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Discussion Starter #1
Hey all,

No posts from me recently because my Acclaim has been running awesome, but I do have a question.

The transmission in my car seems to hate the cold. When I start it up in the morning on cold days (or after work if it's really cold), it is a little slow to shift up into 3rd the first time. It will stick in 2nd until 40-45mph, float at that speed in 2nd for a few seconds, shift into 3rd a little hard, and then be good the rest of the drive. When I leave work, if it was a cold day it will do the same thing, but my drive starts in the city, so I only have one opportunity to go fast enough to make it go to 3rd, otherwise it will stay in 2nd. After this first hard shift, it shifts smoothly (the lockup even works on the converter).

A few other facts: On days where all of my driving is in town, it will eventually go into 3rd at city speeds. Also, on the very coldest of days (single digit mornings), at the first stop sign, it won't go back down into first at a stop, and will try to take off in 2nd. Sometimes it will go to first when taking off, sometimes it will just sit in 2nd.

This funky behavior is only when it is cold, on mornings where it is above 35-40 degrees, the car behaves perfectly. This transmission came from a junk yard and at first I thought it was just tight from sitting, but when it got cold again this fall the weird behavior started again. I'm reasonably sure that the fluid is at the proper level because I was checking it daily until it got cold out and never saw the level drop. (Turned out to be power steering fluid. I was wondering what a persistent puddle was on my driveway and was baffled that the tranny fluid level never changed.)

Are there any ideas on what this could be? This is my 2nd winter with this transmission and this behavior, so I'm more curious than anything.
 

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I would start by having the fluid and filter changed and the bands adjusted. Who knows what fluid was used? Originally, Dexron II was called out for that transmission, but Chrysler moved to ATF+3 and then ATF+4. These days, only ATF+4 is manufactured, and it is recommended as a replacement for all vintage fluids back to about mid 1950s.
 

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A bottle of Lucas in the transmission can help to revitalize the seals. I'm usually not a believer in snake oils, but Lucas works, in my experience. It restored the seals in my p/s pump from the point where I was having to carry a bottle of fluid to maintain power steering function to not having any problem with the system for two years. I had some similar problems with my Spirit's transmission, which I assumed to be due to seals (not something I want to have to delve into at all), so I put Lucas in, and noticed a marked improvement. Yes, it is still sort of a band aid, but it's a darned good one in my opinion, the experience with the p/s pump has made me a believer. You may want to flush the transmission with fresh ATF (a regular fluid change only gets about half of the fluid out) when you do the bands and filter. Make sure you tighten down the external locknut very well; in my experience, the FSM torques are a bit low, and lead to it bouncing loose.
 

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My transission has the same problem. As mentioned, changing the fluid to AFT4 and changing the filter has done the best for me. Lucas is as thick as molasses and made my transmission shift worse in the cold weather. If the fluid change does not help, as a long shot, you might try Sea Foam. It can help soften seals and clean a dirty valve body.
 

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ATF+4 is a synthetic oil and has fantastic cold temperature performance as well as other benefits. A little more expensive, but worth it IMO.
The kickdown linkage is under the battery area and may be hanging up worse when cold. Battery acid can mist the area and start corrosion between the steel and aluminum parts.
The cable and bellcrank assembly should 'flop' fairly freely towards the idle position. The same goes for the other end of the cable where it attaches to the throttle body. There should be a return spring to assist the cable back to the idle position.
Don't grease the cable as it will probably make it drag worse and give something for grit to stick to. A foaming graphite light lube like the Mopar rust penetrant works well on the cable ends.
Finally, worn and leaking front/rear clutches in your 31TH will cause late shifts and there is really no way around a needed rebuild if this is the case.
 

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Discussion Starter #6
Thanks all. The fluid is ATF+4, it was quite low when I got it from the junk yard and I have added at least two quarts over the first few months it was installed. At first I thought it was leaking since I added so much, but the level has been good for several months now. I don't think that the kickdown is sticking, I had that problem with my old transmission (wondered why it would jump into neutral when I floored it), so I checked that right away. I will look into checking the bands like mentioned above. I just had another adventure with this car, so check my other thread.
 
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