Auto Trans

[John L.]

I'm in the process of rebuildig my 68's tubo 400 trans. The trans guy told me I should replace the modulator however the replacement modulator would be smaller. Does anyone know of a source for either a new larger style modulator or knows someone who rebuilds modulators?

Thanks for the help....................

John

[Jim T.]

Re: Auto Trans

Is the modulator on your 400 bad, like in leaking or was this just a general statement by the mechanic that it should be replaced since he is rebuilding it? My modulator on my 70 400 is original and not leaking and does the job. Course it could go out today, but I am not going to change it out until it does. Did you check GM to see if they still carry the 400's modulator?

[Jim T.]

Re: Auto Trans

Is the modulator on your 400 bad, like in leaking or was this just a general statement by the mechanic that it should be replaced since he is rebuilding it? My modulator on my 70 400 is original and not leaking and does the job. Course it could go out today, but I am not going to change it out until it does. Did you check GM to see if they still carry the 400's modulator?

[Joe L.]

Re: Auto Trans

Jim and John------

The modulator valve for 68-77 Corvette THM-400 applications is GM-discontinued. I presume that the "smaller" unit which your transmission man is referring to is an aftermarket-type unit.

[Joe L.]

Re: Auto Trans

Jim and John------

The modulator valve for 68-77 Corvette THM-400 applications is GM-discontinued. I presume that the "smaller" unit which your transmission man is referring to is an aftermarket-type unit.

[John L.]

Re: Auto Trans

Thanks Joe,

My modulator is still working however the trans guy mentioned that it could go any time. I was looking for a lead on a new OEM looking modulator so I wouldn't have to make repairs on the car for awhile.

John............

[John L.]

Re: Auto Trans

Thanks Joe,

My modulator is still working however the trans guy mentioned that it could go any time. I was looking for a lead on a new OEM looking modulator so I wouldn't have to make repairs on the car for awhile.

John............

[Jim T.]

Re: Auto Trans

Your car will still go if the modulator fails, I say this because once mine got disconnected,thats another story, anyway it will move but won't shift, this was over 30 years ago, but this is what I remember. I am still using mine and like your mechanic it could go any day but I am not worried, especially since Joe says GM doesn't have one for it, I will just have to try any auto parts store. It is so easy to change out, one bolt and remove.

[Jim T.]

Re: Auto Trans

Your car will still go if the modulator fails, I say this because once mine got disconnected,thats another story, anyway it will move but won't shift, this was over 30 years ago, but this is what I remember. I am still using mine and like your mechanic it could go any day but I am not worried, especially since Joe says GM doesn't have one for it, I will just have to try any auto parts store. It is so easy to change out, one bolt and remove.