[beee240]

I recently bought a 88 wrangler with a 258 5sp and everything is breaking on it! My main concern is that our recent snowstorm in Baltimore showed me that the 4wd doesn't work. I replaced the harness(connected correctly to front axle and transfer case but not sure about other connections in engine compartment). Does anyone know what could be causing my hubs to not engage even though the front drive shaft is spinning? I also have problems with the carb. which was replaced two months ago(slightly eratic idle and sometimes I will have to floor it for a split second to get the damn thing to accelerate smoothly).
If anyone has any info on where the vacuum lines for the 4wd go near the engine please give me a clue.

Bryan

 

[Guest]

Wow, lots of questions... /wwwthreads_images/icons/smile.gif I can't answer all of them... I'll try for one though... /wwwthreads_images/icons/wink.gif

On the 4wd not engaging... there are some vaccum lines that attach to the axle boss on the passenger side of the vehicle (at least on 94's). This is what engages the 4wd. Lots of people are upgrading to a pull-link system.

If you can afford it, get rid of the carb. Those things are known weaknesses in the 87-91 YJ's...

Watch out for bad grounds, too!

Another Jeepgeek!
Jon YJ94

 

[beee240]

My first attempt at fixing the 4wd prob was to replace the vaccuum harness for it. I know that it is hooked up right to the front axle,but after checking it out some more this morning, i think that my vaccuum motors(or whatever they are behind the air cleaner) seem to be bad. As for the carb., I may just try a Holley. Does anyone know how many CFMs would be ideal for the 258?
Thank YJ94 for your suggestions.
PS . Where can I get the pull-link system and how much do they run?

 

[260]

Here's the link for the cable:
http://www.off-road.com/jeep/reviews/rocklock/rocklock.html

I've asked a lot about what carb to put on a 258 and the general reply was around 390 cfm was the biggest you would want to go.

87 wrangler - 258

 

[Guest]

Here's a clickable link http://www.off-road.com/jeep/reviews/rocklock/rocklock.html

I remember there was a discussion not too long ago about the vacuum motor... I think it was a relatively "simple" fix... i.e.: standard tools and standard knowledge can apply... /wwwthreads_images/icons/smile.gif

Good luck!

Another Jeepgeek!
Jon YJ94

 

[109]

The main problem with the vacuum shift system is the axle collar itself. It gets stuck on the splines from lack of lubrication. You need to remove the shift motor from the axle tube and lube the splines and collar with axle grease.

You would need to do this regardless of the actuator system, whether cable or vacuum. Hope this helps and Good Luck!! /wwwthreads_images/icons/smile.gif

 

[Dirt Dog]

/wwwthreads_images/icons/smile.gifI really don't have any answers for you but I had to add this.
/wwwthreads_images/icons/tongue.gifWelcome to the world we love and cherish. We call it Jeeping./wwwthreads_images/icons/wink.gif

I knew everything when I was 16......How come I'm so stupid now?

 

[Guest]

check out www.off-road.com/jeep/tech258bbd/Major.htm
i just bought an 87yj and am having trouble getting it to run smooth. have been giving it a once over an still dont have it right yet. my 4wd works great. looks like you have some help on that subject. good luck!

 

[035]

was thinking about your 4wd not working, i would try to narrow it down to a vaccum problem or a mechanical one first.
do you get the advisory light that says 4wd?
how about with the transfercase in 4 low/high and the engine running, pull the 3 vaccum lines off the axle, does one have vaccum?
have you taken the 4(i think) bolts that hold the vaccum disconnect onto the axle off and see if the collar can be slide left/right from the middle shaft onto the right shaft half way?
maybe try to operate the vaccum disconnect with another source of vaccum to move the shaft with the shift fork in/out?

3/4tonYJ
My Jeep Page

 

[beee240]

There is no light that comes on when i engage that transfer case.

 

[035]

i assume the engine is running when you checked, it has to be for the disconnect to engage.
below the battery on the fire wall is a vaccum switch (i think it's blue) has one vaccum hose hooked to it and maybe one or two wires i can't remember.
hook up a vacuum source or just swap a hose that has vacuum (while engine is running) onto that switch and then see if the light comes on then? Just testing the switch, it sould come on.
if it don't come on, then check for vaccum at the hose you took off in the first place, (this hose comes from the axle disconnect, it only has vaccum if the axle disconnect has splined the shafts together).

how about the other stuff?

3/4tonYJ
My Jeep Page

 

[Guest]

Did you check the hubs? I had the same problem with the front drive shaft spinning, but the wheels not turning. I opened the hubs up and found that the driver side hub was totaled on the inside. replaced them and all is fine now

 

[beee240]

Found the problem!!!!!
It is the set of little pumps behind the air cleaner (3 pumps).
There is no vaccuum from any of them.
So, does anyone know what that entire setup is called. (the three pumps and the assembly that it sits on)?????[question]

 

[Guest]

yo beeeeee
you need to check out:
www.off-road.com/jeep/tech/258bbd/Major.htm
enter address complete as shown.
very valuable info and the answer to your question.
i ran a hard copy of complete menu at site.
you will really get off on this site as your 88yj will pertain.

good luck

steve

 

[beee240]

The little pumps I was talking about is a vaccuum switch. Couldn't find one that looked to be in good shape so I went for a new one. $115.50 (ouch), but it may solve more than one of my probs.
Thanks for all of the input/wwwthreads_images/icons/smile.gif