Tedd Thompson

This comes up quite often on this forum especially on the roto automatic. I found it interesting reading...... Tedd https://www.hagerty.com/media/mainte...missions-ever/

joe_padavano

Bashing the TH200 kind of sets the stage for this article. There was nothing wrong with that trans in it's original application. The problems started when GM put the trans where it didn't belong. That's not the transmission's fault.
Also, the RH5 didn't even make the cut...

Koda

I was expecting the DeSoto DynaFlow's on there, but I guess they weren't really automatic.

rocketraider

I had always thought Flight-Pitch Dynaflow started in '57 Buicks and was offered to Chevy as Turboglide, partly to give Chevy an alternative to the heavy cast iron PowerGlide and partly to help Buick amortize FPD development costs. Pontiac, Olds and Cadillac had HydraMatic and sure weren't going to have anything to do with it.

Unreliable or not, FPD evolved into TurboHydraMatic. And as Joe has pointed out, GM often put versions of it in cars it wasn't suited for.

Disagree on two-speed Fordomatic being a PowerGlide knockoff. It was based on Borg-Warner engineering and design and IIRC (the books are packed away) utilized torque converter, air cooling and was actually a 3-speed trans that, in Drive, started in second gear and shifted once to high. Low, like PG and DynaFlow, had to be manually selected. It also utilized the "modern" PRNDL shift sequence while everyone else retained PNDLR or some variant of it.

Between 1961 and late 62, there were nine different valve body revisions for the Roto375 in an effort to get it to work smoothly and reliably. Cadillac wouldn't have it and Pontiac used it only in the short wheelbase cars, opting to keep 4-speed HM in Bonnevilles and Star Chiefs. But Oldsmobile used it across the board.

Olds64

Thanks for the link Tedd. It's good to know that Olds wasn't the only one with transmission troubles.

rocketraider

You have to admire the spirit of these transmission engineers. AT technology was still in its teenage years in the 50s but by 60s it was fully formed. Turbo 400s, SelectShift CruiseOMatic and especially Torqueflite set standards for performance and durability that haven't been equalled.

But DAMN an electronically controlled transmission. Two of the four I've owned have been troublesome, the 4L60E especially. Then again considering what I paid for it that Bravada was the biggest POS I've ever owned and is the vehicle that made me switch to Fords for daily drivers. Between a bad car and a worse dealer, GM and their transmissions can kiss ol' Rhody.

matt69olds

It’s been my experience with troublesome 4L60E transmissions that just can’t be fixed are usually caused by electronics or electrical parts outside the transmission, or internal porosity that can’t be seen. The fancy solenoids only do what the PCM commands, and if the PCM either receives or commands faulty info, the transmission will never work right.

Occasionally, porosity in the aluminum casting will internally leak pressure. I built a 400 for a buddy that kept eating up the direct clutches. The trans core came out of a well used mid 70s station wagon. Upon tear down, it looked like every other running driving core trans. Different center support, different direct drum, tried 2 different kinds of transbrake valve bodies, line pressure was always good, I put 2 sets of direct clutches every season for 3 years. He broke the driveshaft and cracked the case, I swapped the guts into a different case. He is now going on 2 years since last repair. BTW, this trans is in a turbo LS swapped 71 Javelin. Last time he had it on a dyno it made well over 1400hp.

77toronado

The second car I ever owned was a '63 Pontiac Grand Prix with a roto hydromatic. In my youthful ignorance, I thought - no big deal, I'll just swap it out for a TH350 when the time comes. Yeah - no. My first "WTF" moment was when I saw that my starter was bolted horizontally through the transmission, instead of vertically into the engine block as it was on my generic small block Chevy powered car. Ah, youth and lack of knowledge before the days of the interwebs.

I eventually got it to shift reasonably well, but it took literally dozens of laps around the neighborhood, with several stops to get out, pop the hood, and adjust the TV linkage with a pair of wrenches a 1/4 of a turn or less each time. Ok, my definition of shifting reasonably well kept getting down graded as the process went on.

btw, I came into this thread expecting to find the slimjim at least mentioned. I was not surprised at its place of honor in the list.

olds403

The 200 is quite the light weight transmission. Go look on http://www.scottmcclayengineering.com
I have one of his drums in my 2004r (overdrive version). Scott is good to deal with. Not saying I would run a 200, but he helped me with my 2004r.

