I'm looking for a '68 or later TH400 valve body, including governor, and oil pan for my TH400. I can pay cash or I have a '67 TH400 I could trade whole or just the SP parts (minus converter). Anybody? o No:
Th400 I have a complete TH400 with converter in Parts for Sale from a 70 Riviera. It was attached to the engine that I wanted. I listed it for $150??? I am in Minneapolis, Minnesota... but I have a trucker friend that drives to Jersey every week. Let me know.
Nailhead I have a valve body that I took out when I went with a tran brake manual body.Also a gov.probably a pan too,I'll check tomorrow,and I'm only 2 hr 45 min from buff. gary
Th400 Joe I have the valve body from a th400,governor,and a gm pan thats deeper than stock,if you want I can switch it for a stock depth pan.PM me if still interested. gary
Joe, Can I ask why? I just installed a 67 TH400 and am wondering if I don't know something about it that I should....
I have found a valve body (thanks Jim :beer ) and thanks everyone for the replies. Adam, There's really no particular problem......I am just trying to get my 1-2 shift point higher to match my mild cam and stiffer springs......and the '67 VB doesn't allow part throttle downshifts. I have heard the '65-'67 VB doesn't cooperate well with shift point changes. I'd like to raise it to shift automatically at 4800-5000 RPM if I can. :3gears:
That makes me feel a little better about my V-B. This may add more confusion instead of helping you, but I have had no problem raising the shift point all the way to 6300 RPM with my 67 trans just by lightening the governor weights. The only other mod was the expensive trans-go shift kit.
What exactly did you do to your weights to get that? And how is your 2-3 shift? I heard that is the one that is so stubborn to get higher. Also, mine has always since day 1 had a tendency to short shift frim 1-2 under light throttle no matter how I set the vac modulator. I tried a stiffer gov spring and that helped a little, but it still does it when the tranny is hot and it is SO annoying. I usually drive civilized but I hate being in second gear before I hit 10 MPH :spank: Also, I'm wondering how part throttle downshifts will act with Dual Quads..........I may just end up wanting to switch back ou:
If you have the Steven Dove book it shows a diagram with how to trim the governor weights, but that only applies to full-throttle shifts. You have to have the kick-down wire hooked up and working too, for the full throttle kick-down to work right. Hm, sounds like something funny is going on with your governor pressure. I'll go through step by step. Please don't be insulted if you've already covered what I ask as I'm not sure what you've tried so far. I would unplug the modulator entirely and see what your shift points do. It should only upshift at high engine speeds without the modulator. If you still have very low part throttle upshifts at this point I would think you have a stuck modulator valve or the valve body is leaking at the gasket or something similar. Unplug the modulator and drive it. Tell me what happens and we can go from there.
The Trans-go shift modifier kit may be a good reason why the shifting characterisitics were changed. Changing the governor weights also raises the shift points. Changing springs that come in the T-G kit may help. However, on the base valve body, changing the governor weights alone won't correct the problem that many 65-67 SP valve bodies have. Larry alone tried many combinations that did not work. When he got the 1-2 correct, 2-3 was either too early or too late. There are also many different valve body combinations for the SP trans. Models BA, BS, BT, BU and BW have different calibrations. The Sportwagon model BW is the only one to my knowledge that has a 3-2 valve. I am working on getting some pics of the different valves and how they affect the shift points. Some of this was covered at the BPG meet in Salem at the tech session. Am pretty sure that Allan W included this on the DVD. The short shifting of 1-2 is caused by a smaller land on the early shift valves that modulator and detent oil reacts upon. The smaller land on the valve is a major reason why some models of trans will not kickdown into first unless vehicle speed is less than 20 mph (depending on gearing). The 67 and earlier SP trans' that I have had apart have the smaller valves. The 3-2 valve is used to allow some part throttle kickdown to 2nd when vacuum drops below a given point. Models without this valve have smaller lands on the 2-3 valve so that there is no reaction to modulator pressure and the trans stays in 3rd. This allows the throttle to go into the point of activating the SP converter, raising rpm by high stall instead of kickdown. I can go into this more, but I think this covers most of it. When the SP was no longer made, 68+ trans' were now set to part throttle to 2nd by just accelerating as normal. The vacuum drop would shift the trans to 2nd. As to a part throttle kickdown with dual carbs, I think it would be a much better thing to have. Right now, with no kickdown, the 2nd carb would likely open before the trans goes into high stall. This may not be an acceleration problem, but more a fuel usage one. With a part throttle kickdown, you will get a boost in power without even the secondaries of carb #1 opening as the vacuum drop will shift the trans to 2nd. You can ask Tom Kelly (kiloton) his take on the SP trans with later VB I did for him last year. His 66 GS has the dual carb setup and SP TH400 conversion. Many other modifications may work just as well, but this is just may take on this subject. Mark
Adam, my kickdown is working, and my shift points are definitely higher with the switch plugged in. That's very re-assuring! And yes, no 1-2 downshifts above 20 MPH really sucks.......I can't wait to get this thing straightened out. :Brow: With all the torque from the motor I can see the engineers logic in wanting it to stay in gear up until full throttle.......you really don't need it, but it sucks when you want to get up and go but have to floor it to get there, sometimes you just don't want to go that fast. ou:
Thanks Mark! I had to read it 3-times, but I think it finally sunk in. Mark, If I'm mixed up anywhere, I defer to your thoughts as it sounds like you know lots more than me about the TH400. I can see what Mark is saying now about the PT downshift and it does make sense why it would be better. However, your early upshift still must have to do with a leak or stuck modulator. with the kickdown hooked up, and the vacuum line to the modulator blocked/unhooked, does it still have early upshift? At least that should give you an idea if when you get the VB changed it is likely to cure the stuck valve or leak that might be there. Gee, I suppose I might change my VB before fluid goes back in my trans, although the no pt downshift might help or make no difference in a mostly race application. I'll ahve to give that some thought....
