Here is my update on the Allison AT 1545 torque converter. I received the one from the man I bought the truck from and had agreed to pay freight. The torque converter alone is 65# so UPS is about $50. I was glad to have it, knowing that a clutch pack problem would be very unlikely to have got past the filter, into the pump and valve body...which then goes to the torque converter.
The truck only had 10k miles so the OE tranny, received in a box, did not have much gear or bearing wear. The oil pump looked brand new. But wow, the fourth aluminum piston had melted into the frictions and steels leaving a huge amount of contamination of small particles. Since the tranny was apart, while the parts had a gritty feel, they did not appear to have been ran with that friction material in the fluid.
I was pleasantly surprised that the tranny in the box had so little wear and when I received the torque converter, it had noticeable wear on the input hub and pink fluid...so had had water in it. It obviously didn't match the condition of the rest of the tranny. It looked like it had come from a lot higher mile machine.
The owner did not say, but I deduced that when he changed the tranny, he used the original from the truck and not the one from the replacement tranny. He set the replacement one aside, seeing the shaft wear, which was the one I received. Later he said that he may have made that switch, but it was unexpected to me. That means I have the newer torque converter in the truck with the (much more) used tranny. But it's clean and painted, so had good appearance when he bought it.
I set about to have the old TC rebuilt, so I would have a rebuilt tranny with a proper, rebuilt torque converter, not one that had the contaminants and had almost 020" of shaft wear. I think that the malfunctioning tranny he put in has the OE torque converter and that it is undamaged, but since it has the same symptoms (four and rev), I'm not wanting to count on it being un-contaminated. It would be foolish to put a fresh rebuilt tranny behind a contaminated TC.
My quest for rebuilding took me to a shop that was going to open it up, about 45 miles from me. When the guy with 30 years experience looked at the hub, he cringed. He knew that the input hub was different than all other converters, due to the locking feature. He went to the Allison parts books and then the rebuilder books and that particular input hub had not been made for years.
Without it, the TC is toast. Allison made these trannys ONLY for the military A3 and the torque converters have no parts available. You can get all the components needed to rebuild the tranny by using the non-locking 545 parts, with the exception of 2 seals (are available).... but the torque converter is not available and parts don't exist ready-made to repair it. I though about a sleeve and in general had a bad day.
Rustystud suggested a CA shop and I found out they were bought out by Transtar. That shop recommended a sister facility, also a rebuilder called Dacco Inc in Cookeville, Tennesee. I contacted them and a salesperson knew my predicament and had done an upgrade. I found that the input hub was not a problem for them, they would make a billet hub and that the inherent weakness in the locking clutch mechanism could be replaced with a three clutch lock up. In essence, the rise of trucks racing has given the torque converter fabricator/rebuilder the ability to rebuild them better than new. But at what price?
I expected a quote that rivaled the cost of rebuilding the entire tranny, maybe more. I was extremely surprised and very grateful for the quote they gave me for the upgrade. Wow in fact. I wouldn't want them to be locked into a price by saying what they did mine for (PM me), but I'm extremely grateful.
There may be other shops that can rebuild them but Dacco did not take advantage of the rarity of this vital part and I highly recommend them.
While the rarity of these A3 transmissions can make them difficult and are ripe for high prices, the transmission mechanical parts are readily available (same as the 545), and the locking torque convert can be rebuilt, made better at an extremely reasonable cost by Dacco.
Now the fun of putting the rebuilt tranny into the truck...after I see if my tranny mount PTO (which I still believe to be the same as the 939 series truck PTO) has room (lots tighter than a 939). FYI There are 55 teeth on the 1545 PTO gear and 64 on the one in the 939, so will go 55/64 ths as fast. It looks like a floor mod is necessary to fit a tranny PTO... but where do I put the pump?
