Thanks guys. If I overhaul my own can I upgrade to the preffered parts of the 90-93 700R4's? If not I'll just find a used 90-93 trans. turbo 350, and 400 would mean new driveshaft and bad highway driving.
I would just find a good, tested, or low mileage '90-'93 model instead of swapping parts, less confusion. The splines on the tailshaft are the same between TH350 and 700r4, depending on application, all you would need to do is shave an inch or so off of the output yoke on the driveshaft since the 700r4 are about 3" longer than the TH350, done it before, no balance issues. The TH400 splines are different. And yeah, you'll lose HWY miles with either one, but depending on the size of your rear tire and rear gearing it wouldn't be a major pain since it's not a daily driver.....
No reason to discount the 700r4 & go with something else. I have one in my roadster & love it. It's true they have a finicky cable issue but several companies like TCI have replacement valve bodies that revert to high pressure if cable isn't adjusted correctly. I run the lock-up on mine but only on 4th gear. I use no vacuum lines- just an 80's Vette brake switch that also has the cruise control hook up. I use the cruise connections on the switch for the trans. Hit the brakes in OD- converter unlocks.
1993 is a 4L60, one year only electronic controlled with a TV cable, I have a couple of them on the shelf. I have found the 88-92s with the MD8 case to be the best so I would think a rebuild kit for one of those would have the good parts, unless the 93 has the same internals but with a solenoid controlled valve body.
The '93 is a one piece bell housing (4l60E),one year only, controlled by TV, electronically controlled for lockup only.. '94 (4l60E) two piece bellhousing, completely electronic, shift solenoids, no TV Yes, MD8 case is the best for internal parts.
The tailshaft is shorter in the 4x4 models to allow the T-case to bolt up. You would have to completely disassemble both transmissions to swap tailshafts, plus the rear pinion planetary my not be compatible (older model 4 pinion, new one might be 5 pinion, won't work) so the gears wouldn't mesh...
If you are up for the challenge, rebuild it yourself. Grab a Haynes manual for the GM automatic transmissions, it has step by step instructions with pictures. I used it to rebuild mine, it was my first rebuild as well. There are many websites out there that will also show you how to make the special tools needed to do the job. Its not that hard and with upgraded clutches it cost me about $170 to do. Parts probably cheaper in the US.
Keep, you are correct, there are many sources for rebuilding. There are also how-to rebuild DVD's for sale on ebay which are nice also. If the kid doesn't feel comfortable in his own abilities i'm not suggest something like that. I'm just steering him in the right direction what to look for if he doesn't plan on rebuilding the one he currently has, that's all. If he wants to rebuild the one he has, and he could upgrade parts if he chooses to do so, but the hard parts are more expensive to upgrade in an older trans, sometimes it's better to start off with a little bit better components to start with to avoid headaches in the future.
Ok any recomendations on who sells the best kit to redo the 84 trans I already have? I know a 90-93 would be better but I'd rather not deal with trying to get one and just fix/upgrade mine. I'd like it to handle 450HP for a future engine but it would be a stock 250hp for now. If I'm being dumb and I need to get a 90-93 then I will but if its overkill I'm happy with the current one for free.
If you plan on big H/P upgrades you will want to step up to the newer trans ie bigger input shaft and more clutches.
If you can find one from an 88-89 Suburban it should have a cable drive for the speedometer. Vans may be the same deal. Everything else (pickups) is electronic, and Suburban and vans are electronic by 1991 - I've yet to run across a '90 to check which way one is, could be either. An electronic is not the end of the world, but a cable drive already there lets you hook right up to the speedometer you have with no modifications or changes.
I fpund this one for $325. Thoughts? It was fully rebuilt has harden sun she'll and 4l60 upgrade kit which I believe is better clutches and two extra , they machined something to fit the two extra , input shaft upgrade and new valve body with upgraded springs , corvette servo , and 2,200 stall , it was built for nitrous motor so I wasn't running big cam , but never used nitrous I pulled setup b4 break in period was even finished
I had the same thing happen to me in a o/t truck. It cost me $900 for the rebuild and it works OK now, but completely blows as a mild performance trans. I HATE it. It's only going to be in there 'till I can get a good th-350, mileage be damned. Maybe I just got a bum deal, hope your build goes better.
An often overlooked defect in the 700R4/4L60 non-electric trans is the 2/3 accumulator. Most people don't realize there actually is one, it's incorporated into the 1/2, 3/4 servo assembly and is relatively hidden in a trans breakdown picture. The very common problem you speak of is usually the 2/3 accumulator check valve (check-ball capsule). Sometimes the metal tangs under the ball become displaced or fall off allowing the ball to float around and not go immediately into the seat when the shift occurs not allowing fluid pressure to not build up, thus the missing shift "at times". It's located in the case, extending into the servo cavity. The valve body/spacer plate has to be removed, and you will need a slide hammer to pull it out, then drive in a new one with an appropriate punch. Sonnex also makes a valve to install in addition to the new check-ball capsule to eliminate the possibility of more problems. I recommend to remove the 1/2, 3/4 servo assembly when installing to make sure it goes the correct depth and to clean possible aluminum metal bits from the installation. A/C Delco check-ball capsule #8634400 Sonnax kit #77701-076
I used a transgo hd2 kit in my off topic truck with a 4l60e plus a huge trans fluid cooler. In conjunction with this i have a 'vette 2nd servo and a sonnax billet 4th. The trans shifts firm and quick and has held up to the abuse for quite some time now. Posted using the Full Custom H.A.M.B. App!
Doesn't solve the mileage he was seeking, the difference between 2900 and 2100 rpms is a lot. But, no third gear HAS to be a bummer. Good luck.
Just my humble opinion but a 350 or a 400 will last a long time in a rod that is not driven many miles a year and the little bit of gas saved with a 700 isn't worth the cost and shifting problems.
Post is about nine months old, folks, some newbie had the bright idea to bump it up with some tips that, while nice, the OP is long past needing.
When I was building my car I bought a 700R4 out of a 91 Caprice at a local junkyard. I had a local transmission shop go through it then installed it in my 48 Ford behind a 350SBC. I got on line and found Bowtie Overdrives' site and read a lot of their information on the 700. I installed their TV bracket on the Eblebrock 1405 I run, and I believe the kit included a new cable and spring for the shuttle valve in the transmission. Then set up the TV cable as instructed ( same instructions as GM ) wide open throttle point ,etc. I can honestly say that I have not made any further adjustments and have driven it about 20,000 miles since. I just have a switch on the dash for lock up that is in series with a GM brake light/ lockup switch. As many have said in this and past posts about the 700 , the geometry of the carb linkage to the TV cable is absolutely critical. Do this geometry correctly and , other than the inherent mechanical weaknesses in the earlier units , the transmission will work fine.
The Hamb has many members and the different reactions can be comical. When a newbie asks a question, some direct them to the search function. If someone uses the search function and brings up an old thread they are chastised for it. Why not post advice to an old thread? It might help the next guy who finds it using the search function.
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