Hi, I have had my TH2004R installed for a few months now but still working on some issues, and these need to be addressed I guess (but don`t want to hear!). Swapping the TH2004R in is not a common thing over here, so we`re off to new frontiers, tried to play by the rules, but still...... My shift points used to be way off, geometry was bad since we didn`t have a correct TV cable system for the original Rochester 750 cff. By modifing one of the two I`ve ordered(both didn`t fix properly, are there no sets for the original set up with the Rochester), we could improve the shiftpoints to: 1-2nd: 3600, 2-3rd 3900, 3-4th 4500rpm. I was given the info by the builder they should all be at 4500rpm. Line pressure is good though, matches with a list I`ve seen from Bowtie (I have a CK), the pressure compares favourably.What do you thing has to be done to further improve the shift points? I`m suffering from back-and-fourth shift in 2-3, veeeerrry anoing, it used to be gone, but I started dripping oil, and it seemd it has gotten worse. Had no oil issues but went on a trip of 600miles, at a speed of 100mph and around 2900-3000rmp and suddenly had a "new toy" to play with. Can a low on the transfluid provoke such symptoms? The builder said I would not need an aux. oil cooler with the converter I have (standard 2200-2400 stall, non-lockup). I was wondering if I might be overheating nevertheless. I`m really a bit unhappy with the situation, I thought it was a good thing swapping my transmission but now I`m having second thoughts. Jens
^^x2 If you are running a non-lock up converter I'd think you'd most certainly need a bigger, secondary, transcooler. The lock up helps keep the system cool, with out that it needs a way to get rid of the extra heat. Do you have pictures of your TV cable and throttle linkage? A picture is worth a thousand words. I forget what the cable likes for actuation, but iirc, when I did a 700r4 conversion on a '69 Firebird, I looked at the throttle bracket on the carb, found a point on it that moved ~1" to ~1.25" (from memory, could be different) from idle to WOT, drilled a hole in the bracket at that point, put a small screw,phillips head, that the TV cable end would *snap* over the head of, in the hole with a nut on either side of the bracket to tighten it up. It worked great for that car after setting the tension on the TV cable using the adjuster on the cable. Wish I'd taken a picture of it =/
Hi , don`t be too shocked, the line pressure is where it should be(have the data somewhere, will look it up and post it! And I`ll take a picture or two for you to judge). As mentioned before, it has improved it`s shiftpoints, and relaxed on the bang shift I experienced before(didn`t really drive it with the cable too much out of adjustment). Like i said, totally new territory, can`t just roll the GS to somebody who`s familiar with the swap, we had to go by the info and the knowledge we had. So far, no burned transmission, no brownish ATF. Thanks for the input, and your recommondation is an aux. cooler? In a 305 Monte e.g. did they also have them?These cars were also not too high on hp and torque, maybe comparable to a low comp 71?
They had a locking converter, that's the difference in the cooling requirement, not the HP put through it. It's not the short WOT burst that typically cook ATF, it's the long extended drives that it can't dissapate all the heat from a slipping converter.
By the time the overdrive units appeared just about all the automatics had trans coolers built into the radiator end tank. The performance or heavy duty cars would have an oil cooler in the other end tank. Can't recall any overdrive equipped cars that didn't have an end tank trans cooler o No:
So I don`t really get it why that thought was turned down in the first place, I even asked for the cooler.....I`ll get to it asap, might be a big live saver. As stated before, improving shift points from 3600rpm in all 3 gears to the beforementioned points(1-2nd: 3600, 2-3rd 3900, 3-4th 4500rpm) does show that the geometry is better, or not? How can it be the line pressure is ok and still have the shiftpoint issues? Jens
I'm no expert but how many "burnouts" have you done? Maybe you shot the governor spring out?o No: As for the oil cooler, I am planning on running 2 of them in front of the radiator, when in doubt over build it! By the way do you have a trans temp gauge hooked up? More information is never a bad thing.
