General Motors transmissions

Jump to: navigation, search
(Transmission dimensions: Add text; format table; minor clean up)
(TH400 (3L80), TH375C, TH475 (3L80HD): Add SP info)
Line 1,296: Line 1,296:
  
 
===TH400 (3L80), TH375C, TH475 (3L80HD)===
 
===TH400 (3L80), TH375C, TH475 (3L80HD)===
1987-up 3L80HD is the HD version of the TH400 found in light trucks.  It has 27 spline output shaft and is 34.5" long overall in 4x2 version. Found cast on the bell housing in medium size letters is 'HD'.  The TH400 transmission was used between 1964-1990. 1987 was the year the transmissions were renamed using the alphanumeric designations.
+
1987-up 3L80HD is the HD version of the TH400 found in light trucks.  It has a 27 spline output shaft and is 34.5" long overall in the 2WD version. 'HD' is cast into the bellhousing in medium size letters.  The TH400 transmission was used between 1964-1990. 1987 was the year GM transmissions were renamed using the alphanumeric designations.
 +
 
 +
[[File:Th400SPpan.jpg|right|260px]]
 +
===TH400 Switch Pitch===
 +
Switch Pitch (SP) transmissions were available from 1965-'67 in full size BOCad cars.
 +
 
 +
The name "switch pitch" comes from the vanes in the torque converter being able to change their angle (pitch) in order to increase the stall speed to get the vehicle moving easier. 
 +
 
 +
There are SP TH400 and SP TH300 transmissions. The SP 300 were found in 1964-'67 and were two-speed. The SP 300 converters are 12", the SP TH400 are 13".
 +
 
 +
====SP ID====
 +
The easiest way to identify the SP is by the pan shape. On the SP TH400, there are 3 concave and 1 convex dimples and a 'shoe heel' impression. The shoe heel impression is where the filter picks up fluid and the pickup is shaped just like a shoe heel (see photo below). Filter is a Wix p/n 51879.
 +
 
 +
*[http://web.archive.org/web/20070807215149/http://www.buickperformance.com/switchpitch.htm Switch Pitch info]
  
 
===TH400 model ID codes===
 
===TH400 model ID codes===

Revision as of 14:56, 17 January 2013

Personal tools
Namespaces
Variants
Actions
Navigation
Categories
Toolbox