Transmission problems shifting

[Dutch4]

Hi all, I have a 71 4x4 burb with the th400. It leaked badly from the shift selector shaft and had a none drain bolt pan. I emptied it and replaced the pan. I removed the selector shaft and replaced the seal and reinstalled the shaft. Put the internal linkage back together and put fluid back. I ran it after I put 3 quarts in thinking it still had a bit in it since I didn’t drain the converter but it took about another gallon. I am sure I put the external linkage together correctly too. Now when I start it. It goes forward where reverse is supposed to be. Any ideas? Did I blow reverse by letting it idle while so low on fluids? I shifted it through the gears while the pan was off and all seemed normal. Thank you for your help. Oh and by the way, the owner said he had the trans rebuilt

[RustyPile]

If the shift pattern has changed, it's obvious you assembled something wrong or misaligned.. Go back over your work before condemning the transmission.

As an afterthought.. With the proper tools, the seal can be replaced without removing the shaft.

https://www.bing.com/search?qs=SSA&p...ANAB01&PC=LCTS

[AussieinNC]

Put the truck up so you can get under it, with the rear wheels free to turn
Remove the shift rod lever from the selector shaft outer end.
Place the shift lever on the column in Park.

Grab the selector shaft in the trans and move it into the Park position, by turning the shaft clockwise as far as possible.
Assuming the truck is in the air with its wheels free to turn, make sure the trans is now in Park by trying to turn the drive shaft.

If the driveshaft still turns, there is an assembly issue with the shaft and internal comb / valve body selector valve. Most common error is to put the comb on backwards, which can make the selection pattern off.

If the trans is fully in Park, check the rear trans mount to see if it has collapsed (very common). Replace it if its failed. Check the engine mounts also.


After trans mount is confirmed as ok or replaced, adjust the shift rod between the bottom of the column and the shift lever so its a free fit.

Try the trans function again....

Let me know what your results are.