7040 allis chalmer

[nattynuts5886]

I have a 7040 allis chalmer and back in the fall we used it to chiesle plow and when we finished my dad went to hook the disk up when he went to back the tractor up nothing happened it didn't move. We left it go fo a day or two then started it and it went into gear as usual and we drove it to the field when we stopped it to put it into a lower gear and get everything ready for the field. when we went to put it in gear it did the same thing. It didnt want to go into gear and it didn't move once it was in gear. It neaver made any nosies indacateing that the transmission failed. It is a power shift. Any ideas what is wrong.?

 

[Harry in Ky]

When you say it didn't want to go into gear, do you mean the power shift lever wouldn't shift out of neutral, or the lever shifts as usual but no gear is engaged? Those early powershift valves had some problems with internal linkage failures and a number of improvements were made as time went on. The 7040 was one of the earlier ones and may still have some of the older style parts if it's never been apart. What you're describing could be either a shift valve or inching spool issue, both of which are incorporated in one valve body. The body is easily removed for service(unless you have the auxiliary right side fuel tank). If you wish to attempt it, I can explain what to look for in more detail.