Trans mount measurment??

So, i need to fab a mount for my trans but I am in need of a measurement to make things less complicated. Can someone measure from the center of the output shaft to the center of the trans mount?

??? say what? what are you asking, center is center.

Im looking for a vertical measurement. We're talking a stock 3spd transmission with the round mount cast onto the tailshaft housing. Im using a NON van full synchro 3spd with a bottom mount. Ill be making a "hoop" that bolts to the tranny on the bottom and hangs from the trans mount on top. I need to know how far from the center of the tailshaft the round cast mount is. From the center of the output shaft to the center of the trans mount. Just like i said.

Thats just it 64, I don't have an old trans to base things off of. I know where i can get one but i don't want to crawl around in the mud to dig it out just yet. Based on the info donavan posted i may be doing some other mods too.

Donivan I see that 700r4 has the cast tranny mount in it. Will the 700r4 bolt up to a 250? if so how do you get it to shift correctly? What year 700r4 would be needed to make it shift correctly?

You can bolt the 700 right up to the 250 no problem. all you need is the lockup control module so she's shift correctly. I have plans to run one behind my old GMC 302, though that will take an adapter.

with respect to "shifting correctly" there is no magic to the 700R4. They install and shift just as simply and correctly as any th350 or th400. The shifting is 100% hydralicly controled just like all other auto transmisions. The trans has to have no internal problems and you must rigg the throtle position cable corretly. Also and BUT, an incorectly wiried up TCC can make the hydraulic part of the shifts all wrong.

The only thing people get unnesssesarily all freaked out about is the TCC lock up which is actually quite seperate from the rest of the trans. The problem here is most people can't get the TCC to work right because they are afraid to change the wiring and switches inside the oil pan . And there is alot of BS out there implying that they are all the same inside and all you have to do is buy someones external wire kit. The TCC is not rocket science , it is a simple switch and solinoid inside the pan connected to a couple external electrical controls. There are kits that have everything you need to change inside the oil pan.

The biggest problem by far with the TCC is that there are about 32 different switching and wiring configurations under the oil pan, from GM set up for whatever vehicle that trans was in. some have extra switches opperated by tempature and some alow 3rd and 4rth gear lock up. You need to change that internal switches and wires to something very simple to work in your van. Its actually very easy to do but most people don't correct it and then sit there scratching their head and concluding that the trans is no good.

M1D

Its quite simple: The 700R4 is generally a good trans. The first few years (pre 87) had problems with light wieght parts and things like that. Like Don said 87 on to around 93 are the simple ones, thats what I'm talking about. All those years were computer guided engines. Seperat from that fact, they also had many differnt wiring set ups inside the trans pan that had nothing to do with the computer. Just Like my 1988, which I had to re-wire inside. I had the damdest time trying to get mine to work and that was because mine was wired internally for a 1993 truck with four preasure switches and two heat switches and a forth gear switch that worked opposite of what was needed. Ablsolutly the only thing my computer has to do with the trans is to "at times" provide an electrical ground to the TCC solinoid (your 700R4 should have the solinoid grounded inside the trans pan through a presure switch or two) This is to alow the TCC to engage IF the other external controls "agree", (brake pedal switch and/or Vacuum switch) also alow for engagement, but all switches have to agree its time. The computer on my machine is nothing more then another off/on switch that your van wont have. Seriously, its not rocket science.

The later years of this trans that has many solinoids controling each gear shift is called the 40lLE or the 60 LE and the 80LE. That is the series of trans that must have the moduel to control the shifting.

Basically in you 700R4 there is a solinoid that alows oil presure to go to the TCC and lock it up. That soliniod is two wire, power and ground. The power wire comes out of the trans and through a brake pedal switch that opens the cercuit when brakes are applied(dissengaging the TCC) and you can also have that power feed through a vaccum switch so when the engine load increases too much; increased manifold vacuum will brake the power to the TCC and disssengage it. You can get an adjustable vacuum switch, recomended.
The ground side of the TCC solinoid can also be switched (my computer does that, it uses all kinds of imformation from many other sensors to decide, but essntially all it can do is say yes or no for TCC lock up, what I like is I can program what thoses values must be. I can very easily change up exactly when and how my TCC works and at what speeds it can or cannot engage at.

For your 700R4; some afternmarket kits just ground the TCC solinoid to the trans case in the pan and bypass any internal presure switches. I don't recomend this as it will alow for TCC lock in both third and forth gears, I think that makes problems. I also don't recomend using just whatever presure switches are in the trans valve body untill you know what they are and what gallary they are in. Some are in the third gear passage some are in the fourth gear passage. Some factory switches are heat sensative to dissengage the TCC it the oil geats to hot(which it can if you are not running the external vacuum switch) Some factory switches either one or two pin, may ground or not and/or may be normally open or normally closed. I recomend a kit that provides a normally open single poll switch that is installed in the forth gear port. With the ground wire conected to this switch you will get TCC lock only in forth gear. You need to have your power wire through a manifold vacuum switch and I highly recomend a normally closed switch be used on the brake pedal to dissesngage the TCC the instant you touch the brake pedal.

M1D

I'm running a 700 out of an 83 Camaro, simple and easy, I doubt a 6 banger is gonna tear up those "weak" parts.

I don't mean week as in no good, What I mean is in later years they beefed up a few items.

M1D

you can see on this guide that the three letters, which are codes that can be deduced from a shop manual for that application, indicate that the engine size is identified ( the v6 trans is built lighter then the v8 trans) and "solinoid wireing type" is what I was blabering on about. My GM shop mannual for the 1988 fire bird (donner car) shows 23 different internal wiring/switching configs for just that year and model alone. My whole point in all this is that most people think thier trans is junk because it dosn't act right and in reality many transmisions are junked when all they need is the internal wiring to be matched up to what it is being used in.

I don't think any of these transmisions are considered "not good". I really think only some body into serious performance or a transmision rebuilder might notice any difference. For what we use them for any year is fine as long as the trans is good. You might want to stick to a V8 trans though.

Also I do believe its the later years that become increasingly more complex in the internal wiring and most of those aftermarket kits return them back to the simple opperation. And its easy to change

The biggest problem I had with mine was believing I had one year and model of trans until I opened it up to fix it and found out it was not at all what I had been led to believe it was.

M1D

' love the net! That's how we all got to meet up as well!!!!
B.W.

Couple other things about beliving your trans is no good.
Because of where the TCC draws its oil presure souce from; it the TCC is electriclly activated and trying to lock up right from the get go it will make the 1,2,3 and 4 shifts all hapen way to early. Did I say too earl, no I ment way way too early like as in (all els being correct) moving away from the stop sign at normal city acceleration you will be in fourth gear befor you get to 30MPH. Most guys who just installed there trans go stright to the logical thought that the TP cable is too tight. So they jerk with that until there fed up and conclude the trans has a problem and is no good.

When you want to adjust the TP cable and/or just feel how your trans is shifting. Simply unplug the TCC wireing from the trans and test drive without it.

Also many of these lock up trans have a grounding switch wired into the 3rd gear oil gallery so the TCC can lock in 3rd. I think this is not good especialy for older transmisions and alot of re-builds. I have whitnessed the TCC lock in 3rd and stay locked through the 4rth gear shift. This makes for a hard 3rd/4rth shift and depending how much ware the trans has it can also cause some kind of miss alingment of shafts and you get a vibration in 4rth. Just touching the brake pedal releases the TCC and the vibration is gone and does not re-occure even when the TCC re-engages in the allready established 4rth gear.
This was happening in my trans so I eliminated the 3rd gear lock up capability.

M1D