Where is the PARK in a manual trans???????

[Deere Jon]

A few of my fellow coworkers and I was discasing this today. Farm tractors have had park built into the transmittions for years, why cant our five and six speeds have park also. It seems there is a logical explanation for this but we could not figure it out.



I also don't want to hear any talk about parking breaks or emergency breaks because they suck a magor "ford"

 

[dan brooks]

... why cant our five and six speeds have park also.

Probably because 75% of the people out there can't distinguish between first and reverse - adding park to a manual would really confuse 'em.

:-laf



Seriously, I have no idea, but it probably has more to do with cost than anything else (like all the other important stuff they leave off... ).

 

[Paychk]

Gee... I thought there are 6 possible park positions, I personally prefer granny or reverse. Or are you referring to a place you can start the engine without pressing the clutch in?

 

[cguthrie]

ok most of the tractors that i've seen with park have been auto manuals so i'm not sure what your talking about? the ones that i've seen you could just shift through the gears without using the clutch so if you know more tell me about it. Like paycheck said, the tractors that are manuals i would just lock them in gear or there was a (heres what you didn't want to hear) parking brake on them.



Chris

 

[bgilbert]

The way I do it, try to find a level parking place, wait to see that its not gonna roll, get out, and I use two wheel chocks around one of the tires. Thats if I'm not gonna be with the truck. For shutdown, turn it off, put it in gear. I never use my parking break, it doesn't wanna release afterwords. I'd really like to have one of those cable/lever type driveshaft parking breaks.

 

[Lnwing]

manual "park"

I've owned several Masseys with this type of park mechanism. It's a very positive "parking brake" when it's in good condition. Like anything else, though, it's subject to abuse.

The "brake" is actually a straight-cut gear on the output shaft of the transmission, and when it is engaged, a "pawl" is rolled into the gear, locking the shaft. Obviously, the tractor should be completely stopped before engaging the park, or bad things start happening. When you start jamming it into park while still on-the-roll, teeth get sheared from the gear, and linkage gets twisted, which can make it difficult or impossible to disengage without a nudge from another tractor. If you decide to fix it, including replacing the gear, get your wallet out. Split the tractor and start digging; the park gear is the last one out of the transmission!

IMO the existing parking brake on our Dodges looks pretty good!



FWIW,



Lynn

 

[DKarvwnaris]

Probably because 75% of the people out there can't distinguish between first and reverse - adding park to a manual would really confuse 'em.

:-laf

QUOTE]

Because this is sadly all too true, would you really want a locking pin in a manual transmission for a light duty truck? I can just see a new truck owner, who just traded in a fwd 5 speed car forgetting to disengage the park gear or pin in their manual transmission. This would be followed by a sharp and distinctive "SNAP" sound as the moron releases the clutch shearing the pin off. Followed by a close approximation to a coffee grinder as the broken pin runs up into the the other gears. Not something I would consider a wise choice for the auto industry to utilize. Having a park pin gear in an automatic is not for the vehicle to be held in place with anyways, it is merely to prevent the lazy person who doesn't engage the park brake. Ever try to get a parked vehicle out of "P" that is on a hill that did not have the parking brake when shut off? The park gear pins are not designed to hold back the weight of the vehicle on anything but perfectly flat gear. The only difference between "neutral" and "park" in a car is the park gear provides a stop for the car when it is being started,mainly so the vehicle does not immediately push forward of back while cranking.

So I guess the parking brake is best solution as it allows the vehicle to be held in place yet still have the ability to be moved if someone starts the vehicle and forgets to take the shifter out of "park" gear before letting the clutch out. Sorry you had to hear about parking brakes, but thy are there for a reason, not just for emergency stopping.

 

[Deere Jon]

Fool proof way to prevent stupidity!!

Make the shift leaver be the leaver that engages park. You would have to pull it from park to put in first or reverse. I assume our trans use shift collars to connect gears to the shafts. All they would have to do is make a cam that engages first and third gear while leaving the input shaft free and the truck could go nowhere. The thing that brings this up is it is cold here and most of us don't want to shut our trucks off while opening a gate, or we don't want it rolling down the hill while letting the engine warm up.



Thanks for your replys

 

[DPinkston]

The thing that brings this up is it is cold here and most of us don't want to shut our trucks off while opening a gate, or we don't want it rolling down the hill while letting the engine warm up.

Thanks for your replys

Not intending to stir the pot, but this is the very reason I keep my parking brake in working order. I can't imagine driving a straight shift without a functioning parking brake. I have had to replace several cables over the years but it's cheap compared to the convenience and safety.

Danny

 

[DKarvwnaris]

Make the shift leaver be the leaver that engages park. You would have to pull it from park to put in first or reverse. I assume our trans use shift collars to connect gears to the shafts. All they would have to do is make a cam that engages first and third gear while leaving the input shaft free and the truck could go nowhere. The thing that brings this up is it is cold here and most of us don't want to shut our trucks off while opening a gate, or we don't want it rolling down the hill while letting the engine warm up.



