WE, 700 questions, please

[mrvette72]

My late '87 700r4 is fron an unknown car, but in my 355ci ~420 ft lbs '72 vette,...it has a Superior shift kit in it, not that I"m happy with it, I did spec Trans Go...but 5 years ago the builder used Superior...
I had a usual 3/4 clutch pack failure recently, and with the 1/3 band I replaced the clutches, and band...now here is a general question...
from the early days of a 350/400 I remember hearing of TransGo stating they actually lowered line pressures and blocked accumulator valves for increasesed shift hardness....wonder if that would be a better way to go in this 700r4, and maybe it's not too late to get a Trans go shift kit??? I was looking at the valve body and noticed the first gear valve was just just plugged with non moveable aluminum...interesting to say the least....it won't hold first gear, not that it's critical anyway....
it won't go into O/drive under hard acceleration either...I am wondering about dropping the line pressures and doing a mod to the accumulators..but not sure what to do...thinking of just removing the springs completely and then I donlt know how to drop line pressures....??

any suggestions???

thanks GENE

mrvette72@interstateweb.net

 

[MeanBuicks]

Caution!

Dropping line pressure is NOT recommended practice to increase a transmission's torque capacity! Quite the contrary.

Also, you will generally be inviting more trouble by trying to install one valve body kit over another. The only real way to accomplish this would be to totally uninstall the Superior kit and return your valve body to stock specs. Then put in your second kit. If you have remnants of one kit left over, it may never act right.

As far as increasing the point at which your transmission will shift into overdrive, a TCI TV plunger & sleeve, part #374400 can help that situation.

 

[HOTTOGO]

Just my guesses here...

I think I read somewhere that the 700's are not designed to go into OD at WOT. (well I just noticed MeanBuick's has just replied to your post as I was writing and he will know more than I) Like he said unless you know what you are doing combining kits can be similar to "Russian Rulette" Line pressure is a product of pr spring and boost valve dia. and lowering it would be detramental to your cause. I have an '89 IROC w/700r4 and I have a trans go shift kit, w/stronger pr spring .500" boost valve w/Corvette servo which all works very well w/about 2000 miles on it since the mods.

 

[mrvette72]

Well what about blocking or removing accumulator springs..??? that should make the shifts hard as hell all the time...sometimes they are plainly mushey....

 

[petesgn]

.

"I was looking at the valve body and noticed the first gear valve was just just plugged with non moveable aluminum...interesting to say the least...."


I think what your looking at is the lock up converter valve train.

 

[mrvette72]

Pete, your' correct, faulty memory...it's the converter valve....so in a later computer car it's not drilled for valves at all, and in this 1/2 step tranny with earlier valve body they just stuck aluminum plugs in place of the valves...apparently...now that I look again under less pressure to get something done...

GENE

 

[HOTTOGO]

Originally posted by mrvette72
Well what about blocking or removing accumulator springs..??? that should make the shifts hard as hell all the time...sometimes they are plainly mushey....

Yes you can modify the accum's don't just remove spring, some kit's recommend and even supply spacers to limit movement, or you can drill, tap and plug feed ori's w/setscrews. I would recommend waiting for more replies or posting more or directly contacting "WE4" (Bruce @ PTS) or "MeanBuicks" (Greg @ TCI) They can help you do what you want to do and do it correctly.

 

[6PacktoGo]

Originally posted by mrvette72
My late '87 700r4 is fron an unknown car, but in my 355ci ~420 ft lbs '72 vette,...it has a Superior shift kit in it, not that I"m happy with it, I did spec Trans Go...but 5 years ago the builder used Superior...
I had a usual 3/4 clutch pack failure recently, and with the 1/3 band I replaced the clutches, and band...now here is a general question...
from the early days of a 350/400 I remember hearing of TransGo stating they actually lowered line pressures and blocked accumulator valves for increasesed shift hardness....wonder if that would be a better way to go in this 700r4, and maybe it's not too late to get a Trans go shift kit??? I was looking at the valve body and noticed the first gear valve was just just plugged with non moveable aluminum...interesting to say the least....it won't hold first gear, not that it's critical anyway....
it won't go into O/drive under hard acceleration either...I am wondering about dropping the line pressures and doing a mod to the accumulators..but not sure what to do...thinking of just removing the springs completely and then I donlt know how to drop line pressures....??

any suggestions???

