i have just joined the forum and a great bit of 700r4 technical information to dispense.some of you may know me from turbobuick.com and elsewhere .if you dont that ok.our main focus is 2004r,700r4 ,th400 and our aod hybrid overdrive transmission for gm vehicles.we currently are making different gear ratios ,billet drums ,transbrakes etc for the aforementioned units.the purpose of this post is not to soley promote our products but to let you out there know we are serious about what we do ,and will dispense any and all technical information those of you may find useful.i usually will answer questions with other answers to others qs from the past which are kept in a database.thanks for listening and ill leave some of the info ive left on other forums so you can get an idea of what we do..


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a 2004r and a 700r4 as built by us can reliably handle in excess of 600 horsepower.with that being stated selection will be more closely related to hosepower,torque,maximum engine speed,power curve ,vehicle weight ,induction systems and final drive ratio.a heavy car with an engine that will see a maximum of roughly 5200 rpms such as in this case the 700r4 will provide increased vehicle acceleration through the extra torque multiplication generated by the 700r4s compound planetary gear sets when operating in reduction,verses the 2004r.if the engine makes power to 6500 rpms ,the 2004r will provide increased performance by reducing starting line ratio which limits traction and reducing the engine rpm drop on a 1/2 ratio chance.this improves performance by keeping the engine on the fat part of its torque curve allowing a greater amount of flywheel torque to accellerate the weight of the vehicle at the right time.a 700r4 brought to 6500 rpms will drop a greater amount of rpm on a 1/2 ratio change putting the engine below the torque curve and introducing a flat spot in accelleration by putting the engine in a state of operation where it will need time to gain rpm to a level where maximum performance can be obtained.this also causes a severe vaccum drop accross the engines induction system further reducing the engines ability to ingest air and gain rpm.a forced induction system such as a turbocharger or nitrous will be less sensitive to this phenomenon as well as camshaft with wide lca angles such as 114 to 118 degrees common with the small block chevy v8 and also good dual plane intake manifolds such as the performer rpm or dart dual plane.


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an interest has developed in the 700r4 products.our main specialty is redesigning failure prone parts so they can be pushed beyond the limits including a safety margin and then making them an integral part of our custom built street / strip and racing transmissions.the parts being discussed here have been in use in a very limited quantity and in testing for quite some time.you may ask why havent we mass produced them yet if they have passed the test etc.in simple terms ,at this company we build custom ratio planetary gear sets ,transmission brakes,e4340 input and output shafts,clutch drums,shift recalibration kits and the like of our own design for the powerglide ,th400 ,th350 ,200 ,2004r,700r4 and our hybrid aod transmissions.this places a tremendous burden on me as the owner of the company from both a mental ,physical and financial standpoint.there has also not been a tremendous interest in them until now.the items we are making in quantity are produced due to the demand of the product by those who have found we have triumphed over inadequate factory designs and allowed them to use" written off "transmissions in the most demanding applications.this brings us to the failures in the 700r4 design.from a technical standpoint my views of the 700r4 are drastically different from even the most seasoned rebuilders and transmission specialists in the country including several engineers at gm hydramatic division.i have identified certain things that are inherent in the mechanical and hydraulic design and function of a 700r4 that make it stand alone in the arena of transmission comprehension.i would like to say first that i do truly believe these things to be valid and are usually denounced by those who do not understand the "held divided by the driven concept"of simple compound planetary gearset operation.all th 400 ,th 350 ,200m,2004r,4l80 designs use an input ring gear to initiate reduction in first gear,this means the clutch pack will drive the ring into the sun gear and create primary reduction and then use this to initiate reduction in the what i consider the reverse planetary.a 700r4 on the other hand does this by using the sun gear to initiate reduction in first gear .this reverse the held and driven members and creates a unique situation in that the amount of teeth in the gearset that transfer the initial load is reduced and a tremendous amount of stress is placed on the drive side of the input sun gear.now in second and third the transmission goes back to what some would consider conventional planetary gear set operation.please note however that the driving force applied to the the sun gear in first gear is via an aluminum drum with a steel input shaft that are splined together.it is at this union of parts that stress cracks and imminent part failure becomes a real world problem.there have been attempts by other companies including torque drive engineering to eliminate this by reinforcing the drum at this area and it is from input i have recieved from others that it does work to a certain degree.i however do not share the same idea on the piece from them .we have broken three in the past and finally i came to the realization that i must draw upon my knowledge of transmissions and close comrads who understand metallurgy to provide others with a part that will not leave them stuck at the side of the road.another problem is output shaft failure.this is certainly due to the fact that the sy/ty crowd is cranking up the boost ,but also due to other factors.let me say first that a 2 wheel drive output shaft in a 650 horsepower car is something i have never seen break.i have seen several broken in 4 wheel and all wheel drive 700r4s.this is in part because the 4wheel/all wheel output shaft is much shorter in length than the 2 wheel counterpart and we loose the torsion bar effect gained by the longer output shaft which causes shaft breakage.by using an e4340 material that is specially heat treated and making the lube hole down the core of the shaft smaller

 

Capital letters at the beginning of sentances and a couple more paragraphs would have made it more readable.

