Ok, so heres the deal I have a 1999 Ranger with the infamous pvh (pulse vacuum hubs) We have narrowed the issue down to most likely being the hubs with the seals and o-rings are not sealed up OR the lockouts themselves are bad. We tested the vacuum and got about 25 foot lbs and about 12 when switched back to 2-wheel (this from what I have found it pretty good if not mroe than what you need to get the proper vacuum. SO has anyone successfully fixed this system without ripping the vacuum system out and doing some type of mod or switching to rugged ridge manual lockers? Any info would be greatly apppreciated.

(Also we did replace the hub bearing assemblies, o-rings, and seal...but do these need geased the crap out of to hold a vacuum or what?)

-Josh
I love my ranger but it is very very very frustrating not having 4-wheel and still wanting the shift on the fly to work. If we cannot find the solution anyone have a good mod to make the existing hub lockouts into a manual version? I know these mods exist I just havent found very good instruction to do so.

 

Just get the manual hubs. You are wasting your time and money trying to get the vacuum hubs to work. When you think you might need 4x4, leave the hubs locked in, it will not hurt a thing. You will be able to shift on the fly that way. The other option is to swap the CV axles and the hub/bearing assembly from a 2000.5 or newer ranger with LIVE axles. The parts can also come from a 95-01 explorer or 01-05 sport trac. The front will always be engaged, the shift on the fly will work all the time, and with little/no loss of mileage. Every 4x4 ranger after 2000 has live axles and they are stronger and more reliable.

 

x2 just get the manual hubs or swap the axle. easiest thing to do is just get the manuals and leave them locked when u think you'll need them like brian said. I have them and unless you're really lazy or have no legs then i don't see the big deal of locking them.

 

Can anyone explain the process of switching to manauls? Or is there a HOW To?

 

here is the how-to. Its easy and its def. worth it.

https://www.ranger-forums.com/forum2...b-install.html

 

I dont think you tested the hubs correctly. You need to measure leak down. It can't leak any more than 3 inhg per minute.

IMHO, the easiest way to test these is lift the front off the ground and have it in 4wd. If you can spin the tire and the half shaft doesn't spin its the hubs.

 

We have found a pdf page that is a diagnostic to what appears to be from maybe a ford tech. or something similar it has the whole run through of how to diagnose. From reading around the manual lockers aren't the fix all that I'd like them them to be. If i could make my stock rims look decent without the hub caps I would be more intersted but in any case geting out of my truck in 3 feet of snow to engage both then get back in and then go...its a pain. When i have a system that worked just a few weeks ago perfectly fine. Obviously if we can't find and fix the problem I wont have any other choice then to either do the mod or get the manual lockers(which have been breaking on people and I only have one company to choose from [AVM])

 

also...the wheel bearing hub has been replaced with the o-rings and main seal (that darn thing cost $50 each from ford and 35 from rock auto) the vacuum lines appear to be in good working order. So we think the seals need to be seated properly/lubed or it might be the lockers themselves but you would think one would work while the other may have failed. We did have signs of dirt and muck inside the one hub but not the other so... we are going to try and diagnose with a hand vacuum pump.

 

Just a heads up, the breaking AVM hubs are not nearly as common as you might think. Most people who break them are really beating on their trucks. The normal problem is that they can fall off the friction clips with a ton of torque, when is even fairly rare. I wouldn't even really worry about it unless you are running 33-35" tires with a front locker or really low gears for the most part. I ran them on my 98 ranger with 33's for a few years and beat on them hard, and I personally never had a problem. Before I went out to the snow, I just locked the hubs at home. When I get up into the snow, I could switch back and forth between 4x2 and 4x4, and plow through 2+ feet of snow without a problem. Then the electric transfer case motor became much more of a problem than the hubs, as the motor would freeze up when the bottom of the truck got packed with ice and snow.


