Lock Up VS Non Lock Up- pros/cons

[JBreu]

I'm in the process of selecting a stall converter for my 700-r4 transmission.ANyone here have a 700-r4 and not running the lock up? I'm thinking of getting a non lock up converter and using the Transgo Converter Conversion Valve........ Thought/Opinions greatly appreciated!!

 

[clint]

i have a 700r4 in my 81 i bought last year there is tv cable but no eletrical hook-ups i have to assume it is a no lock up type converter seems to work ok ...cruise rpm is decent on the highway with 3.73 gears

 

[SSedan64]

A Non-Lock is much better for engines with large Cams. Lockup's can transmitt a lot of engine firing pulses with long Duration Cams, jerky feeling.
Non-Lock TC's are much more efficient up top than Lockup's when not locked.
To do WOT shifts with the TCC locked requires a multi-Disc TCC clutch, 5-7 Disc, $$$.
There's only about 150-200rpm difference between Non-Lock & Lockup TC when cruising.
Non-Locks do produce more heat but, a good Cooler will take care of that.
IMHO, Non-Locks are much better for Hi-performance use. Lockups for mild Perf, MPG & cruising.
Todd

 

[madmaxx57]

i have a lockup on my 700 and dont like it..my 200 is a non lockup..that i like much better..seems alot smoother in general..

 

[JBreu]

I ended up ordering a 3200-3400 stall converter non l/u from PTC Converters......I hear they are a great company ...Can't wait to get it !!

 

[madmaxx57]

just remember if go non-lockup converter..i'm pretty sure you have to do something else to the trans..i dont remember what..might want to check with a trans guy..

 

[t5montecarlo]

There's only about 150-200rpm difference between Non-Lock & Lockup TC when cruising.

Not true. The rpm difference will depend upon the cruising speed and the stall speed of the converter. Locked = locked...no more stall.

To do WOT shifts with the TCC locked requires a multi-Disc TCC clutch, 5-7 Disc, $$$.

Don't lock until cruising. WOT should unlock the converter.

just remember if go non-lockup converter..i'm pretty sure you have to do something else to the trans

It has been quite some time since I read about eliminating the lock-up feature, but I agree it is not as simple as just disconnecting the plug or buying a nonlock-up converter; I also remember reading there are some other plumbing mods necessary to maintain keep the life of the transmission...but don't quote me on that. As stated, check with someone like Art Carr.

 

[madmaxx57]

i was told thats what killed my stock 700 i put in my 57 chevy..i just didnt bother with hooking it (wiring) up, as its got a tpi setup..about 500 miles..started having some issues..i dont remember what exactly..but when i took it in for rebuild, the trans guy knew what i had done..lol..sooo i went with lockup and........i dont like it..so on my 200 in my old camaro i had him build it for a non=lockup...that one i like!

 

[JBreu]

Yeah, when you install a non lock up converter, you need a converter conversion valve, TransGo part # 7-ccv, Converter Conversion Valve: For installing non-lockup converter. Corrects lube flow thru converter....on the early 700r4's with the 27 splines...they were deadbeat trannys...The later 700r4 with the 30 spline were much better.........With this valve, I'll be all set.....

 

[SSedan64]

There's only about 150-200rpm difference between Non-Lock & Lockup TC when cruising.

Not true. The rpm difference will depend upon the cruising speed and the stall speed of the converter. Locked = locked...no more stall.

(( I know this would be different with a Hi-stall racing converter, The above is assuming stock or modded stock size converter. ))

To do WOT shifts with the TCC locked requires a multi-Disc TCC clutch, 5-7 Disc, $$$.

Don't lock until cruising. WOT should unlock the converter.

(( Many racers lock the TCC when shifting @WOT. This will burn a Single Disc TCC up quickly. The 2004R will shift into 4th @WOT & lock the TCC. Most 700R4's wont do this, excluding Vette, T/A & Z-28. There is a simple Valve Mod to allow this in other 700R4's. ))