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Discussion Starter #1
It was mentioned in a different thread but i thought i'd start the conversation as a new one to keep that one on topic...

I've also heard before (not on any particular make or brand of vehicle) that using the gear selector to change gears is not good to do all the time. Why not is my question?

I don't see the difference between the transmission getting a signal to shift from the data it pulls or getting a signal to shift from the gear lever.


(i guess i can understand not leaving the gear selector in neutral when drifting down hill but that's different than just selecting gears at your whim... although is there an issue leaving the t-case in neutral drifting down hill?)
 

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ewalberg - 5/3/2005 1:10 PM



I don't see the difference between the transmission getting a signal to shift from the data it pulls or getting a signal to shift from the gear lever.
1.) How about on a long highway down grade to save the brakes?

2.) Off road to maintain better control, especially when crawling down hill??

I so much prefer the manula selection on the pre-2002 G's, as opposed to the Tip-Tronic or whatever it's called. Wasn't someone with this newer and "better" shift method complaining about the lack of control here recently?
 

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Discussion Starter #3
Yeah, i use the lever all the time (without issue) but i've heard people say it's not good to do so, so i'm just wondering if anybody knows a real reason why it's not good. I can't think of any.

I cant remember who it was, but they found that triptonic has a safety feature that will automatically shift for you anyway even if you don't want to. With our version, there's no safety feature so you "could" over-rev on a super steep decent. But it'd have to be pretty damn steep with 340 ft-lbs of torque on the V8. I know for a fact that there's a rev limiter so you can't throttle yourself into the red even if you want to.

I do basically like the old style better because it's more effortless to tap between 4th and 5th. (i use that all the time) BUT it is a hassle to get into first, which i don't like, but i take it as a mechanical version of a safety feature. It reminds me of reverse on a manual transmission, you have to be deliberate to access such an infrequently used gear.

I like more the manual transfer case... it's a physical action. I kinda wish the diff locks were still manual too. I think on the newer trucks though you don't have to shift the gear selector into neutral when you push the button. That's kinda cool. It took me a couple tries to get quick at working the two levers... i'm assuming i'm supposed to be shifting into neutral before dropping it into low range?

On the new tacoma's you have to stop the truck to shift into 4wd. how sad... now that is regression no matter how you look at it.
 

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ewalberg - 5/3/2005 3:20 PM
....they found that triptonic has a safety feature that will automatically shift for you anyway even if you don't want to. With our version, there's no safety feature so you "could" over-rev on a super steep decent. But it'd have to be pretty damn steep with 340 ft-lbs of torque on the V8......
If that "automatically shift for you" thing exists (menaing that it'll shift to second even if you've manually selected 1st) then I certainly hope it's electronically taken out of the picture when you have the center diff locked or something. An un-anticipated upshift when you're trying to engine brake down a steep decent would almost certainly be disasterous. It would take a heck of a steep, long decent to push red-line, and if you had the traction to push the motor to redline, then you'd have teh traction to modulate the brakes a little and avoid it too.

And 340 ft lbs is what's available under POWER, full throttle, at some rev value. What's resisting during engine braking going downhill is a heck of a lot less than that, in large part due to the fact that while your foot is off the gas, the throttle butterfly is fully closed and each compression stroke starts with a vacuum in the cylinder. If that cylinder could be filled with air, and no fuel, on each stroke, you'd have lots better compression braking. That's part (in addition to the higher CR) of why diesels have so much better compression braking than petrol engines. The cylinders are always filled with air, only fuel is deprived to make more or less power with the gas pedal.

If you had a nice controlled downhill area, you could do a test. Roll down the hill as normal, engine running, foot off gas. Then do it again with the ignition OFF and your foot to the floor on the gas pedal. See which way results in higher speeds at the end of the slope

-Dave G.
 

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I have never broken a Auto box on a G and used the manual shift many many times to get max acceleration when being chased by unwelocme Soviet or DDR forces,I think today its called sport mode. I dont, know about modern boxes tho, The old boxes were 4 spd and other than 1st locked down, the other 2 that is 2nd and 3rd would allways change up one gear if manualy selected but at much higher revs.I never gave much thought as to why it worked like this, I was just blooming glad it did and got me out of many a scrape with the enemy.
The other hugh advantage was the unique feature that only the MB auto box had when fitted to a G.
 

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I am amazed that not one person wanted to know what the unique feature of a G auto box is. or do you all know.
 

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Pray Tell!!

4x4rancher - 5/6/2005 4:50 PM

I am amazed that not one person wanted to know what the unique feature of a G auto box is. or do you all know.
Prey [sic] tell. We're waiting with baited [sic] (at least it smells that way on some [xx(]0 breath.[:D]
 

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OK, I'll bite.

4x4rancher - 5/6/2005 1:50 PM

I am amazed that not one person wanted to know what the unique feature of a G auto box is. or do you all know.
I do know that on my 98 there is a signal line that tells the auto box brain that the the transfer case is in low range. I haven't quite figured out what it does with the knowledge though.
 

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4x4rancher - 5/6/2005 5:31 PM

It can be tow started in first gear.
Even the new ones?
 

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Get outa town!

An auto box you can bump start? That's HUGE! How'd that get by this long without general public knowledge?!?!?

-Dave G.
 

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Answered My Own Question

DUTCH - 5/6/2005 6:15 PM

4x4rancher - 5/6/2005 5:31 PM

It can be tow started in first gear.
Even the new ones?
From page 9 of the "Driving" booklet part of the "Owners Manual G-Class":

It is not possible to tow-start the engine in an emergency.
This is for a G500 (and probably others) with the 722.6 5-speed automatic transmission.
 

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Towstarting the G

The towstart feature is linked to the older autoboxes having a second hydraulic pump on the output shaft. That was dropped some time ago.

I had an old 220 that had that feature. Used it once. It was quite a shock when the pressure finally built up and it suddenly clutched first gear. Glad I had my seatbelt on.
 

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4x4rancher - 5/7/2005 1:19 PM

I thought the thread was discussing the older auto boxes.
ewalberg was talking about the 722.6, 5 speed auto. It started in another thread and he moved it with a new thread.
 
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