How to go about pinion angle on a 5.3/t56 swap?

[oakhill510]

I am working on a 69 Camaro with 5.3/t56. My next move is to have the rear end narrowed. I read that the rear should be in the 3 degree (positive?) range.

Well, I am still doing my research. So, do I just tell the guy who's doing the narrowing that I want a 3 degree angle? Or do I have to find out the ange of my motor/tranny first and then find what angle I need the rear end to be?

One more thing, If I do need to find the angle of my motor/tranny first, how do I go about that? Need schooling here.

[Sbeck09]

The typical amount is 3 degrees, but it can vary slightly (typical range is 2-4 degrees). The more important thing is for the angles to be equal but opposite at both ends of the driveshaft. Transmission will point down toward the back of the car and diff input will point up toward the front (if you drew a line from the center of each end they would be parallel). This measurement should ONLY be done with the suspension at ride height.

To find the transmission side angle you can do it a couple different ways. I went off of my crank since it will be in alignment with your trans shaft. Some guys Use the starter housing since it is machined true.

Tremec has an app with an angle finder that is pretty helpful and there is many videos from reputable companies like DSE on YouTube that walk through the process.

[oakhill510]

I see, 3 degree doesn't mean the angle is suppose to be at, it just that when everything is parallel, its usually in the 2-4 degree angle.

My problem is now after reading your very helpful reply is, doing the measurements at ride height. I installed the ridetech 4 link cradle already and wont be able to install the coil overs and the rest of the link until I narrow the rear end have the perches welded on.

Is this one of those situation where I might have to use shims to adjust the angle as needed?

[Z06vet]

The upper bars of the 4 link are adjustable. Once you get the car finished, everything installed inside & out, set the car at your desired ride height. The biggest issue here is most usually related to the engine & trans angle on an LS swap. Using the holley clamshell style swap mounts will set your driveline at an acceptable angle. The lower the ride height, the more critical this is. As an alternative, you can cut & raise the trans tunnel to give you adequate room to raise the tailshaft of the trans to be able to attain acceptable working angles between the trans and the rear pinion. Ideally you can weld the tabs for the 4 link onto the axle tubes with everything mocked up at ride height. There will be plenty of adjustment for pinion angle via the upper 4 link bars. I have maybe 10 swaps using the 4 link from ridetech and other brands. I don't recall ever having the rear pinion angled up more than 1 degree. Doing so causes the driveshaft to slope upward from the trans to the rear end, causing bad angles, and vibration at highway speed. The combination of angles- (or working angles) engine/trans, driveshaft, and pinion- must all be set within an acceptable range for smooth operation. Take a look at the tremec driveline angle app for you phone. This should help you get everything where it needs to be

[oakhill510]

Alright, my motor/trans is in. My trans angle is -3.3. I haven't set my pinion angle yet. The problem I’m having is my driveshaft angle is positive. If it was anywhere in the negative, I’ll be all within spec with the tremec app.


Is a driveshaft being in the positive angle, normal?


Anyways, I am going to set my angles to
Trans -3.3
DS +1.8
Pinion -3.1 (nose up)


For now, do I can weld my upper tabs.

[Z06vet]

What engine & trans mounts did you end up using? Go back & read my original reply to your post above. You cannot have the driveshaft slope upward to the rear end. The rear pinion angle will most likely end up being at or near zero, depending on your ride height.

[andrewb70]

Alright, my motor/trans is in. My trans angle is -3.3. I haven't set my pinion angle yet. The problem I’m having is my driveshaft angle is positive. If it was anywhere in the negative, I’ll be all within spec with the tremec app.


Is a driveshaft being in the positive angle, normal?


Anyways, I am going to set my angles to
Trans -3.3
DS +1.8
Pinion -3.1 (nose up)


For now, do I can weld my upper tabs.

So basically similar to this:

178448

You have to raise the back of the transmission or use a CV driveshaft.

