The junkiest automatic transmission ever manufactured?

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I had a 98 Yukon that had a 4L60E in it and that was the biggest piece of crap I ever had. I loved everything else about that truck but the trans ruined it for me.
 
Originally Posted by Gasbuggy




So your opinion of the 4l60E is different?



With it's glass sun shell? Not really.

Also, thanks to those who mentioned the CD4E. I was trying to remember the name of that turd, but couldn't.
 
Originally Posted by demarpaint
What did you think about the C6? Thanks.


The C6 is a Very Good unit, But has a Synchronous 2-3 shift like the A727. And to be clear BOTH the A727 & C6 are just as strong as a TH400.....It's a nit-picky thing that I notice on every test drive.
 
Originally Posted by 2002 Maxima SE
The AXOD, AXOD-E and AX4S 4 speed transmission used in the following:
1991-2003 Ford Taurus
1991-2003 Mercury Sable
1991-1994 Lincoln Continental
1995-2000 Ford Windstar

The sychronous shift of the AXOD/AX4S caused them to wear out pretty quickly at low miles. Not to be confused with the AX4N (much, much better) due to non-sychronous. I believe the AX4N was designed for the SHO (V8 those years) which led to a more robust engineered (or over engineer for V6 model) design.


The AX4N came out in some 95 Taurus-Sable, maybe earlier for the V6 SHOs. I had one in a 96 Sable with the Duratec.
Once rebuilt, the AX4S in my 96 Windstar (3.8l) has been holding up well, 131,000 miles since the rebuild, which is longer than the original lasted. It set a code, something about number 1 piston. I was able to drive it to the transmission shop.
I think my 90 Taurus wagon had a AXOD attached to a Vulcan. It lasted until the body rotted away.
 
Originally Posted by clinebarger
Originally Posted by red7404
YES the Chrysler A-727 Torqueflite. is a very good trans.


The A727 is a very good unit, The only thing I don't like about them is the Synchronous 2-3 shift. The Front/Intermediate Band (2nd gear) has the be knocked-off at the same time the Direct Clutch (3rd gear) comes-on, This requires precise timing that's not possible in a pure hydraulic trans.
A Bind or Cut-Loose(Flare) will ALWAYS be there, A "ever-so-slight" Bind is the best you could ever hope to achieve. If the 2-3 shift on a A-727/46RE/47RE/48RE feels just slightly weird to you.....This is why! A completely "Clean" 2-3 shift is just not possible!

The GM 2004R/TH200/TH250/325-4L 2-3 shift's work on the same exact principle!

700R4/4L60E's work on a similar albeit different principle.....The 2-4 band has be knocked-off while the 3-4 Clutch comes-on during a 2-3 shift, Like the A727, A slight overlap of the 2 two Holding & Driving components is the best you can hope for. The difference being that it's not technically a Bind, The 2-4 Band & 3-4 Clutch "ON" at the same time is what gives you 4th Gear, So it goes like this on a 2-3 shift with a slight overlap........2nd4th3rd
Why a completely "Clean" 2-3 shift is not possible on this unit neither!

*A Cut-Loose(Flare) Synchronous issue on the other hand will burn frictions in a hurry!!!! Several 700R4/4L60E's suffered from this from the factory. And not as easy of a fix as a front band adjustment like A727 & it's derivatives.

The TH350/TH400/TH425/4L80E have a Non-Synchronous 2-3 shift......The Direct Drum has a Over-Running Clutch/Sprag/Mechanical Diode/Roller Clutch (Several names for the same part), This allows the Direct Clutches (3rd gear) to come-on while the Intermediate Clutch (2nd gear) can remain applied.
This type of unit has a completely clean 2-3 shift.








Fascinating stuff... too bad I've never driven one of those transmissions. BUT now I'm wondering. The A760H in my Tundra has always felt weird on the 1-2 shift, particularly if on a hill. Would you know if its the same sort of synchronous shift?

Bit of a derail, sorry.
 
Originally Posted by dave1251
Originally Posted by Triple_Se7en
The old 4-speeds seemed to outlive the new, current 8+speeds.



Not even close. The 8 speeds are just if not more durable.

Them new fangled transmissons with 6 to 10 speeds. Old people refuse to adapt to change.


Maybe so but who wants a transmission that shifts gears every 5 mph?
 
Originally Posted by Dave1027
Originally Posted by dave1251
Originally Posted by Triple_Se7en
The old 4-speeds seemed to outlive the new, current 8+speeds.



Not even close. The 8 speeds are just if not more durable.

Them new fangled transmissons with 6 to 10 speeds. Old people refuse to adapt to change.


Maybe so but who wants a transmission that shifts gears every 5 mph?


They shift so smooth you can barely tell during normal driving. Click it over to sport and it behaves more like what it essentially is... a 6 speed transmission with 2 overdrive gears.

