Transmission / Overdrive: '63 Hawk 289 auto transmission issue?

[Ricardodude]

My recently purchased '63 Hawk 289 automatic runs well and drives quite nicely, seems to shift fine and low gear works as well but when ever I come to stop in gear the engine loads up and the rpm drops quite noticeably and the car feels like it wants to stall. It acts like it wants go 10-15 mph without me touching the throttle and even occasionally stalls when I lift my foot off the brake and apply just a bit too much throttle, yet idle speed is steady and normal (750 or so) in neutral. I end up putting the car in neutral at stop lights. I've read a bit about adjusting the linkage and have a shop manual that details the process but I've also noticed that the dipstick stop cap thingy has been brazed back on suggesting it came off the stick and I wonder if it has been placed at the correct spot and if possibly the transmission is over filled causing this issue. Any advice would be appreciated as I have stalled it in intersections and that's not good for my heart :-)

[StudeRich]

You need to examine the throttle Linkage from the Carb. to the Bellcrank and the (2) Return Springs as well.
Notice the Bellcrank has a Stop Lever on it that should rest on a adjustable stop Screw, that clearance between the two is one of the adjustments that need to be correct.
Also the proper hole in the Bellcrank Lever that the Rod to the Carb. goes in: Forward for 4 brl. Rearward for 2 Brl., the adjustment of the Carb. Rod etc.

One of the Reasons I mention all this, is that if the Linkage and Carb. Lever do not return CONSISTENTLY to the same point, you get this variable Idle.

There COULD be issues with other things like a Vacuum leak at the Manifold or Carb. so: CHECK, Check, check !

Sometimes the Pictures in the PARTS Catalog (Fuel Section) gives one a better understanding of how things work than the Shop Manual can tell you.

[StudeRich]

[QUOTE=Ricardodude;n1999318]/Cut/ '63 Hawk 289 automatic runs well and drives quite nicely, seems to shift fine and low gear works as well/Cut/

/Cut/ I've also noticed that the dipstick stop cap thingy has been brazed back on suggesting it came off the stick and I wonder if it has been placed at the correct spot and if possibly the transmission is over filled causing this issue./Cut/

On Statement # One: are you just saying that when you select "L" it works OK? Because they do "Normally" Start in 2nd. when in Drive.

On # 2 Quote, If the "Cup" on the Dipstick was been Brazed between the two notches pressed into the stick, it will be plenty close enough. Are you checking it, Warm, Level, Wheels Blocked and in DRIVE ? I don't think Low Fluid will cause that anyway.

The "Engine Loads up" at stops issue sounds like a different situation like; Carb. flooding or excess Fuel Pressure.

[Ricardodude]

Yes it starts in 2nd but first is available if I shift to low so I meant to imply that the transmission seems to work fine under normal driving but it's the coming to a complete stop while still in drive that creates the problem of dropping engine speed lower than the normal idle speed. If I understand correctly most automatic transmissions should not move the car forward much without any additional throttle (idle speed) where as this one will coast up to 10 or 15 mph without me touching the throttle yet in neutral the idle speed rises to 750 or so. If I try lowering the idle speed further it just makes it more likely to stall if I'm in drive at a stop light. I neglected to mention that the previous owner swapped in an Edlebrock 4 barrel carb. on a modified 2 barrel intake with a 1" spacer and an electric fuel pump as he said the original pump did not supply adequate fuel for the 4 barrel, so i wonder if the linkage to the tranny might be off kilter?

[az64stude]

Does the carb have the DASHPOT installed? Maybe that is not adjusted or working properly.

[az64stude]

[Ricardodude]

No dashpot on the current set up. I thought dashpots were intended to prevent the carb from coughing out when you suddenly pulled your foot off the throttle by more slowly reducing throttle to the idle port part of the carb....what i'm experiencing is more like having your foot on the throttle and brake at the same time....

[az64stude]

What about a broken motor mount or throttle linkage sticking or hanging up on something. Also do you have more than one throttle return spring? Maybe kickdown rod on transmission is hanging up on something. Pictures may help someone here.

[StudeRich]

Yes, that's a good suggestion, the Rods to the Pedal have been known to stick when the Throttle Boot is not fitted correctly or Carpet is snagging it.

That is important to know that the Carb. has been replaced with a Edelbrock.
Very few People understand that when doing that change the entire Linkage adjustment is upset and needs to re-adjusted per the Carb. Idle Stop adjustment Instructions in the Fuel Section, and THEN the Throttle Pressure adjusted per the Transmission Section of the Shop Manual.

Also, if you feel ANY movement of the Gas Pedal on harder acceleration, the front Engine Mount rubber insulation has been ripped loose from the steel plate and mounting Stud allowing too much Engine movement.

[StudeRich]

The LEFT Front Engine Mount.

[Ricardodude]

That's very helpful information ! I will try to get the car on the hoist and start examining the linkage and the engine mounts and report back what I find....

[jackb]

I don't see it mentioned, but, 750 in neutral is way too high. If your engine will not idle at 550-600, you've got significant issues as stated previously.

[JoeHall]

Reading your posts, it sounds like carb problems. Over the decades I have ran several AFB clone (Edelbrock), but once had one I could not get it to idle down, without bogging, as you describe. Never did figure it out. When all is well, with factory or clone carb, the car should idle smoothly at 550-600, in gear, and take off smoothly when you push the accelerator. I have also found the original, dual return springs to be overkill, and always remove one completely, and substitute a weaker spring for the second spring. I have also removed and threw away every dashpot I have came across on Studes, as they were to comply with EPA regs, and not to make Studes run better. Set up this way, you don't have a gas pedal that's nearly as hard to push as the clutch pedal, and much less fatiguing when driving further than across town. Again, your problem seems carb related. I'd start with installing a 4B manifold, and toss the 2B to 4B adapter the PO installed.

[Ricardodude]

Again thanks for the info and suggestions. As far as I can tell the PO had the 2 barrel intake machined to accept the 4 barrel as there is a detailed instruction sheet in the paper work I got with the car that comes from a magazine or perhaps even here on the forum and then he added a 1" spacer that may have come with the carb. I can get the idle speed down to 600 but it's not too happy there and seems more prone to stalling as I come to a complete stop and then try to move again. I believe the tach/dwell meter I have been using was not very accurate (on board tach doesn't work). I have used another tach/dwell meter and it shows current idle around 650-700. The car idles nicely once warm and drives well except coming to a stop where it drops to perhaps 500 rpm in gear. I checked the linkage on top of the engine and verified the 7/64" gap from the throttle lever stop. I have yet to try putting the car in D and removing the bell crank lever and positioning the trans. lever in the middle position (as per the manual) to see if it is out of adjustment, as I try to make adjustments one at a time and test. The best analogy I can come up with is, it acts like there is transmission pressure to move when at a stop light, foot on the brake and in gear, such that the eng. speed drops significantly. When as I take my foot off the brake and start to give it some throttle, if I give it a little too much it coughs and stalls

[jackb]

I agree as the above # 12. You have a carb problem. Likely a mal-adjusted Edelbrock or perhaps air leakage around the added spacer and/or the intake manifold. If tuned correctly, your car should idle and purr at around 550-600 rpms. If it doesn't purr, it is not the tranny (remotely possible-see linkage again). Just remove the linkage from the throttle arm and see how it runs. GL

[StudeRich]

Did I miss that you said the Ignition Timing has been checked at 4 to 6 degrees BEFORE Top Dead Center, on the Line to the Left, (Retard) side of the "IGN" Mark, and the Dist. initial Dwell at 550 RPM is between 28 & 32 Degrees ?