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DRR Trophy
Picture of Bigdrive88
posted
Having a issue in my dragster where I am getting a flare on the shift Approx 300 rpm. The weird thing is that it doesn't do it on the 1st run of the day, but every run after that is shows up on the data logger. Every time I take the car out it is the same scenario. I have checked the shifter adjustment it seems perfect. Seems like when the fluid gets up to temp it will do it. Any ideas. It has a cast valve body in it. I am contemplating a aluminum VB. I ran one in my old car. Thinking about changing this one over on the new car.
 
Posts: 185 | Location: Hagerstown | Registered: September 01, 2014Reply With QuoteReport This Post
DRR Trophy
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I would try resetting the band first.If its ok cold but not fully up to temp sounds like band slipping


The difference between ignorance and stupidity. Ignorance is lack of knowledge. Stupidity is the inability to learn. Don't be stupid
 
Posts: 419 | Location: des moines iowa | Registered: January 10, 2020Reply With QuoteReport This Post
DRR S/Pro
Picture of Big Steve
posted Hide Post
Shift flares can be tricky
Its a timing thing between the band releasing and the high clutch applying. Band release and clutch apply is fed from the same hydraulic circuit coming from the VB. It tees off once it gets to the pump casting. Flare normally occurs when the band is fully released before the hi clutch is fully applied.
Unless you have low line pressure a valve body swap will not help.
Are you logging trans pressure? If so what is it?
For sure check your band adjustment, easy to do and its free and should be part of any normal maintenance program. Personally I like 72 inch lbs and out 3 turns but 3-4 turns should be fine. Count how many turns it takes to get to 72 inch lbs that way you know where it was at before you adjust it.
Could have a bent band adjuster pin, I have been there done that

Do you know what the clutch pack clearance is? Too much clearance can cause a flare due to more area behind the piston to fill

This message has been edited. Last edited by: Big Steve,
 
Posts: 2448 | Location: Moving back to the door side | Registered: April 30, 2010Reply With QuoteReport This Post
DRR Sportsman
posted Hide Post
quote:
Originally posted by vetman:
I would try resetting the band first.If its ok cold but not fully up to temp sounds like band slipping


The band is low gear
 
Posts: 123 | Location: Over here | Registered: November 28, 2007Reply With QuoteReport This Post
DRR Sportsman
posted Hide Post
There is a small check ball in the high gear drum. If that ball isn't sealing well ive seen it cause flairing.


Denis LeBlanc

 
Posts: 475 | Location: Manchester, NH | Registered: February 03, 2006Reply With QuoteReport This Post
DRR Sportsman
Picture of TD3550
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Like Steve stated Band first. Critical It should be a maintenance check several times during the season. The check ball issue will cause issues also Perform the pressures check at the servo on the stands in a safe environment. Do this hot.If infarct there is a boost valve and spring issue they make various kits to increase pressures pending there are no other internal issues. just some pointers.
 
Posts: 1409 | Location: Under a Truck | Registered: August 23, 2013Reply With QuoteReport This Post
DRR Trophy
Picture of Bigdrive88
posted Hide Post
OK. Thanks for all the responses. I will start troubleshooting it and checking these out & see what I find.
 
Posts: 185 | Location: Hagerstown | Registered: September 01, 2014Reply With QuoteReport This Post



DRR Trophy
posted Hide Post
Make sure your rooster comb isnt bent or on it's way out (broke around the pinch)
 
Posts: 291 | Location: Midwest  | Registered: January 12, 2015Reply With QuoteReport This Post
DRR S/Pro
posted Hide Post
Add fluid?


Raceless in California!
 
Posts: 4534 | Location: Vacaville  | Registered: January 07, 2004Reply With QuoteReport This Post
DRR Sportsman
posted Hide Post
saw this when I ran hydraulic fluid...
 
Posts: 555 | Location: somewhere between been and never was | Registered: November 03, 2002Reply With QuoteReport This Post
DRR Trophy
Picture of Bigdrive88
posted Hide Post
Transmission is full.

quote:
Originally posted by BP758:
Add fluid?
 
Posts: 185 | Location: Hagerstown | Registered: September 01, 2014Reply With QuoteReport This Post
DRR Trophy
Picture of Bigdrive88
posted Hide Post
No hydraulic fluid here. FTI fluid is what I have ran for a few years.


quote:
Originally posted by I Hate Dragsters:
saw this when I ran hydraulic fluid...
 
Posts: 185 | Location: Hagerstown | Registered: September 01, 2014Reply With QuoteReport This Post
DRR S/Pro
posted Hide Post
quote:
Originally posted by Bigdrive88:
Transmission is full.

quote:
Originally posted by BP758:
Add fluid?


Maybe add a little fluid over full of you have a catch can to eliminate fluid running away from the pump? Just a thought


Raceless in California!
 
Posts: 4534 | Location: Vacaville  | Registered: January 07, 2004Reply With QuoteReport This Post
DRR Pro
Picture of Paul S/Q
posted Hide Post
fought a flare for 1/2 a season once ... tried 4 different spring rate servo springs, band adjustments , different rate high clutch springs , leaving some out , different clutch pack clearances , on and on ... finally Marco asked what fluid I was using ... told him a popular synthetic racing ATF ... he said put regular old Type F mineral oil ... walaaa ... NEVER another problem with that trans flaring at the shift .... I use either Marcos fluid now , or Transynd in the other trannys now .. something to try possibly
 
Posts: 785 | Location: hopefully pickin up a check in the winners circle | Registered: November 29, 2006Reply With QuoteReport This Post



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