 

i cant argue with that.

 

so maybe your the one to ask ... can a 700r4 be pushed to 190m.p.h. and stay together? once we get this kick down thing squared away we will be sit to try it ... the tranny is the only thing we are not sure of at this point ... thanks ...tao

 

One hard pull up to 190 will be no problem. Youll start to run into problems when you maintain that speed for a continuous amount of time. The trans fluid will begin to heat and foam which will cause slipping and loss of speed.

 

You can modify the throttle valve plunger sleeve, by eliminating the 4-3 downshift passages with 2 allen screws. To get it to last at that speed, you will need to make a 50-50 or a 60-40 mix of Cat oil, (PN# 8T - 6571 30 weight) along with Mobil Dexron III (non-synthetic) or Aamco Dexron III (non-synthetic). I have helped others with hi-speed 700R4's, and this works out very well for weekend warriors. If you live at the raceway, then use the Cat oil straight.

 

this is usually not a problem after taking some precautions to eliminate areas of concern.in order to overdrive a planetary gear set ,,output must be faster than input.this type of speed biasing turbine shaft speed (input),and output shaft speed (output)places a high centrifugical load on the input sprag.over long periods of time this can cause the sprag to burst.new sprag on every teardown should be cconsidered mandatory.the mechanical diode type sprag offered and then discontinued from borg warner automotive should not even be considered at such speeds.the blocking off of part throttle modulated tv oil so it cant stroke the tv downshift valve is something of concern if you are afraid of engine overspeeding by a forced or modulated part throttle kickdown.i do this by closing a hole in the seperator plate if calibration of shift valve springs and governor verses final drive require it.also as many may not be aware of there is engine braking in a 700r4 in 4th gear WITHOUT the application of the overrunning clutch in 4th gear.leaving the low reverse clutches as loose as you can and using steels with turbulator holes will reduce clutch drag at high planetary speeds .lifting and then reapplying the throttle is not reccommended.foaming of the fluid shouldnt be that big of a problem imo but if others think so i would be curious to know why.if you use the late pump gasket and dont overfill the transmission i think youll be safe.if you do get oil out the vent it would be wise too connect a vaccuum hose from the vent to an area where the oil wont spill on the exhaust or tires etc

 

I've read and thought about what you'all have suggested and have come up with a new Idea. here it goes

what I would like is to eliminate the auto upshifting and downshifting all together. So what I would have is a manual without a clutch. so even if I am sitting still and put it in 4th it would go to forth. I would have to over ride the detent cable, govenor, and what do I do about the lockup solinoid and the other soliniod. Is this possible and would it be pratical without major redisigning of valve body.
I think this would solve all of my problems or create new ones.
LOL Thanks for your input

 

we do make such a valve body.lockup options are also available with it

 

Hehe congrats taonindo you just reinvented the wheel. Your looking for a manuel valvebody. I only know one person that had one of these and the only complaint he had was that it was slow to downshift. Not really sure if there was a problem with his or it is just part of the valvebody.

 

thanks ... with my vast amount of knowledge of trannys ... no wait that was sombody else ... looks like im starting to get the jest of it (maybe) ... we are looking in to the manuel valve body didnt seem to find it yet on chris's site but still looking ... tao

 

some items arent listed.give us a call or send an email

 

Hey Dana! I work for a CAT marine engine dealer- the correct part number is 8T-9571 (you had "6571", which could turn out to be the part number for a dozer balde or something) for a gallon of Caterpillar 30wt Transmission and Drivetrain oil. Want a five gallon pail? Try 8T-9572.

I always heard non-ATF was the quickest way to destroy a tranny?

 

nope.

the additives in the oil is the key to problems or not with an automatic tranny.

Same holds true with motorcycles that have a wet clutch

 

i always use atf,but have seen this brought up many times before and want to hear the pros.i dont like the hydraulic oil because i feel it is too thin and aggravates crossleaks inherent in the design of all automatic transmissions.prove me wrong,im curious to hear what good this oil does and may consider using it in the future.