It's also pretty nice to cruise down the road at 60mph with the engine barely above idle.
 
Originally Posted by Skippy722
Originally Posted by Dave1027
Originally Posted by dave1251
Originally Posted by Triple_Se7en
The old 4-speeds seemed to outlive the new, current 8+speeds.



Not even close. The 8 speeds are just if not more durable.

Them new fangled transmissons with 6 to 10 speeds. Old people refuse to adapt to change.


Maybe so but who wants a transmission that shifts gears every 5 mph?


They shift so smooth you can barely tell during normal driving. Click it over to sport and it behaves more like what it essentially is... a 6 speed transmission with 2 overdrive gears.

It's also pretty nice to cruise down the road at 60mph with the engine barely above idle.


I once had a BMW X3 loaner. That thing shifted through all 8 gears by 40 mph. No thanks.
 
Originally Posted by supton

Fascinating stuff... too bad I've never driven one of those transmissions. BUT now I'm wondering. The A760H in my Tundra has always felt weird on the 1-2 shift, particularly if on a hill. Would you know if its the same sort of synchronous shift?

Bit of a derail, sorry.


The Aisin A760x 1-2 shift in non-synchronous.
In fact the only synchronous shift on this unit is the 5-6 shift......B2 clutch comes on & C3 clutch has to come off.

This unit is quite unique among 6 speed automatics as it uses 4 mechanical diodes to achieve as many non-synchronous shifts as possible.....Unlike say a GM 6L80E/6L90E that only has 1 mechanical diode for Low Range Braking.....Every forward shift is synchronous.

Page 119 shows a power flow chart for your unit.......HERE
 
I'll throw one out that perhaps doesn't count because it's not a traditional automatic. The F1 Trans that Maserati used. Doug DeMuro called it the worst transmission he's ever driven and the worst ever conceptualized. It has produced some of the most hilarious forum complaints and commentaries I've read. You see horror stories about guys picking them up cheap and then sinking 10-20k into them just to get the trans behaving. A guy a few blocks over from me bought a Quattroporte years ago, I would see it around town and always wanted to stomp on it with my old first gen CTS-V. Then I saw it parked behind a foreign car repair shop for about a year. Then it was back on the road for a couple of years. Now it's behind the same shop for almost another year.
 
Originally Posted by Dave1027
Originally Posted by dave1251
Originally Posted by Triple_Se7en
The old 4-speeds seemed to outlive the new, current 8+speeds.



Not even close. The 8 speeds are just if not more durable.

Them new fangled transmissons with 6 to 10 speeds. Old people refuse to adapt to change.


Maybe so but who wants a transmission that shifts gears every 5 mph?


Or costs a fortune to rebuild, if you can even find someone with the skill set required to actually repair or rebuild it. FTR I like the ZF 8 speed, but would hate to pony up the cash to rebuild it if I owned something with it.
 
Originally Posted by clinebarger
The Aisin A760x 1-2 shift in non-synchronous.
In fact the only synchronous shift on this unit is the 5-6 shift......B2 clutch comes on & C3 clutch has to come off.

This unit is quite unique among 6 speed automatics as it uses 4 mechanical diodes to achieve as many non-synchronous shifts as possible.....Unlike say a GM 6L80E/6L90E that only has 1 mechanical diode for Low Range Braking.....Every forward shift is synchronous.

Page 119 shows a power flow chart for your unit.......HERE



Thanks! Just has this 1-2 shift that feels like it slides into geart, and not in a good way--maybe it's just low rpm and high convertor slippage or something. I've ignored it as I've thought not too much of it, but your comment made me think about what was going on inside the transmission (which unfortunately is beyond my understanding).
 
Originally Posted by demarpaint
Originally Posted by Dave1027
Originally Posted by dave1251
Originally Posted by Triple_Se7en
The old 4-speeds seemed to outlive the new, current 8+speeds.



Not even close. The 8 speeds are just if not more durable.

Them new fangled transmissons with 6 to 10 speeds. Old people refuse to adapt to change.


Maybe so but who wants a transmission that shifts gears every 5 mph?


Or costs a fortune to rebuild, if you can even find someone with the skill set required to actually repair or rebuild it. FTR I like the ZF 8 speed, but would hate to pony up the cash to rebuild it if I owned something with it.

That's basically it, isn't it? It's still a wear item, but now it's like 10% of a new car it seems ($3k and up?). Not sure if it was always like that, but it gives one a big pause.
 
Originally Posted by supton

That's basically it, isn't it? It's still a wear item, but now it's like 10% of a new car it seems ($3k and up?). Not sure if it was always like that, but it gives one a big pause.


