your climate system on vent, turn on the fan so you'll be able to tell you have air flow, then put it into 4wd high (being parked is ok). If the system goes from vent to defrost, you definitely have a vacuum leak.
There is also a relay that the front hub hoses connect to that could be bad.
All of this is in the video. Here's the link:
Thread Starter
|
Hotshot
Joined: Jul 2002
Posts: 14,285
Likes: 12
From: Bend,OR
thanks, i did try my auto function this morning and they are not engaging. I watch the video and see if i can troubleshoot. I contacted ford and all the replacement parts are under the warranty i have for the truck except the hose itself. so in the end i will only be out the $100 deductible. Although i will test the hose first as that should be a cheaper fix if that is all thats necessary.
Thread
Thread Starter
Forum
Replies
Last Post
Jeff C
1999 - 2016 Super Duty
9
Jan 6, 2005 08:30 PM
