Vette X 3

My tranny in my '82 shifts way too early-45ooRPM at WOT. Reading up on this, I have ordered a spring kit from B&M. My question is what tips can someone offer me regarding removalm of the cover, access, etc with the tranny still in the car?

Since lighter springs delay the upshift, I assume the combination of inertia and spring pressure force the wights outward causing the upshift. Correct? So, lighter springs and or reducing mass of the weight will delay 1-2? All my shifts occur early, but of course 1-2 is most noticed from stoplight to stoplight

Why are there two different spring weights in there are which one does what?

Bill

mrvette

I'm not very happy with mine either....

1-2 is early....

and the rest are all late....but not at WOT, then the thing hangs up and untill I lift, THEN it slams/stacks 2 shifts at once....I swear, I think a manual valve body would be better.....
for traffic, start out in 2nd gear and have over with it....
shift to 4th at 30 mph, no one going anywhere anyway...so what the hell??

GENE

terry82

i would go with b+m shift valve body ,i think it would shift harder and probably change the shift points.

MIKER

GENE, no friggin' wonder your always bad mouthing the 700R4 transmissions. Yours needs help. Surely you don't think that everyone elses 700R4 transmission performs like yours do you?

mrvette

Well, I am of the olde school, in that a 400 was modded with Trans-go shift kit some time over 30 years ago....tranny went over 300k miles and still slammed 3rd so hard it would spin rubber with a 323 rear....in a '70 Lemans/GTO convertible....and 255 rubber....

now, the problem is....ALL GM trannies are in need of a great amount of help, for histerically they don't last but about 60k miles of decently difficult driving,....NOTE I didn't say HARD driving/towing....
this from the daze of the old 'Slim Jims', on up to today....
yeh, sure there is an exception to every rule, BUT I have NEVER had the privilage of owning ONE exception....in 40 motoring years....through Chevy/Pontiac/Olds/CAddy, you name it....

Yeh, I have a hard on for THM division....
How comes damn broke and hard up Chrysler who finally gave up after being the whipping boy for all my life, THEY still had the best damn automatics on the freaking market...gimme a 727/904/999 automatic anyday......

frankly, GM THM division needs dismissed....case closed....

just WISH I knew more about the history of the 700 before I installed it, years ago....I had one what was dieing in my '87, but I figgered a decent rebuild would have done it wiath a Trans Go kit, but upon getting this tranny rebuilt, the guy used a Superior Tranny kit, apparently it's supposed to be BETTER than the Trans Go for a 700, BS far as I know....
I know this much...any tranny needing about 200 mods/fixes to it to have a chance of survival under difficult conditions....is a POS from the factory....

I remember when the ATSG site was free, not it's not, wish I had printed that LONG list of fixes for the 700, man the list ran about a dozen pages, covered so many screw ups and points of interest it makes a world class commentary on how lousey the 700 was...THIS was applying to the 'late' '87 UP units, including the 4L60e.....

I been into that 700 now about 3x over the last 3-4 years or so, and nothing about it is impressive....now that silly 999 Dodge 318 in my work van....has hauled more *** and weight than that damn vette and 700 EVER could....and only once at about 300k miles I had to do a second gear band, and did the clutch packs at the same time,...back to running like new in ONE DAY, not like that 700, which is God's own damn mystery.....

sorry to sound so pissed off, but that whole issue is a sore point with me....I hate repeated failures, and lousey performance, and apparently I"M NOT ALONE either.....

GENE

Vette X 3

Gene, in any of you excursions into that 700R4, did you mess with the governor springs at all and can someone tell me what kind of job it is with tranny still in car? Trying to figure out whether to shave weight from the weights or just do the springs. If springs, which one do I mess with-the heavier or the lighter-or both??

Bill

mrvette

Bill, no one ever could suscinctly tell me what to do at the time for modding that governor...so....I noticed in the construction it's very similar to any other governor, so I removed the spot welded on extra weights from the wings...and left the rest alone....I think maybe I drilled a hole in it..maybe not, as I can't remember which tranny was which on that detail anymore....

