1955 Trans Fluid

Started by eggs55, August 23, 2015, 09:20:44 AM

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eggs55

I've been having problem with the downshifts on my 55 60S hydromatic transmission.  As I pull up to a stop, its seems to fight coming down into 1st gear.  Upshifts seem work well.
A little more background...I bought car not running 5 years ago.  Previous owner said the trans worked well, but I never had a chance to see that.  I pulled the engine & tranny and obviously doing so drained all the trans fluid.  Did some research back then to find the correct modern version of the spec'd fluid...I settled on Penzoil ATF. However, the trans never seemed to shift quite right.  The car was built 12 years before I was born, so I honestly don't know what "right" is for that era of trans.
Over the years, I have fiddled with the idle speed, kickdown rod, fluid level.  While it has gotten better on the upshift side, the downshifts still are difficult which makes braking a challenge.
I'm back to wondering whether I put in the correct fluid.  Can anyone tell me what they have used that works well? Is it more likely a fluid level issue?...too much or too little?  Idle speed too high?  Or, do I really have a trans that needs a rebuild (please no!)

Appreciate any guidance I can get.

TJ Hopland

I have read (no actual hands on experience) that those early Hydramatics were known for kinda abrupt rough shifts when they were working and required periodic adjustment (bands I think) to make sure the internal timing was correct.  Some of the shifts (2-3 maybe?) require just about every mechanism to operate in a perfect sequence to pull off a smooth shift.  If one of the mechanisms say a band was too loose it does not grab as fast as it should means that something else is turning at the wrong speed when its band or clutch is applied which makes it not smooth and possibly hard on things.  It could mean that its sort of trying to go into 2 'gears' at the same time.  Even if the 'gear' you are supposed to be in is mostly in there could be another one sort of partially on and dragging.   Autos don't actually engage and disengage gears so there is no grinding, its all done with brakes and clutches so you can actually kinda get 2 at once which obviously is not a good thing.   Again this is just stuff I read.  I am not a transmission expert and for sure don't have any hands on experience with that model, I'm only just getting to know the next one in the series which was same but different than yours.

Any idea if the trans has ever been rebuilt?  If its still original or even say 25 years old now the internal seals and materials are not going to be in very good shape.   I just had a 57 (different model but still similar) that seemed to shift alright but like you didn't have a lot to compare it to. 

We took it in because it was intermittently gushing fluid out the front seal.  Shop said the pan had been off it before but otherwise it looked to be all original.  Seals were all hard, servos all leaking, and clutches were all delaminating.  They also said some of the bushings were wearing which I guess was not uncommon for those even with low miles.   Basically we got away with a standard soft kit and a bushing kit.   They said if we had kept driving it we would have started damaging hard parts which tend to be hard to find which usually means if you can find them you are going to pay.  Now that its done the 2-1 downshift is much less abrupt and it overall seems smoother.  The shop said they had done a similar GM trans to mine a few weeks before me and the forward fluid coupling (thing that looks like a torque converter) was damaged beyond repair so they had to find a replacement.  Apparently took 2 weeks to find it and was a good used one for $1500.     

Mine was a different model so the way the shifts feel on mine may not be the same as the way yours should be but I figure I would share what we found when we got ours apart.   I was planning on getting it done at some point anyway just because we didn't know if or when it had been done but the sudden leaking of fluid kinda kicked it up the priority list and now I'm glad we did it.  Could have done a lot of damage and left us stranded somewhere.   Another nice thing about the rebuild is modern parts = modern easy to find fluid.  Shop told me they are not fans of Dex6 except for stuff that came from the factory with it, they like plain old somewhat universal Dexron/Mercon.
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

savemy67

Hello Steve,

Welcome to the Cadillac LaSalle Club Discussion Forum.  We have something in common.  You own a Cadillac manufactured in the year I was born, and I own a Cadillac manufactured in the year you were born (assuming 1967 from your post).

There have been a number of discussion threads about transmission fluid on this forum, so I encourage you to do a search and read the posts.  My recollection is that the currently available version of Dexron should work with the '55 transmission, but I will defer to the 'mid-fifties owners, some of whom will hopefully reply to your post.

Since the transmission uses the same fluid for upshifts as well as downshifts, it is unlikely that the type of fluid is causing the symptom you describe as reluctance to downshift to first.  A Cadillac should shift relatively smoothly, so if you are noticing a big difference between upshifts from first to second and downshifts from second to first, you can hope for the problem to be cured by an adjustment of the idle speed or kick-down linkage, but plan for a rebuild.

If you haven't already done so, I encourage you to purchase a '55 Cadillac shop manual.  The manual will tell you how to check the fluid, adjust idle speed and the kick-down linkage, and how to rebuild the transmission.