Thanks Gary! :TU: Sounds like a plan.......I can't wait to read that :Brow: Adam, it's not that my 1-2 shifts are always early......that's what's so wierd......it only short shifts if I don't come to a complete stop or if I'm too light on the gas. The full throttle 1-2 shift is right about where it should be for a stock motor I guess, I just want to bump it up to take full advantage of my cam and spring combo. The dual carbs also add a lot to the top end, and there's more there above 5000 RPM than there is above 4500. :3gears:
Adam, Am going to try to dig up some 1-2 shift valves and get pics tomorrow. The 2-1 kickdown was a puzzler for years and I had to take may trans' apart to finally determine what was happening. The short shifting Joe refers to has to do with starting from a dead stop. Most of the early TH400's would be in 2nd by 20 mph (again, depends on the gearing) and no matter how hard you were on the throttle (kickdown switch not engaged) would shift by then. Once in 2nd, they would not go back to 1st unless the kickdown switch was engaged. Even then, it would have to be less than 20 mph to go back to 1st. If the kickdown was engaged from the start, it would shift out of kickdown at around 4400-4800 rpm. I had a 67 LeSabre trans (BU model) that did just that. With 2.78 gears in a 64 Skylark it went into 2nd by 20 mph and would not go back to 1st unless floored. Once in third, no part throttle as well. Only back to 2nd when floored. I still have that trans today in a 67 GS400, but with a VB from a 69 Olds 98 and it works nicely with part throttle downshifts and shifts both gears flat out at around 4800 rpm. Starting with the 70 GS models, Buick completely changed the 1-2 shift valves to what I call a single stage setup. This valve has modulator oil reacting directly on the shift valve which gives a wide range of 1-2 upshift points. If you get to drive a 70 GS455 or Stage 1 with the original BA or BB trans, you will see how flexible the shift points are. The deeper you are into the throttle, the later the 1-2 shift happens. All this while not in kickdown. A 3.42 equipped GS455 or Stage 1 will go back down to first between 40-45 mph. :eek2: At Salem, Dennis Manner told me that he had the Stage 1 BB trans designed this way, much to the dismay of the Hydramatic division. In stock form, the early SP trans' were very good. I am not saying they aren't. Just that they were meant more as drivers at the time and not expected to perform as we want them to today. Updating the trans to a later design VB will only enhance the performance and enjoyment of our cars. Mark
Mark, the guy who is getting a valve body for me asked me what year i prefer......I told him '68 -'70.......should I have told him '70 or later instead? ou:
Sheesh, just when a guy thinks he knows something..... ironically, my 67 trans is a BU. So Mark, do any of the other post-70 trans besides the BA, and BB have the part-throttle shift-valve? Maybe I'll be able to tell myself with your pics? I have a 70 BA but hate to rob the valve-body off it for my already rebuilt BU. Well Joe, I'm glad all that stuff I added at least got you the info that you probably need a 70-up valve body
Ok, here is a not so good pic. The valve on the left is a 1-2 valve from a 70 GTO trans model PQ I think. The one on the right is from a 68+ Pontiac or Buick. The important ends are facing each other at the tops of the valves that kickdown oil reacts against. Notice how much larger the GTO valve is. That valve will have a higher kickdown to 1st than the other. The right valve is a very good one anyway. I know I have an SP valve in a box of parts I brough to Salem. Have to get in my garage tomorrow. It is MUCH smaller at the tip than the right valve. A 67 GS400 BA valve is very close to the right valve as well. Not as big as the 70 GTO one, but will work nicely. Sorry Adam, but the 67 BU valve is a small one. Once Joe gets his VB out of the Riv, he can check the size of what is in there. My guess is that it is pretty small. The 70 BA valve body is a great one to have. Am fairly sure that all 68 on up have the 3-2 valve. On those VB's, the 1-2 valve should be checked for size. I can get measurements tomorrow and will check to see what I have around that is usable. Joe, try to see if you can find out what model trans the VB you are getting is from. Am pretty sure you will be ok with whatever you get. Mark PS. forgot to add that ONLY the 70 BA and BB have the single stage 1-2 valve. BT and BC did not use it. In 71 only BA/BS BB and BT (Riviera GS) had it. It was only a GS Valve used in A and E body cars for Buick. Some other divisions used it, but only on some models.
