Dropping a Dynaflow

[rmartens]

I'm looking for advice and tips on diagnosing and/or dropping the transmission in my '56 Century (322 motor). It's been a daily driver for awhile, but a few weeks ago it began getting more and more difficult to shift from neutral into drive. I forced it into D a few days ago and listened to things crunch and munch. Put it in P and heard a steady noise like a piece of metal hitting a fan. Shut it down, restarted, was quiet, tried D again and same scenario as before. Pulled the pan--no major quantities of metal flakes there. Don't have a shop manual--any special tricks for disconnecting the torque tube? FYI, I live in the Sacramento area.<P>------------------<BR>Rick<p>[This message has been edited by rmartens (edited 12-05-2000).]

[Gene Brink]

Rick,<P>Been longer than I care to remember since I last crunched a Dynaflow but I'd bet you have several broken stator blades (the broken pieces are kicking around being turned into smaller pieces - once they get small enough you will find plenty in the pan). My experience has been one where you don't go very far before you have a whole bunch of "neutral" gears to go with park. Should be fun finding an intact transmission to use for parts (or to rebuild). Hopefully someone else out there will have more knowledge than I and will have a happier answer.<P>Good luck, Gene

[rmartens]

Gene:<P>Thanks for the reply. I assume you're talking about the variable pitch stator setup? Isn't that located in the torque converter? My understanding of these transmissions is quite limited!

[gearhead]

Removing your dynaflow is not difficult, but is a lot of work. Put the car up on jack stands supporting it by the frame. <P>First, the rear springs, shocks and panhard bar must be removed. Don't know if the 56 uses tube or lever shocks. Doesn't matter! Emergency brake cable and brake lines need to come off.<P>This will allow the whole rear axle assembly to separate from the car. You may have to do something with the gas tank, but don't think so.<P>Next, there is a 4 bolt flange at the back of the dynaflow that needs to be removed. When this is done, the axle and torque tube can just be pulled out the back of the car. When I did my 55 dynaflow, I kept the wheels and tires on and just rolled it back. Be sure to have the car pretty high in the air to clear the torque tube, and then get the dynaflow out.<P>From there, getting the transmission out is just like any other tranny. It is very, very, very heavy!! I got mine out with a floor jack, which was probably a mistake. It absolutely requires a tranmission jack to get it back in, so it is best to get it out the same way. Doing it with a floor jack is not really safe due to the weight. <P>When the dynaflow is out of the car, get two neighbor kids who play on the offensive line of their high school football team to load it into the back of a truck to get it rebuilt. I would highly recommend having the rebuild done by an expert rather than doing it yourself. These are not like any other transmission and they are a nightmare for the neophyte. You are on your own to find an expert, but they do exist. Check around, you will be able to find someone locally.<P>Getting it back in is pretty straightforward except for lining up the splines. I found that it works best to put the axle on a floor jack so the wheels are off the ground. The torque tube input shaft can then be rotated by turning a wheel. This will enable you to line up the splines and get the thing back together.<P>Good luck!

[palbuick]

I think the first on your list would be to find a shop that will do the trans, and do it right, then ask for a price to remove and install, and a price for bench work. Usually when a shop removes rebuilds and reinstalls a trans there is a warrante. Sometimes on bench work there is no warrantee.<P>good luck<P>Jim Schilf / palbuick

[Guest]

I had a similar deal with my 60. The tranny guy found parts of the starter floping around inside the bell housing. Maybe you'll get lucky and won't have to go through it. I herd of a guy in Atwater (Ca.) who might be able to overhaul the dynaflow. Good luck, Mitch

[Gene Brink]

Rick,<P>Correct, in the converter. I would pretty much second Gearhead's comments although I have pulled more than one Dynaflow by pulling the axle back enough to separate the splines by looping a come-along around the axle and rear cross member of the frame and then "jacking" the axle back enough to clear things. Was able to leave everything connected EXCEPT the shocks. (This on a '54 Super back when a replacement from the bone yard was all of $25. It may well be that a '56 will not allow one to do it this way.)<P>Good luck, Gene

[Guest]

Hi rick...Im "up the street from you...so to speak..." I had my 55 DF done by the guy who does them for Buick Specialists up here in Kent....He is an old tranny guy from way back and he knows and loves and most importantly appreciates these old Buicks...My 55 was way rough, had a 56 core I got with my parts car as mine needed some hard parts, but he has some NOS stuff that he uses, a real nice guy...easy to talk to and deal with...<BR> As for R&R....These torque converters only line up ONE way....I thought there was two way cause of two drain plugs....not so...If you can see your drain plugs(opposite each other on conveerter) then mark the flexplate and converter so it goes back in same way....mine ...I couldnt see any plugs...was a dealer replacement and converter was connected wrong...I took flexplate off and turned it in X number of ways on the converter...with trans. out of course...it only goes one way....this will affect the balance of these 2 as I have been told they were balanced as 1 when initially built..<BR> RENT or find a tranny jack....IF you are brave enough to try to use even a large floor jack and it slips while in the air....whatever part of you it lands on will be either amputated or pulverized....This is no joke....I did my engine and trans rebuild at same time and rejoined them in back of my truck...it still took 2 strong guys to get trans lined up....it is a royal pain...<BR> removal...rear end removal is as stated above except pull wheels, but leave brake drums on....however high the back end of the car is when its pulled...it should be in same position as the lone U-joint is in rear of the trans....you cant see it from out side....when you got the rear of car up in air, make sure torque tube is not touching the frame at the part where it goes thru the frame....will make it a pain going back in..<BR> You are all wondering how I know all this...I am seeing the light at the end of the tunnel on my drivetrain overhaul/restoration....<BR> a friendly tip....if after you get the rear end/torque tube out, A: check the bushing at the front of drive shaft...if its grooved, it needes replaced...this is what works with the seal in front of torque tube to keep tranny fluid in the tranny in stead of torque tube...Replace that seal at the front too while its out.....B: jack rear end up so its higher than front of torque tube, if any fluid comes out, note type and whichever type it is that seal needs replacing...if its tranny fluid, the front seal I just told you is the one....if its not, Find a guy who knows torque tube drive shafts/3rd members as the rear of the shafts are splined and coupled with a roll type pin....56 uses fine splines....Just for kicks....BEFORE you pull trans, put rear on stands and see if it will work back there...have heard lotsa problems with 56'6 stripping out the splines at the rear of driveshaft where it goes on pinion...would give you similar noises/problems....<P> Most important, have a couple strong guys to help you as this trans is heavy...about 300-350lbs....be grateful...they went to an aluminum bell huousing in 56...55 is all cast iron!!!!<BR> One more thing...when you pull the trans, converter WILL stay attached to trans as its bolted from inside some how....DO NOT TRY TO FORCE CONVERTER OFF!!!! If it does come off when you pull trans, you have major internal damage....<P> I highly recomend my trans/rearend guy...I spent less on my DF than my 67 turbo 400!!!!!<P> Drop me an E @ dlw29@hotmail.com<P> don55<P> Sorry so long, but theres lots of tricks to these....the weight is a HUGE factor though...I look fwd. to hearing from ya....

[Guest scott mich bca # 6619]

R MARTENNS,<P>Where are you located? Perhaps I can recommend an expert in your area.<P>Scott<P><BR>

[Guest]

rmartens<BR>Check the rear end before you pull the trans as don55 recommends.<BR>The steady noise ?like a piece of metal hitting a fan? when you put the trans in P sounds like the output shaft is rotating and that the park dowel is not able to engage the notched wheel on the output shaft. When you turn the engine of the dowel sets into place and the noise is gone when you restart the engine. If the output shaft is rotating when the car is stationary you have a rear end problem.<P>Vegard<BR>Norwegian BCA member<BR>

[rmartens]

