Taro Ohno is rebuilding a 250 GTE 3761 in Japan, and is in the process of going through his transmission. He sent in these great pictures along with descriptions. There are some special tools that are needed for this rebuild, but anybody with expereience rebuilding a manual transmission should be able to do this job.

Fig-1: Removed the top cover on the main box. Three rods, speed
control forks and 1~4th pinions appeared.

Fig-2: Removed the speed control rods and forks. Synchronizing
mechanisms are came in view.

Fig-3: Input shaft and 4th gear pinion are not able to disassemble. And
4th gear pinion and 4th sliding gear are fixed tightly (close fit). It is
impossible to lift out the main shaft assembly without using the special
extractor.

Fig-4: Using the special extractor (inserts the output shaft between the
blades of extractor and tightens the rock nut) removed the shaft
completely from the main gearbox.

Fig-5: This is a pink metal bush of the 1st gear idle pinion of the output
shaft. The working surface showed signs of wear, crack and
overheating. The play between the idle pinion exceeded the maximum.

Fig-6: 1~3rd idle pinions, input shaft and 4th pinion, 1~3rd pink metal
bushes and synchronizing rings. Overheating signs are appearing on the
inner surface of pinions and surface of bushes. Seizure zone was
showed on the conical surface of each synchronizing ring

Fig-7: Crack, wear and overheating were showed on the idle pinion
shim.

Fig-8: Cavity of sliding sleeve and the speed control fork were worn.
The play between the cavity and fork exceeded the maximum
(maximum is 0.2mm on the both sides of it).

We look forward to more pictures from Taro! It's not everyday we get to see the inside of a 250 transmission.

Although I may be skippin ahead on Taro's rebuild, I wanted to make a point since he has such good photos to illustrate this issue.

Through the magic of Photoshop, I wanted to show why you need to make a special plate for adjustments after the transmission is assembled. The arrows point to where each shift rod enters into the trans case to the shifter section. On the left side of the picture, you can see three holes where springs drop in to index with the dimples in the shift rods. When making adjustments, these springs need to be compressed, but the transmission cover plate that normally presses against these springs would make adjustment impossible. A narrow metal plate needs to be made to that presses these three springs down, and is held in place by the two studs on either side of the holes.

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