Re: Converter Lock-up
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Forum Ambassador
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Gator -
In general, automatic transmission technology was still in its infancy, back then - still in the process of moving away from fluid couplings, which offered nothing but slip, to true torque converters, which turned much of that slippage into torque multiplication. However, the only other automatic transmission of the period to offer such a feature at the time was made by Borg-Warner for Studebaker, known as Automatic Drive, in the early 50s, though later abandoned due to high cost. (Perhaps the plan was to adopt the Twin Ultra beyond the Golden Hawk, then.) Drivers wouldn't experience anything like the Ultramatic's Direct Drive clutch in any other US vehicle until the mid-70s. I'm no engineer, but suspect that the rest of the manufacturers compensated for the torque converter's loss of power through careful selection of rear axle ratios. WRT automatic upshift. It should come as no surprise that owners were doing the same thing with those early Powerglide units as owners with the original Ultramatics - manually upshifting to High. Powerglide went to automatic upshift in '53; the Gear Start Ultramatic offered same thing in '54. As for use of the term "direct drive", other manufacturers routinely refer to the 1:1 gear in an automatic as "Direct" - even noted as "D" on their shift quadrants. Kind of a moot point since Ultramatic production ended after 1956.
Posted on: 2012/1/6 10:14
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Re: Converter Lock-up
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Forum Ambassador
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As I recall, when moving down the highway PowerGlides and Dynaflows could do quite nicely without the DD clutch assy. Both stayed in production until the early 60's so am sure there was no top end limitation caused by the transmission.
The fact your car is protesting makes me think either there is still something amiss--or perhaps you are comparing sound levels in a 60 year old car with minimal sound deadening to a recent model. As mentioned, check the linkages and if you have a tach see what the engine is actually doing. I believe I saw some posts or perhaps even published data on average engine RPM at 60mph using typical ratios. I'm not a math person but numerous on the forum are so it should be able to be calculated if nothing is found.
Posted on: 2012/1/6 10:34
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Howard
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Re: Converter Lock-up
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Forum Ambassador
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Without bothering with the math, most Ultramatic-equipped Packards had a 3.54/1 rear axle, and with typical 15 inch bias tires of the era, I'd expect engine rpm at 60 mph to be about 2500 rpm. Modern radials will increase that a bit. So just put a tach on it and go for a ride - that should end all the speculation.
Posted on: 2012/1/6 11:14
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Re: Converter Lock-up
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Home away from home
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Absolutely HH, I still plan on performing all of the previously discussed items and I'll be checking linkages this weekend. Next will be pulling the governor for a check and clean at first opportunity whether it needs it or not. I agree that it's not in my best interest to compare the car's characteristics to a more modern well insulated automobile...the old gal's carrying 60 years worth of beatings around and has a few groans and rattles, the speedometer cable's dry and she is rightfully protesting. I have a hand held instrument that measures dwell, RPM, voltage etc. and will hook it up to confirm actual RPM's once and for all however after performing the "LOW" to "HIGH" manual shift last night and paying a lot more attention to how the transmission performed in "HIGH", I'm quite sure that the converter lock-up isn't happening. The only thing I didn't do was put my foot in it to see if it would kick down so realistically, if lock-up is ocurring, shouldn't the kick-down from DD to converter happen?
Posted on: 2012/1/6 11:56
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Re: Converter Lock-up
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Forum Ambassador
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If you would like to read a little about early automatics and the Ultramatic, here are a few articles and reviews done by Popular Science at the time. If you do a search for Packard or Ultramatic in the archives numerous articles are there..
www.popsci.com/archive-viewer?id=WCQDAAAAMBAJ&pg=139&query=ultramatic www.popsci.com/archive-viewer?id=PC0DAAAAMBAJ&pg=101&query=ultramatic popsci.com/archive-viewer?id=DC0DAAAAMBAJ&pg=98&query=ultramatic
Posted on: 2012/1/6 12:25
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Howard
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Re: Converter Lock-up
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Forum Ambassador
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Gator, do you have engine compression slowing the car when you take your foot off the gas at speeds above 30 or so? If you do, you HAD lockup. If you then step on the gas and the car behaves like a stick shift car in 3rd, you still have lock up. If not and the engine "over revs", you don't have a firm engagement of the clutches.
If you drive with your tach in the driver's compartment and note a drop in engine rpm above 30 or so under light throttle and higher rpm occurs when you hit the gas, same thing - DD clutch not holding but you should still engine compression braking effect.
Posted on: 2012/1/6 13:43
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Re: Converter Lock-up
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Home away from home
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You just gotta love those old Popular Science articles!...thanks for posting the links HH. I read all 3 of them and found some very interesting information that shed some light on a few questions I had. The one that explained how the Governor directed oil to lock the converter up was very informative. I especially like the one describing the test drives in the "200" with manual tranny and the "300" with Ultramatic. Who in their right mind would put their car in "HIGH" and let it roll backwards down a 35% grade using the accelerator for braking???...unreal...I see why they nick-named them the Ul-Traumatic now...I liked the way he described the 110 MPH lap around the test track too...just re-enforces the fact that my old Clipper would be hard pressed to make it around at half that speed without blowing something up...
Posted on: 2012/1/6 13:48
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Re: Converter Lock-up
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Home away from home
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Quote:
In all honesty Owen, once I confirmed that both "HIGH" and "LOW" were working, I concentrated on trying to feel DD engage and in doing so, I let off the gas at variety of speeds to try to help it out and never felt engine braking occur...and didn't feel anything like the converter locking in either.
Posted on: 2012/1/6 15:44
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Re: Converter Lock-up
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Home away from home
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One thing I haven't seen established yet (maybe I missed it or forgot it from earlier in this thread) is the final drive ratio.
Maybe someone can chime in on where to verify these ratios by number on the rear axle housing. The correct ratio for an Ultramatic equipped car is 3.54:1 CORRECTION-- except as Gator pointed out, there is also a 3.23:1 on a his '53 Clipper Deluxe. If the number is hard to read or you suspect there might have been some gear-swapping going on, you establish a good approximation of the ratio through a visual check: Jack up one rear wheel. Put chocks under both sides of the other wheel and the two fronts. Support the car with jack stands. Put a chalk mark on the driveshaft on the side facing the jacked wheel. Put another chalk mark on the inside of the jacked-up tire where you can see it easily, the bottom is good. With the car in neutral, turn the driveshaft by hand, counting how many rotations of the shaft it takes to return the wheel chalk mark back to its original position. It should be 3 1/2 tunrs. If you get up to 4 turns, or very close to it, before the wheel makes its single revolution, you have a too-high (numerically) rear axle ratio from a non-Ultramatic equipped car. The correct final drive ratio for the Ultramatic automatic is 3.54:1 (But see correction above) The manual overdrive trans is supposed to be 4.1:1 The standard 3-speed manual would have 3.9:1 ratio (These numbers are from the '52 specs, depending on your model there might be some variation. Remember, I'm not a bona-fide expert.)
Posted on: 2012/1/7 16:25
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Guy
[b]Not an Expert[/ |
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