Automania/Repair & Maintenance

AUTO QUESTIONS AND ANSWERS FOR WEEK 23 YEAR 2000

by Bob Hagin

Q. I have a 1982 Isuzu pickup truck. It has 243,000 miles on it and I only drive it to and from work. I haven't kept it up very well and now the rear end is making a lot of noise. I checked the level of the oil in the rear end but I couldn't feel any with my finger so I put in two pints that I bought at the parts store. It didn't help much and I'm afraid that eventually it will stop working altogether. I want to keep the truck because everything else is working OK and I'd just have to buy something else. A friend told me that the he'd help me put in a rear end out of a junked Isuzu pickup but I haven't been able to locate one in local junk yards. Is it much work to buy new parts and have my friend help me fix it or should I find a shop that will do it for me cheap? D.B. Portland, OR

A. Keep searching for a used replacement differential unit, even if you have to go on the internet and search one out around the country. It's fairly easy to replace the differential center section complete and universal shop manuals like those published by Chilton, Motor or Haynes will tell you how to do it. On the other hand, rebuilding the one that's in your truck now will be pretty expensive. The four roller bearings alone may run a couple of hundred dollars, depending on who you buy them from. I can only guess at the cost of a complete set of gears for the unit, but the time estimate given is between four to six hours of skilled, technical labor so the price there depends on your local rate.

Q. I would like to know if using 87 octane unleaded regular gasoline in an engine for which the manufacturer recommends 91 octane unleaded will cause any damage. The engine is in an Acura 3.2TL. R.L. Dixon, CA

A. Since Americans are notorious for neglecting and abusing their vehicles, I believe that Honda over-designed the electronic engine management system in your Acura to accommodate almost any modern fuel. In simple teams, the higher the octane number given a particular fuel "blend," the slower the burn rate and the more resistant the engine is to detonation and "pinging." Since the difference between 87 and 91 octane is only a few points, I think it's safe to say that slightly lower octane fuel won't damage your engine.

Q. I'd like to buy a used Ford pickup truck, about a '94 Ranger, but I'm not sure of what engine I want to get. I understand that the four-cylinder model will give me better fuel mileage but I'm not sure if it has enough power to stay up with traffic while carrying a medium load. The truck has two different V6 engines available, one was a three liter and the other was a four liter. How much better gasoline mileage will the smaller V6 engine get? I'm not sure if I should get the long or short wheelbase truck or one with a long cab that has more room in back. A.R. Tucson, AZ

A. You need a more in-depth analysis than I can give you since we don't have that kind of statistical input from readers. For more background on the '94 Ranger (or any vehicle), check it out in an April issue of Consumer Reports. We don't get all versions of all vehicles but we did a road test of a Ranger Splash pickup in '94. It was a long-cab model with extra space behind the seat and it had a 4.0-liter V6. We liked the fact that it seemed to have plenty of power for the tasks we did but we only have test vehicles for a week. The mileage wasn't great at 18 mpg average, and we all noted that while the regular cab model of '93 we tried cramped us, the long cab on the '94 was very comfortable. As an aside, Ford 3.8-liter V6 engines are having head gasket problems, but we haven't gotten complaints about either the 3.0-liter or 4.0-liter V6 in that year Ranger. You may not have lots of '94 Rangers to pick from so be prepared to take what you can get.