# Replacing 1977 Pontiac Bonneville's transmission **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** pontiac, bonneville\ **Created:** [May 15, 2019, 9:46pm UTC](https://community.cartalk.com/t/replacing-1977-pontiac-bonnevilles-transmission/140413 "2019-05-15T21:46:29Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![MikeJ](https://avatars.discourse-cdn.com/v4/letter/m/a9a28c/32.png) [@MikeJ](https://community.cartalk.com/u/MikeJ)\ **Post date:** [May 15, 2019, 9:46pm UTC](https://community.cartalk.com/t/replacing-1977-pontiac-bonnevilles-transmission/140413/1 "2019-05-15T21:46:29Z")
I have a 1977 Pontiac Bonneville with the Metric 200 transmission. It is failing. I want to replace it with a THM 350. Is this a direct swap with the proper length shaft? What should a rebuilt cost? ---
**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\ **Post date:** [May 15, 2019, 11:29pm UTC](https://community.cartalk.com/t/replacing-1977-pontiac-bonnevilles-transmission/140413/2 "2019-05-15T23:29:01Z")
A 350 and the 200 are the same size externally. You can buy a 350 trans from performance parts suppliers for $1800 or so. You will need a new torque converter - another $200 or so. I read that the 200 uses a throttle kickdown linkage where the 350 did not. The 350 may need a vacuum line connection to the engine for that function, not sure. ---
**Author:** ![MikeJ](https://avatars.discourse-cdn.com/v4/letter/m/a9a28c/32.png) [@MikeJ](https://community.cartalk.com/u/MikeJ)\ **Post date:** [May 16, 2019, 12:23am UTC](https://community.cartalk.com/t/replacing-1977-pontiac-bonnevilles-transmission/140413/3 "2019-05-16T00:23:39Z")
Thanks for the info. Not sure the car is even worth that much. It runs ok when it has enough fluid, but it leaks like crazy.