NSW Corvettes

Technical Tips => Transmissions - Differentials => Topic started by: Mattrix on July 20, 2009, 11:02:27 PM

Title: L82 auto transmission question
Post by: Mattrix on July 20, 2009, 11:02:27 PM

Hi all
Just wondering which auto transmission my L82 would be running? I need to sort out a new gasket for the sump but don't know how available this would be for it (and don't know what exactly to ask for). Can anyone help? :)
thanks
Matt

Title: L82 auto transmission question
Post by: gtc on July 20, 2009, 11:33:26 PM

I believe the standard auto transmission on the '78 was the Turbohydramatic 400 (THM400), which is a very well known box, used on Commodores of the period (VB, VC, etc).

According to my documentation, if it's a THM400 there should be a Build Code on it such as: 78K or 78Z and underneath that there should be a model and production sequence number such as "78CAxxxx", where xxxx is the sequence number.

PS: This thread should be under Transmissions - Differentials, not Forum News.

moved.  Admin

Title: L82 auto transmission question
Post by: 77CVT on July 21, 2009, 09:06:08 AM

Check here (http://www.nastyz28.com/chevy-transmission-identification.php)

Title: L82 auto transmission question
Post by: Chromie on July 21, 2009, 10:28:15 AM

Hi:x
Its is simple to work out what auto transmission you have
A TH/400 has the vacuum modulator valve located at the right front corner (above the auto pan)
A TH/350 has the vacuum modulator valve located at the back right rear (above the auto pan)
Early to mid (1974/75approx) ran TH/400 and the later years ran the TH/350:spook

Title: L82 auto transmission question
Post by: Mattrix on July 21, 2009, 04:27:18 PM

Brilliant work, thanks all! Heading for a blue slip on Friday (most likely), so fingers crossed I pass!

Btw, I knew it belonged in here, but in the *old* days no-one would look at a thread unless it was where I originally posted it. Good to see some moderation and organisation happening now :)

Matt

(Thread Split to Electrical Tech section)