Date: Fri, 20 Jul 2007 13:19:18 -0700
Reply-To: Scott Daniel - Shazam <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Shazam <scottdaniel@TURBOVANS.COM>
Subject: Re: Talk to me about AT's!
In-Reply-To: <BAY125-F273EB6172710FB9C3C64E5A0F40@phx.gbl>
Content-Type: text/plain; charset="US-ASCII"
Very true on towing an automatic vanagon - you can't, unless you remove the
axles.
There's one other thing someone mentioned.....
Do it with the engine running.
Be silly to tow a van with its engine running, but that would probably
protect the auto trans.
Trans in neutral.
scott
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Dennis Haynes
Sent: Friday, July 20, 2007 12:12 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Talk to me about AT's!
FYI
The problem with towing does not have to do with gear loading, but
lubrication. There is no splash lubrication of the gears, shafts and
bushings in the automatic section. All lubrication is provided by the pump,
which is only driven when the engine is turning. Some transmissions such as
my mercedes have another pump driven by the output shaft. This provides some
lubrication for short towing and also allows for push starting if you get it
rolling fast enough.
Dennis
>From: Michael Elliott <camping.elliott@GMAIL.COM>
>Reply-To: Michael Elliott <camping.elliott@GMAIL.COM>
>To: vanagon@GERRY.VANAGON.COM
>Subject: Re: Talk to me about AT's!
>Date: Fri, 20 Jul 2007 10:06:38 -0700
>
>Dennis Haynes typed:
>
>[snip]
>
>>However,
>>you may also have an adjustment or control problem preventing the tranny
>>from working completely as it should.
>>
>>For going up hills, when the accelerator is floored, a forced down shift
>>should occur automatically.
>
>That's the "kick down" mechanism, yes? Mine works but it does require a
>fairly manly stomp on the pedal -- just gradually flooring the
>accelerator does not cause the transmission to downshift.
>
> >
>[snip]
> >
>>This will shoot you up most hills. If the hill is
>>extended or you find it hunting between 2 and 3, then manually down shift
>>and back off the throttle to maintain ~ 4,200 rpm. This will keep the
>>engine oil from overheating.
>
>Okay, interesting. I was holding closer to 3,800 rpm. 4,200 is a sweeter
>spot?
>
>>
>>For going down hill, the rule of thumb is go down in the same gear as you
>>would go up. Since the tranny does not know you are going down hill,
>>manually down shift and definitely let the engine braking do some of the
>>work. If you are still going to fast, you want to use the brakes to scrub
>>off speed and then cost again. You don't want to ride the brakes all the
>>way
>>down. There is some skill, art to doing this properly. THese conditions
>>are
>>where larger brakes and vented rotors have benefit.
>
>Thanks -- this makes sense. My unfamiliarity with auto transmissions had
>me thinking about warnings about towing vehicles with auto trannies --
>unless set to neutral? I worried that maybe the axles are meant to be
>the "output" from the gears, and the engine the "input," and that
>driving the transmission from the wheels may cause problems.
>
> >
>[snip]
> >
>>A lower gear makes heat as there are now a lot of gears turning to make
>>the
>>reduction.
>
>Thus the marked change in the sound of the transmission -- the sonic
>character that had me wondering how much stress I was putting on things
>while climbing for a long period in 1 or 2.
>
>>This also makes for a lot more wear but overall it is better
>>than
>>forcing the torque converter and lugging the engine.
>>
>
>Thanks, Dennis -- I hope I'm not the only one who will find this
>information useful.
>
>--
>Mike "Rocket J Squirrel" Elliott
>71 Type 2: the Wonderbus
>84 Westfalia: Mellow Yellow ("The Electrical Banana")
>74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
>KG6RCR
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