How well did you now the previous owner?  If the car was not running when you purchased it, that would indicate to me that the condition of the transmission was at least questionable.  A 1955 Cadillac is a cool car.  How much time and effort have you put into it over the last five years?  What are your plans for the car?  Do you have any photos?  Good luck with the car.

Christopher Winter
Christopher Winter
1967 Sedan DeVille hardtop

TJ Hopland

#3
Here is the chart for that transmission.   My memory was right its the 2-3 shift where everything has to change.   If you look at 3-4 only change is the front clutch.  1-2 the front band and clutch alternate states.   So that means the 3-4 is hard to screw up.  1-2 is not too bad but for 2-3 to be smooth everything has to be right.   Print out the chart and pay attention to the shifts, you may be able to narrow it down to one component, if its a band it may be a simple adjustment.



Chart came from here if you want to read.   This article is about the next model after the one we are talking about but they did include this chart for comparison.   http://ateupwithmotor.com/terms-technology-definitions/hydramatic-history-part-2/2/

Here is part one of that article.   http://ateupwithmotor.com/terms-technology-definitions/hydramatic-history-part-1/

Another member fond these articles in a previous discussion about earlier transmissions and I thought it was good reading.
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

Philippe M. Ruel

#4
The 1st generation Hydra-Matic has somehow "stiffer" shifts than later transmissions, due to the presence of a fluid coupling instead of a torque converter. But nothing dramatic.

A poor band adjustment will give either "harsh" or "slippery" shifts.
A delayed up- or downshift is often caused by a "lazy" hydraulic valve. When transmission is not used for a long period of time, fluid may form sticky depots (gums) in tight places like between a valve piston and its bore, hence a difficulty for oil pressure to move this piston a certain way, or for detent springs to move it the other way.
Gum may go away sooner or later, or never. Or it may go away and get stuck in another place. There exist miracle chemicals supposed to dissolve gums in transmissions, but nothing beats a proper rebuild.

According to the chart posted by TJ, it should affect 4-3 downshifts as well, which you can test by trying kickdown from 4th gear, unless there is a specific valve dedicated to it. Depressing gas pedal to the floor while in 4th gear at reasonable speed (say, 40-50 mph) should result in instant 4-3 downshift.
1952 60 Special in France.

eggs55

Thanks to all for the information. 
On up-shifts, if there is a problem, it will occur between 2 & 3.  (1 to 2 & 3 to 4 do well) Does best when accelerating at least moderately.  Idling down the road its rougher 2-3 , but still OK.  If I brake just when it wants to shift into 3rd, I can induce some slipping.  On downshifts, Kickdown from 4 to 3 works like a charm. Its a bit hard to tell, but from what Ive heard, I suspect it the 3 to 2 change that wants to hang up...its a bit difficult to tell how much its 3-2 vs 2-1. I'm going to work a bit more to adjust idle speed because the rpm just doesnt seem to drop like I would expect it to.  Almost seems like it has to be forced down by braking.  Anyone have thoughts on any good product to de-gum sticky valves?

My main question regarding the fluid type & level I think is answered...problem isnt there it doesnt seem. I have a 55 shop supplement manual.  I suppose I should purchase the '54 which likely has some info I dont have.  No idea on whether the trans has been rebuilt, but I suspect so, and its probably 30 years old!

Lastly, Christopher, I attached a few pics of Grace.  At this point I have worked through most of the mechanical systems on the car, and all working well except for a few nagging issues like this one.  I've tried hard to keep it mechanically all original (I cheated a bit putting in electronic ignition vs points).  I've removed and buffed out almost all the SS, full rear bumper & tips been re-chromed.  Front bumper is next.  Body is in good driver condition, but have plans someday of taking it down to metal & getting it like new again.  Finished re-painting & re-upholsterng the interior to original last year...excluding carpet.  Just kinda picking away at it as time and money allow.   Goal is to make it look great, but if I'm not willing to take it out for a ride Ive gone too far!  I feel good about how far its come until I look at some the pics on this site!

I like to take it to shows, but really dont have the time for t these days...rather just be driving it.
   


savemy67

Hello Steve,

Thanks for posting photos of Grace.  She looks good for an old lady.  I think there is something especially appealing about the rear roofline of the '55s.  Keep up the good work on your car, and hopefully you will be inspired by others' work depicted on this forum, and not discouraged.

Christopher Winter
Christopher Winter
1967 Sedan DeVille hardtop

Bob Kielar

Try going to Mid-Century Cadillac Forum and post your question there.

Regards,
Bob Kielar
Keep Cruzin
1955 Cadillac Fleetwood