Manual Cogs or a Slushbox — Chris Collard’s Rant
There has been a long-running debate over the question of which is better, the free-and-easy automatic transmission or the venerable manual gearbox. Though I’ve spent plenty of time in vehicles with a slushbox between the mill and rear wheels, I will disclose upfront that I prefer manual cogs. This is not to say that the automatic does not present benefits. Many admirers of the automatic cherish the idea of not having to think about which gear they should be in, when to shift, or managing the clutch. However, these attributes are in my opinion, vastly outweighed by good old manually selected gears. Here we go…
Fun Factor: For the pure joy of driving the crown goes the manual transmission. Need I say more?
Thermal Management: This one goes to the manual hands-down. The reason automatics are called so, is because they replace a human-operated clutch with a torque converter, internal bands, and friction plates (clutches). Shift points are determined by hydraulic, vacuum, and/or electronic means, and all the driver has to do is, well, nothing (reread Fun Factor). This is what allows an automatic to stay running while still in gear at a stoplight. The issue is that these components are designed to slip, and slippage generates heat, which can be the death kneel of the automatic transmission. I’ve been on the trail many times when someone with a slushbox had their tranny boil over. In extremely cold climates, the fluid thickens, components contract, and tolerances loosen up. None of this is good for a piece of machinery that relies on hydraulic pressure. It is a good idea to run the engine for a period of time long enough for its latent energy warm up the transmission.
Water Ingestion: The manual gearbox has this one in the bag, no questions. If an automatic takes in water while fording a deep body of water, it’s toast. Draining and replacing the fluid will be of little help, as the lining of the friction clutches will absorb the water and basically disintegrate (if you keep driving it; I suggest turning it off immediately and getting towed to a shop). A manual, on the other hand, will function just fine. Other than the need to flush it thoroughly in the near future, it will get you off the trail.
The Bump-start Factor: Again, the manual takes this one with ease. Anyone with an automatic whom has experienced the “click” associated with a dead battery will attest to this. A manual transmission is perfectly content being pushed, pulled, or coasted down a hill and “bump started.” An automatic, not so much.
Compression Braking: Aside from vehicles equipped with electronic features such as hill decent control and tow/haul modes, an automatic can cause you serious grief while descending steep grades. Hauling a heavy load or towing a trailer will compound the problem. For example, the road to the astronomical observatory in the San Pedro Martir in Baja, Mexico, rises from near sea level to 9,200 feet in about 40 miles, and the majority of elevation gain is in the last 10 miles. Descending this grade with a non-tow/haul automatic will most likely melt your brakes and have you reciting the Hale Mary before you reach the midpoint. With a manual you can select a low gear and let the engine’s compression do most of the work. Yes, this can be done to an extent with an automatic, but with much less efficiency.
Low-speed Technical Terrain: The automatic has some defined advantages in technical terrain…unless you are going down hill. Because it will slip indefinitely, an automatic allows you to surmount obstacles literally at a snail’s pace. However, most automatics have relatively tall gearing, which increases slippage and the associated heat generation (reread Thermal Management). Over an extended period of time this can become an issue. A stick, via careful use of the clutch and gently applied throttle, will force you to master your driving skill (or smoke the clutch…).
In steep descents (or the backside of the obstacle you just cleared) the manual, which allows the driver to use the gears for compression braking, wins nearly every time. The reason is that with an automatic, the engine is continuing to “push” the vehicle; thus relying completely on the brakes to manage speed.
Got a problem? I wouldn’t consider myself a great mechanic, but if I had my druthers I’d rather be tasked with dismantling a manual transmission over an automatic. I’ve had the 5-speed (as well as the transfercase) in my `82 Hilux apart, and short of needing a press and a few specialty tools for certain components, they consist of nuts, bolts, and gears. Also, you can find shop capable of a makeshift repair on a manual just about anywhere in the world. They probably won’t have what we might consider “proper” tools, but they will figure it out.
If you can’t Find’em…Grind’em:
Taking the human element out of the shifting and gear-selection process is arguably better for the transmission and everything attached to it. Stabbing the accelerator and dropping the clutch when one is ticked off at their boss (or soon-to-be ex-spouse) is rough on everything from the pilot bearing to the axle seals. Then there is the grind-a-pound-for-me missed shift, which results in fine (or not so fine) metal shavings drifting around with the transmission fluid through bearings and other machined surfaces. Unless you are running a high-stall torque converter, the drivetrain preservation nod goes to the automatic.
On the Track: This is where the slushbox shines. Sammy Hagar sums it up in his I Can’t Drive 55 lyrics, “One foot on the brake, and one on the gas.” Short of the aforementioned heat dissipation issue, an automatic will allow you to dive into, and push through corners faster and with more control. The theory behind this is left-foot braking. Rather than lifting from the throttle and dropping a gear or two when entering a corner, an automatic allows you to downshift, brake with your left foot, while delicately applying pressure to the skinny pedal (throttle). The result is later braking, greater control, earlier acceleration, and lest chance of jerky clutch input causing the tires to break loose. Having said all this, the manual is still more fun to drive.
Urban Assault: As for driving around town in traffic, sure, I’ll give this one to the slushbox…but who wants to drive in the city.