Nope, no temp. gauge at it right now, maybe I`ll give it a second thought though. As for 2 transcoolers, I`m no expert neither (as you can clearly see) but have read that the transmission needs a certain temprature level to work correctly, so too cool isn`t the way either, as I understand it!
The shift points aren't all based on the TV cable. The cable controls line pressure and the valve body, governor, servo controls the shifting. If the trans has a Grand National or similar valve body it'll shift differently from the same trans with a Caprice valve body. This means the shift firmness and when the shift occurs can be very different based on the valve body and other internal bits used in the build. The actual shift points will be based in part on your rear-end ratio and in part on the amount of throttle being used. A part throttle 1-2 shift in a car with a 2.73 gear is very different from a full throttle 1-2 shift on a 4.11 geared car. Add in the different valve bodies and you can see a huge range of actual around town shift points depending on the combination being used. I'd say first off find the leak and fix it. It'll probably be a gasket not sealing right or a bolt that came loose after a few heat cycles. It's not uncommon for things to loosen up after they get used a bit. Just need to find it and snug it down again. Secondly make sure you have the right amount of fluid. I have the manuals instructions on how to get it right if you need it.
I`ll check on all the bolts and pieces tomorrow, thanks for the info. Where would it leak the fluid if it had too much in it and would try to get rid of it? Is there something like "designed" leaking spot to prevent the transmission from putting up too much pressure? Thanks for your offer on the manual, maybe I`ll come back to you. Jens
The fluid will generally only leak out if a seal isn't tight enough or if it's grossly overfilled. Sometimes after sitting for a long time the fluid in the converter can also end up leaking a bit. If it's a quart or so over than it shouldn't cause it to leak. Some in the turbo Buick world actually run it slightly overfilled to prevent the filter from being uncovered under hard acceleration. Here's the info for filling from empty: 1) Add the recomended amount of Dexron II automatic fluid to the transmission through the trans dipstick 2) Let the car idle in park. Do not race the engine (don't raise the rpms). Shift into each gear position one at a time. Return the shifter to Park. 3) The fluid level should be 1/4" (6.3mm) below the ADD level on the dipstick. 4) Drive the car for 20 miles or so on the highway to ensure proper heat buildup in the fluid and trans. 5) The fluid level should now read FULL. Checking the level: 1) Warm trans by driving 20 miles or so on the highway 2) Park on level surface and leave engine idling 3) Put the Parking/Emergency brake on and shift into NEUTRAL 4) Remove dipstick and wipe it clean, then reinsert it fully and wait a few seconds 5) With engine running the level should be between the second notch and the FULL HOT line (If fluid must be checked when its cool than fluid should be between first and second notches) Haven't checked through everything in this thread, but it has some info and tips that may help you figure things out http://www.nastyz28.com/forum/showthread.php?p=445122
Thanks for the info on the filling and checking process....not too easy, I had a thread about it sometime ago! Yep, it`s a CK-build transmission. Here are the pics of the brackets, tell me what you see and think about it, if it`s good or where and how I should go for it again...
It looks like your TV cable holder bracket is too high... Did you measure to make sure you get the 55 degree rotation.. This all has to be right or it will never be right. Keep in mind that there were factory Q jets that had TV cable provisions so you could rob parts and build your setup with all GM parts and no mods. I have used a carb from a 85 Astro van with a 7004R, and also from a 80s Olds 307 powered car with a 2004R. http://purplesagetradingpost.com/sumner/techinfo/700R4p1.html
Hi Sean, very good and detailed link you posted here, thank you very much...I`ll have to go for it again, I guess. Will these back and forth shifts disappear? They appear not too often(only when quite warm) but really get on my nerves! Where can I get a setup you`re talkin about, can these still be ordered somewhere? What`s the correct name(the one you type into google and find sellers)?.Since I don`t have salvage yards around here with old american cars I`m depending on people selling these pieces! Jens
Send Ken an e-mail and see if he has any info that can help. I'm sure he'd know exactly what parts are needed and may even have them in stock. http://www.everyday-performance.com/