Thanks for all of the advice on getting the Dynaflow repaired. I just had a mechanic friend come over for a listen and he concurs with Vegard--somewhat. With the car in Park, it started fine and tranny was quiet. When put into drive (wheels off the ground) the tranny noise was a relatively consistent whine, but when I tried to put it back in P it sounded worse yet. Shut it down, restarted, still same sound as when I had shut it down. Shut it down again, went out and jogged the rear axle--a bit of a turn, a few clunks, then the park pawl locked as it should have. Restarted quietly in P. Repeated the exercise completely with identical results. Buddy thinks it has something to do with the park pawl not retracting properly for D and/or not dropping back in properly in P. <P>Sure would make my day to find out that this is something that can be taken care of without removing the tranny, but I'm not holding my breath! If any one out is willing to scan in a few pages out of a shop manual showing the potential miscreants here, I'd appreciate the chance to visual the scene.<P>If I do take the tranny out, how many of the seals and shims in the torque ball need to be replaced? There is some tranny fluid leakage at the joint.<P>RLFORFUN--who's your Dynaflow guy in Atwater?<P>Any other recommended mechanics in the San Francisco/Sacramento/San Jose area?<P>Thanks for all your input!<P>Rick<P>

[rmartens]

I just talked to a transmission mechanic who thinks it may be a yoke problem and may cost me $1500 on the bench.<P>Is this realistic?<P>Rick

[Guest]

Howdy , I paid signifigantly less than that, 1,500 is about what Buick Specialist gets for a complete DF....I will check with my tranny guy and see what he says....If you want ,drop me an Email and I can pass along his phone number..he is a good guy...knows his DFs as well as std. trans.<P> dlw29@hotmail.com<P> Thanks, don55

[rmartens]

Well--so it is now two years later--and I finally have the transmission sitting on the ground beside the car.

I've taken the torque converter apart to get it off the main shaft. Everything looked fine and dandy inside--no broken blades, debris, etc. (Not that I recommend taking one apart for fun--but it's a real thing of beauty inside that turbine housing.) I bolted it back together and put it aside. No obvious problems on either end of the transmission case--nice and clean inside the torque ball as well.

I do not have the kind of money required to take this project to a shop for R & R. I would like to do what I can to try to figure out what the problem is and replace the damaged part if that is possible for what limited $$ I have.

Given the symptoms described in my original posts, where should I start? Should I remove the tail end? Bellhousing? Valve body? I want to find the problem--but I also don't want to have parts flying when I open something up. I'm hoping not to screw more things up in my quest for answers and possible repair.

Thanks in advance,

Rick

[Guest 53and61]

Rick,

You can overhaul your Dynaflow yourself. I did my '53 a few years ago, and it's not impossible if you have the shop manual, a lot of time, and a lot of patience. It took me 3 months worth of weekends. I would advise taking nothing apart without the manual. You will have to substitute for the special tools mentioned in the manual, but as I recall that wasn't much of a problem. Make sure you have a clean work space.

[Guest]

Rick,

Almost two years later and you are still at it. Good news that the stator is intact (trust your gasket was okay when you put the converter back together?). Easy to check the park pawl as it is inside the output shaft housing. Just remove the u-joint from the output shaft, unbolt and remove the output shaft housing. If the park pawl is bad you should be able to determine that as the assembly is pretty simple. If something has broken you may have trouble locating replacement parts.

Good luck,

Gene

[Guest Skyking]

I also rebuilt my DF on a 55 I had.....Having the repair manuel is a must. As stated above, cleanliness is a very big issue. Make sure every part is clean before assembling.......

[rmartens]

Thanks for the advice and encouragement! Keep it coming!

Gene--not sure about the gasket on the converter--were you joking? There was/is no gasket on mine--and I'm positive about that, because I was marveling at the quality machining that made that thing work without a gasket.

Seems like getting a manual is the first step. Does it need to be the shop manual for the '56 Buick, or will the Motors-type manual for the appropriate year range be sufficient? I've misplaced my shop manual (suspect its in a storage locker 750 miles away) but do believe I can find a few pages out of a Motors manual at the local Car-Quest.