I may have gotten hold of some light springs also...
I know I greatly increased the shift RPM's though...from 2000 to more like 2500 minimun and 4 on a moderately heavy foot...


edit...OH, with tranny in car it was easy still, as the tranny tunnel was altered a lot, holes on both sides, and widened on pass side, and so forth for access.....covered with metal, and reglued up when/where appropriate....my car is a hotrod all the way, so modding is not an issue...

GENE

Vette X 3

either no one here has tackled this job or no one did it well!

mrvette

I"m hardly what is considered an auto trans 'expert' but then again I have read here about many a complaint on expensive units 'professionally' built....

so that leaves me with fixing my own screwups....

that's life.....

case closed......


GENE

Vette X 3

Hah! You don't sound like the kind of person who gives up easily... By the way, did you say your 700 shifts early and you went with a heavier weight? I believe you lighten the mass of the weight to make the upshift occur later. I'd like to change out mt '82 700r4 for a post '86 model, but then the splines are different....and it never ends.

Bill

carl a

i got 300,000 miles outts my 700r-4 in my 89 gmc safari before i smoked 3rd and od ,so i got nothing to complain about the trans,so we beefed one up to put behind the 383 in the 73..(since,the odometer broke in that truck,and we changed to another 700 r-4,,same engine and i use the truck 3-5 days a week for work and never have to add oil between changes- every 3,000)

mrvette

Carl, all I can say is the guy across the street here had a 1500 pickup that did very little actual WORK, and he had 3 trannies in about 5 years,....he was NOT pleased....sold it and got something else....

I know well the list of complaints over the decades on GM trannies.....it's allways the same story...SOME of them last forever, or so it seems, and some of them need rebuilding every 2-4 years, the bad ones seem to vastly outnumber the good ones....but not the Torqueflight Mopar trannies....so WHY???

I have no first hand knowledge of the O/drive MOpar trannies, I know the Mutsu's are not worth a damn though....

I hear of Ford's o/drive trannies with high failure rates also....



Boody, I lightened the weights, just can't remember if I cut the spot welded extra loading/plate off, or drilled hole (s) in it to lighten it...done both...been a while..sorry....
can't specifically remember about the spring either....but I know the shifting points are ok now, but every once in a while that damn tranny will lets the engine run away and not pulling jack tschidt, and so I have to lift, and that's when it goes to shift 2/3....meaning the clutch pack is going, or far down that path....

POS....LOok, any damn tranny that takes a list of mods a mile long to live under heavy duty use, is a POS....face it....

the mods to a 2004r seem only about 1/4 mile long....;-)))

GENE

wombvette

I had to do this on my 66 to balance the 336 gears with the weight etc of the car. You can literally move the shifts from very fast to no shift at all. The kit should have instructions with it. As I remember the weights change the shift points up or down, the springs spread or compress the shift points. I had no real luck at changing The 1-2, but got the 2-3 and 3-4 exactly like I want them. It is easy to remove the cover and slip the governer out, so you can play with it at will. It only takes a few minutes to try another combination. Save your original set up and make notes. There are hundreds of combinations possible.

Vette X 3

Searched the web high and low and can't find a picture of what the governor cover looks like or what holds it on? Can anyone direct me? I know it
s slightly in front of the speedo gear and just above the pan level. What secures it? a clip or what?

Bill

mrvette

I"ts about 3" diameter, and looks like a wheel bearing front end dust cover,.....held on place with a large 1/8 diameter C clip each end into the tranny case/casting.....the C is somewhat distorted in shape...

like I said, I cut a hole in that side of the floorboards for two reasons, to reroute my speedo cable, access that governor, and work on the shift linkage with ease....I use an aluminum cover and RTV sealant with screws into the glass just cut it out when I need to...sometimes I don't even remover the seats....let alone rugs....

GENE

MIKER

Bill, I'm not a transmission expert by any stretch of the imagination but I learned a little back when I first installed my used 700R4. It failed within 1000 miles. After that I spent good money for a high performance rebuild by a high perf. trans builder / friend of mine in 2002. It's worked perfectly ever since so I haven't needed to give it much thought.
He tried to teach me a few things along the way but there was too much information and too little time.