Charlie Jones

The roto-hydramatic AKA " the slim jim " is bad , that I will agree .
But, since the title of this thread is " the worst automatic transmission " , I will give you my candidate for worst automatic transmission .

It was called the "automatic transmission " and it was developed and introduced as an option on the 1937 Oldsmobiles .
They sold a few , but not too many . And it wasn't a true automatic .
You selected neutral , drive , low , or reverse with a quadrant , like the Hydra - Matic .
But it had a manual clutch .

In 1938 GM was looking to amortize some of the development costs , so they talked Buick into offering it .
Buick called it the " Self - Shifting " transmission .
Buick's transmission plant had been building this trans , as well as Old's stick shift trans
Buick sold some , but the warranty levels were so high that Buick recalled all Self - Shifting cars .
They removed the transmissions , and replaced them with conventional three speed stick shift transmissions .
A few missed the re-call , and one survives in California today .

Buick was extremely quality oriented ( when better automobiles are built ) and the whole affair soured them on Oldsmobile designed transmissions .
They refused to use Hydra-Matics when offered them and probably lost sales to Olds because they didn't offer an automatic .
Buick finally developed their own automatic , the Dynaflow , in 1948 .

I doubt that Olds did much better with the " Automatic Transmission ". They still offered it in 1939 but few were sold . Olds didn't offer an automatic again until mid-1940 .
That was the Hydra - Matic we all know . The first truly automatic transmission .

rustyroger

I agree with Joe's comment about the TH200 being a decent transmission put to inappropriate use.
Over here in the 1960's the Automotive Products Company designed and developed a 4 speed automatic for BMC (Britain's largest automaker at the time) to be used in their small fwd cars.
It was a very good transmission when it was new, cars so equipped could keep up with their stick shift siblings with perhaps a 10% penalty in gas mileage. It shifted smoothly, kickdown was very quick, and it replaced a rubbery imprecise manual gearshift too.
The downside?, the bean counters at BMC decided it should share its oil with the engine, like the stick transmissions, instead of having the transmission run in its own oil supply, using something more suitable than 20w50 engine oil.
If you were lucky, and changed the oil every time you changed your underwear you might get 50k from one, 30k was the normal life expectancy. It was expensive too, a £97 option on a car that cost £800 in stick form.
Surprisingly it soldiered on until the 1980's, mostly selling to retirees who clocked up miniscule annual mileages.

Renault also marketed an automatic transmission which was a stick shift controlled by what passed for a computer in the 1960's, drivers were often disconcerted by sparks coming from the control unit, the shifting was likened to an inept learner who hadn't mastered clutch control. It didn't last long.

Roger.

matt69olds

Seems like the bean counters are always screwing things up!!

rocketraider

That's the understatement of the century, and not only in automotive world.

Accounting types do cost-benefit analyses to figure out how cheaply they can build something and have it last till the warranty's out. That backfired on the 200/250 transmissions, especially on cars sold in mountainous regions or in the case of hairdryer Buicks. Warranty claims were out the roof. And HydraMatic said they couldn't make a transmission to hold up behind a Turbo Buick. Uh, you made transmissions that held up behind big-inch Chevys, and Buicks, and Oldsmobiles and Pontiacs... The bean counters wouldn't LET them build such a transmission until their CBAs were shown to be worthless.

rocketraider

Roger, I have always wondered about the European predilection for having engines and gearboxes share a common oil source. Then Citroen and their hydraulics... one of the most advanced cars in the world but everything worked off a common hydraulic system. Brakes, steering, suspension, transmission- you hoped nothing started leaking! Kss-kss-kss...

newmexguy

Ford FMX. Imho it's garbage. The bell housing and tail housing were aluminum, the center section was cast iron. No market for them. The bell housings and tail housings make for good cores when going to the U Pull Its. The Windsor bells may have some value for irrigation pump motor adaptation, most of which here are V type Chevy.

droldsmorland

To date, the only auto trans IMO that has the ballz to "stand up" ballz deep is a TH400/4L80E or an Allison. Maybe the 6R140 in my F250. Beyond that maybe an exotic glide set up for 1000HP blower motor... after that row yer own or go home.

