Driveshaft angle and lift

[pdgradney]

I just did a nv4500 swap into my 79 2f powered 40. As a result of this new swap my rear drive shaft is angled incorrectly do to the transmission being lower than the rear axle . The options that I have come across that should fix this problem are

1) cut into the fire wall and lift the engine higher, allowing the drive train to start at a higher angle...I would rather not cut my tub.

2)Add a 4" lift kit, lowing the rear axle with respect to the transmission.

3)Add shackle extenders...not sure if this would work. If this does work, I definitely am leaning towards this as the simplest and cheapest options.

I currently have a 2.5" super lift with one leaf removed from the front and rear. I'm planning on reinstalling the rear leaf that was previously removed. Also, options 2 and 3 will allow me to get the 33x12.5 tires that I am planning on getting.

I've attached a picture of the drive shaft and a picture of my current shackles. As you can see for the drive shaft pic, I only need about 2" to level out the drive shaft. All advise and suggestions are greatly appreciated.

 

[Fast Eddy]

I think you should post some more pictures. That is all kinds of wrong.

You need longer shackles, for sure. Your driveshaft is all kinked up. The angles are wrong. You really need the transmission to be higher. Dropping the axle 1.5" with more lift isn't going to solve that problem.

 

[TCinVA]

I really think you should somehow get you drivetrain higher,I've never seen anything like that. Maybe a 1" or 2" body lift and/or some trimming on your tunnel. You could hit a parking lot block mall crawling with that setup. Good luck.

 

[1 Bad FN FJ]

rear

I like the angle, now would be a good time to do a spring over.

 

[Degnol]

Do you have a rear mount/crossmember to support the transmission?

 

[srgould41]

You could use some longer rear shackles for sure. I don't see how you could get any flex in the rear with the springs nearly hitting the frame at ride height.

 

[reddingcruiser]

2x Fast Eddy. Something else is going on with this suspension. Flipping the rear spring frame brackets would be a good start. IMO, it doesn't look like using longer shackles is the answer. How about some more overall pics of rig and suspension.

 

[srgould41]

Adding the leaf back should help a bit. I am wondering at the spring length, though. They look a bit long for a stock application. Flipping the shackle mount might be an option as Reddingcruiser suggested. I did that on mine so I could use 60 series springs.

 

[DSRTRDR]

You could use some longer rear shackles for sure. I don't see how you could get any flex in the rear with the springs nearly hitting the frame at ride height.

nearly look closely, there is a divet already in the shackle mount

 

[srgould41]

Yep, now that you mention it

nearly look closely, there is a divet already in the shackle mount

 

[Fast Eddy]

IMO, it doesn't look like using longer shackles is the answer.

Not the answer to the driveshaft issue, but at least a partial answer to the springs resting on the frame at ride height.

 

[mtman86]

Adding the leaf back should help a bit. I am wondering at the spring length, though. They look a bit long for a stock application.

4" lift kit w/ appropriate length springs( to restore proper angle to shackles), 1" body lift, shim trans up on rear cross member. Should get a better drive line angle. Hate the body lift, but you're kind of stuck. Shackle angle needs to be slightly less than straight verticle(lower bolt should be closer to rear bumper than upper bolt).

 

[Irish52084]

Put a 4" HFS lift with ! 1/2 in shakle then call tom woods and get a cadan drive line. this should make llife better also 4 degree shims in the front. Irish

 

[Cdaniel]

 

[pdgradney]

Do you have a rear mount/crossmember to support the transmission?

Yes

nearly look closely, there is a divet already in the shackle mount

I'm not sure what you guys are talking about. What "divet."

I didn't have time to take more photos of the drive train. To give a basic description, the transmission is at a downward angle from the engine, which results in the rear drive shaft being lower than the axle. The rear drive shaft is so short because the transmission is 6" longer than stock. Truthfully, it's like trying to fit a square peg in a round hole. I'm trying to make the best of a bad situation.

From what I've gotten from you guys is, my suspension is not on correct and larger shackles would help that issue but not do much for the drive shaft. Ironically, the suspension was one of the few things that i had a "professional" shop do. Never again will any body touch my truck.

If I add a 4" lift, will that solve the angle problem? Some of you suggested a body lift. I don't see how a body lift would change the angle.

I'll post pictures of the drive train tomorrow. Thanks again for you help.

 

[baxter650]

Spring over lift.

 

[mtman86]

[QUOTE=

If I add a 4" lift, will that solve the angle problem? Some of you suggested a body lift. I don't see how a body lift would change the angle.

Body lift will allow additional space between top of trans and floor pan/tunnel, allowing you to raise the rear of the trans/tc. This will help your drive shaft angles, along with a taller lift kit, to place the tail of the trans higher than the pinon joint(differential).

 

[Cdaniel]

Not sure what the best solution is to that drive train angle Surely you're not the 1st guy to put an NV4500 behind a 2f?

A body lift would allow you to tilt the drive train up and could help the situation, but not an elegant solution. And body lifts have their own set of challenges.

To avoid vibration the pinion and drive train center-lines need to be fairly close to parallel. Looks like they are not at the moment.

The rear shackle/spring situation needs to corrected regardless of the drive train issue. That has to ride like a rock!


A double cardan (CV) joint on the drive shaft isn't going to help unless you rotate the pinion angle to be parallel to the drive shaft angle.

 

[lcwizard]

Why a 4500 instead of a H-55 . i doubt the 2F has the guts to push that deep of overdrive. You need to reconsider the placement of the transmission or the rocks will do it for you

 

[DonkyFly40]

Why a 4500 instead of a H-55 . i doubt the 2F has the guts to push that deep of overdrive. You need to reconsider the placement of the transmission or the rocks will do it for you

X2!!!!!