Grass is always greener on the other side of the torque converter. Lockup is cool, but, the clutches can shed material into the fluid flow and clog a journal, or jam a shift valve. That sucks expensively. Non lockups slip forever, and generate lots of heat, and will cook fluid, but can often be set right with a fluid change, assuming you do so before the ruined fluid has time to hurt a bearing or a valve. Need LOTS of cooling, and a TC with more efficient stall ratio to make it work nice AND stay nice.

 

Newsflash: Cheap parts and poorly maintained equipment is liable to fail in all sorts of ways.

You can't be seriously suggesting a non-lockup converter has any advantage whatsoever in a modern vehicle, can you? Especially in a diesel truck application? The early 727 and 68RH Dodge Cummins trucks were notorious for horrendous fuel mileage when towing and a strong propensity to cook the fluid doing so as you mentioned. Some of the new generation autos coming out over the past few years can lock up in every gear for the obvious benefits provided by that capability.

 

68RH?
NOW who's talking out their ***?
If you don't know the correct models of trannies, how can you know anything else?

Next I suppose you'll try to tell me an A 518 is really a 46RH?

Mark.

 

So are you 518 guys without lockup and a good tc happy

 

I have an 89 with the 727 and it does good towing and gets about 20mpg consistently. However if you tow very heavy loads up steep hills the tranny gets hot VERY fast.

I have a 518 out of a 92 I rebuilt and converted to a lock-up converter to put in it in the future. The only thing to it is getting an input shaft from a lock-up trans (lock up ones are hollowed out) and a 47RH valve body. The non-lockup VB is the same, it just doesn't have the solenoid for the lock-up (That's what it looks like from the outside anyways). You'll have to get a plug from a later model truck also so you have the wires for a lockup switch.

 

I am.

 

To correct my younger, not as knowledgeable self, technically nothing is slipping, but you are "shearing" the transmission fluid. Besides the bands or clutches in the trans "slipping" while engaging or hunting from 3rd to OD the majority of your heat is created from the fluid coupling in a torque converter when unlocked. If its getting hot or shuddering while locked the lock up clutch is giving you the middle finger when you get on the go pedal. Problem with most first gens is we don't have lock up or enough ponies to junk em!

 

I guess everybody else smacked Nadir (low) Point (seems fitting, actually) for his attitude. No, I was not suggesting "advantage over". Read the first sentence in my post: "the grass is always greener....." I pointed out pros and cons. What would really be cool, and I don't know if anyone's brought it to the truck world, would be an automatically-shifted manual with a real clutch. The supercar guys like Ferrari and others have those, easily identified by the "flappy-paddle" option. Then you get the durability of a manual tranny, the convenience of an automatic, and only have to worry about loose wiring or a loose air-hose messing up your ability to shift gears, or even disengage the clutch.

In short, perfection ain't gonna be attained in this world. Pick the imperfections that offend your the least, and then minimize'em.

And, try not to be a dick about it.

 

Geddys_uncle, back in the 60s-70s there was a kit for a "Clutch Flite", which is exactly what it sounds like, an automatic with a clutch.
Over the years I have seen 3 or 4 of them, they always intrigued me, but the price for such ancient pieces also scares me.
Even so, these things were put behind blown supercharged Hemis and lasted well, so it wouldn't be a stretch to see a more current and upgraded one survive behind a Cummins.

There is also no reason why this set-up wouldn't work with the current crop of automatics, given someone with the willingness to do machine work.

Mark.

 

Ouch.
Which "suggests" non-lockup had some advantage. Newsflash: it don't.
There are no "pros" to non-lockup TQ converters. That's why they have not appeared in new vehicles for at least the last 15 years. Wake up. Newer, better designs for non-lockup converters make them a far cry more "adequate" than the original/stock examples, but that's about it.
That's happening just as soon as the diesel truck buyers are ready spend supercar prices on a pickup. Like maybe... never. Ya think? But things change, we'll see. One thing that never seems to change is how people tend to cling to outdated knowledge.
People living in the past are easily identified by their flappy brains clinging to old technology.
Modern autos no longer have any "durability" issues compared to manuals. That is largely due to locking TQ converters, among other things. Again, update your knowledge or keep it to yourself, please. At least stop trying to mask your ignorance with personal attacks on me.
It's being done. Bought a new vehicle in the past ten years?
Think about that next time you decide to take a potshot at me.