Replaced a Posi with a spool now the car moves around
#1926165
10/05/15 12:21 PM
10/05/15 12:21 PM
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Joined: Feb 2005
Posts: 2,528 Mansfield, Tx
Jacob Pitt
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So went from a Posi and stock axles to a Strange spool and axles this past winter on my Mom's bracket Duster. Now the car is un stable going down the track. It just moves around and searches a lot. I thought maybe the spool was highlighting the fact that the frontend didn't have much caster so I rebuilt the frontend with all new ball joints, tie rod ends, and new QA1 upper control arms with 3.5 degrees of caster. This didn't change the way the car handles at all. It has old Comp Engineering shocks on the back with HD springs and the front has some old Koni shocks. All the suspension and tires have been on the car for a while and the only change that seemed to cause this problem was the spool and axles. Any ideas what may be causing this issue?
2013 NHRA D4 Stock Champ #4 in the World IHRA Stock 2x IHRA Div.4 Stock Champ 14x Track Champ All using a Ultimate Converter Concepts converter. Call Lenny today 704-892-6837
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Re: Replaced a Posi with a spool now the car moves around
[Re: Jacob Pitt]
#1926174
10/05/15 12:29 PM
10/05/15 12:29 PM
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Joined: Feb 2005
Posts: 20,203 PA.
pittsburghracer
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"Little"John
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What tires are on the front and back of the car? Have you measured the circumference of the rear tires? Is the rear of the car sitting much higher than the front?
1970 Duster Edelbrock headed 408 5.984@112.52 422 Indy headed small block 5.982@112.56 mph 9.42@138.27
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Re: Replaced a Posi with a spool now the car moves around
[Re: Jacob Pitt]
#1926182
10/05/15 12:46 PM
10/05/15 12:46 PM
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Jacob Pitt
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It has M/T ET fronts and M/T slicks. They can from the M/T truck and were matched when new to 1/4" of rollout. The rear does have some rack to it being a stock suspension car. It does have a 8 3/4 rearend in it. I haven't measured to see if it is bent but the old axles came out very easily and the new ones went in very easily.
The really weird thing is it doesn't go right or left every time. It leaves straight and then just starts to sashay around.
Last edited by Jacob Pitt; 10/05/15 12:54 PM.
2013 NHRA D4 Stock Champ #4 in the World IHRA Stock 2x IHRA Div.4 Stock Champ 14x Track Champ All using a Ultimate Converter Concepts converter. Call Lenny today 704-892-6837
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Re: Replaced a Posi with a spool now the car moves around
[Re: Jacob Pitt]
#1926204
10/05/15 01:22 PM
10/05/15 01:22 PM
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Joined: Feb 2005
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Jacob Pitt
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I will check the slicks again but wouldn't that cause the car to pull one way or the other? This car sways back and forth all the way down the track until you let off the gas.
2013 NHRA D4 Stock Champ #4 in the World IHRA Stock 2x IHRA Div.4 Stock Champ 14x Track Champ All using a Ultimate Converter Concepts converter. Call Lenny today 704-892-6837
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Re: Replaced a Posi with a spool now the car moves around
[Re: Quicktree]
#1926215
10/05/15 01:46 PM
10/05/15 01:46 PM
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Joined: Feb 2005
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Jacob Pitt
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Air pressure is checked before every run in all 4 tires.
2013 NHRA D4 Stock Champ #4 in the World IHRA Stock 2x IHRA Div.4 Stock Champ 14x Track Champ All using a Ultimate Converter Concepts converter. Call Lenny today 704-892-6837
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Re: Replaced a Posi with a spool now the car moves around
[Re: Jacob Pitt]
#1926234
10/05/15 02:14 PM
10/05/15 02:14 PM
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Joined: Jun 2003
Posts: 9,225 Charleston
sixpackgut
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tires growing at different times
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Re: Replaced a Posi with a spool now the car moves around
[Re: Jacob Pitt]
#1926239
10/05/15 02:21 PM
10/05/15 02:21 PM
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Joined: Nov 2003
Posts: 5,160 Texas
dannysbee
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With it going both directions an arbitrarily moving each direction I would look real hard at the housing. It sounds to me like each slick is trying to force the direction of the car going down track. I would not think that it would take much to cause a problem.
Getting old just means you were smarter than some and luckier than others.
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Re: Replaced a Posi with a spool now the car moves around
[Re: Jacob Pitt]
#1926240
10/05/15 02:22 PM
10/05/15 02:22 PM
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Joined: Jul 2004
Posts: 19,318 State of confusion
Thumperdart
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It has M/T ET fronts and M/T slicks. They can from the M/T truck and were matched when new to 1/4" of rollout. The rear does have some rack to it being a stock suspension car. It does have a 8 3/4 rearend in it. I haven't measured to see if it is bent but the old axles came out very easily and the new ones went in very easily.
The really weird thing is it doesn't go right or left every time. It leaves straight and then just starts to sashay around. I run the exact same combo on the street and it`s a wandering fool for sure.........
72 Dart 470 n/a BB stroker street car `THUMPER`...Check me out on FB Dominic Thumper for videos and lots of carb pics......760-900-3895.....
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Re: Replaced a Posi with a spool now the car moves around
[Re: Jacob Pitt]
#1926284
10/05/15 03:09 PM
10/05/15 03:09 PM
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Joined: Feb 2005
Posts: 2,528 Mansfield, Tx
Jacob Pitt
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What is the best method to measuring to see if the rearend is square?
2013 NHRA D4 Stock Champ #4 in the World IHRA Stock 2x IHRA Div.4 Stock Champ 14x Track Champ All using a Ultimate Converter Concepts converter. Call Lenny today 704-892-6837
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Re: Replaced a Posi with a spool now the car moves around
[Re: Jacob Pitt]
#1926289
10/05/15 03:23 PM
10/05/15 03:23 PM
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Joined: Nov 2004
Posts: 6,890 North Alabama
Monte_Smith
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What is the best method to measuring to see if the rearend is square? Find the factory jig holes in the frame and measure to the housing
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Re: Replaced a Posi with a spool now the car moves around
[Re: Jacob Pitt]
#1926424
10/05/15 06:23 PM
10/05/15 06:23 PM
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Joined: Sep 2014
Posts: 4,457 Washington
madscientist
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When they hunt like that something is moving.
I bought a set of SS springs (way back in the day) off a dude with the hangers and everything. Just bolted them in. After damn near getting the tree, the left guardrail, back over the center line, back to the left guardrail, back across the center line and almost into the door of the dude in the right lane I lifted.
25 different pit heros tried to tell me the front end was jacked up, but I kept telling them every time I shifted or lifted it changed directions. I spent a considerrable amount of money on the front end but still, you NEVER knew which way you were going.
I caught it by plumb bobbing off the axle faces and measuring to find that the axle was not square in the car. I started taking stuff apart and that's when I found out the dude used bolts that were too small in diameter throught the front spring eye! So literally, every time you changed load (shifted, lifted, braked etc) the axle could move front to rear in the car. Sometimes the wheel base would be longer on the right and shorter on the left, or it could be shorter on the right and longer on the left.
I ran into the dude several years later and he told me that's why he sold them.
So any time they move around like that I look to the rear end.
Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston
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Re: Replaced a Posi with a spool now the car moves around
[Re: Dodgeguy101]
#1926788
10/06/15 02:08 AM
10/06/15 02:08 AM
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Joined: Nov 2003
Posts: 3,468 Dandridge TN
Dabee
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Check the rear spring front bushings to see if they are loose. Agree front bushings could be loose or worn. I use aluminum front bushings on my rear springs.
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Re: Replaced a Posi with a spool now the car moves around
[Re: Jacob Pitt]
#1926851
10/06/15 08:25 AM
10/06/15 08:25 AM
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Joined: Jan 2003
Posts: 32,394
Quicktree
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Air pressure is checked before every run in all 4 tires. the question is how much pressure. I see so many people running way to low of air pressure. if your sure about everything else try raising the rear pressure up a little at a time.
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Re: Replaced a Posi with a spool now the car moves around
[Re: Jacob Pitt]
#1926852
10/06/15 08:28 AM
10/06/15 08:28 AM
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Joined: Jun 2008
Posts: 10,847 Oakdale CT
gdonovan
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If the only change is the spool it would have to be in the tires.
I suspect one is larger than the other, run into this myself. I lost a slick at an event and had to pop on a backup and the car walked around like crazy.
"I think its got a hemi"
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