98 4WD Vacuum problem

[Quinton]

My pops 98 Ranger 4WD is giving him fits. It doesn't work and we've found out it engages by vacuum. The mechanic put on 2 new of the vacuum hubs and then my dad said the heater was stuck on defrost. He took it back to the mechanic and I think 1 of the new hubs was already bad. He put on another one and now it's stuck on defrost again.

I just read about the AVM manual locking hubs on here. That sounds like the best option BUT would they work if there seems to be something going on with his vacuum? I don't understand how this system engages.

I'm guessing you guys are the Ranger Guru's, so I'm looking for some info to give to my dad to give to the mechanic.
Thanks!!

 

[Original_Ranger84]

Well the problem is mechanics don't understand the system... probably cause its retarded and only lasted a few years before deemed retarded.

The system does run on vacuum. The vacuum relay modual though is the most likely suspect here I think. Because the 4x4 and HVAC system are both vacuum operated by the same unit. so since the thing gets stuck on defrost I am almost positive it is the relay unit. If the defrost doesn't work then neither do the hubs. If the hubs stop workign to then it definately is the relay system.

I actually did a write up on how to get your hubs working again. Chances are that there was absolutly nothing wrong with the hubs and they were uselessly replaced. They are very very simple. its a shell, rubber disc, 2 plastic cups with a spring in the middle and a clip. The thing that most commonly goes wrong with the hubs is vacuum leaks from old rotted and cracked lines. Its easy to replace them you need about 6 ft of line which is like 5 bucks. you know... Heres the link to my write up.

http://www.therangerstation.com/forums/showthread.php?t=73097

As for the Manual hubs affecting the vacuum system... they shouldn't just as long as you block off the old vacuum lines. The plastic hubs click in and push the gear to connect the hub then click back out and release the gear the manual hub does the same thing but instead you manual push it in.

Heck if you want just go the lazy route and convert the auto hubs to manuals with this. http://www.ford-trucks.com/article/idx/9/277/article/Adding_Manual_Control_to_your_19982000_Ford_Ranger_Pulse_Vacuum_Hubs.html

 

[Quinton]

Dang I just read your lazy way to convert the hubs. That sounds like the way to go!
So he would need to have the vacuum relay module replaced first right? Then it sounds like his heater and 4WD should be working properly. But if we could just mod the covers then we'd know it was in 4WD. Is there a metal or chrome plastic cover that would need to be cut out as well.
If I remember right his has the chrome steel wheels, not the wider aluminum ones.

Thanks!!

 

[Original_Ranger84]

Yeah its really nice. I fixed my auto hubs so that they work all the time I want them, but the manual conversion works too, I actually did it so that incase the auto part stops I can engage them manually.

All you have to do is get the cap off, put a flat head between the flat areas and twist counter clockwise. cut off the pin wheels in the middle, punch out the metal mesh screen, put it back on, and push it all the way in to engage and about half way in just until it clicks to disengage.

The vacuum modual would help get the HVAC unit working agian. Assuming thats whats wrong but thats what it sounds like to me. Well if the realys is the only problem then it should fix the problem for both but the 4x4 system is picky so it may not fix the 4x4. I had to replace the vacuum lines and take apart clean and lith grease the inside parts of the hubs to work but yeah.

Do the manual conversion, replace the vacuum relay thing (if they are confused (cause relay might not be the right name for it, its located somewhere under the air box or by it) and that should take care of the HVAC unit.

 

[Quinton]

So if we do those 2 things then how does he put it in 4WD? Like normal or do you have to push in the hubs everytime?
Thanks

 

[Original_Ranger84]

Well if you do the manual thing... then you get out push each of the hubs in. Push them in all the way to engage them, and about halfway (until you hear a click) to disengage them.

Replacing the module will more then likely fix your HVAC unit problem, and possible also fix the auto hubs too.

If you do the manual hub think you still have to turn the knob to get the electric tcase into 4hi or 4lo but then if they hubs don't work then you would get out and manual engage them as well.

 

[accobra65]

great read...unfortunately too late for me as I had the same problem. thanx for the info anyway original -ranger84