Re: Bucking Slightly at Cruising Speeds
|
||||
---|---|---|---|---|
Home away from home
|
I have a 26th series, 327 & Ultramatic.
Transmission: Mine is also very leaky and I top it up as necessary. The low band operates independent like the reverse band, so it not working is probably not affecting high. Have you tried adjusting your low band? It's is rather simple and that may be all it needs. Are you running Type F transmission oil? The Ultramatics, unless they've been rebuilt do not like modern ATF. I would think you would be able to tell if it was your transmission slipping as it should do it under load, such as pulling a hill or giving it more throttle. You could try adding some Lucas Transmission fix to see if it made any difference, but what you're describing doesn't sound like a transmission issue to me, but maybe. Bucking: I would be more inclined to think carburetor issues would be more prominent when the engine was cold, rather than when warm and cruising down the highway. I recently had a similar issue, which occurred when warm, and was erratic. It ended up being a bad coil, which wasn't even a year old. Engine was fine when it was cold and started acting strange when it warmed up. The coil had leaked it's oil, which I discovered because my plug wires were oily under my coil. Replaced the coil and it's been good ever since. Those are my only thoughts at the moment....
Posted on: 7/28 15:50
|
|||
|
Re: Bucking Slightly at Cruising Speeds
|
||||
---|---|---|---|---|
Home away from home
|
Are you sure the bucking is from the engine? It could be the feeling of the DD clutch engagement, if your throttle pressure is set far too high. Sometime drive the car accelerating at low throttle and see when it engages. Pay attention to the engine tone and try to feel a bit of a "thump" as the engine and drivetrain rev-match. If this occurs much above 30 mph then you will want to adjust the throttle pressure. Simply move the respective linkage about an ⅛" at a time towards the carb until it feels right when driving.
Torque tighten the low range brake band to specifications (per the manual) then re-test. If that doesn't cure it, or you are slipping in Low, just forget about it unless you want to drop the trans. But if you're leaking fluid, this should be on your to do list. Keep in mind that the transmissions are the #1 neglected item on these cars due to difficulty in finding parts and service pre-Internet. But once in good shape and kept in adjustment, they should last probably 2 decades or 100,000 miles between major service.
Posted on: 7/28 17:52
|
|||
1955 400 | Registry | Project Blog
1955 Clipper Deluxe | Registry | Project Blog 1955 Clipper Super Panama | Registry Email (Parts/service inquiries only, please. Post all questions on the forum.) service@ultramatic.info |
||||
|
Re: Bucking Slightly at Cruising Speeds
|
||||
---|---|---|---|---|
Home away from home
|
Humanpotatohybrid makes a good point. The service manual, along with this thread, talks about adjusting the throttle linkage and the transmission throttle valve.packardinfo.com/xoops/html/modules/newbb/viewtopic.php?topic_id=28363
My throttle linkage and throttle valve were all whackadoodle, but I adjusted everything back to spec and the direct drive engages just like it's supposed to. It was engaging too soon before. Having said that, at the speeds your talking about, I would think the governor would be overriding the throttle valve and keeping the direct drive fully engaged, which it should be doing when you let off on the throttle so it's using the engine for braking. The more I get things back to spec on my car the better EVERYTHING works.
Posted on: 7/28 18:13
|
|||
|
Re: Bucking Slightly at Cruising Speeds
|
||||
---|---|---|---|---|
Home away from home
|
Correct, a governor sticking at the "low speed" position (inward) could also cause this condition, but it's statistically less likely than someone monkeying with the linkage. And an order of magnitude more of a pain to fix.
Posted on: 7/28 18:17
|
|||
1955 400 | Registry | Project Blog
1955 Clipper Deluxe | Registry | Project Blog 1955 Clipper Super Panama | Registry Email (Parts/service inquiries only, please. Post all questions on the forum.) service@ultramatic.info |
||||
|
Re: Bucking Slightly at Cruising Speeds
|
||||
---|---|---|---|---|
Home away from home
|
Agreed, linkage first. But I found the arm on my throttle valve was not in the correct position either, which may have been adjusted to compensate for linkage that was out of adjustment. It's an easy adjustment.
Posted on: 7/28 18:25
|
|||
|
Re: Bucking Slightly at Cruising Speeds
|
||||
---|---|---|---|---|
Home away from home
|
Yes, Packard specified that the lever adjustment should be within ±1/32, to keep the lever and the throttle valve link "in phase". Having them significantly out of whack will cause odd effects from the resultant non-linearity: the throttle pressure will be lower or higher than would be expected based on pedal position.
Posted on: 7/28 20:03
|
|||
1955 400 | Registry | Project Blog
1955 Clipper Deluxe | Registry | Project Blog 1955 Clipper Super Panama | Registry Email (Parts/service inquiries only, please. Post all questions on the forum.) service@ultramatic.info |
||||
|
Re: Bucking Slightly at Cruising Speeds
|
||||
---|---|---|---|---|
Home away from home
|
Digging in as we speak. I did check my points earlier today, found them to somewhat burned, so there's probably something there. I thought I had a new set, but no dice. Cleaned what I have for now. The coil (Echlin IC-7) tested good. about 1.2 Ohms on the primary winding, 9.84k on the secondary. No indication of leaking.
Checking the linkages - is there a workaround for the throttle cross shaft to carburetor adjustment. The manual only refer to a gauge, PU-312. Meanwhile, I've checked transmission throttle valve link; confirmed 5/32" short of lining up with the pin hole. (Related to this, troubleshooting section does also talk about the Low range and behaving like it's in neutral. The throttle valve link needs to be disconnected to try to free the "timing valve." Will try that later.) I've tried reset the Low range band (torque tighten to 20 ft. lbs., back off 1-3/4 turns), hasn't yielded a change there. Going to recheck all my carb adjustments, too. Thank you all! I'll let you know if there any changes!
Posted on: 7/28 22:12
|
|||
Joe B.
Greenville, NC 1950 Super Deluxe Eight Touring Sedan, Model 2302-5 327 w/ Ultramatic, 6v+ |
||||
|
Re: Bucking Slightly at Cruising Speeds
|
||||
---|---|---|---|---|
Home away from home
|
Well, it's 2:30 a.m. need to call it a night. I've never really had to fight spark, but that stopped me from getting anything checked. I lost spark, cleaned the points and got it back, checked my stuff on the carb, and lost spark again. I got it back, but it's very weak. I tried three different coils, the Echlin IC-7, a Pertronix Flamethrower, and Amazon special... all yielded the same very weak spark. Verified my battery to block ground was clean.
Guess it might just be time for some new points and a condenser.
Posted on: 7/29 1:48
|
|||
Joe B.
Greenville, NC 1950 Super Deluxe Eight Touring Sedan, Model 2302-5 327 w/ Ultramatic, 6v+ |
||||
|
Re: Bucking Slightly at Cruising Speeds
|
||||
---|---|---|---|---|
Home away from home
|
Quote:
Yes, the instructions I gave earlier to simply move it ⅛" towards the carb then road test, repeat/fine-tune as necessary.
Posted on: 7/29 5:13
|
|||
1955 400 | Registry | Project Blog
1955 Clipper Deluxe | Registry | Project Blog 1955 Clipper Super Panama | Registry Email (Parts/service inquiries only, please. Post all questions on the forum.) service@ultramatic.info |
||||
|