Hey all,

Can you believe I got 8" of snow last night, here in Central NY.
Because of the snow, I needed to use 4x4 High this morning to get out of the driveway.

Anyway, here's the info and my problem.

1998 F150, 4x4 (elec.), 5.4 V8, Ext. Cab.
I never had a problem with using 4x4 last winter. (no noises or grinding)
This morning, I switch to 4H to get out of the driveway. No problem, 4x4 engages right away, no noise, smooth transfer. I get on the road and hear a noise coming from the front end (drivers side).
The best that I can describe the noise is,
it sounded like a light grinding noise almost like when the anti-locks kick in, but not quite as loud as the anti-locks.
This noise was constant until I turned the switch back to 2H.
After I put it in 2H, it took a couple of seconds to disengage and the noise went away. Then while driving, 30 MPH, I throw it back in 4H, it engages fine, but then the grinding noise comes back. Again, I put it back to 2H, and noise goes away. I'm worried that it is not fully engaged.
I did search this site, but couldn't find any info for 1997-1999 4x4 grinding noise. I found plenty for newer model F150's.

Could really use some help on this one. We have some nice weather coming back, starting tomorrow, and I would like to get this fixed before the real snow comes.
By the way, checked through my manual and there wasn't much info on 4x4. transfer case etc.

Thanks in advance

TJKinCNY

 

I would crawl under there and inspect for stuff stuck to the axle. Stuff gets caught on it I pulled a bunch of fishing line off mine this summer.Then jack the truck up and check everything for loose/worn joints etc. Check the axle boots for wear/holes. if they get holes it kills them joints quick.

 

You might want to get this moved to the Other Powertrain forum.

 

Thanks for the input Jethat.
I did inspect the entire drivers side wheel aasembly area and found no obvious debris.
I can't get a real close look at the boots until tomorrow when the snow is gone (no garage, just my barn. I will tear up the lawn getting to it)

Last December, I did install new wheel bearing assembly & upper ball joint assemble & lower ball joint on the drivers side. (I had to do this work to pass inspection) I had no problem with 4x4 all winter, so I can eliminate this as a cause.
The axle joint has no play the last time I checked it a couple of months ago. None of these parts have been any problem or produced any noise all year (while running in 2WD). I had changed my oil and while doing that I checked all of my fluid's, greased everything plus checked the axle joints and everthing was fine. I did check the front diff. case and it was full as well.

It sounds like the 4x4 isn't 100% engaged (guessing here) or completely meshed in. When I put it in 4x4, it goes right in, no clinking or clunking and I can feel the front tire grabbing right away. The noise appears when I get up on the road and drive up to normal speed. The faster I go, the louder the noise. (NOTE: it is not real loud but very noticable)

Does my 4x4 system have vacuum assist like the newer models. There is nothing in my manual to let me know.

ANY & ALL help is greatly appreciated.

TJKinCNY

 

Ahh, Thanks, glc

 

sounds like a hub isnt fully locking in. do you have the vacuum style hubs?

 

Ye, that is exactly what it sounds like.
My manual and JMC (online member) both state that I have vacuum assisted 4x4 engagment. I will be looking under the truck this weekend when the snow is gone, and that will tell me for sure. JMC had the problem and he gave me the correct repair proceedure. My manual gives the same info.
Thankfully, it sounds pretty straight forward and a pretty easy fix.

I'll let everyone know how I make out when I get er done.

Hey Jbrew, you have the 4x4 vacuum setup on your '98 ????

TJKinCNY

 

Yea, there's two lines -Pink and Blue . Runs to the Actuator on the axle. If you run thru salt frequently , the spray dries them up that much quicker.

Also if you have done and work on the truck over by the battery, those lines can get pinched very easily. I split both of mine working over in that area - not sure how I did that. Your solenoids are over there as well; on the firewall , make sure those are all connected.

Not sure what would cause the noise you describe. Sounds like one wheel isn't getting locked in to me. Try reverse from a stop, right after engaging.

Actuators can break right off the axle as well - seen that before. I would go thru the air lines first, you might not be getting enough pressure to it - to engage both wheels.

On the 98 , there's a rubber coupling on the passenger side fender-well below the battery - check that too.