Andrew

[oakhill510]

What engine & trans mounts did you end up using? Go back & read my original reply to your post above. You cannot have the driveshaft slope upward to the rear end. The rear pinion angle will most likely end up being at or near zero, depending on your ride height.



I hear you on not having the driveshaft sloping up. Right now it is sloping up. I already tac welder my upper links. Of course it can be adjusted later. I just need get my rear end fully completed so I can move forward on my built. I do have plans to have an experience person adjust my driveline angles when the car is drivable.

The more I am trouble shooting this the more I think it’s the engine trans mount that making my trans angle lower than the pinion angle. I am using hand me down engine mounts from my cousin. Important note that I think makes a different, the Ls swap motor mount came off my cousin BBC Camaro. I am using that same motor mount but on a sbc Camaro.

on the trans mount, I am using G force crossmember for 69 Camaro t56 swap. I have 4 washers shim on it right now that brought the angle to -3.6

[oakhill510]

andrewb70:

Pretty much, my driveline angle is like that. I have 4 washer/shins under the transmission right now to bring the angle to -3.6 from -4.2.

I can add maybe one or two more washers but I will still be in the -3 angle and the DS will still be sloping upward.

[andrewb70]

I hear you on not having the driveshaft sloping up. Right now it is sloping up. I already tac welder my upper links. Of course it can be adjusted later. I just need get my rear end fully completed so I can move forward on my built. I do have plans to have an experience person adjust my driveline angles when the car is drivable.

The more I am trouble shooting this the more I think it’s the engine trans mount that making my trans angle lower than the pinion angle. I am using hand me down engine mounts from my cousin. Important note that I think makes a different, the Ls swap motor mount came off my cousin BBC Camaro. I am using that same motor mount but on a sbc Camaro.

on the trans mount, I am using G force crossmember for 69 Camaro t56 swap. I have 4 washers shim on it right now that brought the angle to -3.6

Do yourself a favor and buy the Holley Camaro swap mounts. They are engineered to put the engine as low as possible in the front, which helps with the angles.

Andrew

[oakhill510]

Do yourself a favor and buy the Holley Camaro swap mounts. They are engineered to put the engine as low as possible in the front, which helps with the angles.

Andrew

You said low as possible. Probably a typo. But yeah I realize yesterday that my front ride height is pretty low. I still haven’t adjusted the coil. I believe if I raise the front higher, it’ll help with bringing the trans up.

When I was getting my upper link tabs tac welded, I did had my front on its wheel and the wheel on stands. After taking the stands off, that when I realize how low my car is to the ground.

If all else fail, Holley mounts it is. 178513

[andrewb70]

It wasn't a typo. The Holley mounts position the engine lower in the front cradle, this makes the overall driveline issue less severe, because it makes the engine more level. Front ride height has zero effect on driveline angles.

Andrew

[oakhill510]

It wasn't a typo. The Holley mounts position the engine lower in the front cradle, this makes the overall driveline issue less severe, because it makes the engine more level. Front ride height has zero effect on driveline angles.

Andrew


I hear what you’re saying. Isn’t the problem with my driveshaft sloping up is because of the engine/trans is sitting too low?

could be my trans crossmember is making my trans angle lower than the rear pinion.

[andrewb70]

I hear what you’re saying. Isn’t the problem with my driveshaft sloping up is because of the engine/trans is sitting too low?

could be my trans crossmember is making my trans angle lower than the rear pinion.

Lowering the front of the engine is the same as raising the back of the engine. Right now your engine and trans are sloping down to the rear relative to the frame. By lowering the front of the engine and keeping the trans where it is, the engine and trans get leveled out more, which will help your overall driveline angles.

Andrew

[oakhill510]

Lowering the front of the engine is the same as raising the back of the engine. Right now your engine and trans are sloping down to the rear relative to the frame. By lowering the front of the engine and keeping the trans where it is, the engine and trans get leveled out more, which will help your overall driveline angles.

Andrew

Oh ****, understood. Thank you