I checked the vacuum on my engine, and it was 11 Hg at idle. I was able to get it up to 13 Hg with a little fiddling of the idle air mixture screws on the Holley Truck Avenger carb. You've got a vacuum leak, and I bet your carb settings are way off. Have you addressed the rest of the setup? What exhaust are you running? Is the carb lean on tip-in if you've got a dual exhaust system? What's your distributor advance look like? You should have 34 degrees total, but you can put in lighter advance springs so your timing comes in at 2,600. You've got a lot more power waiting in that combo. Take some time and get it running right, and I'm sure you'll be more than pleased with the results.
I recently tried to remove the rear driveshaft in my '59 CJ-5 to replace the U-joints. I wasn't able to remove the nuts that hold the rear driveshaft flange to the back of the T-case-mounted drum because the bolt spins with the nuts. Is there an easy way to get a wrench to the back of these bolts to keep them from spinning? I don't have a factory service manual and can't figure out how you're supposed to service the darn thing.Kyle MorrisLexington, Kentucky
The Spicer 18 drum-brake assembly can become a bit problematic as parts wear and as these vehicles change hands through ham-fisted mechanics. The driveshaft flange is held in place by four 31/48-inch bolts that pass through the back of the parking-brake-mounted drum. Normally, the heads of these bolts are captured by a raised ring on the backside of the drum that prevents the bolts from spinning as the nuts are tightened or loosened. The problem is the cast-iron drums often become fatigued and can crack if the nuts are tightened too forcefully.
You can try to get a thin, curved pry bar, a screwdriver, or some other homemade device through the holes in the side of the drum to wedge against the bolt heads and keep them from spinning, but it's most likely going to be an effort in futility. Your best bet is going to be getting a small die grinder or Dremel tool with a mini cutoff wheel and carefully cutting off the nuts.
Once you get the driveshaft flange nuts cut off, you can remove the yoke nut and then the yoke and brake drum. You can try spot-welding new 31/48-inch bolts to the back of the drum to keep them from spinning, using special bolts with a T-shaped head, or just purchase a new drum from ATV Manufacturing (360/256-3843, www.hermtheoverdriveguy.com).
Got a tech question you're just itching to get answered? Send it on in to Jp Magazine, Your Jeep, 6420 Wilshire Blvd., Los Angeles, CA 90048, or e-mail christian.hazel@jpmagazine.com.