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700R4 lockup question


Guest kc6wfs

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Guest kc6wfs

I just realised with my 700R4 I can shift 1,2,3,4 Isn't the lockup supposed to put in in 4th? I did not think it was going into 4th but it is. A good thing.

Question, What is the cheapest way I can hook up the for the lockup converter?

 

What will happen is there is no lockup converter in there. I'm sure it is of the lockup type but what would happen if it was not.

 

What will I notice differance wise with the lockup?

 

Can I lockup in 3rd and still go into 4th with out unlocking and then locking it up?

 

This is all new to me.

Thanks.

 

Dave

 

 

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www.geocities.com/kc6wfs/240z.html

www.NitroPhotos.com

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Dave, you can run it fully unlocked with dummy lockup valve and non-lock convertor or just never hook up lockup on it. Hooking up lockup provides that direction connection (Pete will disagree smile.gif ) and can be had in 2/3/4 without unlocking between gears depending on setup (ie. gains to be had in 1/4 if fully locked for some).

 

You can do it as simple as a 2 wire relay to the plug on your trans and a switch you hit manually and a 'kickout' related to your brake pedal so it always unlocks as you slow down (leaving it locked at idle will kill it fast!). More expensive ways are rpm activiated lockup kits like B&M. I have one cause I got it used/cheap but yet to install. Running it locked up will reduce the heat it creates and add slight mileage gains. If you do lock it up please document before and after rpm's at specific speeds as I've heard you 'only' gain 200rpm or so by locking it so it hasn't hit the top of my list.

 

PS if you have no lockup then it shouldnt' respond at all to your wiring/switch effort as the lockup valve isn't present to be activated...I'm sure Don will chime in with more solid facts.

 

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Of all the things I've lost, I miss my mind the most.

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Ross, I didn't know you could lock that tranny in 2/3/4 - pretty cool.

 

Now, remember the days of the Clutch TH400?

 

Here's an idea I'd like to try some day:

 

- Put a clutch in front of the 700R4 (a la Clutch TH400),

- Do away with the brake activated "unlock",

 

- Run around with it locked all the time (well, 2/3/4, anyway), and

 

- Do a manual valve body (do these exist for the 700R4?)

 

Then I'd have the "control" I love so much in a stick car.

 

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Pete Paraska - 73 540Z - Marathon Z Project

pparaska@home.com

Pete's V8 Datsun 240Z Pages

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Guest Anonymous

That'd be pretty cool Pete. Years ago, when I was in auto trade school, the instructor had a 427 in a 64 malibu. He had a Clutchflite tranny in it. It was like it sounds, a clutch in front of a built 727 mopar tranny. It was hell for strong and launched like it got hit by a train. It was a cool setup.

Lots of classes of circle track use the automatics with clutches (mainly like powerglides though..)

Crower used to make a 'Crowerglide' which was just that, a powerglide with a clutch (which in a drag Z would work pretty well really..).

Anyway, just recollecting old times. Now where did I put that polident... smile.gif

 

Lone

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Guest kc6wfs

Thanks Ross,

 

Funny here all along for the last month I thought i was only getting into 3rd due to the hi r's on the freeway.

I must have a 3.90 rear. Think I'll put it on the jack today and spin the shaft and see what the tires say.

 

Cool, I was woried about some kind of electrical problem or worse trans problem if the converter was not a lockup converter.

 

I don't have the plug for the trans.. How much do ou think the dealer will charge for the plug??

 

Also my trans is a 1984 vintage.

Ross can you with your trans be WOT and still shift into 4th?

 

I'm wondering, thought i read that the 700R4's could not do that except for the corvettes. I am probable wrong.

 

Thanks.

Dave

 

 

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www.geocities.com/kc6wfs/240z.html

www.NitroPhotos.com

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Oh man, you guys are getting "old school" on me now! Clutch's behind Auto's were a popular thing for a lot of the pro-stock drag racers before the advent of trans brakes. A couple guys I used to work with still had a few of these setups on some street cars. Work great for +8000 rpm launch's :D

 

Dave,

Check out the painless wiring kit for the 700R4. I believe it was under $100 (four years ago) and it allows lockup in fourth gear. The only thing I would do different is hook up a toggle switch that would enable the converter to lock up in any gear.

