Tranny problems?

[seadog]

I have 78 cherokee chief with stock TH400.I am sure it has a great deal of miles on it but it still shifts firm.My problem is that when accelerating hard the tranny jumps back and forth from 2nd to 3rd.Could this be as simple as a vacum line?

[rangerkh]

It's probly just the kick down if its under hard acceleration. Maybe someone else has a better idea.

[ March 12, 2003, 08:30 PM: Message edited by: rangerkh ]

[steven79]

check the vac mod on the passinger side of the trans, the rubber line could be too soft and the main kick down is a electric solinoid in the trans and they work together,

[seadog]

Thanks I will try that.

[J10Truken]

Probably a worn out vacuum line to the modulator. Under high vacuum they will collapse and then reopen when the vacuum falls. Just my best guess though.

[gsmikie]

check the vac line to the modulator / change the modulator if a new line did not fix the problem if it still acts up remove the govoner and check the gear and make sure the center shaft moves freeley and is not gummed up clean it with lacquer thinner