Here is a picture of my 700R4 governor cover. If your transmission has never been removed from the vehicle it's likely that you do not have a clip holding it on. It's sort of a pressed in fit. Based on what I've read, the retaining clip is usually added following a rebuild. The clip, if present, is a snap fit that can be popped off using a screwdriver.
To remove the cover, you can tap around the edges of the cover using a hammer and screwdriver to get it started. Then carefully pry at the gap between the aluminum case and the steel cover until it seperates.
I was able to remove my governor without lowerning the transmission or cutting a hole. I'm fairly sure that the earlier model C3's such as GENE's had narrower trans tunnels than our later model C3's.


The governor can be modified to raise or lower all of the shift points collectively. The shift points can be calibrated seperately by changing the spring pressures in the following valves. Having calibrated the individual 1-2, 2-3, and 3-4 shift points in my 700R4 is one of the things that really makes my trans feel right for my car. Many people swap 700R4 transmissions into their Corvette which was calibrated by GM for use in ~5500 lb pickup trucks using relatively low powered engines. We can't expect it to act perfectly when placed into a relatively light weight Corvette along with a high performance engine.


Here is something that might give you a "little" more insight about what to look for in setting up the governor. This is a small part of a Trans-Go shift kit installation instruction which I downloaded about 3 years ago.

The SK 700-G Shift Kit from Trans Go might be worth looking into. The installation instructions are an interesting read. This Kit sounds like it would address a lot of the 700R4 weaknesses.

Let us know how it turns out.
Mike

Vette X 3

Hey Mike,

That is one helluva reply! Talk about tapping into the knowledge base...if I still have any questions, I cant imagine what they would be- thanks a million. I'm sure I am not the only one who will feel more comfortable after reading up on what is involved. I appreciate your identification of the upshift valves as well. Did you need to do anything here? I have a much better understanding of what I am looking for now.

You gotta love this forum!

Bill

toobroketoretire

I recently installed a beefed-up TH700R4 in my big-block '71 and noticed it up-shifted at only 3500 rpm at wide open throttle. As I had a spare Corvette/Z-28 governor lying around I put that in. With the new governor it up-shifted at 5200-5300 rpm (with 23 ounces of springs) so I put 30 ounces of springs in it and that slowed it down to 4900-5000 rpm. As I have a big selection of governor weights and springs it's real easy for me to adjust a governor.

Governor re-calibration kits are available from any transmission parts supply house as well as TCI, Summit Racing, B&M transmissions, and many other vendors for around $50.

ajrothm

I haven't done a 700R4 but did do my T400. I found that I had MUCH better luck playing with weights then I did springs. The lighter springs are supposed to spread the shifts apart as well as raise them....And they did just that. BUT it would really screw with the part throttle shifting and make it "hang" a bit before it would shift. Also it was very unpredictable as to what each spring change was going to do.

I have a thread here in TECH on what all I did to get mine right. You might should do a search for it. I think it was "Dialing in a T400 Governor"....

The ONLY way you will get it right is to make a pass, write down what the shifts are doing, then go home, pull the governor, make a change, then go make another pass and continue to do this. Only make ONE change at a time as sometimes they will make BIG changes in what it does. Every car is different, gear ratios, tire heights, shift points all affect the weights/springs you need.

FWIW, I ended up using the stock springs and the #4/#6 weight in a B&M Governor calibration kit. You can also grind off the weights some to really sneak up on your shift point but there is no going back if you grind too much. Also make sure your TV cable is adjusted correctly as it affects shift points by line pressure. This is very time consuming but worth it once you get it right. I had my governor out no less then 10 times. Then I changed gear ratios from a 3.08 to 3.36 and had to do it all over again. Now I am good to go...mine shifts at 6000 and 6100.

7T1vette

I have to believe that the tranny rebuild companies have a 're-scheduling' process pretty well down by now. There IS interaction between the action of the individual shift valves/springs and the governor pressure action. Main pressure and governor pressure are both used to activate the shift valves, so you likely can't just alter one of them and get the unit to shift just like you want it. I would hope that the tranny companies would have a tech support system that can provide decent info on 'what' springs need to be changed 'where' in order to get the changes you need to occur.