After months of having what I thought was a really bad rear main seal leak, I discovered that it's actually my Dynaflow. I've wanted to swap in a different trans for a while, and since the Dyna has to come out anyways, I figured now was as good as any time. I'm wondering what my options are. Is there any thing that will physically bolt up and work w/o an adapter? If I remember correctly, the SP400 won't even bolt up as the '62 cranks are different than the '64-'66 cranks. If I go the route of an adapter (which I think I'm going to have to), which trans should I use? I don't want to deal with any electronically controlled stuff, so I was thinking either a TH400, a 700R4, or a 200R4? Anyone have any opinions? Any and all suggestions are welcome, I'm just looking for some car guys to bounce ideas off. Thanks guys!
Whst do you mean "use a crank bushing"? I was told something about my crank was different, and to use a ST400 I'd have to swap in a later style crank. Swapping cranks isn't something I'm planning to do so, is a ST400 still the best option? A late model OD trans is starting to be mighty tempting...
Andy, you will 1st. have to find a TH400 flexplate. A 401 or 425 is close enough in balance that it shouldn't matter. Just remember to line up the index holes as the flexplate can go on in any one of six positions. The adapter that was talked about goes into the end of the crank & also supports the TH400 converter. DO NOT open up the hole in the flexplate as this will make it weak in that area. The TH400 plate is not as thick as the DynaFlow plate. Then you have to get the correct yoke for the rear of the TH400 & get the driveshaft modified. The yoke can be kinda tough to find, especially a good one. When it comes time I can tell you what other options you have. Re-position the crossmember. Do something with the shift quadret on the column. All, basically, easy stuff, for the most part. I can get you or supply you with most anything you may need. Of course dealing with Buick's & the rarity of good items it can get to be a little costly.
Thanks Tom! I'll shoot you a PM a little later today, I have a couple questions that you can hopefully clear up. I'll also definitely contact you when I begin the whole process. And I thought ya'll would get a kick outta this. I've posted this whole thread from my Blackberry. Now I can always be on V8Buick! LOL!
Yes, the T-400 is a cool fit.... my first 62' LeSabre blew up the dyna-saur trans so many times, so I decided to fit the T-400 from a 65. DO NOT GET THE 64' YEAR!, it is a one year only trans, so the case, valvebody and more is one year only. You need a 65 or 66 year'd trans. You can easily tell by the shift detents to seperate the years. The 64' had 5 detents, with no second gear hold. IE: PRNDL, compared to the 65/66 years that have 6= PRND2L. The 65 and 66 year'd trans will bolt right in. The flexplate is another issue. my first trans swap in the was to grind the center pilot hole in the flexplate to the bigger size that the dynaflow had. And yes, the crank has 6 holes in it, but theyre is a 1/2 way drilled "pilot" hole that is not drilled all the way through the flexplate. This MUST align with the drilled dimple in the crank as these are externally balanced motors and if you miss the alignment by one bolt hole, the motor will violently vibrate. Now, after the hole was enlarged, I used a few spacers between the flexplate and converter, then bolted the trans to the engine. Back in the 80's, they didnt have crankshaft pilot hole adapters since no one to my knowledge was doing this trans swap, as everyone was telling me it couldn't be done. But since no one could tell me why, I figured that not everyone had the answers, so I made it work, easily. Now, since the trans is in and the converter is too, the crossmemebr needs to be either narrowed. (trans is longer and crossmember needs to be relocated rearwards and since the frame narrows rearward, then it needs to be narrowed) BUT, if you are smarter than the average joe, then find a bone-yard 64' full sized car with the T-400 in it, and the crossmember is already cut to size, and the driveline WILL BOLT RIGHT IN! Then whats left is the trans cooler lines, but you can easliy remedy that. The dynaflow uses 3/8" lines and the t-400 uses 5/16". Pull the lines and rebend some new 5/16"ones. Now the only thing left is the E-brake mechanism.... you'll either have to eliminate it or re-adjust where it needs to function. The T-400 yoke will hit the ebrake cable. If you want a posi for your 62, let me know... I found a trick on that too for a 61/61 fullsize. BTW, I have 3 of the original 64-66 flexplates, 3 T-400 trans and 1 T-400 switch pitch. I am currently restoring a 62 Wildcat, and it will get the 700r4, dual quads, and currently it has a 3:42 posi I installed from 26 years of knowledge.. good luck.. steve AKA MR62BUICK
I have a different point of view. :Smarty: My God, Man, save the Dynaflow!:eek2: I love my dynaflow. There is nothing like a dynaflow:bglasses: (well, til the Nissan/Infinity CVT, and it's not really one speed) except a Bobcat or a Zamboni! My 'Cat has so much torque it's awesome, and it goes right up to way over 90MPH and never strains.:Brow: Have some respect!:rant: PS I know you have a restomod, so the above comments may not really apply to you.:TU: Good luck with your project!:beers2:
If your talking about a GV w/a Dynaflow it isn't going to happen. Each unit is specifically made for each trans, and I don't see them coming out with one for the Dynaflow, ever really. If your talking for the T-400 then ya, they make them for it. But, at that point it would almost be worth it, for me at least, to just swap in a later model OD trans. Mr. Steve, you sir, have a PM! I've debated about keeping the Dynaflow, but I'm a muscle car hot rodder at heart. I need something that I can through a higher stall converter in, and be able to shift, and have fun with. If this was going to be just a stock cruiser, then I would keep the Dynaflow. But it isn't, so I'm not.
Its a personal message..... Andy, just follow what Tom T says and personally I would not stop untill I had a switch pitch th 400 in it with b&m internals in it.... That is the set up that I have in the 65 lark that I am building up.... the b&m kit has the good metallic clutch plates and steels for the clutch pacs and a good sprage in it... The first one that i did , I machined the center hole out to take the larger flange on the 59 401 engine.... and I raced it till the world looked level and it never did tear up.... but like Tom says that weakens the flex plate from what it was and if there is a better route to go then go that way... Tom knows what he is doing.... [ he is a Yankee and talks funny but he still knows what he is doing...:bla: ] The switch pitch is the best set up if you are looking to get raw power to the ground and it be reliable day after day... set up right it actually gives you 6 forward speeds and 2 reverses.... combined with a performance diff gear it is strong performing and durable...
what has to be done to put a dynaflow behind a 64 and later nailhead? i have searched the old post and only see how to swap the other way around. i plan on replacing my motor in my 63 with a 65.
im buying a complete rebuild . i have a 400 trans just didnt want to do all the conversion but looks like it will be easy compared to swaping the cranks. was hoping to keep my dynaflow.
I did the swap to a 65 SPTH400 on my 63 Wildcat. Not that hard of a job. You just need some parts like the yoke for the tranny, tranny crossmember from a 64 car. crank adaptor from Russ on the Nailhead site, he will explain how to use his adaptor. You will need a different starter, flex plate all from 64-66 Nailhead cars. Lokar makes a nice column shift kit. You won't believe how much power gain there is. If you go ahead with this you can ask for help on this sight and the nailhead site. Pat
Who here has done the 700swap? I am looking for what is necessary (probably gonna need a flexplate) etc. After doing some hunting. I'm not sure the 200 will hold the torque. Mike