thanks GENE

mrvette72@interstateweb.net

So, you wanna build a tough 700 that works. First, get the TV boost valve (.500" dia) and intermediate boost valve (.400) from Bruce (WE4). Leave the Superior PR spring in. Get an Alto PowerBand, and the Alto HP 3/4 clutch pack. You can use the stock servo from a Corvette (available at any transmission parts house) or the various billet servos available from Superior or Sonnax. Get a set of heavy duty accumulator springs from Sonnax. Make sure the pump has the correct clearances and a good 10 vane rotor. Use the high RPM rings and vanes and dual pump priming springs. Make sure you have the updated overrun clutch sprag housing, and replace the overrun sprag and the forward sprag. The rest is straight forward professional blueprinting. Mine ran 10.90 behind a 455 Olds in a 3400 pound car. Until the cheap converter (Mamco) broke. Have a true professional high performance transmission builder do this for you, someone who KNOWS late model transmissions. Unless you do it exactly right, and you have over 275 pounds of line pressure, it won't work. You need the correct 3/4 valve and sleeve and the correct TV valve sleeve to make it upshift to 4th under heavy throttle, and some NEVER shift at WOT without a full manual valvebody. Stay the HELL away from TransGo. Superior and Fairbanks are far better. Greg at TCI (MeanBuicks) may have a great kit too, maybe Bruce (WE4) does, I've never used either.

 

[WE4]

Hot damn!!! there's your boy!!

Alan dude.... How are you. Here is the man to talk to.6Paktogo Lonnie Diers is another and Brian Hartmen even a third. All of these guys are one up on me in this dept. I build a good one, but these guys are the cream of the crop. Just my .005 of a cent...

 

[mrvette72]

Thanks guys, appreciate the responses here, one further question, guys on the vette forum are recommending 200r4 instead of 700r4 for shark conversions...well, ok, I guess, but my thoughts are which one is more capable of taking say 450 ft lbs input and lasting longer....
and what are the differances between the 700 and 200 trannies..??? essentially, I have had to get into my 700 here, and last time I dropped the pan to correct yet another goof from my last 'fix' I noticed iron filings in bottom of the pan, but it's been working fine so far for a few months daily driving now...but I"m taking it easy on it, ...wife drives it to work...she's easy too...all I did was the band and the 3/4 clutch pack...I found getting that clutch drum back in place was a real bear, aligning all those fingers and grooves, the internal clutch fingers...any tips on that either???

GENE

 

[HOTTOGO]

'84 and up 700's have a larger input shaft, they have a higher first gear but also a greater 1st-to-2nd gear drop not so good for acceleration, the WOT upshift to OD issue, bone stock the 700's may be alittle stronger but I'd bet you'd be hard pressed to find one stronger than this... http://www.2004rperformancecenter.com/mcartfree/product.asp?intProdID=49

 

[6PacktoGo]

The 200 4R has a couple advantages of the 700 R4 in some applications. First and foremost is the gear ratios. The 200 4R has a low gear around 2.75:1 and a 2nd gear of around 1.7:1. The 700 has a 3.06:1 low gear and a 2nd gear around 1.6:1. The 700 has a big 1-2 RPM drop, if your converter isn't the best, the 1-2 shift will kill you. I've been looking at doing a conversion to make the 700 R4 low gear 2.75:1 and stop the drop, but I haven't really had the time. It is the exact opposite of the way they make the 2.75:1 low gear for a 350.

The next real problem with the 700 R4 is the lack of two specific parts needed from the aftermarket. The first is the lack of a billet input drum with a 4340 torsional input shaft. The input drum is CAST aluminum, and the input shaft WILL eventually strip out. I think Torco (the FAKE Art Carr) is making an input drum with a steel sleeve to help the situation, but I haven't tested one. The second is the overrun clutch sprag. This is ONLY a problem when you make a WOT 4-3 DOWNSHIFT in AUTOMATIC mode. This thing WILL break if you run in OD and kick down to 3rd, period.

I have not had much breakage or failures with my units. Yes, they do wear out and get tired. I have never had the kind of breakage Don Wang has shown on his site.


In your case, if you already have a good buildable (87-91) 700 R4 in your car, I wouldn't change it to a 200 4R because you aren't at the level where the input drum is a real issue, and unless you're racing the RPM drop at the 1-2 shift is not a big issue either. I've got 700 R4 transmissions in several 400 HP and up cars with no problems.

What you need is the services of an expert builder for your transmission who is willing to do it right, including making sure that everything is done right. Built right, it should give you plenty of service.

Eventually, the supply of cores for the older transmissions will dwindle, and more development will be done on the 700 R4, and it CAN be made to handle plenty of power. If someone will build a forged or billet input drum from 6061 or 7075 aluminum, the input shaft is easy. As I said before, the low gear set is a mirror version of the 2.75:1 low gear set for a 350. Even the output shaft could be duplicated in torsional 4340 to prevent breakage.