A TH200 belongs at the end of a boat anchor chain or behind go-cart Yugo or a wheezing 4 or a 6..thats why it was Dee-signed,,,.There was no more 450 hp 500lb/ft big blocks when the bean counters did their debauchery, (GN/GNX exception, but not in torque capacity).

Lay the guts out on a table and compare. That will speak volumes. Allison wins hands down in the truck world. TH400/4L80E wins in the car world.

rustyroger

To be fair, the Mopar 727 was about as good as it got for the ubiquitous three speed transmissions that were the mainstay of American iron for two decades or so, the Ford C6 could also deal with the similar outputs of their Big Block engines. The lesser versions were quite capable of handling the output of smaller engines too. To condemn the 200 as a boat anchor is too ignore the fact that mechanical losses are higher for the beefier transmissions, a TH400 behind a151 four would eat up a good chunk of power before anything got to the driveshaft.

It was really only the BMC fwd cars that got the transmission in the oil pan treatment. When Alex Issigonis designed the Mini he faced the problem of fitting an engine and transmission into a tiny engine bay. Putting it on the end of the engine would mean the radiator would need to be moved to somewhere it needed a remote fan (remember the bean counters?), so incorporating it into the oil pan, or really making the transmission do duty as the oil pan was a cheap and ingenious way of saving space. The larger Austin/Morris 1800 also had the stick transmission as the oil pan, but the automatic versions, which used a version of the Borg Warner 35 transmission had entirely separate lubrication systems. Guess what?, automatic transmissions lasted as long as the same transmissions used in rwd cars.

Roger.

olds 307 and 403

I agree, have seen few issues with the Allison auto trans in big trucks. Even some of the crappiest auto trans have been fixed by either the parent companies or the aftermarket.

69CSHC

Had a mint and babied bone stock 1979 Cutlass Coupe with a 260 in the family way back when. The transmission went twice. Every time it came to rebuilding or replacement estimates, etc. The mechanics had the same comment. They called it the metric 200 and said it was a piece of crap.

Now of course the 260 as small as it was is still a V8 but the 231 V6 that's optional has specs that are similar for 1979.

231 CID V6 = 115 hp ( SAE net ), torque: 190 lb-ft,

260 CID V8 = 105 hp ( SAE net ), torque: 205 lb-ft,

( maybe that additional 15 lb ft was the straw that broke the camels back... ?)

https://www.automobile-catalog.com/m...oupe/1979.html

I've read that they improved them over the years and experienced that as well on the later ones. Had several 85-88s both 3 and 4 speed without issues. My 87 442 that's parked down has a kick *** version coded KZF. I've driven that car every bit as hard as my 69...

matt69olds

There isn’t a transmission more durable than the 400. As long as your working with one of the early units with the sprag style drum, a 34 element sprag, a 3/8 freeze plug, and a 3/16 drill bit is all that’s needed to reliably handle 1000 plus hp. The gearsets, shafts, all the hard parts will handle far more power than GM ever thought possible. The Mopar and ford auto trans are also durable, but won’t handle anywhere near what the 400 will stock. The 727 needs planetary gearset and shaft upgrades, the ford C6 needs machining or factory performance clutch drums for additional frictions, aftermarket or factory performance servos, etc.

I know this thread is worst trans made, just figured I’d share more useless info. It’s hard to imagine that the 400 trans was introduced in 1964, and nothing made since then can rival its brute strength.

rocketraider

It's also amazing that the 400 is a descendant of Buick's miserable experiments in Twin and Triple Turbine/Flight Pitch Dynaflows.

Always wondered how they talked Cadillac into using it in 64. Cad stuck with HydraMatic on the Fleetwood Seventy-Five and commercial chassis thru 65. Guess the 400 had proven itself by then. Cadillac as a rule in those years didn't send a gadget into its showrooms until it was proven to work flawlessly and reliably. 15 years later...

Super Turbine 400 as used in 64 Buicks retained PRNDL shift sequence though in D it did shift 1-2, 2-3, whereas before a Dynaflow didn't shift at all. 65 before it got an L2 position. Not sure on Cad. The dedicated L2 may have been a way to get Olds and Pontiac to buy into it so they'd still have their "super" S range.

I can only imagine the ill will at Oldsmobile when Buick "won" the GM transmission war. You can bet they hadn't forgotten Buick snubbing the "Jerk-O-Matic". Though truth be known a HydraMatic would have made short work of Buick's torque tube drivelines.