Hydramatic shifts hard in third

[Eric August]

My 56 sedan shifts hard into third gear, all other gears shift nice and smooth, Ive adjusted the TV linkage NO help. I was told that a check valve my be sticking because it sat for five years, so I put a addative in NO help. is thier another adjustment? Or is this a sign for rebuild?

[Otto Skorzeny]

Then it's working perfectly!

1-2 is almost unnoticeable.
2-3 is hard
3-4 is even less noticeable than 1-2.

That's how they were new and that's how they are when they're rebuilt correctly. Cadillac was never able to get a really smooth shift between 2 and 3 in the dual coupling Hydramatic.

The 2-3 shift is harsh compared to the others. Obviously make whatever adjustments you can to make it as smooth as possible but don't expect it to be like the other two. As long as your car is shifting into all gears and not slipping, I'd leave it alone.

You say it sat for 5 years. I'd flush the system and refill it it with Dexron.  Never put additives in these transmissions - you will often create more trouble than you solve. After driving the car regularly, it may smooth out a little bit.

[Rusty Shepherd CLC 6397]

Otto, I wonder if your car shifts as smoothly as it did in 1956. I've driven several Cadillacs with the Dual-Coupling Hydra-Matic and although the 2/3 shift is more noticeable than the 1/2 and 3/4, it wasn't what I would consider hard or jerky like it often is in the original H-M and, in fact, it was that shift that the H-M engineers were trying to improve with the development of the new transmission.  I have a video tape of old Oldsmobile ads and promotional films which includes one on the Jetaway.  It's a cartoon feature that features "Old Man Hydra-Matic" as the proud father of young "Jetaway". It begins by showing a car going over some "cliffs" which are meant to represent the three shifts of the transmissions. The first and last "cliff walls" are very short and the landings smooth, but the middle one representing the 2/3 shift is much longer and the landing much harder.  It then shows a man accelerating his car from a stop sign.  The 1/2 shift goes by without any drama, but in anticipation of "the big one" (as the announcers calls it), the man grimaces, chomps down on his cigar and tightens his grip on the steering wheel.   The 2/3 shift occurs almost unnoticed by the driver who is then seen with a big grin on his face.  The film ends with "Jetaway" being awarded a trophy for being "Gear of the Year".  I also recently read on-line a Motor Trend road test of a '56 Olds and the tester was very impressed with the Jetaway because the shifts were barely perceptible.

[Otto Skorzeny]

Don't get me wrong - the transmission shifts smoothly - it's just that by comparison to the other two shifts, 2-3 is hard.

It's hard to tell without driving Caddy Hack's car whether his shift is excessively hard or normal. I just know that many people who aren't used to these cars are surprised by the noticeable shift between 2 and 3 especially when 1-2, 3-4 are nearly imperceptible.

Mainly I want to discourage Hack from doing unnecessary work on his tranny or adding any more gunk to it.

I should point out that the 2-3 shift should not be loud or slam you into the back of your seat - it's just harsher than the other ones.

[Eric August]

The shift from second to third does bring the rpms up higher then the other gears but, when third engages it will jerk you back in the seat. I have the feeling this is not normal for this tranny Im gonna drain out the fluid, refill with Dextron, and drive it. I was hoping someone had this problem as well and knew of some kind of band adjustment I could perform.

[Otto Skorzeny]

Below are some resources you may need sometime. I hope draining and refilling helps. It might. It might also smooth out over time. It sounds like it's shifting into 3rd a little later than normal.

http://www.autotran.us/jhmparts1.html

http://nwtparts.com/

[Rusty Shepherd CLC 6397]

knew of some kind of band adjustment I could perform.

Eric, One thing the Jetaway/Dual-Coupling H-M eliminated was the bands. The promotional film I referred to used reduced maintenance because of no band adjustments as a selling point of the new transmission.

[kelly]

I had a very similar condition on my '57.  A local trans. shop made a major adjustment in the TV connection to the trans.  It had previously felt like I was doing a full throttle acceleration, even at light to modest at light to moderate pressure on the pedal (RPM's ran up higher than they should, particularly from 2nd to 3rd).  Although the 2 to 3 upshift is still firm, as stated by others, it is no longer a head jerking event.  Worth checking.
Kelly Martin

[Walter Youshock]

I went through the same thing on my '57.  Going up hill, I'd have to trounce the accelerator and almost ended up in the trunk more than once.  This was after the rebuild, though.  Before the front sprag blew, it shifted beautifully.

The TV adjustment is critical.

Also, those of us with '57 trannies; there was a modified valve body introduced late in '57 that went in the '58's!  The modifications were supposed to ease the 2-3 shift point and better clean some of the valves and ports with trans fluid so they didn't get gummed up.