Yeah, I'm planning on taking my time. Winter project. Had to build a shed to park the bikes and lawnmower in so that I'd have room to work on the tranny. (Maybe I shoulda put that $$ into the tranny instead...)

Rick

[Judd]

Rick

There is a seal on tourque converter it's around the outer lip where bell and front fit together (replace it you don't want to drop trans later when it leaks) I have 56 manual and a book on Dynaflow repair from 1950 if you need info e-mail me at sjmodels@datasync.com.

[Guest Reatta1]

Boy do I wish I had access to this kind of information years ago when I was in the service. I had a 52 that the dynaflow busted in. I pulled it sitting in an open field in southern Maryland using 4x4's, 2x4's and dug a hole in the dirt under the car and a trench out the side to drag it out through and used a small hydraulic jack to raise and lower it. Never try that again!!!!

[56 Buickboy]

I am in the process of doing dynaflow pressure testing on my 56 Special before pulling my car apart for a complete rebuild. I also have grating noise sometimes as you describe. I have rebuilt some autos but never a dynaflow. Have you checked the trans shift lever linkage for wear and / or adjustment. I too have been guilty of over looking the obvious. Maybe park cannot always be selected fully for this reason.

[Guest]

Rick,

Its been a long time but if I remember correctly there is a thin (very thin) paper gasket between the torque converer housing and cover. I would guess that it stuck to one of the mating surfaces (and hopefully did not tear) when you took the cover off. Judd seems to remember the same thing - perhaps someone else as well??? If I'm remembering incorrectly sorry.

Gene

P.S. The '55 shop manual does mention a pump cover seal but does not show any pictures but should be what I'm talking about.

[critterpainter]

First get a hold of Jim Swanson at Swansons Vintage Buick? He has a one man shop in Sac and knows who would be the best source for your repairs. He specializes in the 320 straight 8 but I'm sure he could help you or tell you who to contact.

Bill

[rmartens]

A local transmission shop has lent me the use of "Motors Automatic Transmission Manual" that covers the '59-63 Buick Twin Turbine and the '61-63 Buick Special Dual Path Drive.

The Twin Turbine unit looks very similar to my '56 Dynaflow--can I use that information or are there significant differences--other than the torque ball?

Thanks,

[Guest Skyking]

Rick, I'm not sure on this but I would say they are totally different, especially the tolerances.........

[Guest miked]

I thought it was pretty funny watchin' the guy's at the trans shop lift it out of my trailer. They were used to TH350s.

[rmartens]

It took me about 30 minutes to get mine from the floor to the workbench...built a tower of 6 X 6 blocks under it to get it 24" inches up, then slid tranny onto a pair of tires and wheels, then rebuilt the tower between the tires and the tranny to workbench height and slid it across from there. I'd rock it one way and my 10-year old (Thanks Kyle!) would put the blocks in place. Then I'd rock it the other and so on. Plenty heavy--and that's with the aluminum bellhousing. Hate to imagine a cast iron bellhousing...

I spent 4 or 5 hours trying to understand how the tranny works--from the book and pictures. I now wish I had spent more time considering all the possible tests BEFORE pulling the tranny--although I don't know what else I would have done--maybe a pressure test and disconnecting the shift linkage?

For those of you who understand the Dynaflow--maybe you can confirm my initial understanding of what goes on. In neutral and park, the input shaft is spinning, turning the rearmost gear (sun gear?) in the center of the planetary set. The low and reverse gears inside the planetary spin in place in the planetary housing--the housing and output shaft are one, and do not move at this point. The reverse gears in the planetary are turning the reverse "drum" which is spinning freely at this point.

