inverted driveline angles?

[MAGONSTERZ68]

well as fate would have it, got tired of dragging headers, oil pan and front frame rails EVERYWHERE, was 4" front 3" rear, looked great, rode great as long as there wasnt a dip, off camber or speed bump!
Raised front end to 2" drop and swapped in 1.5" drop rear spring pack, added cal tracs but have yet to set on all fours to check pinion angles, engine not in yet.
Would like to switch to C/V driveline, has anyone used with 750 crank hp 620 tq application? Durability question for street use.

[dhutton]

My Camaro has the same problem.

How did you fix it?

Speed tech torque arm suspensions

1970 Camaro Help me. A difficult problem in Japan.

Install the Speedtech raised tunnel and raise the transmission. Either that or raise the ride height.
https://speedtechperformance.com/pro...-tunnel-cover/

[dhutton]

well as fate would have it, got tired of dragging headers, oil pan and front frame rails EVERYWHERE, was 4" front 3" rear, looked great, rode great as long as there wasnt a dip, off camber or speed bump!
Raised front end to 2" drop and swapped in 1.5" drop rear spring pack, added cal tracs but have yet to set on all fours to check pinion angles, engine not in yet.
Would like to switch to C/V driveline, has anyone used with 750 crank hp 620 tq application? Durability question for street use.

I used one on my 600 hp 600 tq Camaro without issue.

Don

[Shotaro]

Install the Speedtech raised tunnel and raise the transmission. Either that or raise the ride height.
https://speedtechperformance.com/pro...-tunnel-cover/

Would you like to raise the tunnel, raise the transmission and raise the engine?

[dhutton]

Would you like to raise the tunnel, raise the transmission and raise the engine?

Just raise the tunnel and rear of the transmission.

[Shotaro]

Just raise the tunnel and rear of the transmission.

I'm thinking of making a tunnel, but is there any other way?



Engine. 2.2↓(87.8)
shaft 1.3 ↑
pinion 2.2 ↑


Thank you

[dhutton]

I'm thinking of making a tunnel, but is there any other way?



Engine. 2.2↓(87.8)
shaft 1.3 ↑
pinion 2.2 ↑


Thank you

You could raise the ride height or use a CV driveshaft.

You could experiment with some pinion shims to get the pinion pointing down but I’m not sure it will help.

https://www.summitracing.com/search?...Pinion%20shims

Don

[Shotaro]

You could raise the ride height or use a CV driveshaft.

You could experiment with some pinion shims to get the pinion pointing down but I’m not sure it will help.

https://www.summitracing.com/search?...Pinion%20shims

Don

The rear suspension is equipped with a Speedtech torque arm. You can remove the SIM and lower the pinion angle.



Thank you

[dhutton]

The rear suspension is equipped with a Speedtech torque arm. You can remove the SIM and lower the pinion angle.



Thank you

I would try removing all the shims.

Keep in mind that Speedtech would have their tunnel mod so the transmission is higher than your case. You really should raise the tunnel in my opinion.

Don

[Shotaro]

I would try removing all the shims.

If you take the SIM and lower the pinion angle, the noise and vibration are terrible.

[Pedigry]

I have fought with pinion vibrations and experimented with different angles on my 70 mustang. This all seems to start with the engine/tranny angle, specifically because it is the least adjustable. I unfortunately have a C6 with a gear vendors overdrive attached to the back, which takes up quite a bit of space in the tunnel so I can't get my angle less than 3.5 degrees. I think at that angle, you will always fight a little bit of vibration somewhere in the rear end. I have it on really slight power lift off and only for a second until the driveshaft loads again. It used to be really bad, but now it's livable.

My point is simply, those with shallow trans tunnels or when running large transmistions like T56 or big automatics will suffer from a higher trans angle because we simply can't lift the tranny high enough to get rid of it. The only solution is to cut the trans tunnel and shim it up or lower the front of the motor with custom engine mounts. Since I'm not crazy about the automatic, I'm going to do a manual swap, lol. That will allow me to get rid of the auto and the gear vendors overdrive. Win/win.

Most drive angle problems and layouts have already been addressed in this thread. I just wanted to add that when you are starting with a 3.5 degree trans down angle, your are starting at a clear disadvantage and overcoming that by simply matching pinion angle, especially when you have a driveshaft up angle to deal with is tough. All bets are off when the driveshaft angle is up because under load it wants to climb even further. And that is, of course, dependant upon what rear suspension you have, coilovers, leafs, triangulated 4 link, straight 4 link, panhard bar, etc. Everyone one has a different amount of climb angle under load. But the general consensus is that with a positive driveshaft angle, all bets are off when it comes to standard driveline practices (i.e. matching trans and pinion angles, specific working angles, etc).

