Change trans fluid in 85 Eagle wagon

[kalve]

I got a 85 AMC Eagle wagon with 180K on it an it was sitting 8 years before I got it. I was told by some shops not to change the trans fluid an just top it off were it has high miles on it. The car does fine but when you put it in gear it jerks/lunges going into gear but is fine when driving. Should I change the fluid or just top it off? I found some places that will change it an some that wont in the area. I was wanting them to look at it an tell me if something might be wrong with it since I am going to use it for a daily driver an it sat so long with out being started an drove. What should I do?

[rollguy]

In my opinion it would not hurt to change the fluid completely, if not just for peace of mind.  It is best to get as much of the old fluid out as possible, and change the filter.  Be sure to clean the magnet that is on the pan inside. I use compressed air to blow the fluid out of the cooler as well.  I don't believe that these have a drain in the torque converter, so you may only get about 3 or 4 quarts out.  It is also a good idea to weld a drain plug in the pan while it is off, for easier changes in the future.

[captspillane]

In my opinion the Eagle torqueflite transmissions are less sensitive than others. I had a transmission begin slipping after a fluid flush, but it was a 2002 Ford Ranger with computer controlled solenoids inside it. The torqueflites were designed even decades before our Eagles came out, so they were actually built pretty tough. The Ford Rangers are known to have problems if you don't change the transmission fluid a strict 25K miles. Most other transmisssions are fine with 60K changes. To be safe I suggest every 40K or 50K miles, or every three years.  

A drain plug is a great upgrade to do. Instead of welding one on I suggest using this part. I bought it right off the shelf at Advanced Auto, so its pretty common. It has a tiny drain plug inside of a two piece housing that seals tightly around a hole you drill into the pan. No welding required.

[jim]

Are you sure it's the transmission causing the jerk?  Many of our drive trains develop slack somewhere in the system and it can cause a noticeable jerk when going into gear.  It has been referred to as the safety clunk to let you know it went into gear.

[rollguy]

A drain plug is a great upgrade to do. Instead of welding one on I suggest using this part. I bought it right off the shelf at Advanced Auto, so its pretty common. It has a tiny drain plug inside of a two piece housing that seals tightly around a hole you drill into the pan. No welding required.

I have a drain plug similar to that one on my SX4.  The problem is that it has had a slow leak ever since it was installed. The problem could be the guy that installed it (me) did it wrong, and that is why I suggested welding one on, so it will not leak.   

[captspillane]

Are you sure it's the transmission causing the jerk?  Many of our drive trains develop slack somewhere in the system and it can cause a noticeable jerk when going into gear.  It has been referred to as the safety clunk to let you know it went into gear.

I agree that its not the transmission. A worn, cold, or malfunctioned transmission will slide into gear very slowly. Clunking into gear is actually a very good sign. To maximize the life of a transmission you should actually install stiffer springs in the valve body with a "shift kit" to give it faster, firmer shifts. That minimizes heat buildup and clutch wear.

If your transmission shifts hard into first gear and shifts fine from there I am confident that your carb is set wrong. A poorly adjusted carb will not idle smoothly where it belongs and the AMC Eagle carbs are notorious for being set improperly. Also look at your throttle return plate. On another nest member's Eagle I recently found that his throttle return spring was hooked too low. By moving it further from the pivot point the spring was able to bring the plate snuggly against the stops. Before that it would get stuck just open enough to double the idle RPM. Twice the idle RPM translates loosely to twice the proper engine torque and twice the clunk when going into gear.

[84eaglelmz]

I agree with the above post. My car clunks into gear when the carb is not set right. Other then that, You do want somewhat of a clunk. When it goes in smooth (too smooth) is when you need to worry.

[mmanship]

I just bought a nice 1985 Eagle wagon.  Runs great, shifts nicely, except when I hit passing gear.   I hear an awful screeching.   What might that be?

[AMC of Houston]

Belt or fan clutch screaming when the engine gets revved up?