Re: 1951 Model 200 transmission issue

Posted by HH56 On 2015/12/2 23:31:37

AFAIK, 51 on cars do not have the removable panel --there is just a small round plate that could be removed to access the breather port on 51-4 Ultramatics. The large removable panels stopped with the 50 models.

Linkage is definitely something that should be checked. Make sure the bushings at the rod ends are in good condition and there is not a lot of wear and slop between the rods and various levers. Also check the end supports on the shaft holding the bellcrank assy between the frame and engine for tightness. I believe there are some rubber isolators involved so make sure all are intact.

There is a hole between the two levers at bottom end of steering column where a pin can be inserted to lock them together. Insert the pin and then check that the turnbuckles are adjusted so when the operator lever is in neutral the transmission levers are exactly at neutral too. The SM doesn't cover that very well but there is a brief description at the end of the transmission section just before the troubleshooting starts. The parts are different so details vary some but the principle and linkage operation is the same in earlier models. The adjustment procedure is covered well in several of the 41-50 service counselors that detail various sticking in gear and linkage problems.

Also check the motor mounts. If any are in bad condition so the engine could rock or move excessively under torque the rods and bellcrank assy could be pulled in such a way that if a gear is barely selected it could be pulled out. 51 on had different motor mounts than the earlier cars and can't remember if the later cars used a snubber assy. If there is a long rod like affair between the trans and frame center x member it was there to control fore and aft motion of the engine/trans assy. If present, make sure it is intact, tight, and the rubber bushings are good.

If all that checks out then would be the time to look at the transmission. One thing to check while you do the linkage is disconnect the rods from the levers on side of transmission and move the levers by hand. Make sure there is no excessive motion at the levers caused by a loose interlock block and the detent is strong at each position. A worn or loose interlock block or weak detent could allow the falling out of gear.