T-5 and TKO Failures....

[Clois Harlan]

I posted a question earlier last week and Lew added the following after he returned from his trip. I decided to start a new thread since the orig post had been out for over a week. If anyone can shed any light on this he is finally back and able to answer questions:



Howdy, Thanks Clois for starting all this discussion. YES I NEED some help.
Here is the story, Finished the Cobra in 1997, began going to events , like Run GUN & the Shelby club events on road course and yes I was real slow. The cobra I built with and running a mostly stock 5.0L 1991 Mustang GT motor and T5 tranny, drive train. never had issues til one day it stuck in 4th gear. I was told sometimes doing drags T-5s would do that, it got worse over a year and I made the plan to "UP GRADE to Tremec 3550, not the TKO. I used a Ford Motor sport vender to do the work, new bell housing, King Cobra Clutch / pressure plate and so on. This worked GREAT for 1 year and that includes lots of street miles and 7 events. That was Aug 2002. and ran good til Sept 2003. Just before an event at Road America I added some safety by removing the Hoop style rolll bar and adding a big bar to cover both sides and it goes back to ends of rear frame and a bar forward to attach to frame at foot box side of passenger. It did add more strenght to frame, At that time I noticed a small leak on Rear end pinon ger seal and so went to a shop to have it replaced and check pre-load on reaend and was tolld all is in good shape. Then a few days later there at Road America the car after 2nd day would not down shift to third. just moves easy out of 4th but like hits a wall at neutral. play a little and after a little nail bitting while hammer the brakes and it would go... it got worse real fast and did not feel like it wanted to shift right. going up in gears would go but, down shift was out of question. in the pits a guy was selling a rebuilt 3550. he actually had 3. I could take my pick and price was right. Clois and Jay Nordstrom helped pop out the old one and in with the new. naturally we looked inside the bell housing all "LOOKED" ok. went out and after a few sessions bang it would not shift and then the clutch would not go in to disengage. WE QUIT for the weekend. getting home and pulling all apart we found a spring had broken away from casting on KING COBRA clutch and fallen into pressure plate. HEY that had to be it the reason the tranny was blowing was the clutch was not fully disengaing!!! RIGHT... NOPE WRONG!! MORE to come.... The Newest tranny I paid good money to have the best shop in Milwaukee rebuild. $700. I also downloaded from TREMEC to service manual and started reading and found a source for parts at Liberty Trans Co over by Detroit. ( GOOD BUNCH OF GUYS and they also gave me several good tips to rebuild and supplied all the parts I needed and at a Good Price!) Anyway less than a month after Road America experience, I went to Run Gun in St Louis. first day went the $700 rebuilt unit so I had to think ( new clutch / pressure plate and now a Center Force all in there LOOKED good. so maybe the $700 rebuild was not so good?? put in the one I built. Poof lasted about a day same issue want down shift to 3rd from a fast speed of straight away in forth. Now you are gonna say" how fast in forth when trying to down shift. here is what I do. Flat out in 4th on a straight hitting rev limiter @ about 135MPH and 6 grand RPM... approach a turn and hammer the brake!!! for a couple seconds drops RPM to about 4 grand and MPH near 100 THEN SHIFT down to 3rd and all heal and toe and continue to hold brake till at the turn and on the GAS!. ) So, over Winter, pulled it all apart. NEW BLOCK, for motor, inspected Bell housing, took clutch and presure plate to shop to check and they say it's like new. new fly wheel AL type with new 28 ounce balance to match new crank and motor balancer. rebuilt tranny very carefully and measured all to spec per book from Tremec, another new pilot bearing, new throw out bearing and a new fork arm with all new clips and parts so it is all new!! went to MAM in June with club and shift issues started again but quit before could do much damage, also as motor is new was having a few over heat water pump issues so went home and again started to look all over again. rebuilt tranny again and made special time to review ALL possible measurements to insure all play was in tolerance per book.
Went to Tulsa and it lasted into the 3rd day this time, yes I know the first day I was not pushing it real hard as I was baby'ing the new motor and makeing sure no over heat issues were coming up and also learning the track again as it had been 2 years since driven there, truely urned up the speed on 3rd day. and boom again the down shift to 3rd started to hang up.
got home and looked again close at tranny and as I had not continued to push the bad syncros it was not to bad only 3rd gear was showing slight breakes in 3 dogs and minimal syncro damage. but replaced all new again anyway. Road america came and again after a day it went. Always the same the 3rd gear dogs crack on edges and start to break up like made of GLASS. they eat up brass pretty quick and it is over.
Ok I and really ready for help here.
anything will be appreciated.
Lew Payne