After the 'big' snow we had here in md the last couple of days i've been having a little difficulty getting up and down my driveway in my ranger, though i make it, but i don't think my 4wd is engaging. First, i'd like to know of any way to actually check to see if its working. Second, if its not working, what are my troubleshooting steps to go through?

Also, i've heard that these auto hubs are very unreliable, what is the cost of switch to manual hubs so i know that they're locked in vs replacing these hubs if it comes down to that?


Thanks,
paul

99 ranger ext cab step side 3.0l xlt.
Switch on dash and auto hubs.

 

No manual hubs available for these. First see if the problem is the tranfer case or the hubs. If the transfer case engages I dont think you can spin the front axle shafts easily by hand, if its not engaged I think you can. Or have someone look under at them as you drive slowly in 2wd or 4wd/ In 4wd they should be turning. If so, it is the hubs. See if there is a vac leak by following and inspecting the vac tubing leading to the hub. If that is oK, head for the dealer and be prepared to be reamed.

There also has been some posts about taking the hubs apart to some extent and engaging them semipermanently, I dont know the specifics on it.

 

There is a way to premanently engage the hubs, like the new Raners have done. If you do a searchin here it should come up.

 

Try going up your driveway in 2wd see how far you can go without getting stuck, then try it in 4wd and see if there is any difference. How are your tires? 4wd will not help if you don't have good rubber..

 

Your '99 has the Pulse Vacuum Hublock (PVH) 4x4 engagement system. This thread pretty much has everything you want to know about the PVH system in it:

https://www.ford-trucks.com/forums/s...d.php?t=113363

Here are some diagnostic steps you can follow:

Ranger Pulse Vacuum Hublock Diagnosis & Testing

 

I have new tires, i'm pretty sure the transfer case is engaging, but i'll check that out a little later. I just had the engine replaced in it (oil pump failure) and now that you guys say its a vacumn system i'm guessing the mechanic forgot to hook up some of the lines or something like that? Im pretty sure it was working before we took it to him, although i hadn't used it in a few weeks. I'll just have to take it back to him and see what he can do for me.


thanks,
paul

-edit- where are the vacumn hoses located for the hubs on the engine? I might just so i can see if i can find it myself.

 

-update-


I checked the driveshaft and it is turning in 4hi and 4lo, just no engagement. So its either a vacuum leak or the hubs failed, correct?

Thanks,
paul

 

sounds like. My hub was making a roaring noise after it failed when I would drive, even in 2wd.. I would pull the wheels and just trace the vac line backwards from the hub.

 

Problem fixed.

Took it back to the mechanic and he forgot to hook on of those hoses up when the new engine was put in.


thanks for the help.
paul

 

What do people consider unreliable about the PVH?

I have about 140,000 without any problems... Are these dying at 100,000, 150,000, more? or are they rarely dying?

 

Knock on some wood, fast.

Mine went at 89k. I think the fact that they are plastic is a problem..

 

I am currently at 93,00 miles and I'm on my 3rd set of them. They got replaced twice under the extended warranty (that itself made up for the warranty - they quoted like $700 each time). When this 3rd set started having problems engaging a couple months ago, I looked it up on this forum, and did the "constant engagement fix". And now 4wd engages no problem. It seems that some people just have a lot of problems with them, and some never do. I'm just wondering...2K3 Mach, do you use your 4wd often? I go off-roading about once per month spring-fall and use them a lot in the winter months. My guess is though, that what most people assume is "hub failure" is actually just a vaccum leak problem, which in turn causes the hub to have problems engaging. Because everytime My hubs quit working, it wasn't like they were engaging, and then popping out, they just wouldn't engage at all, or if they did, it would take many tries. When I took mine apart when they started going bad this winter, the actual "hub" parts all looked in good shape, with no abnormal wear. Its hard to explain, but if you have taken the hub apart, you'll know what I mean - There are seals and stuff, that honestly, I am surprised were able to seal it at all, let alone hold pressure under vaccum operation. Has anyone else noticed this when they've taken them apart? Maybe if I get some extra time, I'll take some pics and post them, so people can actually know what I'm blathering about.

 

I live in Cleveland, so we get good snow. I went off road once in the last 2 years, and I hammered it pretty good. If I could, I'd go everyday.

So 4x4 is primarly used in the winter months.

 

I think you nailed it, and I fully agree. Because replacing the PVH hubs also entails replacing seals and O-rings, once the repair is done and the system works again, it's easy for people to conclude (techs and laymen alike) that it was the hubs that failed, when in fact more likely it was a vacuum issue.

I really don't think that a part of the hub asssembly being plastic is a big factor in the failure rate, but then again, I've never had my hubs apart.

I'm sure a lot of people would be interested in pics, including myself.

 

I think you are exactly right rockledge. Everything is replaced when you get the hubs fixed, and you get new seals, which surely seal better than old ones. On a side note....This kind of leads me to belive that if we figured this out here on this forum, I wonder if the dealerships haven't figured out the exact same thing. Except they know that 99% of the public just assumes that the whole hub is bad. So they say they need the whole hub replaced, and then just replace the seals (maybe $20-30 in parts) and then charge you $700. And it now works, so no one ever questions it. I know its unethical, but its had to of happened. Just thought I'd mention that while I was thinking about it. Something to keep in mind if you ever do get them replaced.

I don't think there is any way that the plastic piece would ever be a cause of the hubs failing. The only thing that the plastic piece does is holds the engagement spring..... Well, I was going to try to explain what this all is, but after typing it out and reading it, I decided it would just confuse people more. I'll definatly try to get some pics in the next couple days. That will make explaination easier.