Myths about automatic transmissions?

[_HighVoltage_]

Yesterday I heard something very weird from my Polo's mechanic. He said that all engines above 3 litres need to have automatic transmissions, if you don't want to replace the clutch and transmission every 10000 miles.
I think it sounds absolutely ridiculous and stupid, but maybe I'm wrong? He said that when I mentioned I was thinking of buying a 305 Firebird with a 5 speed manual.
So is it true or not - larger engines fair better with automatic transmissions?

[ESPNSTI]

I had a '93 Firebird Formula 5.7L 6-speed and I put at least 20000 miles on it after I initially bought it when it had 27000 miles on it.
Most of the time I was running it through the gears to red-line, shifting quickly, and I never had any problems with either the transmission or the clutch.
Of course just after I sold it to a friend of mine, he broke the rear axle (or maybe it was a drive shaft).

[avanti]

[Spectre]

Originally Posted by _HighVoltage_

Yesterday I heard something very weird from my Polo's mechanic. He said that all engines above 3 litres need to have automatic transmissions, if you don't want to replace the clutch and transmission every 10000 miles.
I think it sounds absolutely ridiculous and stupid, but maybe I'm wrong? He said that when I mentioned I was thinking of buying a 305 Firebird with a 5 speed manual.
So is it true or not - larger engines fair better with automatic transmissions?

You need to find a new mechanic. He's full of shit.

You do know that those monster semi trucks in the US are almost invariably manual transmission equipped, right? That's behind a 8-14 liter or larger diesel engine... and if they had to replace the clutch (let alone the transmission) every 10K, they'd get an automatic. They don't have to, so your mechanic is an idiot.

[Cobol74]

100,000 miles more like.

[Brother Michael]

I am not a mechanic, but what does the engine size have to do with anything ? Of course bigger engines tend to have more power, but this kind of argument really sounds like someone who has never heard about turbos/superchargers.

[_HighVoltage_]

He is full of sh*t from time to time. I guess his point will be valid for someone who doesn't know how to drive a manual car and the more torque the engine has, will ruin the clutch quicker.
But then, we are talking about a european mechanic and I don't think he has worked on an engine bigger than 3.5 litres....

[DarkReaper]

Meh, my 635 has (as the name suggests) a 3.5ltr I-6 and it is still on the first clutch after 232000km, even though slight wear is surfacing already, thats a hell of a lot more than 10000km.

If you wear out a clutch after 10000km, you are either abusing your car on a racetrack way too much, or you are too retarded to get your foot off the clutch pedal and ride it while driving.

[avanti]

everything will eventually break if used in a manner it was not designed for over an extended period of time.

[jayhawk]

Originally Posted by _HighVoltage_

He is full of sh*t from time to time. I guess his point will be valid for someone who doesn't know how to drive a manual car and the more torque the engine has, will ruin the clutch quicker.
But then, we are talking about a european mechanic and I don't think he has worked on an engine bigger than 3.5 litres....

Even if the car had more torque, the clutch is designed from the get-go to handle what goes through it from the factory. It's all relative.

IIRC, the clutch plate and and disc on that Firebird is big and heavy, probably the same ones the used in the C/K trucks.

[tigger]

Originally Posted by _HighVoltage_

He said that all engines above 3 litres need to have automatic transmissions, if you don't want to replace the clutch and transmission every 10000 miles.

Unless he's a crack mechanic (and I'd be amazed if he is with statements like that) I'd find someone else. God, that makes my head hurt.

Originally Posted by jayhawk

IIRC, the clutch plate and and disc on that Firebird is big and heavy, probably the same ones the used in the C/K trucks.

Incorrect good sir , the F-Body used a Borg-Warner 5 speed, the trucks used (still use?) a New Process unit. But the F-Body transmission and clutch are probably interchangeable with the S10 (at least the ones that have a 4.3L)

[Spectre]

Actually, the only difference on their disc and plate (between the T-5 F-bodies and the NP-equipped trucks) is that the disc has a different spline setup. Otherwise, they're identical between the light duty trucks and the F-bodies.

I found this out when converting a Jag to use a T5 behind the Jag engine.

[NooDle]

your mechanic < common sense < Finalgear

if big powerful engines required an auto, every 18 wheeler in the world would have one. Yet they all have manuals

[prizrak]

Originally Posted by NooDle

your mechanic < common sense < Finalgear

if big powerful engines required an auto, every 18 wheeler in the world would have one. Yet they all have manuals

Actually if that was the case than the RS4, M3/5, GT-R, Ferrari's, GT, Lambo, and Veyron would all be using autos. While some of those have auto clutching/DSG transmissions they are still basically manuals, i.e. there are no TC's or clutch packs with gear sharing.

[Viper007Bond]

As said, more powerful engines require a larger clutch plate(s), so it all evens out.

[JipJopJones]

In some cases, a well built manual transmission will be stronger than an equivelent autobox.

I was out at the mud flats the other day.... I saw two guys blow their auto tranny's when they were stuck in the same mudpit. a guy with a standard had to pull them both out.