Topic: 4WD not engaging

[jfrabat]

Hey, guys, I went to use the 4WD yesterday, but it would not come on.  I imagine it will be a vacuum line that is not correctly connected, but I have not yet opened the hood or gotten under the jeep to check.  But what do you guys think?  Vacuum line or something else? 

I am actually considering the posi-lock for the front axle, but I dont know if it is worth it.  Any comments on that as well are welcomed!

Felipe

[Rob the plumber]

Your vacuum disconnect is probably sticking. The Posi-lock is a great idea. almost a requirement. My disconnect sticks in cold weather. If I heat it with a torch for a second it pops right in.

[jfrabat]

Well, I know mine is not sticking as a result of the cold...  I live in Miami, so 60 is FREEZING for us down here, and today was the first day that the temp dropped below 70!

[oldjeep]

For the price of a posi-lock you can get a non disconnect D30 from a cherokee.

[Jesse-James]

Your vacuum disconnect is probably sticking. The Posi-lock is a great idea. almost a requirement. My disconnect sticks in cold weather. If I heat it with a torch for a second it pops right in.

Mine did this last night, had to bring it in the heated garage at the shop and let the Heep thaw.

[jeepheap]

posi lock. but upgrade you fork. mine took a crap recently and it just sucks to have to pull it apart again. in the cold that you lucky..... 60 is freezing. 10 then other night in delaware with the 40 mhp winds. but then again when you guys get winds there usually a state of emergency becuase it a hjurricane!

[jfrabat]

Do they sell extended vacuum lines for when you lift the Jeep?  By the way, the part about the Posi-lock that makes me not finalize making the decision is the fact that if I do decide to upgrade the D30, the alloy shafts are not compatible with this system, because they do not have the disconnect.  But who knows...  I may end up doing it anyway!

[Jesse-James]

One piece shaft from a TJ D30 eliminates this problem. It's on my list. It's a long list.

[Jeffy]

One piece shaft from a TJ D30 eliminates this problem. It's on my list. It's a long list.

Or XJ shafts from +94.  You also upgrade the U-joints since the (pre-94) YJ's use 260x and the later axles use 297x which can be further upgraded to the 500 series.

[jfrabat]

Hey, guys, considering my vacuum lines are almost 14 years old, I was thinking since I will be looking into this as a result of this problem, I might as well go ahead and replace them (they are really not all that expensive to replace, from what I have seen).  But I was wondering if there was a kit that came with all the hoses and fittings that I could use.  I saw from http://www.hosetechniques.com/ that they have universal kits that would fit my Jeep (no kits specifically made for Jeep, so I got to go with this one) and the hoses go for about $130, but I need to figure out the fittings that I would need to make all new connections and forget about vacuum issues for a good couple of years.  Any comments on this?

[Jeffy]

Hey, guys, considering my vacuum lines are almost 14 years old, I was thinking since I will be looking into this as a result of this problem, I might as well go ahead and replace them (they are really not all that expensive to replace, from what I have seen).  But I was wondering if there was a kit that came with all the hoses and fittings that I could use.  I saw from http://www.hosetechniques.com/ that they have universal kits that would fit my Jeep (no kits specifically made for Jeep, so I got to go with this one) and the hoses go for about $130, but I need to figure out the fittings that I would need to make all new connections and forget about vacuum issues for a good couple of years.  Any comments on this?

That stuff is pretty *bling*.  I think it's a bit thick too.  Maybe 3-4x as thick as the stock lines.

[jfrabat]

That stuff is pretty *bling*.  I think it's a bit thick too.  Maybe 3-4x as thick as the stock lines.

Which brand would you recommend, then?  I didn't look too deeply into this, but it was the first vendor I found...

[garydubf]

we had the same problem on my boys jeep.  For half the price of any of the posi-lok or stock replacement parts we made a plate to block off the hole were the disconnect mounts and slid a junk yard Tj axle in!  No more problems, no more vacuum lines to get ripped off, no more vacuum leaks!  Took about 3hrs once we had all the parts!

[jfrabat]

How does a TJ axle handle the disconnect?  Because if I put a one piece axle, the front shaft will start to rotate during 2H driving, right?

[oldjeep]

How does a TJ axle handle the disconnect?  Because if I put a one piece axle, the front shaft will start to rotate during 2H driving, right?

There's no disconnect on a TJ.  Yes  the front shaft will rotate, but that's what they are built to do