 

Basically, there is a solonoid in the trans that tells the converter when to lock up. A 12 volt source is applied to the solonoid, while the ground path has to travel though pressure switches in the valve body. If there is adequate pressure in 2-3-4 gear, the switch closes allowing the current to flow thru the solonoid, thus locking up the converter. The painless wiring kit only uses the fourth gear pressure switch (2 and 3 gear use the same switch). Also, the 12V source is switched through a simple, generic map sensor and brake switch. This way, the converter will only lock up if there is adequate engine vacuum (i.e. engine is not W.O.T.) and the brakes are not applied. I drew a really nice picture explaining this, but my computer really blows and it just crashed as I was trying to save it.

 

Sorry,

-Andy

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I used the following circuit to control the lock-up on my 700R4 trans. http://www.geocities.com/paul_richer/trans_schem.pdf

When I want to engage the lock-up, I push the button (switch 1), and the converter locks and stays locked, unless I apply the brakes. If I push the brakes, the converter unlocks and stays unlocked until I push Switch 1 again. The toggle switch disables the circuit completely (converter never locks). The idicator lamp turns on when the lock-up is engaged.

 

I've been using it for about a year now and I think its pretty usefull.

 

Paul

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Sorry guys, but I'm going to dissagree with some of you on this one. I have SOOO many articles on the 700 that say do not run the 700 w/o the lock up. Their a few years old now, but unless the information has changed I'd look into it further. I learned the lock up is crucial to the lubrication circuit in 4th. If you run a non lock up converter, at least the one I tried years ago, the check ball in the input shaft must be removed and a special valve and plug is installed in the pump body. The only valve bodies cabable of wot 4th gear were the Z28s and Vettes. Simple solution is like Andrew mentions, wired to the valve in the 4th gear port in the valve body. Takes about 15 minutes to install. Toyshop 909-620-5849 also makes this and is cheap. When you slow down in 4th the engine may buck, but at REALLy slow speeds there isn't enough pressure to maintain lock up and it will disengauge. I recommend the brake switch defeat. Some where along the line lock up and 4th gear are being confused. The 700 has 4 forward gears, the last of course being the .7 OD. Lock up is the process of the converter going to "direct drive" (is it an electric solinoid allowing fluid pressure to the lock up?) eliminating the usual slippage seen in autos. If you've seen the lock up surface in a 700 converter it is incrediably small! Please correct me if I'm wrong and steer me to more current articles.

JS

 

[This message has been edited by John Scott (edited April 03, 2001).]

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quote:

Originally posted by kc6wfs:

Thanks Ross,

 

Funny here all along for the last month I thought i was only getting into 3rd due to the hi r's on the freeway.

 

I don't have the plug for the trans.. How much do ou think the dealer will charge for the plug??

 

Also my trans is a 1984 vintage.

Ross can you with your trans be WOT and still shift into 4th?

 

Sorry for the slow response...as John says lockup and specific gears is independent.

Pete: yes manual valve body 700's have been popular among racers for a while/likely due IMO to their common frustration at tailoring shift points (v. few seem skilled to do it like a few described on this list).

 

Dave: I've fought with getting full WOT 3-4 since I got my trans..not an easy thing to test out due to the speeds I see that at (120mph/6000/3rd) but I've yet to have it..I can 2/3-3/4 throttle it in 4th but that reaches about same as 3rd/6000/hair more but it'll kick to 3rd. I've had the big $ B&M fix put in and another attempt on it as well with no luck so far. Haven't been into since the last attempt to see if some debris from rebuild was preventing that at all. For just the electric plug/pigtail I'd grab it from a yard if GM wants much dough for it. I'd also wire the lockup switch to or v. near my shifter if possible so it is handy and frequently used as Paul mentions. FWIW, I've been advised to use synthetic in mine which is pricey but I'm using it. The most recent builder into my trans is in a few NW car clubs and has done a lot and stood by them so I feel better about my more recent build.

