Re: Ultramatic Shifting Question
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Dear Casey:
Opinions differ. Some opine that using Low is easier on the reaction member in the torque converter. My feeling is that Low to High range is a synchronous shift and not the greatest thing to be doing. However, in the case of a leisurely L/H transition I really don't know what to make of it. I always just put those things in High range because by the time you get to 15-20 mph under normal conditions it's equivalent to second in a three speed and soon going into direct. For breakaway in today's driving I suppose you really need to use Low, except that I know of the method breaking the band when used in an extreme manner. When set up properly the Twin UL does okay in Drive range, but when there's a valving problem the thing can be in two ranges at once so I just never drove the V-8 in anything but High range given that I didn't know whether it had the proper valve body updates. If you feel any tendency for dragging in the Low High shift don't do it because you're putting the thing into two ranges at once.
Posted on: 2012/7/22 13:49
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Re: Ultramatic Shifting Question
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Misread the question in my first response. My bad, but not the first or last time.
Believe originally it was recommended to use high range for all driving. Low was only for emergency pulls. Tim gives good advice but the fact the writer let off the gas before shifting to high goes a long way to prevent issues. I believe some of the trans guys have said it was the shift under load where low was released almost immediately effectively going into neutral letting engine speed up while high was still trying to engage made the clutches slip severely. The clutch plates had to slow the engine back down again and transmit power at the same time. Burning the clutch plates was the primary cause of problems. In late 53 because so many owners were doing the low to high manual shift, they introduced a revised shift timing kit to help the situation. The details are in Sept 53 Service Counselor Vol 27 #9 but essentially it slowed low band release and sped up high engagement. A few months later there was another revision to the timing pin included in the kit to refine the shift a bit more. The pin in the original kit was found to have a bit of an overlap issue under some conditions with two gears at once on occasion. The gear start and later TU's just followed along automating, revising and refining that treatment with controls and piston units more suitable to that operation. There was a learning curve again with the new arrangement but by the end of production, most of the bugs had been worked out.
Posted on: 2012/7/22 14:01
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Howard
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Re: Ultramatic Shifting Question
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Quote from post 1:
" describes how he would start the car in low, get up to 25 miles per hour, let off the gas, and then shift into high". 25 mph in low????? Is that a misprint???? Should it be Five or maybe 15 mph at the max???? Must be a misprint unless the author was discussing drag racing or pulling Airstreams thru the Rockies or similar operation. Mite want to reread the article. If 25 mph in low is correct and exactly what the author meant then maybe he also indicated something like a 2.90 rear axle ratio???
Posted on: 2012/7/22 15:39
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VAPOR LOCK demystified: See paragraph SEVEN of PMCC documentaion as listed in post #11 of the following thread:f
https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?topic_id=7245 |
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Re: Ultramatic Shifting Question
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My 56 Exec with 55K+ miles, very original car and i'm confident an unmolested T-Ultra is still running fine. It does have some whine to it when cold.
My driving for the last 14 years and 20K+ miles is to only use "D" under adverse conditions. Rarely do i ever use "D". At least 90% of the driving is using "H". Low is rarly engaged.
Posted on: 2012/7/22 15:57
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VAPOR LOCK demystified: See paragraph SEVEN of PMCC documentaion as listed in post #11 of the following thread:f
https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?topic_id=7245 |
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Re: Ultramatic Shifting Question
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Home away from home
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Here's an older thread discussing the topic;
https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?topic_id=2914&forum=3&post_id=30322#forumpost30322
Posted on: 2012/7/22 16:02
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VAPOR LOCK demystified: See paragraph SEVEN of PMCC documentaion as listed in post #11 of the following thread:f
https://packardinfo.com/xoops/html/modules/newbb/viewtopic.php?topic_id=7245 |
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Re: Ultramatic Shifting Question
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Home away from home
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As I'm getting to know the T-U in my '55 I find that I get a whine when in Park cold or hot - just like the Power Glide in my parents '57 Chev from new.
I too mainly use the "H" range as my T-U seems to like that better. Upshifts in "D" are still high and a little harsh until the transmission is warmed up but it's getting better. "H" range upshifts are a little late (I guess) and can be felt until it is driven for a few blocks but that's getting better as well. I figure I should give the T-U a little time given that it sat parked for 27 years - actually, given that it has only had the "drop pan and clean pan & screen" with new fluid service, I'm amazed that it works at all. The Ultramatic in my '51 will smoothy shift into Lock-up as soon as engine speed stops climbing or 25mph, whichever comes first - almost always the former unless I'm trying to get up to merge speed on a freeway on ramp. Also, I don't do the freeway thing all that much in the '51 as since there were very few "freeways" when that transmission was designed. I try to drive it and the '55 in the context of their time.
Posted on: 2012/7/22 16:22
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1951 200 Deluxe Touring Sedan
1951 200 Deluxe Touring Sedan (parts ?) 1951 Patrician Touring Sedan 1955 Patrician Touring Sedan |
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