[Coupe]

Walter 
You mention your front sprague "blew" in your '57. I am curious what engine number you have in your '57. Mine is 10707. The man that rebuilt mine said he was surprised I had the original front sprague in mine. Apparently there were problems with that part also during the '57 model year and a change was made. I do not know at what point that happened. Recalls were standard for defective parts then. The dealers just dealt with them as they happened.

The 2 - 3 shift in mine is noticeable but not harsh.

[Walter Youshock]

5762096834 built May 21, 1957--4,999 cars BEFORE the Carter carb started to be used in production.

I was 1/2 mile from the house, taking the car to work.  I stopped at a Stop sign, went to pull out and NOTHING!  Downshifting to 2nd got me home.

This happed a day after a 200-mile hiway trip.  I guess I got lucky...  But, the trans has never been the same and the rebuilder has since died.  It's next to impossible to find older local shops who even want to touch these.

[Mike Welch]

http://www.youtube.com/watch?v=KvJzWimzkCY

[Otto Skorzeny]

Rolls Royce used Hydramatics for years. If you can find a shop or individual that specializes in Rolls Royces, they may be able to help you.

Hyperion is a company that specializes in Rolls Royce Hydramatic transmissions. Perhaps they can offer you suggestions or advice if nothing else.

[Doug Houston]

I bought my first '56 convertible in 1958. The speed clock showed 15000 miles, which was probably correct. The S/N was 56 62 074790. It  had a Carter carb on it. The car had belonged to Cadillac originally, and some things on the car had been changed from original, including the entire interior. The engine had changes also, but all by the factory. So, it would be wrong to say that the car was untouched! I disposed of it at about 147,000 mlles. It was amazingly economical on fuel.

The transmission however, had been unchanged, and operated perfectly. It did give trouble, as a majority of he controlled coupling Hydra-Matics did in the years before 1958.  If I didn't love the car passionately, I'd have dumped it and bought a Lincoln or something else.

All this banter above points up that the transmission had been designed to eliminate the feeling of the shifts, as there was on the earlier Hydra-Matics. The designers of the transmission went to great lengths to get rid of the shifts. But,if you read the section in the '56 shop manual on the transmission, you will see that you are supposed to feel the 2-3 upshift. To know that it's shifting from 1-2 or 3-4, you have to know what to listen for, and not so much, what to feel.  The transmission was, by no means, a masterpiece, expensive, complicated, and unreliable as it was. The car is a dream to drive, and it's hard to find someone who has the schmartz and the willingness to work on the transmission.  With the necessary parts, a THM 400 transmission can be installed on a "jetaway" car. I could be forced to make that conversion some day, but hopefully, not.

I bought the one I now have in 1987. The transmission shifts perfectly. The odometer reads about 27,000 miles. The top appears original, the carpets perfect, and the interior unmolested, but in need of new leather. I'm inclined to believe the odometer. It's in storage, but I look forward to driving it. I also anticipate problems with the transmission, but I'll cross that bridge when I come to it.

[Roger Zimmermann]

Rolls Royce used Hydramatics for years. If you can find a shop or individual that specializes in Rolls Royces, they may be able to help you.

It's true that Rolls used the Hydramatic transmission, but the first version! They never used the Jetaway.
By the way, I have 3 cars with that transmission. I did not myself the transmission on the Brougham, but I did the one of my de Ville and, with 3 transmissions, I did the one on the Biarritz. When cold, the 2-3 passage is more prononced on all 3 cars than when transmissions are warm.
Roger

[The Tassie Devil(le)]

I thought that Rolls Royce used the TH400 Transmission.

Like the Jaguar V12.

Bruce.

[Roger Zimmermann]

I thought that Rolls Royce used the TH400 Transmission.

Like the Jaguar V12.

Bruce.

Yes Bruce, from 1968 for car with LH drive. For cars with RH drive, they still used the first Hydramatic.

[The Tassie Devil(le)]

Boy, that I didn't know.   My brain is getting too full.   Think it is time I went to bed.

But the Jaguar RHD's used the TH400.

Bruce.

[Rusty Shepherd CLC 6397]

Here's what Cadillac said about their new transmission in the 1956 brochure:
"The completely new controlled-coupling Hydra-Matic adds to the efficiency and high performance of previous Cadillac transmission a wonderful new smoothness and durability.  Shifting has been refined to the point where it is virtually imperceptible to driver and passengers".  Pontiac's '56 brochure stated that the new unit had been tested for more than 2,000,000 miles which makes you wonder why the initial problems with it hadn't been resolved before it was introduced.

[Rusty Shepherd CLC 6397]

It's true that Rolls used the Hydramatic transmission, but the first version! They never used the Jetaway.

Roger

Roger,
Do you know why RR never used the Jetaway/Controlled-Coupling H-M? As finicky as they were, they most likely would not have wanted it the first year before they could do their own road testing and disassembly of the unit and examination of every part.  During the '56 model year they would have heard about all the initial problems with it and my guess is that that was what convinced them to stay with the old unit.