In Drive (which is where I noticed the problem and didn't try any other gear), the input shaft is spinning, turning the rearmost gear (sun gear?) in the center of the planetary set. The reaction gear (front gear in center of planetary) is locked by the hydraulic clutch to the input shaft and spins along with the sun gear. The low and reverse gears inside the planetary in essence lock each other in the planetary housing by virtue of opposite rotation, forcing the housing to rotate around the reaction and sun gears, and since the housing and output shaft are one, the output shaft rotates.

If you're on the brake, the output shaft and planetary housing can't spin, which means the input shaft from the torque convertor can't spin--so the torque convertor is acting like the clutch. Or does the drive clutch somehow release?

Here's a question--what would you expect from a partial engagement of the drive clutch? I'm thinking it'd either slip or it wouldn't. If it didn't slip, cluching occurs at the TC. If it slips, you're in essence in neutral. Neither condition should be noisy, right? Unless the R and L gears in the planetary were locking and unlocking intermittently? But my noise was consistent and smooth...Or maybe the clutching action in the TC was noisy under the load of a locked (brakes on) output shaft?

But during one of my diagnostic sessions (on blocks, axle free to spin) quiet in P/N, noise in D. Shut down, restart in P/N, still noisy. Shut down, spin rear wheel, hear click or clunk (something falling into place), restart in P/N, quiet.

Parking pawl not an issue, as output shaft/axle/wheel were not moving. Also confirmed by using drill and socket to spin output shaft in all shift positions except P with no problems.

Still got more thoughts but will wait for confirmation of power flow ideas as described above.

Thanks again!

[Guest 53and61]

Rick,

I didn't carefully check your description of the planetary gearsets and the direct drive clutch, but I think I noticed a misunderstanding of the converter. When its output shaft is locked, the input shaft is still free to rotate, by virtue of the fluid coupling. The situation is somewhat like an input fan aimed at an output fan, with both fans submerged in oil. At idle, only a little energy is lost in the fluid slippage. As input shaft speed increases, much more torque is transmitted to the output shaft. When the car is stopped and your foot is on the brake in Drive, the drive clutch remains engaged and the converter just slips. All this is clearly described in the Buick manual, complete with color diagrams of oil flow. If you'd like, I can send you xerox copies of my '53 and '61 Dynaflow chapters, which should pretty much cover your transmission. Best of luck on the project.

Kit

[Guest Parm]

Pardon me as this is off the specific topic of repairing a Dynaflow. But, it is Dynaflow related.

I am interested in a '63 Wildcat which has a console-shift, Dynaflow transmission. I've heard some not too flattering things about the Dynaflow transmission and was hoping to hear some experienced feedback as to how well it works in a '63 Wildcat.

Thanks in advance to all who can reply.

Steve Parmerlee

BCA # 38881

[rmartens]

Thanks for the continued comments here and via E-mail!

Using the diagrams I have and others that have been sent to me, I'm gaining a much better understanding of how this transmission works. It is a fairly simple design with not too many places things can go seriously wrong. Except in my case, something obviously did go wrong...

Since I suspect a problem in the planetary, I'm thinking that the closest I can come to duplicating my problem (in Drive) on the bench is to lock the input shaft (and its attached reverse sun gear) to the transmission housing. That'll hold the reverse sun gear stationary. Concurrently, I'll lock the low band externally, which locks the drum and reaction gear. With those two steps, I'll be duplicating the Drive situation where the reverse sun gear and the reaction gear are locked together--although in Drive, they'd be moving together, not held stationary.

In Drive, the locked reverse sun gear and reaction gear force the planetary carrier and its attached output shaft to revolve around them, spinning the driveshaft. My noise occurred when I tried to put it in drive with the output shaft locked by virtue of the brakes. Something in the planetary wasn't locking as it should have been. Had it locked, it would have broken the power flow at the TC and there would not have been any noise.

If I lock the reverse sun gear and the reaction gear in a stationary position and attempt to rotate the output shaft around them, I'm hoping I'll be able to duplicate the noise.

Do you think it'll work?

Thanks again.

