i hear that automatic transmissions are a living hell to rebuild

what makes an auto tranny stronger? it's not a question of the gears right? what do you replace to make it stronger? is it worth learning to do oneself? are there any books on it?

 

Clutches and bands help strengthen the tranny, new servos will firm up the shifts. Don't ask me how to rebuild one though, I haven't the slightest idea. I can tear a T5 or T56 apart all day long and put it back together easily enough, but 700-R4's are outside my personal experience.

 

like...whats the difference in parts used for a stock 250HP tranny and a 450HP tranny?

 

Kevlar clutches,Bigger servos,extra clutches in the 3-4 clutch pack give it more holding capabilities.
I built one out of book before.It was not as hard as I thought it would be.But don't get me wrong it does get complicated.Pay attention to all of the specs in the book and it will require some special tool that not every shade tree mechanic has.I.E. Dial indicator,Special snap ring pliers (duckbill) and other selective shims.They also have videos that I have seen for sale in the back of hot rod or car craft.The books I used was one with a Blue cover that I bought from my local tranny shop in conjunction with the GM factory service manual for a 91 Camaro.It accedently fell into my trunk when I left the dealership that I used to work for.IMO it is worth it to learn how to build a auto trans yourself.When I was quoted a price of $1500 for R&R and a rebuild ,I said No way and decided it was time to learn for myself.It can be done.I overlooked something in mine that I should have caught when I built it so I also recommend not drinking any Beers when you build your own


James

 

After watching and helping a buddy rebuild a 4L60E from his 98 Z28 I must say that I am extremely surprised at how easy it is to rebuild them. 4L60s and 700R4s are similiar in design but the 700 has a few less parts.

 

how expensive are parts for a stronger rebuild? it's definately something ill look into in the future.....

 

tci and b&m both offer their rebuild kits, whicha re basically the guts of their trannies for a few hundred dollars. the clutch/springs/gaskets are about 200 and depending on what sungear/shell etc it can be had for about 400-500 bucks.

my buddy used TCI with a hardened shell and gear. Its working great so far and feels incredible.

 

I rebuilt one recently, I couldn't fit in any extra clutches or shims using the TCI kit tho. I didn't get a "hardened drum" or "hardened input/output shafts" that would've made it much stronger, not in my budget. A shift kit was included and will help keep the line pressure up and clutches from slipping as much. The Vette servo components will also help, as will the HI-PO clutches and steels and band.
It broke down into "sub-assemblies" which then broke down into many smaller parts. I highly recommend the video over the book, I have both!
I found the only special tools I needed was a "spring-compressor" for the "drum", and a sheath to put the neopreme seals on the input shaft w/o distorting them. I filed a notch in the side of a screwdriver to grab the large snap rings, the other needed snap-ring-pliers. You also need lots of clean work space, I used a couple of sheets of plywood on saw horses in my In-Laws garage and turned the tranny on it's end in a 5-gallon bucket to make it easier to reinstall clutches and snap rings etc.

 

Go to: https://www.pro-built.net/index.cfm?...ct&productid=5 and this will give you a complete rebuild kit with "all" the upgrades necessary for making this unit live. If you are looking for a video for this unit try http://www.technicalvideos.com/ If you have any questions about this, let me know, and I will be glad to help?

 

Is 400HP/400torque (probably not even that high, but I'd like some cushion room ) too much for a 700R4 in general ? I mean....from what I've read T5's can't handle power well, and a T56 swap looks to be involved and expensive. Is the R4 going to be able to handle that kind of power even if rebuild stronger or will I end up with my tranny going ever 12-16 months? Assuming I put 300 to the wheels, daily drive it, take it to the track once a month, and "have some fun" on the weekends, is the R4 not the tranny for the job? I'd like to keep it because it can be rebuild and just put back in...no car modifications that a T56 or different auto might require....plus overdrive is nice though not required (with that said watch me get a job that requires highway driving)

If it was you, would you just start saving/planning a T56 swap or is it feasible to keep the R4? My buddy has a 400Turbo he wants to sell, but I'm not sure how compatiable it's gonna be, and the loss of overdrive is kinda sucky. I can see it now, june, the 350 is put in, my baby starts up and roars...I drive it onto a sidestreet, blip the pedal and the R4 bombs and I can't drive it for a month. I mean, I'm swapping the motor, if I pull the tranny outwith the 305 I can kill 2 birds with 1 stone need be, but I don't want to rebuild it, and still have it bomb. I need a daily driver as well....

Pro Built, what are your 700R4 Street/Strip trannys good for torque/hp wise? If the whole "rebuild" or swap thing doesn't pan out I might just buy a new one, your website is definately now in my bookmarks.

 

I'd say a Pro-built one should hold up to 500-600hp or more with the right parts and I'm expecting mine to live well with 400-450hp.
I'd say keep th R4, if you're not confident you can rebuild it yourself and make it live, then save up and buy a street/strip ready one "new" @ roughly $1200-1400, or local rebuilds or used at swap meets for $700-1000.
These tranny's are very durable despite the reputaion that was caused by neglected, misadjusted and early '80's units. Mine had over 158K miles of abuse with little signs of weakness despite weekend trips to the local Dragway.
400 THM tranny's are heavy, eat a lot of HP and NO O/D, but are plenty strong. I'd use one once the power level exceeds 600hp.
T56 swaps a too costly for me, and then there's extra expense of upgrading the clutch/pressure-plate etc.

 

What's the difference between the 700Rr4 and the Turbos? This from a five speeder. The crate Turbos are hundreds less, and boneyards have lots of Torbos.

Also, since either tranny can handle street horses, isn't the rear end and the gears in it the major concern?

 

Turbo 350 and 400 have no overdrive. If you plan to just cruise the strip every Fri night with it, fine. If you drive any distance, you will suck up gas because of lack of OD.

 

Does that pro built kit allow WOT upshifts into OD?

 

does a 400 slide right in or are changes required?