Packard Forum Index » V-8 (1955-56)

About two years ago I had my Ultramatic rebuilt locally.
It shifts beautifully now. But, the thing still moos when it locks up. I believe this is a torque converter problem.
It still leaks oil when not running. When it was rebuilt the seals on the selector shaft and throttle pressure rod were replaced as well as the seal on the bell housing. I am thinking this leak may come from the torque converter. Maybe there are some bushings on it or seals. It has also developed a problem when I come to a stop. The engine shutters and shuts down. I can overcome this by goosing the engine. I feel maybe the thing is staying locked up.
If I shift to neutral before stopping, the thing is ok.
Any ideas will be appreciated. I had a similar problem on an ultramatic I rebuilt myself many years ago that I corrected by adding a can of Slick 50 transmission additive to. Tried it this time with no luck.

Believe the mooing is fairly common. Most avoid it by just letting up on the gas at the shift point. Packard issued a few bulletins regarding the various engagement issues and sometimes noises DD clutch made over the years. Fixes tried range from cutting slots on the lining face to having a slightly different contour of clutch, change of dampening springs to mentioning hard glazed lining as a possibility.

The governor is supposed to drop the direct drive out around 10-15 mph. Perhaps it isn't or is too slow in releasing. Not sure why the extra gas would help unless the idle is awfully low in conjunction with a delayed release. Rebuilt recently, it should be free but possible governor or even DD clutch is sticking. To diagnose, would probably require a pressure test as there are two valves plus the clutch itself involved.

If you put the car up on a lift, can you get an indication of where oil is coming from? Anything from converter should be coming out the weep hole and spread all across the trans bottom. Anything from shaft seals should be mostly located in the area of leak. One other possibility is the oil pan itself. If the bolts were torqued down excessively in past and pan flange was not straightened when rebuilt, it is possible the bolts deformed the area around them. The bolt and hole area will then make contact and be tight before the straight areas between bolts have a chance to compress the gasket. If that is happening, you should see some evidence all along the edge of pan.

I would like to add, the the lock up occurs almost immediately, about 15 mph in drive and around 5 mph in low.
Could throttle pressure adjustment cause this?

Yes-and some other things. Do the rest of the shift patterns more or less follow these bulletinshttps://www.packardinfo.com/xoops/html/downloads/STB/55T-6.pdf andhttps://www.packardinfo.com/xoops/html/downloads/STB/55T-7.pdf If they do, then check out service counselor 29-5https://www.packardinfo.com/xoops/html/downloads/SC/SC-VOL29NO5.pdf and the article on page 30 re the direct drive engagement.

I took the car for a test drive today. I assume the problem to be torgue converter lock up due to the symptoms. The lock up starting in low happens at 5 mph. I think it is lock up since there is a noticable change in rpms. Starting in what I call drive 2, no low range, it also locks up at 5 mph. After I am at normal driving speed, I can hit the gas and drop out of lock out as normal but it immediately locks up after I remove my foot from the gas. This I assume is normal. When I complete a full stop the car shutters and dies. After it dies, evidently the lock out dissapears and I can start the car and idle in gear as normal. Also if I shift to neutral before stopping, I can shift into gear after the stop and the car appears normal until in motion and the early lock up appears.

I checked throttle pressure and it is ok. I am using dexron fluid and was wondering if that could be a problem.

Thanks for the info on the service bulletins.

Stalling when stopping sounds like failure to drop out of DD back into converter when speed drops below 18 or so mph. I'd strongly suspect the governor, but I'd await a response from a better-informed Ultramatic expert, Ross.

Sounds like a sticking governor to me too. The good news is the governor can be serviced without removing the transmission.

(o{I}o)

I go with the stuck governor: The governors rely on the rear pump for pressure to send to the valve body. That is why you get up to 5 mph before it shifts; before that, there is no significant rear pump pressure. When coming to a halt, it takes a while for the rear pump pressure to dissipate, and by then the direct clutch has stalled the engine.

As mentioned, cleaning the governors is no hard task on your car. You might want to double check that the spool in the high-speed governor is not in backwards.

While you are in there, I would also remove the rear upper valve body, which has the direct shift valve in it, and make sure all is well and correctly assembled. This can also be removed without removing the whole valve body with a little imagination and fiddling.

Please let us know what you find. Inquiring minds want to know.

I'll take the car back to the guy that did the rebuild and have him pull the rear housing and check the govenores. Five years ago I would have done it myself. I will post what the problem is when I know for sure.
Thanks to all for the great info.

Checked the govenors today. They are ok. Checked the valves, they are okay. Tomorrow the trans gets pulled to check the converter. I'll post what the final correction is.