FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: Stick or Automatic ??? DATE: Sat, 23 Oct 99 23:40:45 GMT ORGANIZATION: A1 Internet news-server NEWSGROUPS: rec.autos.4x4 In article <3810d0be.4236891@news.glinx.com>, sbest@TAKEOUTglinx.com (sbest) wrote: >On Thu, 21 Oct 1999 09:07:28 -0400, "Randy Given" >wrote: > >>I'm planning on getting my first 4x4 in the >>next couple months. I've always had a >>stick/manual, but I've seen a LOT of 4x4s >>with automatic transmissions. Is there a >>reason besides simple preference (i.e., >>is there something about automatics on >>4x4s that is preferred)? > > > 2 feet, 2 pedals, this seems like a no brainer for me! > > If you do mainly road driving with a little bit of snow and mud thrown >in, it really doesn't matter, get what pleases you. If you are serious >about taking your 4x4 into some tricky spots, go for an automatic. > > The torque convertor multiplication can give you as low a ratio as any >granny gear, and the smooth shifts make accelerating on slippery surfaces >a joy in comparison to a manual. What if you don't want a shift? You might be able to avoid upshifts, but there are *very* few auto's where you can prevent a downshift. I HATE the auto on my dad's Mercedes in winter....it has a shift-life of its own (in favor of heating up both engine and tranny). >With a good low rpm torque engine there >is little likelihood of stalling an auto on dangerous sections of trail, >unlike a novice with a manual. In larger trucks if you stall you lose your >power brakes and power steering. Pretty scary, in fact could be deadly. > > An auto is more capable, period. I drive manual shifts as well, in fact >I have 2 of them. I like them but they are limited compared to an auto and >take much more skill to maneuver in the tricky sections. You don't have much control over most trannies, definately not in upshifting (unless one has a late Tip-tronic style auto, or an aftermarket modified auto-control), and even less in preventing it from downshifting when stepping on the gas pedal....there are many cases where you want more throttle, but not a downshift, especially in low grunt diesels. > As for repair costs, it can cost nearly as much to have a clutch >replaced as to rebuild a 3 speed auto. If you can replace a clutch >yourself you can drop an auto transmission and carry it into the tranny >shop saving yourself $200-$300 in the process. If you can replace the >bearings in a manual transmission you have more than enough skill to >overhaul an automatic. A broken manual transmission will usually cost you >more to fix than a worn out automatic. If you look after the automatic, >change the fluid yearly, don't tow in overdrive and install a large cooler >on it, it will last very well. > > The only advantages a manual transmission has is better holdback on >hills, which can almost be duplicated with careful brake use Actually, a manual allows you to use your brakes, but still not lock up your wheels....hence anyone claiming 'use your brakes instead of your engine' has a poor argument, unless in the posession of a offroad-worthy ABS (which doesn't start skidding uncontrollably *over* sloppy stuff). >and low drive >gears, and the ability to bumpstart, which is pretty much impossible to >duplicate with most autos. Buy good starters, seal them well, run good >cables and don't run your battery flat or carry booster cables. Mercedes auto's used to have an second oil pump on the tranny side, to allow this bumpstarting.... -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: sbest@TAKEOUTglinx.com (sbest) SUBJECT: Re: Stick or Automatic ??? DATE: Sun, 24 Oct 1999 04:11:59 GMT ORGANIZATION: Business Internet NEWSGROUPS: rec.autos.4x4 > sbest@TAKEOUTglinx.com (sbest) wrote: >> The torque convertor multiplication can give you as low a ratio as any >>granny gear, and the smooth shifts make accelerating on slippery surfaces >>a joy in comparison to a manual. > On Sat, 23 Oct 99 23:40:45 GMT, w.j.markerink@a1.nl (Willem-Jan Markerink) wrote: >What if you don't want a shift? >You might be able to avoid upshifts, but there are *very* few auto's where >you can prevent a downshift. I HATE the auto on my dad's Mercedes in >winter....it has a shift-life of its own (in favor of heating up both >engine and tranny). Most North American (all I can speak for) 3 speed autos would hold in 1st or 2nd forever if that is where you left the shifter. With the standard shift or a soft shift kit they can do the shift exceptionally smoothly, much better than most guys could ever up or down shift a manual. I can pull a fast sliding shift with a manual (especially useful for rope towing) but it is kind of rough on the clutch. The main reason for holding in gear is that a rough shift would upset traction. A smooth shift with slight adjustment of the throttle will cover this up nicely the rare occaision it is needed. I'll bet more guys stall on a difficult technical section than ever disasterously lose traction on a slippery section from and auto shift. After some courtship time has passed you get to read the shifting pattern of many transmissions, especially the older hydraulically shifted 3 speed autos. The newer 4 speed electronic autos are more complicated but probably would become familiar with time. Now my wife, I can't figure