I just got my '57 T-Bird back after having the trans rebuilt by a very reliable shop here in Ventura, CA..
The trans had 'reputedly' been rebuilt about 15K ago.. !985... We have owned the car since October 1973..
I reason for the rebuild... I got tired of the trans leaking oil on the garage floor and it started draining fluid into the pan which raised the fluid level causing it to 'burp' oil onto the exhaust manifold, which caused smoke like the car was on fire... Probably not to far from same..
When I took the car to the trans shop they called me with a long list of repairs that the trans needed... Every gasket/seal was leaking, the valve body was bad and very possibly the converter needed rebuilding... The oil was leaking down from the converter via the valve body..
The shocker was when I was told that the engine would have to be removed to get the trans out... I objected.. I went down to the trans shop to investigate.
I was informed by the shop owner that the only way the trans can be properly removed from a '55-57 T-Bird is to remove the engine. In some cases people have taken short cuts, cutting the welds on the trans mount cross-member.. However, even this does not allow enough room to properly remove the trans.
I told the owner of the trans shop that I knew the trans had been out of the car twice since we have owned the car and that in neither case was the engine removed.. The car was put back on the lift and the trans mount inspected.. It still had the original welds..
OK.. So now what do we have? Obviously the trans had really never been rebuilt, it had been 'repaired' while it was still in the chassis.. I showed the shop owner my entries in the vehicle log book, where-in the trans had been worked on in 1981 and 1985, both times by very reliable local transmission shops... Both of which have been out of business for many years..
Upon getting the trans out and on the bench it was found that many items were wrong with the trans.. clutches were burnt, bearings/bushings bad, the converter was worn out, as was the valve body.
The choices to me were... Repair the trans as had been done before, then in a few years have a leaking transmission... Or properly rebuild the unit. Since we have no intention of selling the car, and if I should decide to do so I will want top dollar for it, I decided to have the trans completely rebuilt with new parts.
While the engine was out several issues were discovered, motor mounts, ignition wires, a cracked exhaust manifold, leaking valve cover and pan gasket.. All of the engine issues were taken care of..
We now have a car that is again drivable to anyplace that we might want to go...