 

That is some excellent info with great detail you gave me.
I'll print off what you wrote and take it right to the truck when I'm ready to correct the problem. It's funny you mention the the passanger side firewall, and the fender area. As you recall, I just had the truck completly painted and they removed everything but the cab and hood. They disconnected the battery as well during all the work. They had everything torn apart because they wanted to give me a complete job. After I got the truck back, I knew I needed a new battery because the last one was 7 yrs old and a bit weak. Maybe I hit something ????
Anyways, awesome info you gave, shouldn't be a problem to fix.
I'll post what I find when it's done.

Thanks again, for replying.

TJKinCNY

PS: the official measurment from the snow storm I got the other day was 11".
Some places up north got over 2 feet in one night. The "Sled-Heads" were happy.

 

where exactly is this coupling, and is it blue in color. I may have come across this today. If there isn't a problem with vacuum pressure, is it safe to assume this coupling is ok.

After looking things over and testing everything out so far,
I took a short (200-300yds) trip on the road and the noise is still coming out of my driver side tire area. With the window down and driving 20mph max, I can still here the noise. It is not a grinding noise but more like a ratcheting noise. Not very loud but loud enough to tell me this is not a normal operating sound. It does not get worse when I am turning. I checked the front diff. case lube and it was full. I had no problems last winter and now this. Any and all info and help from this point would be greatly appreciated.

Thanks in advance,
TJKinCNY

 

Yea , it's almost like a fast plastic sounding clicking noise - somethings trying to engage, but is failing to do so.

I heard the noise before. - Thing is, I don't remember what I was driving at the time.

Personally, I think it's a lazy hub. There's been allot of those in the past. It's usually $100 part inside the hub AND this only happens on the drivers side from what I gather.

http://www.thedieselstop.com/archive...o=&fpart=1.htm


Also - Don't rule your vacuum supply unless you have tested. The rubber coupling is attached the the pass/ side inner plastic fender well - It might be hanging, all that secures them to fender well is a plastic type plug. There has to be TWO lines (Pink and Blue) on the 98's - Feed and Return.

Try cutting off cliament control (AC/DEFROST = same) - Turn control to "off"/Turn h/c to "cool"/ Turn blower "off". ~ Now , try engaging again. This should verify there's no leaks under the dash causing the problem.

BTW - Did you try the trans section ? Kingfish and Mark know their sh^t ..

 

I did a copy and paste and posted this in the Tranny area as you recommended. Hopefully, Kingfish & Mark will lend a hand. I will try out the other checks you suggested. I will look at that coupling today, I'm pretty sure I came across it yesterday.
By any chance do you have the correct vacuum pressure that I should be reading at the Pink & Blue Hoses. I do have a gauge.

By the way, when I posted this in "Other Powertrain" JMC posted some excellent diagrams of the front end breakdown. That helped alot seeing the breakdown. I'm stating this, in case anyone else runs into this and uses the search tab for info.

Thanks again,

TJKinCNY

 

If you had 4x4, then the vacuum system is working. That engages and disengages the front diff. Hubs do not come into play as they are always turning. I would look to see if the CV boot is cut as it could be a bad CV joint. It would quite possibly only make noise when you have power to the wheel. When you are putting stress on them. Otherwise it is just free wheeling. If it was the hub bearings itself, I would expect them to make noise all the time.

 

All great info, Thank you !!!!

I looked at the the CV Boots yesterday and they looked in good shape but I will take a better look at them today, paying closer attention. I put a new wheel bearing assembly on the drivers side last winter. It was making some noise and had a little play. I did run the 4x4 after this repair and there was no noise all winter. When you say "hub bearing" are you refering to the wheel bearing assembly I put in. (are we talking about the same thing)

Thanks again Kingfish,

TJKinCNY

 

Yes we are talking the same thing. Unlike older or newer 4x4s, the 97-03 did not have a "hub" that locked or unlocked at the wheel. Locking was done at the diff and the front axles always turned. The weak points of the system are the vacuum motor, vacuum lines, solenoids that lock and unlock, and CV joints when they go bad due to deterioration of the boots, cuts in the boots. Once that happens dirt gets in and lubrication comes out. Other weak points are the switch on the dash (ESOF), TC shift motor (ESOF), or GEM module. Yours sounds like it is all to the front, either something like JMC stated in his post where you get a partial engagement at the diff, or a possibly bad CV joint.