her out... >>With a good low rpm torque engine there >>is little likelihood of stalling an auto on dangerous sections of trail, >>unlike a novice with a manual. In larger trucks if you stall you lose your >>power brakes and power steering. Pretty scary, in fact could be deadly. >> >> An auto is more capable, period. I drive manual shifts as well, in fact >>I have 2 of them. I like them but they are limited compared to an auto and >>take much more skill to maneuver in the tricky sections. > >You don't have much control over most trannies, definately not in >upshifting (unless one has a late Tip-tronic style auto, or an aftermarket >modified auto-control), and even less in preventing it from downshifting >when stepping on the gas pedal....there are many cases where you want more >throttle, but not a downshift, especially in low grunt diesels. I don't have many complaints with my prechamber injected 6.9 International with a C6 Ford auto behind it. It actually is very much like a spark ignition engine with its 3500 rpm limit and modest low rpm torque. I have another truck with the 6.9 and the manual transmission for a good comparison and while I enjoy the stickshift, its clanky shifts suck compared to the finess possible with the automatic in my van. A friend of mine has a 94 Dodge Cummins with the autotrans and quite frankly I hate driving it. It always seems to shift out of sync with what the motor is looking for. Another buddy has a Cummins in an older Ramcharger (some info about it on my webpage) with a 4 speed stickshift behind it. With the torque of the Cummins it is almost stall-proof. It works much better than the auto truck for the exact reasons you state. I would certainly agree with you on that particular engine. The only sure rule is that there are no sure rules... :-) >> >> The only advantages a manual transmission has is better holdback on >>hills, which can almost be duplicated with careful brake use > >Actually, a manual allows you to use your brakes, but still not lock up >your wheels....hence anyone claiming 'use your brakes instead of your >engine' has a poor argument, unless in the posession of a offroad-worthy >ABS (which doesn't start skidding uncontrollably *over* sloppy stuff). Notice I said "which can ALMOST be duplicated with careful brake use" I certainly agree with you, a manual in low will roll down a slippery hill slowing down (or accelerating as little a circumstances allow!) as much as possible while allowing every wheel to rotate and maintain all the control possible, whereas trying to do the same thing with brakes (esp drums) can lead to single wheels locking up. Incidently LSDs help reduce this effect in my experience. The best advantage an auto has is that a properly set up engine won't stall. I have, er I've known guys that applied a little too much brake on a manual while rolling down a slick downhill, locked up, stalled the engine, and then went for "Mr Toad's Wild Ride" with the brakes and steering inactive, the truck accelerating and sliding sideways while trying to restart the engine! With a small truck like a Suzuki with no power steering or power brakes this is a none issue. An auto would sap too much power from the already underpowered engine and the slick shifting Japanese manual is a joy to play with. Not so an American piece of heavy iron. >>and low drive >>gears, and the ability to bumpstart, which is pretty much impossible to >>duplicate with most autos. Buy good starters, seal them well, run good >>cables and don't run your battery flat or carry booster cables. > >Mercedes auto's used to have an second oil pump on the tranny side, to >allow this bumpstarting.... Now THAT would be nice. I don't know if you could put compressed air to a band on a North American transmission and achieve the same effect or not. Steve Best, Nova Scotia, 4x4 van website: http://www.glinx.com/users/sbest Date sent: Sat, 20 Nov 1999 23:16:17 -0800 From: Kirk Cowen To: w.j.markerink@a1.nl Subject: you were right... Hi Willem-Jan. I replied to Coby's newsgroup message to you like this: Coby Hughey wrote: > No, they won't. You won't stall the converter if you've got adequate > torque, Oops, I hope that statement is a brain fart on your part Coby, otherwise it shows us that you've been blowing a lot of hot air... Read my lips; YOU CANNOT STALL A TORQUE CONVERTER WITH A "SICK" ENGINE, because IT CAN"T DEVOLOP ADEQUATE (enough) TORQUE!!! You WILL be able to stall the converter if you have a good engine with lots of torque. > you will use the torque multiplication much less if you've got more > than adequate torque. Dude, you've been sleeping in class again!! Your torque converter (multiplier) works on the difference of speed between the input element, and the output element, PERIOD. It does this AUTOMATICALLY, except when they install a lock-up clutch; then it's no longer a torque multipier when it's LOCKED-UP!! At that point, it's just a fluid coupling. > What is it about torque converters that you don't understand? You're > showing a sincere lack of comprehension as to their operations; is > there anything I could help you with in terms of understanding them? If you nail the gas at a stop light, the engine accelerates until the converter is absorbing all the torque the engine can produce (and if you've got a