2002 wrangler auto trans hesitates when cold.

[Dbrignac1]

I have a 2002 jeep wrangler sahara auto transmission 69.6k miles. 400 miles left on the power train warranty!!
Serviced transmission at 63k.

conditions when it happens:

Has happened only when cold.
Has never occurred in reverse. I back out my driveway on most days.
Occurs in forward only and only during that initial minute or so.
Very intermittent.
Can sometimes cause it to happen if I repeatedly go from forward to reverse.

symptoms:

I accelerate, for a split second nothing happens, then a "thump" and then Jeep moves forward. It is as though the transmission either "slipped" or did not react to the acceleration.

It also seems that just before it occurs, many times the engine idle becomes very unsable. It is as though the engine "shuddered" if you will.

Any help would be appreciated.

[Ray H]

The TF999 3 speed tranny is notorious for doing this when its low on fluid. If you check the fluid in P it will read ok but is actually almost a quart low. Most mechanics (and owners) check it in P because thats the common method. They dont bother reading the manual, which says to check it in N.
Check your fuid in N with it hot. fill it all the way to the top full mark and see if it still hesitates when you change directions.
That tranny is pretty bulletproof but does have the fluid starvation issue, especially when its low or on steep hills. The fix for this is to either slightly overfill it or buy a deep pan that holds more fluid. I bought the deep pan because it has other good points such as a drain plug and more fluid which helps cooling.

[Dbrignac1]

Ray,

Thank your for your response. I took your advice and checked the oil while hot and in N. I had to add right at 3/4 quart of oil.

It has now been two plus weeks and have had no issues. It was very infrequent, however, it I tried to make it fail, I normally could.

Since adding the oil, I have been unable to make it fail.

Thank you for sharing your knowledge.

Cordially,

DBrignac

[Ray H]

Originally Posted by Dbrignac1

Ray,

Thank your for your response. I took your advice and checked the oil while hot and in N. I had to add right at 3/4 quart of oil.

It has now been two plus weeks and have had no issues. It was very infrequent, however, it I tried to make it fail, I normally could.

Since adding the oil, I have been unable to make it fail.

Thank you for sharing your knowledge.

Cordially,

DBrignac

Im glad to help. Its good to get some feedback. Too often people just disappear and you never know if you were of any assistance.