Searched extensively and no luck.... I have access to a '64 BU code ST400 short shaft trans core a friend has. Could I use the output shaft and tail housing to rebuild a '70 year 'long' shaft TH400 from an Electra into a short shaft unit??? Not sure of the spline count and dia. of the '64 output shaft. I already learned this evening the '64 unit won't be a switch pitch one, so should I snag it for the just mentioned or o No: Thanks....
The ST400 is just what Buick called the THM400. I know 64 was different than the 65 and later, but I think that just has to do with the hydraulic circuitry. The other parts should be the same. I looked in my THM400 book by Ron Sessions, and it states the output shaft for the 400 is 1.365 inches O.D., and has 32 splines. The extension housing should be the same.
the early tail housings were smaller than the 68 and up versions. they used a different yoke. you can change to a later tailhousing and use a regular yoke from a 68 and up trans if you dont have a correct 64-67 version
I couldn't use the original ST400 yoke I had for my '66 ST400 - the driveshaft shop came up with another yoke from a later model Chevy 4x4 and it fit perfect. I don't know if that answers your question of not .
Thanks guys-- So it sounds like the tail housing is different, but the shaft itself is the same if I understand correctly. If so, I don't have what I need to convert a long shaft. Should I bother to snag that 64 trans I wonder... I already have a built short shaft TH400 for my Stage 1 project (plus the numbers matching BB trans in the car I'm afraid to touch) But I was looking at having a back-up....
This BU code 64' ST400 housing will have the nailhead bellhousing pattern- wont work with your BBB. 67 or newer will have the BOP style housing. The 64 (non switch pitch) is the lesser of the desirable ST400. 65-66 will have the switch pitch, short shaft. 67 was the last year for the switch-pitch. Erik
Thanks Eric-- It actually looks like it has the BOP bell to me-- caught my attention laying around near my buddies shop. I should have mentioned, in my searching, it seems some LeSabres w/ 300 engines used this trans in '64, if I recall correctly. At any rate, I was hoping to swipe the output shaft and short tail housing from the case for converting an easy to find long shaft BOP TH400 case to a short one, but it sounds like the tailshaft on that ST400 won't work with the '70 driveshaft yoke...
The actual tailshaft is the same, but the extension housing is the "small seal" one, used up thru 67.. And there are early "twin ear" TH-400 cases out there, as the 300/340 series engines had that bellhousing pattern. Only the nailhead used the "round top" cases. All the ST-300 two speeds I have seen, from that era, have the later style BOP "twin ear" cases. I have a complete 64 TH-400 in the shop, took it apart to inspect the differences some years ago, and that whole trans has sat in a bucket since then.. no real use for it. I would look for the later model short shaft, if I were you. JW
Thanks Jim. I appreciate your input. I'll pass on that trans. Luckily I'm set with two 'short' TH400's already. I would've lain awake at night wondering if I should have hauled that trans out of the weather if you people hadn't of educated me otherwise.... I might remove the kickdown switch from the case, however.....
Hey Dan I could use a dip stick from that 64 for my 64 wildcat, the mechanic working on it broke it at the cap where it plugs in and welded it back on and it doesnt look good, depends on price. Mine still works. I have one from a 63 but its to long. PM me Thanks Gary:beer
Hi Gary-- unfortunately, the dipstick and tube are gone. I looked through the hole in the case and saw water standing in the pan (only reason I remember the tube being gone) Sorry, but if I hear of one (what years fit???) I'll let you know....
Dan, Thanks for the response. The only year to fit Mine is 64 only. The mech. that welded mine didnt know how to weld but it will work until I can find one. Gary
Your welcome. One year only part.... Some guys parted out a '64 Electra recently in Spokane, I noticed the car is gone from their place but saw this Craigslist ad which could be the same person, maybe they have your part... http://spokane.craigslist.org/pts/1671063015.html It's just for the bumper, but maybe they have more. My in-laws live in Port Ludlow, not too far from you....