honking big torquey engine, you'll be able to stall the converter). ONCE THE CONVERTER HAS BEEN STALLED, ANY MORE TORQUE PUT INTO THE CONVERTER IS TURNED INTO HEAT, LOTS OF IT!! The converter is multiplying the engine torque to it's designed maximum value, and that value is then multiplied again inside the tranny when the planetary gearset is in low. The resulting value is multiplied again inside the transfer case (if yer in low range), and inside the rear end through the gears. Once the truck starts to roll, the torque demand begins to drop off as away you go!! Engine 2500 rpm (or whatever the stall speed is)+ transmission input shaft 0 rpm=MAXIMUM TORQUE MULTIPLICATION IN THE CONVERTER. Torque is the grunt that gets your truck moving, and keeps it moving... run out of torque, and you have to shift down (multiply it). > Ask some questions; I'm sure there's many here wiling to help you > understand. That is, if you've got the "desire" and "ability" to > understand. This is why it's a nightmare to come down a long hill with an automatic tranny and a gvw maxed out truck. There isn't ANY torque multiplication in the converter, because it is being driven by the weight of the vehicle through the rear end/transfer case/transmission low gear... and it's missing that extra torque multiplication inside the converter. The converter isn't designed to sense the speed difference when the tranny is going faster than the engine... it's like coming down a hill in second, or third gear in a standard tranny, instead of low. > >Bye, > > > >Willem-Jan Markerink > > > > The desire to understand is sometimes far less intelligent than > the inability to understand > > > > > > Coby, I had to learn this stuff to pass my hydraulics section... I really didn't understand it either until I had to learn it. The math involved in choosing a gearset, or rear end ratio is simple physics math, nothing wierd or esoteric. PAW/JC Whitney/Summit cary a book on auto math that lays it all out for you, and it's actually interesting to get down and crunch the numbers to see how to pick a gearset. Krik FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: What's better for towing -Manual or Auto? DATE: Sun, 25 Jun 00 22:11:42 GMT NEWSGROUPS: rec.autos.4x4 In article <3955e83a.2883947@news-server.optonline.net>, cprstnc1zz@optonline.net (Ken) wrote: >In general, an automatic is preferred for towing because the torque >converter absorbs jerks and multiplies torque. Sounds cute, until you look at the typical 1st gear ratio of auto vs manual....mostly, if not always, 1st-auto is much higher than 1st-manual. That makes at least the claim of a torque multiplication 2x hogwash....you're lucky if 50% is left, instead of 100%. Also note that the moment the vehicle starts rolling, torque multiplication immediately drops....ending at 1.0x when rpm's match completely. And this is still with the same higher 1st gear.... -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!] FROM: w.j.markerink@a1.nl (Willem-Jan Markerink) SUBJECT: Re: 4 Wheel ABS & 4 Wheel Drive DATE: Thu, 31 Aug 00 13:31:37 GMT ORGANIZATION: A1 de Internet Provider uit Twente B.V. NEWSGROUPS: rec.autos.4x4 In article <20000831070905.04660.00000340@ng-fi1.aol.com>, aloliveira@aol.comspamBgon (AlOliveira) wrote: >>The TJ's that I have wheeled with really had trouble coming to a stop on >>50+ deg dirt/gravel down hills. They were going more than 5 mph at the >>start of the run and needed to stop for a hairpin/drop off. Their ABS >>'appeared' to be on all the way to the tree. I was spotting for them >>and never saw a skid on the front tires. Back tires, yes, but not near >>enough grab to stop them. > >My guess as to why the rear locked and not the front is that if they were going >down the hill nose first, all the weight was on the front wheels. The rear were >light and locked up. The solution here would not be to disable the ABS but to >lock the CDL and keep it in 4L and use the engine to slow the vehicle. If all 4 >wheels lock up you might still skid but then you have no directional control. Anyone driving downhill on a steep dirt road *without* engaged 4wd (including locked centerdiff on fulltime rigs) shouldn't behind the steering wheel in the first place....they deserve to crash, once the rear wheels lock up instantly, and the front wheels hardly ever lock up at all. Or: why sit behind the steering wheel if you choose to loose steering control completely, by only looking at the brake pedal? And this is also the best example of why slush-boxes stink for offroad....with a manual gearbox you can push heavily on the brakes, without wheels locking up, but still building ramps in front of the wheels (remember, in 4wd, they either lock all at once, or none), since the engine will still rotate the wheels....the same with an automatic means a much higher chance of lockup. This combination of 'rolling' & 'ramp building' is also how good ABS-systems act....much longer periods of lock-up, followed by controlled rolling (present on the latest Land Cruiser (100-series), among others). Add 'diesel' & 'torque at idle' and you know why gasolines have a huge disadvantage as well....;-)) -- Bye, Willem-Jan Markerink The desire to understand is sometimes far less intelligent than the inability to understand [note: 'a-one' & 'en-el'!]