Thanks for your replys

I understand the reason you brought it up, It is one of the only drawbacks to a manual. I also make sure my E brake is always adjusted up and the cables tight.



You haven't resolved the idiot factor with your solution, You could still start the truck in "park", and accidentally release the clutch. I guess they could install a detent switch in the "park" section of the gear set like reverse has for lights, but it would have to also kill the ignition immediately if someone placed the shifter in park before shutting the engine off. You would run the same risk of slipping a foot off the clutch too soon. This is alot of liability to worry about for the manufacturer and still have the only physical disengagement device in the hands of the owner, the CLUTCH!!

I guess you either suffer with an automatic all year, or suffer with a manual on the few times you need to leave the engine running and get out of the truck. Minor inconvenience to me. I have a wheel chock in the bed for these moments.

I would like it if the Manuals were equipped with a "park" too, but til then, I will simply engage the transfer case into 4wd and leave the transmission in Neutral, with a firm parking brake to hold all 4 tires in place. I have yet to have mine roll in the many years of doing this. The 4wd in addition to the parking brake I feel is why.

Be careful what you wish for, Mercedes has several transmissions in Germany that are electric manual shifts. You don't have a clutch pedal, it is all engaged with a computer. Kind of like the tiptronic in the VW's and Porches. Not good!!! I wouldn't want to loose my clutch to something like that, this is what they would probably go to for a solution.

PLEASE DON"T OFFER IT AS A SUGGESTION TO DC, they've screwed up enough stuff already!!!!

 

[Paychk]

All they would have to do is make a cam that engages first and third gear while leaving the input shaft free and the truck could go nowhere.

The act of engaging any gear is locking that gear to the main shaft (output shaft), so what you are proposing wouldn't work. But it could be done with a locking paw similar to what automatic transmissions use, this would have to be located on the output shaft. I don't see any reason it wouldn't work except cost, bean counters have a lot of sway in the world now a days.

 

[MChildress]

My JD tractor has the park position on the gear shift. I'm not sure of the machanics but you can have the clutch engaged or disengaged with no ill effect. They did away with the e-brake with this park position.

 

[DKarvwnaris]

My JD tractor has the park position on the gear shift. I'm not sure of the machanics but you can have the clutch engaged or disengaged with no ill effect. They did away with the e-brake with this park position.

I never thought of a tractor transmission. You are right, they have another position for the shifter to slide into. My grandfather's old tractor had this. It left the input shaft still in neutral, but slid a tooth against the output shaft. I wonder if the transmissions sized for our trucks are big enough for the revision A 5 or 6 speed has alot of shift channels as it is.

Knowing how cheap DC has become, I think we'd be waiting a long time. Not many people would think the park capability is worth designing. Few get out of their trucks anymore, most garage doors in suburbia are powered up/down etc.

 

[GBechtold]

PLEASE DON"T OFFER IT AS A SUGGESTION TO DC, they've screwed up enough stuff already!!!![/QUOTE]



Thats an under statement :-laf



My grandfather has a JD 2520 with power shift it has the park position and you have a clutch to put it in gear but once you get it moving you don't need it.

It's kinda like that gyraflight trans dodge had out in the 50s or 60s sorta like a week version of an Allison.

How about putting a disc brake or a band brake like the OTR trucks used on their drive shafts back years ago it probably wouldn't that hard to do.

 

[DKarvwnaris]

How about putting a disc brake or a band brake like the OTR trucks used on their drive shafts back years ago it probably wouldn't that hard to do.

I bet a fixed yolk kit with a disc brake mount on the transmission or transfer case output would work well. I have seen them on a few of the aluminum bodied Fed Ex trucks and some bread trucks. They use a cable operated caliper to hold them in place, those would be a good backup, wonder how much if any drag the rotor and pads would put on the output yolk?

 

[GBechtold]

I bet a fixed yolk kit on the transmission or transfer case output would work well. I have seen them on a few of the aluminum bodied Fed Ex trucks and some bread trucks. They use a cable operated caliper to hold them in place, those would be a good backup, wonder how much if any drag the rotor and pads would put on the output yolk?

You could probably adjust the drag if you made it mechanical instead of hydraulic operate it with either a cable or linkage my freind has an old AutoCar cabover from the 40s and it has a disk brake on the drive shaft and it has likage going up to the cab to a parking brake lever.



Also I saw some where some cranes have an electro magnet on their drive shaft and the flip a switch and it creates drag I believe the company is Krupp?

 

[f.boyle]

I would prefer an air brake system!!!!!!I'm working on it but having trouble with the 4x4 front end. our engines are all set up for an air compressor, the rear end is easy enough to rig but the front?????????

Chainsaw