I understand not wanting to look at the manual hubs without center caps on factory wheels though. Just understand that some of us spent several years trying to get our factory hubs to work reliably and never did, and boy were we thankful when a manual version came out. Good luck with whatever you figure out.

It sounds like you have your options figured out though...
- Fix automatic hubs
- Modify automatic hubs to stay locked all the time
- Replace with fairly inexpensive manual hubs
- Convert to live-axle system that came on 2000.5+ rangers, 95-01 explorers and 01-05 sport trac (also a great option and stronger than any of the others)
-

 

My truck is a PVH, it worked perfect and I still put avm's on. Just for peace of mind. I have never broken a hub, I do drive rather spirited in the snow.

Its not a real PITA to lock them either. If it is snowing or if its in the forecast I will lock my hubs and drive if i need 4wd or not they are locked. I will lock them while the truck is warming. You really should walk around the truck any to make sure your lights and what not are working. Its just a simple click locked in or out.

I have question for you.

Does your heater work as it should? A vacuum leak upstream of the pvh solenoid can cause 4wd issues as well.

 

Heater is working properly and has kept me warm the past few mornings because of the dip down to the mid 30's in Ohio. Im pretty convinced at this point that the system is not sealed up. So we will try to check every point of weakness we think it will be found in the hubs themselves.

 

I did have an issue where the pvh hub would get stuck. It needed to be cleaned and re lubed with a light lubricant that does not evaporate. ie dont use wd-40

 

Did one side still lock in and the one that sticks did not? or is it possible if one goes bad the other wont engage or is it possible one engaged and the other one didnt whick cause the one that wasnt broken to break because it had engaged but the other did not? Hopefully that all made sense?

 

It didn't. lol
My 98 had one hub the wouldn't disengage most of the time. I guess that's better than not engaging though.

 

Keep in mind the front diff is open. If one hub locks in you wont get any power to the front wheels as all of it will go to side not locked in.

Pull your hubs and see if they are damaged or stuck not moving.

 

they seem to push and click like a pen to catch and release. We will lube but they seem to be ok?

 

They sound ok.

AVM's if you cant resolve this vacuum issue.

 

So if i read this correctly I can potentially have one hub locking in and functioning correctly but since they both didnt lock in there is no power to either front wheels...if this is the case it is definitely worth investigating my lockouts...one was all gummed up with water/mud/goo when we did the original replacement of the wheel hub bearing deal.

 

Yes. If only one hub is locked with an open differential, the power takes the easier path which would be the unlocked hub/axleshaft.

 

I am happy to announce that today I have successfully trouble shooted/diagnosed/fixed my PVH system! It took a lot of reading on forums likes these and a faith in finding the problem instead of deciding to just go ahead and switch to the manual AVM hubs! Thanks for all the information you have provided for I have probably used bits and pieces of most peoples insite to either find the problem or eliminate the possiblility of others.

In the end we found it to be this. I have a leak in the mainshaft seal on the driver side. When that seal failed it had caused the vacuum system to fail. When one hub does not get locked in the other wheel will not get power (thanks brianjwilson for that info it really helped out today) the transmission shop had simply said it was the hubs that went bad. So I had ordered and replaced both hubs not knowing exactly what was wrong. We then replaced all the o-rings and seal and we had instaled the seal incorrectly. SO we thought we sovled the seal problem but created another but not installing the new seal the correct depth. We had tested the vacuum lines and found them to be holding vacuum as they should. Today we were able to pin point the leak to how we installed the seals and were able to correct the problem. Nothing was ever wrong with 1. the hub bearing 2. the lockout hubs 3. the vacuum line 4. the vacuum solenoid 5. transfercase/differential...but indeed it was the main seal. For more specific information of how we installed the seal incorrectly ask. I dont feel like explaining it tonight. ha. All I do know is, is that my 1999 ford ranger with pvh hubs has been fixed and will hopefully last many years.

again thanks!
Josh

 

Glad to hear you got it worked out!