Hi--

I've found a couple threads similar to this but not exact. So, please bear with it if it seems like a repeat question.

I've got a 97 F150 with a 5 speed manual and the floor based lever to engage 4x4. (No outside hub to turn)

When I pull the lever to 4hi nothing happens. I can do this stopped, in neutral, with it warm, cold, rolling, anything. No 4x4.

(I know this because I live in a snow bound land and they just ain't pulling)

BUT if I stop the truck, put on the brake, leave it in neutral and go into 4lo and drive and repeat a few times, it actually goes into 4lo. (It's doens't always catch the 1st time I try 4lo)

Then, I can put it in 4hi and it works fine in 4hi till i put it back in 2.

No grinding, clunks or nuthin.

The dash indicator always shows what it should. 4hi or 4lo no matter if 4x4 is engaged or not.

I recently had a clutch put in the truck and the problems seems related to that event BUT I'm not sure as the clutch was put in in the summer and I didn't try 4x4 till the following winter.

ANy insights would be great!

Thanks
Kelly

 

Your '97 uses a center axle disconnect. This is actuated with the movement of the transfer case shifter. The movement of a switch causes the solenoids to engage allowing a vacuum source to engage the front axle. I am unsureon how this switch is wired but the switch may also cause the dash lights to come on.

Since you think the clutch job had something to do with it I'd look at what is involved in the clutch job. I'll guess the tranny and xfer case were dropped out to accomplish the work (that's what I'd see a shop manual telling me to do) and now something in the likage isn't aligned quite right.

Best bet is to look for anything that may be near the linkage path and see if it can be adjusted to make a better contact, if that's the problem.

Another possibility is the solenoids or the vacuum motor in the front end.

Pop the hood and listen with the key on. As you shift the truck into 4HI the solenoids should click to actuate. No audible click then you may need to do a voltage test for positive ID. Where they are located on a '97 is a mystery to me. On newer trucks they are on the passenger side firewall.

To ensure you have a vacuum motor failure you'll have to check for vacuum at the differential and jack the front end up with the truck running and in 4HI. If you can freely spin both wheels, the drive shaft does not turn, and you have vacuum at the differential...then you have a bad center disconnect.

Hope this helps.

-Kerry

 

Thanks!

I'll check all that stuff.


I read another thread that talked about putting it in 4hi with the engine off.

Is that a trick I should try? Anyother tricks with regard to getting it working without doing anything mechanical?

Thanks again!

Kelly

 

Putting it into 4HI with the engine off will lock your transfer case into that position (if that's working correctly) and front driveline with it, but you won't have proof whether the axle is engaging (no vacuum source with engine off).

You've pretty much done the non-mechanical checks by driving it and finding it not working. No clunks, sounds like a front end not engaging...it sounds like you're going to have to get mechanical or at least electrical.

-Kerry

 

I have the same setup, same year truck. Same problem. Had the truck into the dealer yesterday--they're telling me that I need a new vacuum motor and a new "gear kit" to replace a shear pin and "forks". All looked pretty clear to me in their shop diagram, but I'm hearing from other sources that the dealer may be full of S**t; my real problem is likely something else.

One difference; my truck doesn't seem to go into 4X4 regardless of speed or backing up, however I do hear the solonoids clicking under the dash and hood. Thoughts?

Jordan Murphy
`97 F-150 4x4 (4.6L, 5sp, auto hubs, lever actuated)

 

in a shop up here in alaska that i have friends that work at , the first thing they check is the thickness of the grease in the hubs. if its its summer grease they completely clean everything and put in a very thin 'winter grease' . not sure if that will help you ,but sometimes shops get slow this time of year and try to 'build paychecks on whatever comes in the door, good luck ,bob

 

the grease that they switch to is called ' grease gun in a can '. I know it sounds hokey but iv done it myself and it works. normal hub grease thickens up with cold , sometimes to the point of actuslly acting as a sludge and hampering hub actuation, good luck , bob

 

Jordan,

You can check for vacuum at the center disconnect as long as you have already ruled out the transfer case is engaging by locking it in 4HI with the front end jacked up to see of the front drive shaft doesn't turn. The vacuuum lines test requires you to trace out the lines and find where they engage the differential. With truck running and in the lever in 4HI checking this will provide a vacuum as long as the solenoids are engaging. With both of those checks completed satisfactorily (front drive shaft locked and vacuum at differential) the problem will lie in the differential itself. What is in the diff? the vacuum motor, the gear set, shear pin and a fork. Sounds like the front diff is munched. Suprised they haven't hit you up for a new set of axles as the ends must be roasted. Did they do this without opening up the differential cover? I'd ask them to prove it again, then- put this in writing- tell them you want to inspect every piece that goes into the front end and every piece that comes out and you won't pay for the repairs if you feel the part is still good. If they have to go to the extreme of replacing that much stuff they'll have no problem showing you what they have. You've seen the diagram so you know what the parts look like.

-Kerry

 

Kerry--

Thanks for the detailed posts. I have yet to look closer @ my truck as it's just not been that nice out up here yet (Calgary). Once it's warmer I'll be doing what you suggested.

PLUS my wife's Durango (don't ask) is in the shop. Started spewing rad fluid.

Thanks again.

Kelly

 

Kelly,

Glad you found the posts useful. Still not to sure on the locations on a '97.

P.S.
Want your weather back? It's 16 degrees and snowing... probably a bit warmer than what you're seeing, but not typical of the lowlands of western Washington.

-Kerry