 

PSS my dad started driving his LT1/T56 240Z earlier this week! yet to actually talk to him but wanting to for more details smile.gif

 

 

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Of all the things I've lost, I miss my mind the most.

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Guest kc6wfs

Thanks Ross,

Ya I bet it's something in there thats keeping it from shifting at WOT into 4th.

Think I will go to the junk yard and pick up the electrical connector this weekend.

I'll have a lot of time on my hands due to no electrical power to the house next week.

Getting it rewired due to a electrical fire in the attic! Thank god for insurance.

 

I'll let you all know how the lockup stuff goes.

 

Ross, Did you ever see the site that tells what every mod for the 700R4 does and ease of instalation?

 

I'll try to find it and post it here when I get to work.

 

Dave

 

 

------------------

www.geocities.com/kc6wfs/240z.html

www.NitroPhotos.com

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quote:

Originally posted by kc6wfs:

Thanks Ross,

Ya I bet it's something in there thats keeping it from shifting at WOT into 4th.

 

Ross, Did you ever see the site that tells what every mod for the 700R4 does and ease of instalation?

 

Some said the $35 part from B&M does it and others said it only allows 3-4 at 2/3-3/4's throttle. I got the full WOT 3-4 $125US or so kit to no avail yet. A real bugger on the roadracing track as I've finished a corner exit ONTO a straightaway at 110mph to only have 10mph left for the whoooollllleeeee stretch which really sucks and I don't like holding it at 6grand in 3rd down a straight..

 

I don't think I've seen the site you mention Dave? I've refrained from going into my trans on my own except for filter changes as I know their's a few unique tools to them and my trans is a PITA to access/service let alone remove. Governor can't come off without dropping it down a lot/dizzy removal etc...new motor mounts and trans xmember will make it easier but still a hassle....I've debated an access 'port' from inside the car like Jag's have (or at least had).

 

 

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Of all the things I've lost, I miss my mind the most.

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Ross (and others),

 

I'm able to get a full 100% throttle 3-4 shift in my 700R4. All I did was install the B&M throttle valve and the strip shift kit. Not sure if it was the shift kit or the throttle valve, but I can shift into fourth at WOT. Also, the trans itself came out of an '87.5 Z28 with a 350 TPI. This might have something to do with it, it's probably very similar to the trans they used in the Corvette that year.

 

If you've ever considered doing a shift kit, the B&M kit is very easy and well documented. The shifts are little stiff for normal street driving, but work very nice with the drag radials.

 

Good luck

-Andy

 

------------------

"But I don't sit idly by,

I'm planning a big surprise."

 

Andrew's Land of Z and Honey

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quote:

Originally posted by Andrew Bayley:

Ross (and others),

 

I'm able to get a full 100% throttle 3-4 shift in my 700R4. All I did was install the B&M throttle valve and the strip shift kit. -Andy

 

 

Yup, sniff, that's what was put in mine with no success yet frown.gif

 

this summer it'll likely get torn into to have a looksee....

 

 

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Of all the things I've lost, I miss my mind the most.

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Guest kc6wfs

Hi Ross,

Bummer about the 3/4 upshift at WOT.

It is nice.

I also was thinking about cutting a axcess door for getting to the side of the trans.

Looks like it would be easy enough to do.

 

I'll look for the url.

It was nice to see what every mod does for the 7004r and how hard it was to do the mods.

Tells of special tools needed also.

 

Dave

 

 

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www.geocities.com/kc6wfs/240z.html

www.NitroPhotos.com

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I think Andy is right about his WOT shifts due to being from a Z28. Like the Vette, it will hold in 4th. Anything over a 5K shift from 3rd in mine would stay in 4th. 7K used to yeild about 135-140 mph in 3rd! Anyone know if valve bodies can be transplanted from a Z28 or Vette into a regular 700? Probably more to it than that. I know they really improved the transmission in the later years. First years were trouble and gave the 700 a real bad reputation. Maybe the earlier ones can't or shouldn't take a wot in 4th w/o substantial upgrades in the pump etc.

JS

 

 

 

[This message has been edited by John Scott (edited April 09, 2001).]

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