Piston Slap: The Case for the Front-Mounted Transaxle?

Sajeev Mehta
by Sajeev Mehta
piston slap the case for the front mounted transaxle

DAG writes:

Why don’t automakers design front-wheel-drive cars with the transaxle in front of the engine? This moves the front wheels forward and improves weight distribution; offers better potential for aerodynamics and leaves space under the hood for pedestrian protection. With a turbo four-cylinder, the engine could have clearance from the firewall. Also, the engine and transaxle could be mounted on a pivoting subframe, hinged at the front, to drop down at the back for major maintenance; disconnect steering and exhaust to drop cradle.

The engine would sit in the space where rack and pinion generally resides; steering gear design would be a challenge for direct mechanical actuation. Perhaps traction would be reduced. Would crashworthiness also be affected?

Sajeev answers:

Interesting query! I’m happy to play devil’s advocate to your modern-day Cord powertrain layout:

  • Potential aerodynamic benefit is eliminated via pedestrian safety regulations. Larger front fascias increase surface area in contact with humans, thereby reducing physical damage from knee-bending.
  • Head protection isn’t likely, thanks to our cab forward designs — more cab, less hood and a greater chance the pedestrian’s head still slams somewhere needing 10 cm of space above the engine intake manifold.
  • Hinged subframes bring crashworthiness concerns. While I can’t google up proof, subframes are designed to prevent the engine from intruding into the passenger compartment in a head-on collision. They normally move down and/or under the firewall, and a hinge introduces a fail point in something that must not fail.
  • Not concerned about steering system interference; most vehicles use electric steering now.
  • V-shaped engines would be tough in this configuration. Perhaps one day we can have a V6 engine renaissance. Perhaps it will lead to something deliciously looney like a second-gen LS4. That’s not likely with this design.

This is probably another case of automakers doing their jobs by not reinventing the wheel, by protecting us from what we want. But hey, if it worked on the Cord …

[Image: Shutterstock user Andy Dean Photography]

Send your queries to sajeev@thetruthaboutcars.com. Spare no details and ask for a speedy resolution if you’re in a hurry…but be realistic, and use your make/model specific forums instead of TTAC for more timely advice.

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2 of 24 comments
  • Greg Locock Greg Locock on Apr 05, 2017

    "Not concerned about steering system interference; most vehicles use electric steering now." They still have steering columns and steering racks. Main reason I know of is that the space in front of the engine is wasted for crash because it is resisting engine mass as well as the rest of the cabin. If the engine hits the crash barrier immediately then you can use the space behind the engine to decelerate the safety cell.

  • JamesGarfield JamesGarfield on Apr 14, 2017

    Doesn't anyone remember the RUXTON? It used a reverse Inline-8 engine-transaxle, FWD design: https://en.wikipedia.org/wiki/Ruxton_(automobile) And it actually slightly pre-dates the Cord. They are VERY rare. Only 33 of them known to remain, with only about 16 in running condition. The latest restored one auctioned for about $370,000. If you want a really fascinating read, check out this thread on its insanely immaculate restoration: http://forums.vwvortex.com/showthread.php?6206837-1932-Ruxton-build-thread-or-quot-How-I-became-an-unwitting-restorer-quot

  • Lou_BC "Owners of affected Wrangles" Does a missing "r" cancel an extra stud?
  • Slavuta One can put a secret breaker that will disable the starter or spark plug supply. Even disabling headlights or all lights will bring more trouble to thieves than they wish for. With no brake lights, someone will hit from behind, they will leave fingerprints inside. Or if they steal at night, they will have to drive with no lights. Any of these things definitely will bring attention.I remember people removing rotor from under distributor cup.
  • Slavuta Government Motors + Government big tech + government + Federal police = fascist surveillance state. USSR surveillance pales...
  • Johnster Another quibble, this time about the contextualization of the Thunderbird and Cougar, and their relationship to the prestigious Continental Mark. (I know. It's confusing.) The Thunderbird/Mark IV platform introduced for the 1971 model year was apparently derived from the mid-sized Torino/Montego platform (also introduced for the 1971 model year), but should probably be considered different from it.As we all know, the Cougar shared its platform with the Ford Mustang up through the 1973 model year, moving to the mid-sized Torino/Montego platform for the 1974 model year. This platform was also shared with the failed Ford Gran Torino Elite, (introduced in February of 1974, the "Gran Torino" part of the name was dropped for the 1975 and 1976 model years).The Thunderbird/Mark series duo's separation occurred with the 1977 model year when the Thunderbird was downsized to share a platform with the LTD II/Cougar. The 1977 model year saw Mercury drop the "Montego" name and adopt the "Cougar" name for all of their mid-sized cars, including plain 2-doors, 4-doors and and 4-door station wagons. Meanwhile, the Cougar PLC was sold as the "Cougar XR-7." The Cougar wagon was dropped for the 1978 model year (arguably replaced by the new Zephyr wagon) while the (plain) 2-door and 4-door models remained in production for the 1978 and 1979 model years. It was a major prestige blow for the Thunderbird. Underneath, the Thunderbird and Cougar XR-7 for 1977 were warmed-over versions of the failed Ford Elite (1974-1976), while the Mark V was a warmed-over version of the previous Mark IV.
  • Stuart de Baker This is depressing, and I don't own one of these.