Clutch in before RR Crossings

[MotoSook]

I had a meeting at a remote site this morning, and I was driving the Fat Bastard Carrera. I went over a bunch of railroad crossings, most of them at cruising speed, and some of them were not smooth by downtown Chicago pothole standards..

Anyhow, I found myself clutching before I hit the tracks so as to take some of the suspension impact off the engine. I held the clutch in until I got pass the bumps. I must have been doing this for a while in my other cars, because it didn't feel like a new habit...

Anyone else do it?

(And for the Safety Police, I was moving fast enough not to stall on the tracks to cause a derailment if an oncoming train had to drop anchor! If you don't know how to keep your car running over a railroad track...you should be driving Nike walking shoes )

[Rot 911]

Same here. I guess subconsciously I think I might have to also brake if the bumps get too bad.

[jluetjen]

I don't clutch -- but I do tap the brakes just before the crossing so that the car loads the front and then unweighs it again as the nose comes up -- hopefully just when the front wheels cross the tracks. This reduces the load on at least the front tires. I believe that Vic Elford also suggested this trick to ease the shock of hitting a rut when rallying.

[trj911]

I do the same thing. And I will cover the brake with the other foot just in case. Wierd huh! I thought I was the only person to do that.

[MotoSook]

I just remembered something. Several years back, I was in my 911 going over a railroad track after an hour or so of driving on an interstate. I the tracks were less than 1/4 mile from the off-ramp. I clutched in when going over the tracks, and when I released the clutch to continue on my way, I give it gas and didn't go accelerate...Argh! I pull over and inspected things. The engine spun nicely, but no power to the ground.

Looked inder the car and there hung one of my axles. The damn allen bolts on the CV come loose and the tracks must have jarred the last bolt off the threads...

No entirely related, but if I had not clutched in, I might have bent more than one bolt (MAYBE...the bolts were backed out well before that, but there was one that was probably bent when I re-applied power after the tracks). Fortunately, I was able to get 5 of the 6 bolts in and continued my trip.

[VaSteve]

Originally posted by Souk


Looked inder the car and there hung one of my axles. The damn allen bolts on the CV come loose and the tracks must have jarred the last bolt off the threads...

Why didn't the car just go in a circle? Like a one legged duck swims. Seriously.

[Oldporsche]

clutching it before bumps such as railroad tracks will take the driving load off the suspension. Gets a little smoother ride.

David Duffield

[rcecale]

I clutch for speed bumps as well...just seems like a natural thing to do.

Randy

[bsaffin]

Originally posted by VaSteve
Why didn't the car just go in a circle? Like a one legged duck swims. Seriously.

Wouldn't that only work with LSD?

...Bruce

[JP911]

I've always pushed in the clutch going over railroad tracks in all cars I've owned (some of which should have been left on the railroad tracks).

[VaSteve]

I'm pretty sure I do it. Not many RR tracks here near me. But the reason for that is, generally I need to significantly slow down. As such, I need to pick a different gear to get going/keep going. Same thing with speed bumps like Randy said.

[audi2.7t]

Originally posted by VaSteve
Why didn't the car just go in a circle? Like a one legged duck swims. Seriously.

Not to be a wise a$$ BUT ,having grown up on a farm ,I can assure you that a "one legged" duck swims just as straight as a two legged duck ,also ,wouldn't it require a full diff lock to enable forward drive on one drive shaft ? .

p.s.
I also clutch and pre-load the front end before ANY significant bumps or holes......learnt that on the farm too ,(Wales has some of the best rally courses in the world)

[VaSteve]

Originally posted by audi2.7t
Not to be a wise a$$ BUT ,having grown up on a farm ,I can assure you that a "one legged" duck swims just as straight as a two legged duck ,also ,wouldn't it require a full diff lock to enable forward drive on one drive shaft ? .

Wise-a$$es are welcome here!!!

[audi2.7t]

Originally posted by VaSteve
Wise-a$$es are welcome here!!!

Why does your talking duck only have one leg ??

Well ,if you had a duck that can talk would you eat it all at once ?

boom ,boom ,tushhh...

[concentric]

I do this too, and take my foot of the gas...
My car is really light in front and reacts quite violently to rough dips and stuff like RR tracks, so I take my foot of the gas pedal so I won't lurch the car when the impact jars my body around.

Sometimes I use the Elford trick when feeling frisky.

JCM

[gar]

Originally posted by VaSteve
Why didn't the car just go in a circle? Like a one legged duck swims. Seriously.

Because the in an open differential system, power is transmitted through the path of least resistance.

That's why if one tire doesn't have traction, your ability to create initial forward momentum will be limited.

The solution would be a limited slip, or a locking differential. In the case of four wheel drive vehicles that are actually used off-road, the transfer case is locked to allow power to be delivered to the axle that still has traction. With regards to each axle, a limited slip or locking differential can be used in addition to the locked transfer case -- the net effect being that only one of four tires needs to have traction to allow forward movement. For those without limited slip or locking differentials, a supple suspension is the key, as wheel lift due to a stiff suspension can cause a loss of traction and thus forward momentum.

[Schrup]

I don't clutch in, but I do usually stab the brakes like John. During the last Canadian trip I was following Dane through some canyons when we came up on some tracks right after a corner at about 70mph. He bottomed out real bad, so I slammed on the brakes & released just before the tracks, but still hit pretty hard. It could have been a lot worse, I think my car is a little lower than his.

[TerryH]

I usually try to catch air as I slalom those gates that are in the way, blinking and clanging.....

[goat]

Originally posted by Schrup
I don't clutch in, but I do usually stab the brakes like John.

I have got in the habit of doing the same thing.

[VaSteve]

Originally posted by TerryH
I usually try to catch air as I slalom those gates that are in the way, blinking and clanging.....

Terry this is for you:

http://www.oli.org/





...(I knew you were kidding)