[Guest Parm]

rmartens, if you're replying to my general question about whether the Dynaflow transmission is a good or bad design, I'm afraid I'm the wrong guy for your reply. I'm not the mechanical type. Wish I were, but I'm not. Let me put it this way, when someone uses the word "planetary", I think of the stars.

I'd just like to know whether I should stay clear of a car with a Dynaflow (aka., Turbine Drive) transmission found in Buicks of the early 1960's.

If not, then how does it compare in performance and reliability to the Hydramatic or Turbo-Hydramatic (the latter I'm assuming is a far superior to the Dynaflow).

Thanks.

[rmartens]

Sorry I didn't make it clear. They seem simple enough, but I don't have enough experience with them to compare them to anything else.

The Dynaflow doesn't actually shift in the transmission itself when in Drive, so to call it an "automatic" transmission might be a misnomer. The torque convertor serves as a fluid clutch and provides provides a high and a low range of gearing. The transition from low to high is smooth and almost imperceptible. I'm not sure if I can actually feel or hear a shift or if I'm imagining it!

With a smooth-opening four barrel, driving my old Dynaflow under some relatively hard acceleration feels like driving a port-injected engine with a quality automatic--smooth!

The books say Low in a Dynaflow is for "emergency use". So in essence you're left with a two-speed--so your mileage won't be great. I can't say how that compares to the other AT's you mentioned...

Rick

[Centurion]

Parm, I have attempted to begin responding to your questions under your '63 Wildcat topic. I do not profess to be a transmission expert, and clearly there are folks on this forum who are far more knowledgeable (technically-speaking) than me. Perhaps if you "jump start" your '63 Wildcat topic again, you can get some more of the kind of input you're seeking.

[rmartens]

I've started tearing down my Dynaflow. So far I can't see anything readily apparently wrong, and I've taken apart the torque convertor, front pump, high accumulator, clutch pack, and eyeballed the planetary gear set. Haven't yet pulled the valve body out, but the pan is clean. From the looks of the rebuilder's paint marks, I'd guess there's less than 10,000 miles on the last rebuild. Nothing looks worn.

Where should I look for trouble?

I know I'll need some gaskets and the rear thrust mount. My mount was shot, and basically the torque tube was carrying the load of the rear of the engine and tranny at the X-member.

Thanks,

Rick

[Guest]

rmartens, I think your problem is not in the trans. In 1956 Buick changed the rear end design and eliminated the lock pin in the drive shaft to pinion shaft coupling. This allowed the spline coupling to work and fret. I have taken a few 56' drive shafts off differentials and found lots of rust and no splines. Buick had a campaign to drill the torque tube and drive shaft and add a grease fitting to the spline area to stop the fretting. If you are not finding anything obivous in the trans I would check drive shaft to pinion coupling. Put a wrench on the drive shaft spline at the trans and see if it is coupled to the rear end. You may have to put some force on the wrench to see if it slips. If so you took the trans apart for nothing. Sorry

Jamrh20

Jim's Dynaflow Service

[Guest Skyking]

Rick, check the front pump. Make sure it isn't wearing into the pump plate. A worn plate could give you the noises you heard......

[rmartens]

After not finding anything immediately and apparently wrong in the mostly disassembled Dynaflow, I pulled the rear end out from under the car this weekend. I locked up the rear brakes and tried turning the drive shaft with an 18" wrench on the front u-joint I had pulled off the transmission. There didn't seem to be any excessive play and the driveshaft wouldn't turn with the brakes locked.

After talking to a buddy of mine and describing the way Jim had described the driveshaft to pinion coupling, my buddy suggested trying to pull the driveshaft out of the torque tube.

I tried, and it moved 4-5 inches out. When it was in the pulled-out position, I turned the driveshaft and could hear the splines slipping. But when it is pushed in, it is as tight as ever.

If this is the problem area, where is there enough room for the driveshaft to move that far forward to cause the noise and slip I experienced?

How do I disassemble the rear end? Or at least enough to confirm or deny what seems to be happening? Does any one have copies of a pertinent manual they could scan in? Thanks!