 

[WE4]

Brian Hartman makes the drum. I have seen and installed. Nice piece but it moreless prevents the drum from "splitting" and not the splines just tearing out. He makes some neat stuff for the 700 but still no input drum. His shafts are chryoed but again, they are still of a stock composit and design. I have had good luck with 700's but I have also experianced what is on Don's site too. We have literally "exploded" them before. Kinda fun actually.
Anyway basically, it all depends on what application you are using it in. Then once you chose your path then you find the guy Alan was describing earlier.
"What you need is the services of an expert builder for your transmission who is willing to do it right, including making sure that everything is done right. Built right, it should give you plenty of service. "



Bruce
WE4

 

[6PacktoGo]

Originally posted by mrvette72
Thanks guys, appreciate the responses here, one further question, guys on the vette forum are recommending 200r4 instead of 700r4 for shark conversions...well, ok, I guess, but my thoughts are which one is more capable of taking say 450 ft lbs input and lasting longer....
and what are the differances between the 700 and 200 trannies..??? essentially, I have had to get into my 700 here, and last time I dropped the pan to correct yet another goof from my last 'fix' I noticed iron filings in bottom of the pan, but it's been working fine so far for a few months daily driving now...but I"m taking it easy on it, ...wife drives it to work...she's easy too...all I did was the band and the 3/4 clutch pack...I found getting that clutch drum back in place was a real bear, aligning all those fingers and grooves, the internal clutch fingers...any tips on that either???

GENE

I've got a few questions for you Gene. What is a "shark" conversion? How much experience do you have with extreme close tolerance transmission blueprinting? How much experience do you have with customizing valvebody kits, especially on latemodel stuff? I'm not picking on you, I'm trying to find out how to guide you to where you need to go. If I don't know what you know and what you are capable of, I can't tell you what you need to do.

The 700 will take 450 ft/lbs and live a long time -IF- it is built right. There's a whole lot more to it than it appears. You need to have the clutchpack clearances and the band adjustment near perfect, and then the pump and valvebody have to be as good or better. The late model units are VERY complex hydraulicly.

The number one problem with the 200 4R and the 700 R4 is the legions of people who insist on building them like the average builder slings an old 350, 400, or PowerGlide together, and it WILL NOT WORK that way.

 

[WE4]

DAMN RIGHT!!!!

You Go 6PAKTOGO! !!!!

They just do not understand this!

LOL

 

[mrvette72]

6 pak, that may explain some of the metal, that overrunning sprag....4-3 downshift in auto mode...sometimes I do that, I guess I should slide the lever back?? that should take care of it....
I do notice differant shift points from lever position...holds gears longer in 3rd position, instead of 4th (d/over).....I also have the converter locking in 2-3-4 gears, only one unlocked is 1st....it's actuated by brakes, of course and if I flip the switch the other way, i'ts computer controlled lock at 50 mph...
does leaving it 'manual' locked in traffic toss undue stress to the unit??? I have tended to do that myself more often than not, allthough wife does not...she likes softer shifting...
I got rid of the loose vette 2k stall converter on the last 3/4 clutch job, and put in a tight 1200 rpm converter to kill that 'revvy' slipping feeling it had....I like it beter, but wonder if that's tossing more loading on the tranny itself now.....I suspect it does, but even as a stock unit in a silly 5000 lbs truck the unit was supposed to live....

GENE

 

[mrvette72]

6 pak, WE, I have gotten into this unit as a first time tranny experience....these days, things are real tight money wise....5 years ago things were better....that's life...
at any rate I"m a 58 year old hotrodder, with a '72 shark and a rollerized 355 ci DPFI engine...
ZZ9 cammed...420 some ft lbs torque nice and lo on the scale...should make about 430 some odd HP, but I think 375 is more like it...really....;-)))
at any rate 5 years ago I put about 1200 bux into this conversion for the Florida freeways here and cruising at 80 mph with 3336 rear, that' 2500 rpm...I have 275 rear rubber...and a rack and pinion steering I did myself my own design last winter...and rewired the car myself, did the injection by myself too....I"m an old ET...so that is easy for me....
but like I say out of all the trannies I have ever run, one of the best was a 400 with 350,000 miles on it, behind a 455 for the last years...and it still scratched 3rd with a 307 rear in an old goat....245 rubber....
loved that tranny, indestructible...wish my 700 was just 1/2 as good....even....I mean that goat with boat was 7000 lbs, vette here is barely 3200, and engine is over 100 ft lbs shy off that 550 ft lbs of the 455 Pontiac....so that's why I am seriously disappointed in the 700....
at any rate, I"m looking for insights and advice on what to do in the future, It's running now, thing is with metal in the pan....not for long, I'd guess....but fluids look good, and it's feeling ok for now...
I still think the shifts are WAY too soft, so that was my thinking to get them harder,...block the accumulators....not sure how to do that, but willing to try...I have the ATSG manual from the supply house, same as my old '87 vette manual really, same tranny, really....and ton's of literature on it...everything I can find off the web....frankly I"m thinking I would have been better off with a 200r4, but I didn't know they came with a chebby pattern...5 years ago...