I had to look up the cost between a 545RFE and an 8HP70 8 speed for a Durango for my own curiosity. Brand new 8HP70 is $2,575. The 545RFE is $4,357 for a brand new one and $2,455 for a remanufactured one.
 
Originally Posted by Skippy722
Originally Posted by supton

That's basically it, isn't it? It's still a wear item, but now it's like 10% of a new car it seems ($3k and up?). Not sure if it was always like that, but it gives one a big pause.


I had to look up the cost between a 545RFE and an 8HP70 8 speed for a Durango for my own curiosity. Brand new 8HP70 is $2,575. The 545RFE is $4,357 for a brand new one and $2,455 for a remanufactured one.

Hmm, cheaper than I thought. Toss in R&R at a shop though and it's still $3k I bet.
 
Originally Posted by supton
Originally Posted by Skippy722
Originally Posted by supton

That's basically it, isn't it? It's still a wear item, but now it's like 10% of a new car it seems ($3k and up?). Not sure if it was always like that, but it gives one a big pause.


I had to look up the cost between a 545RFE and an 8HP70 8 speed for a Durango for my own curiosity. Brand new 8HP70 is $2,575. The 545RFE is $4,357 for a brand new one and $2,455 for a remanufactured one.

Hmm, cheaper than I thought. Toss in R&R at a shop though and it's still $3k I bet.


Definitely, but I was thinking the 8 speed would be way more than the 5 speed speed!
 
Seems odd. Maybe it's economy of scale--maybe the 8HP70 simply is getting more of them made per year. I wonder if its also being made "cheap"--not in a derogatory sense, but literally designed to be low cost. Maybe not so much less parts but just less expensive parts.
 
Originally Posted by supton
Originally Posted by clinebarger
The Aisin A760x 1-2 shift in non-synchronous.
In fact the only synchronous shift on this unit is the 5-6 shift......B2 clutch comes on & C3 clutch has to come off.

This unit is quite unique among 6 speed automatics as it uses 4 mechanical diodes to achieve as many non-synchronous shifts as possible.....Unlike say a GM 6L80E/6L90E that only has 1 mechanical diode for Low Range Braking.....Every forward shift is synchronous.

Page 119 shows a power flow chart for your unit.......HERE



Thanks! Just has this 1-2 shift that feels like it slides into geart, and not in a good way--maybe it's just low rpm and high convertor slippage or something. I've ignored it as I've thought not too much of it, but your comment made me think about what was going on inside the transmission (which unfortunately is beyond my understanding).


Your welcome, Though I didn't completely answer your question....

The biggest ratio "jump/spread" in almost all automatic transmissions is the 1st ratio to 2nd ratio.
Your ratios (:1)
1st 3.520
2nd 2.042
3rd 1.400
4th 1.000
5th 0.716
6th 0.586

*The difference between 1st & 2nd is 1.478.....2nd to 3rd is 0.642. And the ratios get closer & closer from there.
*The bigger the ratio spread from one gear to the next.....The greater chance there is for a rough shift.
*Manufacturers generally err on the side of a Softer upshift than they would to a Firmer upshift, The average Consumers/Customers will complain about a rough shift. They probably just missed the mark on yours.....Happens all the time.
*My brother has a 2018 5.7L Tundra, And I don't care for the 1-2 shift either.....And the TCC scheduling is weird in my opinion!

Back in the good ole days.....We would simply enlarge the 2nd clutch feed orifice or Limit 2nd clutch accumulation, Unfortunately it's not that simple anymore.....Custom tuning of the ECM is the only way to correct this.

The Aisin A760x is a otherwise good/robust unit & will last a long time.
 
I generally think Toyota (Aisin?) has something against the concept of convertor lockup--they are quick to unlock and push too tall of a gear. I can repeatedly get lower rpm in my truck by commanding downshifting on a hill. It'll push 6th unlocked rather than 5th locked. I'm guessing it's to prevent wear and tear on the trans, but it just grates on my nerves. My Camry it turns out is the same way; in 3rd gear it won't lock up until some high rpm, and is very quick to unlock even still (if I'm heavy on the throttle and have OD locked out).

Oh well. I just live with it. They seem to be long lived, so I just put up with it, and worry about other things in life. Around town I just lock out gears if I think it best.
 
Originally Posted by supton
Seems odd. Maybe it's economy of scale--maybe the 8HP70 simply is getting more of them made per year. I wonder if its also being made "cheap"--not in a derogatory sense, but literally designed to be low cost. Maybe not so much less parts but just less expensive parts.


Transmissions like the ZF 8HP70, Ford 6R80, GM 6L80E/8L90E ARE far cheaper to manufacture, And believe it or not.....Have fewer parts than say a Chrysler 545RFE, Ford 4R70W, GM 4L80E. The machining alone to build a 4L80E is staggering compared to a 6L80E.
 
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