Transmission Crossmember with 4L60E and 5.3 LS Swap
 

Hey guys, transmission mounting question for my swap.

My specs:
5.3 LM7
4l60e

I basically have this kit:

https://lh3.googleusercontent.com/yH...3=w589-h328-no



I have installed the engine mounts in the rear holes because the oil pan was too close for comfort on the crossmember. My issue is now I have the engine and trans mounted but with the trans crossmember pictured above, the trans sits too low and oil pan hits the engine crossmember... It's almost like I need to add a 2" square piece of tubing to raise the trans up to make it work. Is this normal?

Kinda like Hart_Rod did in the picture here is what it appears I need to do:

https://lh3.googleusercontent.com/D2...Q=w790-h536-no

Re: Transmission Crossmember with 4L60E and 5.3 LS Swap
 

What is the angle of your engine/trans?....you'll need it to match the numerical angle of your rear diff...engine trans down...rear diff up

Re: Transmission Crossmember with 4L60E and 5.3 LS Swap
 

Will I have to buy a tool to figure out the angles?

Re: Transmission Crossmember with 4L60E and 5.3 LS Swap
 

If you don't have one they're not that expensive....I've got a couple of dial angle finder and several digital ones....I'd recommend the digital...you can get them at Lowe's and such....I got most of mine of ebay...
You'll want to keep the centerline of the diff and the engine/trans running parralel...a loose standard is rear diff pointing up at 3deg...engine pointing down at 3deg..
Here's a good video to watch...explain s alot.....https://m.youtube.com/watch?v=Idk3BVDVHq4

Re: Transmission Crossmember with 4L60E and 5.3 LS Swap
 

that looks like a after market cross member, are you sure it is not upside down.
Also you have the double gold plate on the mount, are you sure that is needed ? my instructions said not to use it for that application.

Re: Transmission Crossmember with 4L60E and 5.3 LS Swap
 

I bought an angle finder from Home Depot, stuck a 2x4 under the mount to simulate 1.5" lift and its a little too much, I think 1" lift and it will be perfect. That will put me at 10 degrees on both the angles of tranny and pumpkin.

So here is another question. I watched that cool video that explains the importance of drive shaft angles, you know the one with the sprockets on the shaft and the guy uses a credit card like we all did with playing cards in our bike spokes? The credit card made it possible to hear the different speeds the shaft spun depending on good or bad pinion to trans angles. Personally I was an ACE card, but some of my friends were jokers ;)

Anyway, is it safe to assume that even though I'm using a 2 piece drive shaft that those angles still need to match? Or does the angles need to be different than 10 degree or less on both ends? Carrier bearing change that?

https://lh3.googleusercontent.com/ca...B=w728-h970-no

https://lh3.googleusercontent.com/4A...7=w728-h970-no

Re: Transmission Crossmember with 4L60E and 5.3 LS Swap
 

That's actually 4deg..which is ok as long as the pinion angle matches...but in the opposite direction

Re: Transmission Crossmember with 4L60E and 5.3 LS Swap
 

2-Piece shaft with upper and lower u-joints parallel
In this case, you are trying to get the upper and lower u-joint angles parallel to each other. Note that the sketch is a bit misleading as you may need to have the middle u-joint at a 0 degree operating angle.

Upper lower sections same angle

3: 2-Piece shaft with equal angle shaft sections
In this case you are basically spliiting the overall shaft angle between the trasnmission and the axle in half. This gives you two shorter shafts connected end to end and each one is set up with equal operating angles on each u-joint. With this type of setup, you may need to adjust both the pinion angle at the axle as well as the angle/height of the center support bearing. This will likely take a piece-wise process, adjusting the pinion angle, measuring and adjusting the center support bearing, etc.

Re: Transmission Crossmember with 4L60E and 5.3 LS Swap
 

Forgive my ignorance here. Are you saying tranny to midshaft ujoint same angle, and then midshaft ujoint to diff same angle?

So like tranny to mid ujoint could both be 4degree, and then the midshaft to diff could be 6degree? Something like that?

And by the way, I mentioned I need to lower my trans more to get to the 9 or 10 degree that my diff is sitting at. So I was on the path of just making those two angles the same and not worrying about the mid ujoint.

Let me know if one of these is correct, thanks for help.

Re: Transmission Crossmember with 4L60E and 5.3 LS Swap
 

What happened to your diff angle?...it shouldn't be that much...is the axle on factory spring pads..factory height...lowered ...lifted ?

Re: Transmission Crossmember with 4L60E and 5.3 LS Swap
 

There are several ways to do a split d-shaft..the way in the drawing splits the total angle in half at the hanger bearing...some setups run the front shaft straight inline with the engine trans centerline..then drop to the rear diff...it's not good to run a joint with no angle...the angle of a joint keeps the needles rolling in the cups and lubricates them..a joint straight won't roll the needles...based on everything I've read...