Blocks Vs. Shocks: What Fits Where
Question: I have an '89 Chevy fullsize Blazer with a 5-inch block in the back. Will shocks from the same-year Blazer that has a 3-inch block fit mine?
Answer: That is kind of a "yes, no, or maybe" question. No, it will not work if the shock was originally sized properly for extended and collapsed length. Most likely it will be 2 inches too short and will not allow the suspension to drop down its full amount. OK, maybe you can live with that, but it's really not a good idea to let the shock be the suspension stop, either in an extended or compressed position. This can lead to bent and broken shock shafts and ripped-out mounts.
How to check for the proper length? Take both shocks off, block the front wheels so the vehicle cannot move, and then jack up the rear of the vehicle by the bumper until both rear tires are totally off the ground. Now measure the distance between the upper and lower shock mounts. Might want to add an inch or more as a fudge factor for when the vehicle is at full articulation-that is, one wheel up with the axle on the bumpstop and the other fully dropped, as it may be a bit further. This is the extended length that the shock needs to be.
Set the vehicle back on the ground and measure the distance between the two shock mounts. Write this number down. Measure the distance between the bumpstop and the axle, keeping in mind that the bumpstop will compress. How much is your guess, but guess more, rather than less. Now subtract that number from the first number you wrote down and this gives you your compressed length for the shock. It's not going to be exact, but most likely close enough. Most of the lift kit companies and/or shock manufacturers have charts that show the various lengths available.
What I usually do when building a vehicle takes a bit more time but is a lot more accurate. If it has coil springs, I put the vehicle on jackstands, remove the coil, and cycle the suspension with a floor jack to get my measurements. If it has leaf springs, I take a main leaf only and install it. That way, it's again easy to cycle the suspension with a floor jack. On a spring-over axle suspension you have to add a block to the thickness of the remaining spring leaves that you plan to use in between the axle and the main leaf in order to get the proper measurements.
Oh, and a quick check to see if you got the compression length right is to take a small zip-tie and put it on the shock shaft, right next to the body of the shock. As the suspension cycles, the zip-tie will move and then stay at the furthest compression point.
Land Rover Disco Oil Leaks
Question: I have a '99 Land Rover Discovery with the 4.0L V-8 engine. It now has about 120,000 miles on it and an oil leak that seems to be coming from the rear of the engine. There is not a Land Rover dealer near me, so perhaps you could be kind enough to tell me where this leak is coming from, and if I can fix it myself or have it repaired by a local shop.
Answer: I don't get many Land Rover questions and I find them pretty hard to answer due to my inexperience with them. However, in this case I think that I have an answer that you are not going to be very happy with. The leak could be coming from lots of sources, and hopefully it's nothing more than a leaking valve-cover gasket. That would be good news.
The bad news is that most likely the oil is coming from a leaking cam bore plug or a cam oil-galley plug. It's a common problem with these engines, and yours has most likely been leaking for quite some time and it's now getting worse. It's an easy 30 minutes or so fix using the proper sealant. I would recommend using Loctite No. 243. Doesn't sound so bad, right? Well, the problem is that the transmission, bellhousing, and flywheel have to be removed to get to these plugs, which is a major job.
Best Auto-Tranny Swap For CJ-7?
Question: I have an '85 CJ-7 with a Warner T-5 manual transmission, in place of which I would like to swap in an automatic trans. The Jeep has a 258 six, Dana 300 transfer case, Dana 30 front, and AMC 20 rear axles. What would be the best affordable auto trans that will bolt in? The Jeep is used for mild off-roading and has 32-inch tires on it.
Answer: Jeep offered the three-speed Chrysler-built TorqueFlite automatic transmission as an option. This would be the simplest and most affordable trans to use. However, you just can't use any TorqueFlite. It has to come out of a CJ with the Dana 300 transfer case. One reason for this is that the transmission's mounting face has the proper Jeep bolt pattern and the rear has the proper adapter to the transfer case. My guess is that you're going to have to do a bit of searching to find one.
Another way to go that is quite a bit more expensive is to use one of GM's 700R4 four-speed automatic transmissions. Actually, this is a much better trans in that it not only offers you a much lower First gear (3.08:1 vs. 2.74:1), but the added value of an Overdrive Fourth gear. The drawback to this is that you will need two adapters: one for the trans to engine, and the other for the trans to the transfer case. Novak Conversions (www.novak-adapt.com) has the engine-to-trans adapter (PN 437 AMC-1), and the trans-to-transfer-case adapter (PN 137).