Put on your thinking caps - Lew needs some help!
 

Lew Payne a good friend of mine has been blowing his 3rd gear syncro at every race since last September at Road America.

At every race since that time (Run and Gun, Omaha, Tulsa, etc.) and again this year at Road America after his first session he cannot shift into 3rd. Lew replaced his T-5 at last years R/A with a Tremic 3550. It also lasted less than 20 miles before 3rd gear failure. Lew has become very good at rebuilding his Tremic and in fact we even told him to have someone else re-build his trany.

The only changes he made after Tulsa last year (where he had no problems) and last years R/A was he installed a full (double) roll bar in lieu of his single roll bar on his Classic's Cobra. Other problems he had at Road America last year were: 1. he broke his rear upper adjustable controll arm on his rear end. Lew had his upper controll arm re-welded and then he eventually replaced it with a fixed length upper controll arm before this years R/A race. Lew has replaced his tranny mounts as well as his rear coil overs. He has checked and varified his pinion angle and driveshaft length. The problem persists. We need someone elses Ideas on this one.

All help would be appreciated.


Clois Harlan

My question would be "Why always third gear?" Something causing interference when shifting? linkage? Shifter/linkage clearance in the trans tunnel? Over revving on downshift to third?

Has the bell housing been indexed? Clutch inspected real good?

Curt that was my first thought as well but that wouldn't explain why it's always third gear.

Most of the tracks we go to we go into the corners in third gear, usually from a down shift. I do the same thing with my toploader. I know that the transmission is capable of handling this torque because several of the others are running a similar set-up.

I failed to mention he has a 347 stroker engine. I believe he has indexed the bellhousing because I remember discussing this with him after a previous failure. He bought the transmission from another racer at Road America last year and I believe the trany was new and came with the bell housing. The first three or four times he broke we blamed his inability to re-build the trany on the breakage.

Keep the ideas coming. Jay Nordstrom has suggested that when he had the wide roll bar installed the welder got the frame tweaked and the engine-trans are out of alignment causing stress on the whatever gear he is in when cornering at speed.

By the way the roll bar in Lews Cobra has a forward brace going to the floorbox area that has been welded in (similar to the FIA racers). This is in addition to the wide roll bar that has been welded to his rear frame rails.

Clois,

That is a rather weird problem, but the fact it started after he had the roll bar installed would tend to make me think that the installation of the roll bar may be the cause. As for the welding tweaking the frame, that would be one possibility. Are there any places that he would go down to 2nd gear to run? If so, then an alignment problem should cause 2nd to start failing if he uses it a lot. We have some corners here that are about 25 MPH corners and most use 2nd on them. Not much helpI know, but with no trouble before the roll bar installation, it sure would seem as if that has to be the root cause of the problems in someway.

Ron :confused:

Was the trans tunnel and shifter removed for the install of the forward brace? That is why I was thinking a shifter/linkage interference issue might be it.

I don't know if it was or not but I am inclined to think that it wasn't because he had waited until the last minute to get the new roll bar installed. If I remember correctly Lew picked his car up from the welder at the beginning of the week and had it at Road America the following Thursday.

Most of the tracks we have been to since his install (Road America, Omaha, Tulsa, St. Louis' Gateway and Nashville) are what I consider high speed tracks ie: that most of the dives into corners are made coming out of 4th gear and into 3rd. Only two tracks (Tulsa' Hallett and St. Louis Gateway) have corners requiring shifting ino 2nd gear.

Since I posted this message I have been told that the jig used to layout the frame on Lews car was a series of chalk marks on the concrete at that time. Lews Cobra was built in the early 90's.


Clois

How was the frame grounded during welding? Any chance that the ground went through the transmission? Probably not the case, but stranger things have happened. What oil is he running? Is he using 80W-90 instead of the ATF that is required in the Tremec?

I just called Lew to see if he was following this link and I found out he was in Las Vegas on vacation. I guess he is not going to worry about his trany until he gets back.

At least thanks to everyone here he will have some ideas to start his search.

Clois

CR frame, right? Was the rollbar welded anywhere near the upper mounts for the rear arms? Maybe the frame is still straight but the mount(s) is(are) twisted. (Wild a$$ guess.)

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

Did you check the alignment of the bellhousing / scattershield?

What do you have for a transmission mount?

howdy,
yep checked it and it is a new Ford Motorsport bellhousing they sell to match the 3550 Tremec, same thing in later model Cobra Mustangs like 95 model, anyway I have changed the motor so got new pins to line up bell housing with it.