Any body got A link to how the A4LD works, Having troubles with coming out of OD, I under Stand that 3rd to 4th And the TCC is Controlled buy the EEC but want to get more details? I tried Google but found nothing helpful?

Been driving in Drive, not Over Drive but still having a terrible vibration when I stop from high speed as the trans down shifts, ones it shifts back down vibration goes away.

This is on my daily driver, 89 mustang 2.3 I posted in the ranger forum since the ranger use the same engine trans combo. Have yet to find a mustang forum that is a tenth as good as FTE!

 

Whats your fluid level and condition? It sounds to me that at the least you need to try getting all the old fluid out. Your valve body is probably cross leaking, the vacuum modulator might be ruptured, your governor might be bad. Unfortunately a proper trans diagnosis is difficult to do through a forum. Your best bet is probably a proper diagnosis by an experienced transmission tech. I can help you find such an individual.

Good trans shops are not usually a chain, will usually be a member of ATRA, will be privately owned with the owner present at the shop. BBB reports will favor the shop, along with possible google reviews, etc.

Another sign of a good shop would be found in the response to a simple question. If you ask for a flush, if the shop says thats a good idea, or advertises system flushes, you should avoid the shop entirely. Flush machines are KNOWN to CAUSE damage to transmissions. Good transmission shops won't have one, because they know this and don't want to cause problems for their customer. If the shop answers that they don't do flushes, or that they can do something known as a dynamic fluid exchange, then you have probably found a better shop. A dynamic fluid exchange uses the transmission own internal pump to pump out the old fluid and draw in new. A dynamic fluid exchange is perfectly safe. This procedure is only down after the pan has been dropped, and the filter replaced.

While a flush will not correct any internal damage, I have seen several transmissions act better or perfectly normal after having old dirty fluid replaced with new. Its worth a shot in many cases.

I think there is a strong possibility that your torque converter has started to disintegrate, and as a result is is out of balance and it shudders when it attempts to enter lockup.