Trial and error for those running an up angle driveshafts is just that, trial and error. Best of luck!

[dhutton]

If you take the SIM and lower the pinion angle, the noise and vibration are terrible.

Then it’s time to cut the tunnel and raise the transmission or raise the ride height.

Don

[Shotaro]

I have fought with pinion vibrations and experimented with different angles on my 70 mustang. This all seems to start with the engine/tranny angle, specifically because it is the least adjustable. I unfortunately have a C6 with a gear vendors overdrive attached to the back, which takes up quite a bit of space in the tunnel so I can't get my angle less than 3.5 degrees. I think at that angle, you will always fight a little bit of vibration somewhere in the rear end. I have it on really slight power lift off and only for a second until the driveshaft loads again. It used to be really bad, but now it's livable.

My point is simply, those with shallow trans tunnels or when running large transmistions like T56 or big automatics will suffer from a higher trans angle because we simply can't lift the tranny high enough to get rid of it. The only solution is to cut the trans tunnel and shim it up or lower the front of the motor with custom engine mounts. Since I'm not crazy about the automatic, I'm going to do a manual swap, lol. That will allow me to get rid of the auto and the gear vendors overdrive. Win/win.

Most drive angle problems and layouts have already been addressed in this thread. I just wanted to add that when you are starting with a 3.5 degree trans down angle, your are starting at a clear disadvantage and overcoming that by simply matching pinion angle, especially when you have a driveshaft up angle to deal with is tough. All bets are off when the driveshaft angle is up because under load it wants to climb even further. And that is, of course, dependant upon what rear suspension you have, coilovers, leafs, triangulated 4 link, straight 4 link, panhard bar, etc. Everyone one has a different amount of climb angle under load. But the general consensus is that with a positive driveshaft angle, all bets are off when it comes to standard driveline practices (i.e. matching trans and pinion angles, specific working angles, etc).

Trial and error for those running an up angle driveshafts is just that, trial and error. Best of luck!

it's very difficult.

[andrewb70]

You can solve this by using a dual CV driveshaft.

Andrew

[Alwhite00]

I ended up with a CV driveshaft from the driveshaft shop in my 67 Chevelle. 80mph on the expressway with no issues.



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[Shotaro]

I ended up with a CV driveshaft from the driveshaft shop in my 67 Chevelle. 80mph on the expressway with no issues.



- - - Updated - - -

It seems very expensive.

1967 Chevelle cool

[andrewb70]

It seems very expensive.

1967 Chevelle cool

Yes, but it is the right solution to your situation.

Andrew

[Alwhite00]

It seems very expensive.

1967 Chevelle cool

Believe me. I didn't have a CV driveshaft in the budget nor a 9" ford but now that it's done I am extremely glad I did it. I put 8k on it so far and planning a color tour to Tennessee from Michigan in October and when driving that many miles I can actually enjoy the trip.

[NorCal-SS]

Believe me. I didn't have a CV driveshaft in the budget nor a 9" ford but now that it's done I am extremely glad I did it. I put 8k on it so far and planning a color tour to Tennessee from Michigan in October and when driving that many miles I can actually enjoy the trip.

Ah jeez that throws a wrench in things for me too!

So on a lowered A body, even with raising the trans tunnel and adjustable upper rear arms, a double CV driveshaft is still required? Damn!

And yes love your 67 too! Since I’m already mid thread-jack, how high are your wheel arches from the ground?

[Alwhite00]

Ah jeez that throws a wrench in things for me too!

So on a lowered A body, even with raising the trans tunnel and adjustable upper rear arms, a double CV driveshaft is still required? Damn!

And yes love your 67 too! Since I’m already mid thread-jack, how high are your wheel arches from the ground?

Wheel arches to the ground is not a constant measurement as tire size dictates where it will sit. If I put smaller diameter tires on it ne number will be smaller but the suspension hasn't changed.

I could get you a measurement from the center of the wheel to the wheel arch if that would help you.

Btw. If you could get the engine and trans up high enough to get the driveline angles acceptable you would be fine but in my case I would have to severely raise the tunnel and I didn't want to do that. I wanted to use stock carpet.

Also. I have a single CV joint at the trans end. Normal U-joint on the pinion end