Packard Forum Index » V-8 (1955-56)

Gents,
My ultramatic shifts 'hard' (Low to High) when driving in Drive-Right. It shifts >40 mph with a pronounced 'clunk' (and aided if I back off the accelerator when it sounds like it should have shifted already)

I've checked the linkages a few times and all seem correct so I was thinking of removing and cleaning the governors. I haven't done anything w/ the tranny except change the Type F fluid (it still looks nice and red)and adjust the band bolt as per the SM. The SM (on page 54) references a 'special governor wrench PK-24.' So before I drop the pan I was wondering how special that tool really is or if I would be able to remove the governors with standard tools?

thanks,
Bob

I believe the governor wrench you are asking about is a special long handled allen wrench to reach the governors which are way up inside the transmission. You could probably do the same thing with an extension and a 1/4" drive socket allen wrench.

All you need is an allen wrench to get them out, and you don't need to remove the tailshaft.

For very late shifting, look for:

flyweight has fallen off the low speed governor.

One of the endcaps has fallen out of the shifter detents. The detents will feel very vague if this is so.

Improper assembly of the low-high shift valve. There is a little sheet metal spring seat at one end of one of the bores and that can get trapped under the end plate. You lose governor pressure which raises the shift point drastically.

Thank you Howard and Ross, That gives me confidence to pull the pan this week to take a look see.

Ross, I am light in my knowledge of transmissions, but I will look for those items as possible causes. The detents are fairly vague to me, and Park is just like neutral in that the car will roll if the hand brake isnt engaged.

I do have a set of gauges that i can probably hook up as in the SM, too.

Thank you both again,
Bob

Partial Update:

I removed, cleaned and reinstalled both governors. The low speed governor counter flyweight was intact. They were easy to get to with a socket extension and allen wrench socket. Even easier since I removed the control assembly.

I did notice that the part on the manual valve shaft that pushes the parking pawl into place into it's gear was damaged and therefore won't rotate with the shaft. This would explain why shifter in Park position doesn't prevent the car from rolling. I think I will just leave it as is for now as this can be dealt with by using hand brake and is what some regulars here recommend anyway to avoid the 'stuck in park' situation.

Looking at the Low speed brake unit, there is some shiny metal indicating some dynamic wear on it. Not sure how that happens, as I don't know what could be touching that.
Since the low and reverse brakes are now out, should I bother to take apart and clean them??
I was surprised that the low one just slides off the tubes with little friction. The reverse one seems to be tighter on the connecting tubes.

I plan on taking apart the three valve bodies and cleaning them out since I can. More to come.

Attach file:

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  parking pawl lever on shaft.jpg (89.91 KB)


  low brake.jpg (140.09 KB)


  tranny control assembly.jpg (135.57 KB)

Hi, I thought I'd share an update.

I took the 3 control valve bodies apart, cleaned and reinstalled. I did not touch the throttle pressure screw. No apparent difference.

Spent a lot of time trying to get the throttle linkage properly adjusted. The lever at the transmission has been there a while and the tightening around the gear points on the shaft from the transmission created distinct grooves where the lever attaches. The result is that I can't just move the lever a little, I can only rotate the lever to the next "worn in detent". This means the lever is either a tad too far counter clockwise (rearward) or too clockwise. This puts my adjustment point on the carb linkage to the very front of the linkage threaded shaft or so far aft that it won't work.

I left it at the full CCW position since if it is just rotated off the stop the linkage can be assembled at the forwardmost travel near the carb.
Based on other posts by Ross, this seems to be about right.

When I drive: 'D seems to be fine.
D': even with light pedal pressure it usually shifts L-H around 35-40 mph with a very pronounced (heard and felt) clunk. Then very soon after that a subtle 'shift' to what must be Direct Drive as acceleration is then smooth, solid and increased (consistent with Howard's write ups on how it is supposed to work).

I was able to hook up a single pressure gauge to the transmission and separately measured pressures for the Front Pump, High Range Clutch, and Governor tests as per the "Pressure Test Forms, 55th Series" listed in the SM.

The front pump pressures are low as compared to expected values and the governor pressures don't make sense to me..

ANY suggestions would be super helpful as to what to do next, what can be adjusted etc.

(S/B = “Should be” from 55 Series Ultramatic Pressure Test Forms)


Front Pump Pressure (1)

@ ~400rpm (Idle)
(Should be: 80-110psi)
P 22 psi
N 75-80
‘D 60
D’ 65-70
L 65-70
R 65-70

‘D 10-15mph: 180-200, (S/B 150-170)

D’ Full throttle after shift to H: 120 (S/B: 80-100)


High Range Clutch (2)
(S/B <10psi above Pump Pressure above)

‘D @400rpm: 40psi (P.P. 60 from above)
‘D 10-15mph: 95psi(P.P. 180-200 from above)

D’ @400 rpm: 0 (S/B 0)
D’ @ 20mph: 0 (in Low gear, didn’t shift yet)

Governor (7) D’
13mph 20-25 (S/B 15-18)
28mph 30-50 (S/B 35-40)
56mph 20-25 (S/B 62-69)

NOTE: Thanks BigKev for helping me format this properly.

If your manual lever rotates on shaft.

If you can lower the rear of trans below frame. You should get it out.

Then when out. But it on shaft
Tighten it down. And drill a hole for a roll pin. Or hardened no. 10 bolt. You could tap it. But still use a nut.with a cotter pin. So its won't back off..

Riki,
Thanks for the advice. The lever isn't rotating on the shaft, it stays put. The surface of the lever that goes around the trans shaft has been tightened down so much that there are now grooves that match the gear teeth on the shaft. So it is not possible to move the lever just a little bit unless I ream out the hole in the lever etc. Maybe that is the only recourse or try to find one that doesnt have these deep grooves.

The pressures confuse me since the pump pressures are lower than the form expected values at idle, but higher while driving. This is probably why the High speed Clutch pressures exceed expected while driving, but the governor pressures don't seem to correspond. I did clean both governors and ensure the weights were intact and easily moved.

thanks again for the response.
-Bob