I have a 200-4R out of a GN in my `65. It works perfectly but it has a vibration that I start to feel above 50mph and gets worse as the speed progesses. I have faced the fact that it's lifespan is limited and I will have to replace or rebuild it, but that's expensive for a good one and right now I have too many other things going on and a son in college who keeps springing these :dollar: surprises on us so it's just not in the budget right now. Yesterday I picked up another 200-4R transmission. Here's the story on it: A guy bought it through Carquest, so it's a fresh rebuild. He had it installed and it didn't work. I know this installer and he can be kind of an a$$hole but when the rebuilders called him and suggested he check this or that he told them he didn't buy the trans from them, his customer did, so if they wanted to pay him $65 an hour to do these tests, he would. If not, to hell with them, so they sent him another transmission. This one was removed and was supposed to be picked by the rebuilders but they never did it and that was 3 years ago. Yesterday when he told me about it he said if I wanted it I could have it, so I took it. I don't know very much about automatic transmissions so is there anything you guys can think of that I should check before I install it? I realize that it could be a total waste of time to install it and not have it work, but there may be things I could do once it's installed to make it work. Do you have any suggestions, or do you know of any good, informative books about these 200-4R tranmissions? All I'm really looking for is a temporary trans to use while I put the money together to get a good CPT trans or equivalent. I realize this is a shot in the dark but I also feel I have little to lose but time by trying.
Hey Bill, I'll bet it won't be long before Ken (techg8) chimes in, and others, so you should get some good ideas. Other sources of info that I have found in anticipation of installing one myself are: 1.) turbobuick.net 2.) http://www.ckperformance.com/resources/GM2004RCATALOG.html (Chris wrote a great book, and is a turbobuick.net guru) 3.) http://www.bowtieoverdrives.com/index.shtml (great reference material - not so sure about their actual rebuilds) Good luck! I'll be watching this thread to see how things turn out. Best Wishes,
I found on the web a complete step by step rebuild manual w/ pics for 2004r's and put it in my fav's list but thats on the comp at work - ill chime back in maybe tomorrow and post the link for you.
I like the idea of buying that manual that CK offers for $65. I've only rebuilt one automatic transmission, a TH350, and that was about 30 years ago but they have always intrigued me. I'll start with the manual and do some reading. When I feel I'm ready I'll get whatever tools I'll need and a rebuild kit. Nothing ventured, nothing gained, right? What's the worst that can happen? I fail and waste a little money, although I doubt if that will prevent me from trying again :TU: Thanks guys.
Yes. Since the vibration showed up I have replaced the entire rearend drum to drum, had a new driveshaft built for it and later took it to another place to have the balance checked. They computer balanced it and it made no difference. I also added adjustable upper control arms and set the driveshaft angle exactly where it needs to be. Another indication is I started with 3.73's in the new rearend and the vibration was there beginning at 60mph. Then I switched to 4.10's and it started at 55mph. Now it's beginning earlier, around 50mph and it's getting worse. In addition, it does it at that speed no matter if it's in gear or not. I can run it up to 55mph and slip it into neutral and it's still there. I talked to a transmission shop about it and they told me they knew exactly what it was, although I can't explain it because I don't know automatic transmissions very well but when he explained it it made sense at the time. I got the trans out of an `87 GN that was running 11.30's, and although mine isn't that fast I have made 97 passes down the dragstrip with it, so it hasn't had a very cushy life.
I also recommend that CK performance book. I have it and it is LOADED with good information. Chris has also been very helpful with free advice any time I went to the trouble to call him. As for your vibration, have you checked your driveline angles? When I installed my 200r4 in my 72 replacing a TH350, I found that I had that same type of at-speed vibration. It ended up being a case of bad driveline angles, and I fixed it by putting a .5" spacer under the trans mount on the 200r4. This corrected the angle of the driveshaft and eliminated my vibration. Just something to think about. It certainly could be something internal as well. What code valvebody does the new trans have? your current BRF code from the GN is a "desireable" unit for performance applications.
I ordered the manual from CK but haven't got it yet. I have a digital angle finder and with a full tank of gas and all my junk in the trunk I have 1.6 degrees on both ends of the driveshaft with the back of the trans and the front yoke on the rearend being perfectly aligned at 0. As I use more gas that angle will go up a hair. Don't know about the valve body code. I got the trans out of a GN but it has a big sticker on the side that indicates a GM warranty replacement. Should have been another GN trans but you never know. There is no tag on the side. I have a Transgo kit in it, anyway. This trans works perfectly and has never faultered in that way, it's just the vibration that's getting worse.
This is particularly frustrating right now because a guy in town wants to race me with his `55 Chevy and want to humiliate him in the worst way but I'm afraid to go to the track with this problem and take a chance on blowing it up and oiling down the track for everyone :af:
Bill, I have a buddy that has a bad ass 87 GN with a GN tranny that has maybe 2000 miles on it. He is parting the car out and lives in Milton. It has a 3500 stall and a trans brake that has never been used. I believe CK built it for him. I had the same converter, transbrake, and internals as he did and I was running 7.50's at Holt. His best time before the transbrake was low 7's. Let me know if your interested. Lance
No, the vibration was there with the original shaft so I had a whole new shaft built and balanced. No change. Ran that one about 5,000 miles or so and then took it to a different guy who computer balances them and had it re-balanced. No change.
I know this is an old thread but I wanted to give an update in case anyone else ever experiences a problem like this. If you've read all my posts then you will know what the problem was and it was driving me crazy trying to pinpoint it, not to not to mention throwing money at areas it wasn't needed. The problem turned out to be the torque converter. Yup, I never would have guessed that one either. After talking with dozens of people including transmission shops, only one guy suggested the converter. He is a transmission rebuilder, and when he mentioned the converter I told him that I could put the car in neutral at 65mph and idle the engine down but the vibration didn't change at all so I felt it had to be behind the converter. Maybe so, he said, but there are internal parts in the converter that are still moving at the speed of the rest of the transmission. I had recently swapped out the transmission for a stock rebuilt unit but I really liked my D5 converter so I kept that. No change in the vibration, so now I am thinking that while this theory may be far fetched in my mind, the converter is the only component I have not changed since this whole thing started so I swapped in the stock converter that came with the new transmission yesterday and bingo, that was it. It's gone. You can't even imagine the relief I am feeling right now. My next step is to buy a new stall converter and put the GN transmission back in the car.
It never took place, at least not yet. I haven't even seen the guy lately which suits me fine until I get a new converter. I have not doubt that I'm going to give him the education of his life when the time comes :grin:
