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#1
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Setting pinion angle.
I hope to get my transmission out of layaway if not with my Christmas money then shortly there after. My question is the kit from American Powertrain comes with a driveshaft once you provide them the measurements and I know how to measure for that but if my pinion angle is off how do I correct it? With a shorter or taller trans mount or what? My suspension in the rear is UMI non adjustable. Rear end is a ford 9 inch. I am using the stock crossmember
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468/TKO600 Ford thru bolt equipped 64 Tempest Custom. Custom Nocturne Blue with black interior. |
#2
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Adjustable upper control arms.
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1964 Tempest Coupe LS3/4L70E/3.42 1964 Le Mans Convertible 421 HO/TH350/2.56 2002 WS6 Convertible LS1/4L60E/3.23 |
#3
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x2
But if the angle needs to change at the trans, you can make some shims to have the mount sit higher. Just be careful you dont run out of stud on the mount.
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. Mark S . Who needs nice and pretty, when you can have mean and nasty? KRE Aluminum headed 463CID 73 LeMans. Used to run 10.6x @ 124.55. 3700lbs . So much for 2020...shootin for 9s in 2021...and in 2022 apparently.....looks like 2023 as well. >>My 73 Build thread |
#4
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Floor pan clearance to the driveshaft u-joint is tight on these cars, shimming the trans mount isn’t likely an option.
Honestly you’re going to have to throw some cash at making your adjustments happen in the upper control arms.
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1964 Tempest Coupe LS3/4L70E/3.42 1964 Le Mans Convertible 421 HO/TH350/2.56 2002 WS6 Convertible LS1/4L60E/3.23 |
#5
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Well American Powertrain swears that their transmission mount will work with stock crossmember and should check out fine. The 9 inch bolted right into place beautifully and is centered in the tunnel. The the control arms bolted up perfectly too so is there a chance of everything coming together without me having to do anything?
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468/TKO600 Ford thru bolt equipped 64 Tempest Custom. Custom Nocturne Blue with black interior. |
#6
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Hope for the best, plan for the worst.
You won't know until it's all together, so there's no point fretting about it until then.
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#7
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I have a set of these and they are really nice for the price.
https://www.spohn.net/shop/1964-1967...djustable.html As far as the chance that the pinion angle will be right with all of the mods you’ve done that’s probably not going to happen. Just changing rear ride height with all stock parts usually requires some adjustment.
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68 GTO,3860# Stock Original 400/M-20 Muncie,3.55’s 13.86 @ 100 Old combo: 462 10.75 CR,,SD 330CFM Round Port E's,Old Faithful cam,Jim Hand Continental,3.42's. 1968 Pontiac GTO : 11.114 @ 120.130 MPH New combo: 517 MR-1,10.8 CR,SD 350CFM E's,QFT 950/Northwind,246/252 HR,9.5” 4000 stall,3.42's 636HP/654TQ 1.452 10.603 @ 125.09 http://www.dragtimes.com/Pontiac-GTO...lip-31594.html |
#8
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Yeah, chances are pretty slim the angles would be right, have to understand that with a longer trans, and a shorter driveshaft, the angle change.
Shims are available, and pre-cut to fit, several people make them, and are inexpensive. But as others pointed out, you have limited room to make any big adjustments. Adjustable uppers is probably the best approach, but it may, and probably will take a combo of adjustments to get it acceptable. Keep in mind too that driveshaft diameter and material impacts driveline 'harmonics'. If it still has vibration after the angle are in an acceptable range, you may have to switch to a different diameter/material driveshaft. Another factor often overlooked is that the pinion angle is actually a 'range', because it changes with suspension travel. You may for example cruising on the highway at a particular RPM find that it vibrates, even if you at rest have acceptable angles. Choosing something more 'in the middle' of the range may or may not correct that. You might have to actually go outside of an acceptable range at rest to get the optimum in-use results. The car will settle some too, and since it's a new build, you may have to check it a couple times in the first like 5-10k of miles. Tremec has a phone app for smart phones to check driveline angles, it's not bad, and I have used it a number of times. http://www.tremec.com/menu/tremec-toolbox-app/ .
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. 1970 GTO Judge Tribute Pro-Tour Project 535 IA2 http://forums.maxperformanceinc.com/...d.php?t=760624 1971 Trans Am 463, 315cfm E-head Sniper XFlow EFI, TKO600 extreme, 9", GW suspension, Baer brakes, pro tour car https://forums.maxperformanceinc.com...ght=procharger Theme Song: http://www.youtube.com/watch?v=7zKAS...ature=youtu.be |
#9
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Here's an example of crossmember/trans mount shims:
https://www.crossmembers.com/product...ions-set-of-4/ Some make them in different thicknesses, but it's really not that exact of a science. If you run out of room on your floorboards, you can always jack the car up slightly by using a floor jack with a 8x8 piece of wood or other material of choice, on the floor pan above the trans mount, and jack it up some. You can open a door and jump on the door sill if it's not cooperating. Many cars over time have the floor pans sag, very common issue. One way to check for floor pan sag is if the car has bucket seats, the headrests tip towards each other, towards the center of the car. If it's a bench seat, or at the moment no seats, you can use a level across the seat bracket on each side of the tunnel. EDIT: You can also in a pinch add washers to the body mounts, but that will cause a ripple effect where you have to re-align panels. .
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. 1970 GTO Judge Tribute Pro-Tour Project 535 IA2 http://forums.maxperformanceinc.com/...d.php?t=760624 1971 Trans Am 463, 315cfm E-head Sniper XFlow EFI, TKO600 extreme, 9", GW suspension, Baer brakes, pro tour car https://forums.maxperformanceinc.com...ght=procharger Theme Song: http://www.youtube.com/watch?v=7zKAS...ature=youtu.be |
#10
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I have fixed rear arms.
Just looking underneath at normal stance, the pinion ought be SLIGHTLY below level for Street-Strip, maybe at level for Street. Then (when nobody is around to bother ya) floor-jack the pinion and see how the pinion attitude doesn't change. Only the rear system rises. Then consider the front end height when running the 1/4 mile. Set the front end with blocks under the Engine cradle, and redo the pinion raise with floor jack. I think a Urethane bushed rear system will barely show a change in pinion angle. You just might have the correct angle as-is. I sure do, with stock arms, boxed lowers, and the Straps for frame stiffning. Fun fact: in the 1980s i has a 68 GTO Street car where the upper Arm Frame Crossmember mount holes had 3-holes per side. Had to be factory piercings: it was too neat. Thought that some engine option caused that. Never saw such a pinion-angle selection again. |
#11
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I have the Spohn Del Sphere adjustable rear control arms. Well worth it! Made a big difference in how my el Camino handles, rides and pulls out, I have a standard 2:87 with a 454.. Getting it not to spin used to be such a challenge now that I had everything set with a four wheel alignment, it takes off like a missile..
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#12
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When I installed a 9 inch Ford Rear into my Mid American Stock car Metric chassis, I fixed the pinion angle by enlarging the front holes on the upper trailing arms and and welding 7/16 washers. They were a couple thou over 1/2 inch. I put he rear where it was at ride height then using an angle finder set it where it needed to be and tacked them in.Then I took them off and welded around Try it out,
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1979 Trans Am WS-6 .030 455 zero decked flat pistons 96 heads with SS valves 041 cam with Rhoads lifters 1.65 rockers RPM rods 800 Cliffs Q Jet on Holley Street Dominator ST-10 4 speed (3.42 first) w 2.73 rear gear __________________________________________________ _______________________________ 469th TFS Korat Thailand 1968-69 F-4E Muzzle 2 |
#13
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Quote:
The only way to know for sure is to measure and calculate the operating angles. .
__________________
. 1970 GTO Judge Tribute Pro-Tour Project 535 IA2 http://forums.maxperformanceinc.com/...d.php?t=760624 1971 Trans Am 463, 315cfm E-head Sniper XFlow EFI, TKO600 extreme, 9", GW suspension, Baer brakes, pro tour car https://forums.maxperformanceinc.com...ght=procharger Theme Song: http://www.youtube.com/watch?v=7zKAS...ature=youtu.be |
#14
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All this is over my head. I will let my alignment shop handle it if I have to install adjustables
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468/TKO600 Ford thru bolt equipped 64 Tempest Custom. Custom Nocturne Blue with black interior. |
#15
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You do realize that an alignment shop doesn't do chassis work usually, yes? Pinion angle work is usually done by a chassis shop.
.
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. 1970 GTO Judge Tribute Pro-Tour Project 535 IA2 http://forums.maxperformanceinc.com/...d.php?t=760624 1971 Trans Am 463, 315cfm E-head Sniper XFlow EFI, TKO600 extreme, 9", GW suspension, Baer brakes, pro tour car https://forums.maxperformanceinc.com...ght=procharger Theme Song: http://www.youtube.com/watch?v=7zKAS...ature=youtu.be |
#16
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What do you guys set your pinion angle at? Just set it equal and opposite of the transmission? A few degrees down to compensate for pinion rising under acceleration? Trial and error?
Just curious, as I have been trying to get rid of a second order vibration that I get around 65-75mph. |
#17
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Quote:
The vibration you are experiencing could also be from operating the driveshaft at 1/2 of its critical speed. There are calculators online that can give you the shafts critical speed where it becomes unstable. The only way to change that is to change the driveshafts’ diameter, wall thickness and or material.
__________________
68 GTO,3860# Stock Original 400/M-20 Muncie,3.55’s 13.86 @ 100 Old combo: 462 10.75 CR,,SD 330CFM Round Port E's,Old Faithful cam,Jim Hand Continental,3.42's. 1968 Pontiac GTO : 11.114 @ 120.130 MPH New combo: 517 MR-1,10.8 CR,SD 350CFM E's,QFT 950/Northwind,246/252 HR,9.5” 4000 stall,3.42's 636HP/654TQ 1.452 10.603 @ 125.09 http://www.dragtimes.com/Pontiac-GTO...lip-31594.html |
#18
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Quote:
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#19
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Quote:
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"No replacement for displacement!" GTOAA--https://www.gtoaa.org/ |
#20
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My alignment shop is full service speed shop they do all kinds of stuff
__________________
468/TKO600 Ford thru bolt equipped 64 Tempest Custom. Custom Nocturne Blue with black interior. |
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