cant' win....;-)))

GENE

 

[6PacktoGo]

Originally posted by mrvette72
6 pak, that may explain some of the metal, that overrunning sprag....4-3 downshift in auto mode...sometimes I do that, I guess I should slide the lever back?? that should take care of it....
I do notice differant shift points from lever position...holds gears longer in 3rd position, instead of 4th (d/over).....I also have the converter locking in 2-3-4 gears, only one unlocked is 1st....it's actuated by brakes, of course and if I flip the switch the other way, i'ts computer controlled lock at 50 mph...
does leaving it 'manual' locked in traffic toss undue stress to the unit??? I have tended to do that myself more often than not, allthough wife does not...she likes softer shifting...
I got rid of the loose vette 2k stall converter on the last 3/4 clutch job, and put in a tight 1200 rpm converter to kill that 'revvy' slipping feeling it had....I like it beter, but wonder if that's tossing more loading on the tranny itself now.....I suspect it does, but even as a stock unit in a silly 5000 lbs truck the unit was supposed to live....

GENE

First off, if you have a slip feeling from a 2000 stall Vette converter, the converter is BAD, period. The Vette converter doesn't do that, at least not the REAL one. Those junky homemade aftermarket rebuilts do though, because they just cut the stator to make stall. I use the B29XHD in 99% of all street performance cars with the 700, it DOES NOT slip.

Leave the stock lock up set up (lock up at part throttle, after 45 MPH, in 3rd and 4th only) alone. It works, and causes ZERO problems. It doesn't tear up transmissions or converters. It is VERY likely that the lock up stuff gave you that metal in your pan. And NEVER lock your converter up at WOT or heavy throttle, you're doing NOTHING but DAMAGE.

If you need to lock the converter up to get shift feel, either your converter or your transmission or both are crap. Even with an extremely loose converter you can get plenty of shift feel.

The reason the shift feel and timing change with shifter position is that they are supposed to. There is a valvetrain that does that very thing. ANY time you run the car hard, it should be shifted manually.

Yes, you should manually down shift to 3rd if you are in 4th (OD) and need to use heavy throttle or WOT.

 

[mrvette72]

Alan, guys, I appreciate very much your taking the time to answer my amateur questions...

OK, so i have to move the lever for full throttle high speed work...ok...

second off, about adjusting that throttle cable...the way I have been doing it is putting max tight on the cable, then forcing open the throttoe body to WOT, and letting the tranny kickdown click itself into position...
frankly, I don't care to run at high line pressures, but if that' way it's designed....well ok, I suppose...still wonder about blocking the accumulators, and relaxing the throttle cable a bit....
this input drum you talked about above...
which one is that on the diagram??? is it the huge one with the band around it??? thought it was steel, have to look again maybe next time...
or is it another one inside..???

any clues as to what the steel in the pan is from??? could it reasonable be the clutch internal teeth that fit around that internal drum...and any suggesitions for getting that assy in place a bit easier???

GENE

 

[6PacktoGo]

You can block the accumulators, but that's not going to solve your problem. What you need is the Sonnax accumulator springs and some plugs with 0.040" orifices. I've pinned the accumulators before, or blocked them off. It makes for a violent shift, but it isn't the thing to do.

You have a lack of line pressure, and a lack of line pressure rise. You need the right valves to make it work, see my post above.

Your transmission is not the problem, it's the way it was built. A 200 4R would not be any better, if it were built the same way.

I like the old 400 too. The 400 was designed to absorb 500 horsepower and last 500,000 miles. The 700 was designed when 250 horsepower was a bunch.

If, for example , your 700 was manufactured for a Caprice, you have the following problems:
1. the wrong band servo, unless you changed it
2. the wrong TV boost valve, unless you changed it
3. the wrong accumulator springs, unless you changed them
4. the wrong intermediate boost valve, unless you changed it
5. the wrong TV plunger, unless you changed it

So, no matter what you do, unless you made the right changes hydraulicly (a shift kit will NOT do it), the transmission will not work right, no mater what frictions you install or how well you install them.

If you had a 200 4R out of a Caprice or a Sedan de ville or a LeSabre, it would be just as much a piece of crap. And a shift kit WILL NOT fix it. Neither will blocking accumulators or other tricks.