Bracket Talk
Tranny trouble?

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July 10, 2018, 07:12 PM
joe Diry
Tranny trouble?
Hey guys,

I have made 35 runs on this combo this year and the 60’s have been very consistent within .01. Couple weeks ago the car started rocking backwards when the transbrake was engaged. We adjusted the band at the track following the proper procedures. After making that change, the 60’ has started varying .04 and reaction times are not as consistent. We swapped a different converter in the car and that did not help.

The only thing that we have touched on the car was the band adjustment. Is there something in the tranny associated with the band that could be causing this? You can see that the engine varies on how quickly it climbs when it comes off the transbrake.

It is a FTI transmission with around 150 runs.

Thoughts? Is it worth swapping our spare in and running it or should we continue to swap parts to see if we can find it elsewhere.
July 10, 2018, 07:23 PM
markemark
Although several of FTI’s members will be in Martin MI for the FTI Summer Shootout this weekend (I’d bet they’re already there) I believe the tech help line is still being manned at FTI. Have you tried calling them ??
July 10, 2018, 08:50 PM
Big Steve
What procedure did you use to adjust the band and did it cure the rocking back issue?
July 10, 2018, 09:06 PM
joe Diry
We did call FTI. They said it could be anything and didn’t offer much more information except to say it may be worthwhile to put in the spare.

We followed the following for adjusting the band:
Tighten the band adjustment screw to 72 inch lbs. Unscrew the band adjuster three and a half turns
July 10, 2018, 10:03 PM
Big Steve
Same procedure I use, did it fix the rocking issue?
July 10, 2018, 10:12 PM
wideopen231
Not sure how swapping trans will find issue with one in car. Icould see pulling one out and pulling it down. I can almost guarantee swapping in another will get rid problem,but will not fix transmission.




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July 11, 2018, 01:18 AM
rerun
Was band bad lose? If not you probably have another issue. I have found worn pump causes backing up most often.
July 11, 2018, 07:08 AM
joe Diry
Adjusting the band did resolve the car rocking on the starting line.
July 11, 2018, 07:41 AM
green1
I would be swapping trans so you know for sure that is the issue then if cured have trans gone through. Why waste time trying things when you got a spare. Heck you might find out you got a motor issue instead of trans and trans swap might show you that.
July 12, 2018, 07:27 AM
sst5167
If adjusting the band helped the rocking, but your 60's are moving around a bunch, I would be pulling that thing apart to check out the pump, band condition and even look at the drum. You may have more going on here than just a loose band. Do you have a gauge to check pump pressure?


Mike Boehner
July 12, 2018, 06:18 PM
joe Diry
We have swapped transmissions and see what happens next weekend. Thanks for the advice. If the 60’ times are consistent, we will have it torn down.
July 13, 2018, 08:13 AM
Racer8309
Who did you talk to at FTI??
July 17, 2018, 10:11 AM
FTI
Let me jump in. I am not sure who you talked to here but I would be curious to know. Proper band adjustment is critical. My crew was in Mi. Please call me at the office 1-386-736-5816. This is Greg. I will handle this. there is not a band aid to fix. I just need to know some more particulars. You can send me an email as well at greg@ftiperformance.com.

The band adjustment shoudl not affect 60 foot as the band is applied when the car leaves the starting line,unless the band is slipping. The transbrake engages the reverse clutch while the band is already applied. What makes band adjustment critical is that when the large volume of oil is needed to apply the reverse piston it will drop pressure for a split second as the regulator catches it. If the band is too loose then it will momentarily release allowing the car to rock. The reverse clutch releases when the transbrake is released. If 60 and react is affected and they follow each other then the problem would be in the reverse clutch or the converter or brakes. Maybe this helps. Again I would like to know who told you we couldnt help to put spare in!!!

Greg


FTI Performance
Competition Converters and Racing Transmissions
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