5.3l, nv4500, np205, centered rea mini hybid driveline length questions (1 Viewer)

[aandy767]

Well after reading

Testing the New Pro Comp A/T Sport

And 4wd parts had another 10% off, I'm picking them up today. It wouldn't have taken much to say me one way or the other.

We just put a set of BFG MTs on the kids wagoneer. They seem like a good tire.

 

[aandy767]

Front pinion angle, drive train angle questions

I doing a 4 and 3 link set up

Two questions

I see where folks say set the engine-transmission at a 2-3% slope

Should the rear pinion have the same angle? 2-3%? I think so or zero% on engine-tranny and zero on her pinion

and most import the front pinion I have no weight on the frame or axle and didn't measure the factory pinion angle on the front
my lift will be 4 or closer to 5 inches

The front driveshaft should be plenty long

So, for proper steering and no cut and turn. What should the front pinion angle be? most concerned about steering

 

[Mace]

Pinion angle has little to do with motor angle. But more with what style of driveshaft being used.

Standard driveshaft, make the flanges parallel. so 2* down angle on the drivetrain = a 2" up angle on the pinion.
With a double cardan driveshaft then point the pinion directly at the tcase output.

If you do not do a cnt then you need to leave the pinion parallel to the ground (flange at 90*). This is assuming that you are still using a 40 series front axle. If you don't, the caster angle will be horrible and the truck will wander.

 

[aandy767]

90* on the front is what I needed to know, was not sure about that.

Still not sure why everybody puts a little slope on the engine transmission. Seems like if you put 2-3* you have complicated two pinions. One up and one down.

Might just mount engine transmission level.

 

[SuperBuickGuy]

Front pinion angle, drive train angle questions

I doing a 4 and 3 link set up

Two questions

I see where folks say set the engine-transmission at a 2-3% slope

Should the rear pinion have the same angle? 2-3%? I think so or zero% on engine-tranny and zero on her pinion

and most import the front pinion I have no weight on the frame or axle and didn't measure the factory pinion angle on the front
my lift will be 4 or closer to 5 inches

The front driveshaft should be plenty long

So, for proper steering and no cut and turn. What should the front pinion angle be? most concerned about steering

1) the angle depends more on how far under the frame you want your transfer case to hang - I wanted the case flush, so that pretty much dictated a CV rear - which also dictates the pinion aiming straight at the t-case. my rear angle is 90* to the ground, and honestly I guestimated the rear at 10 or so degrees off). Given how short the rear driveshaft always is on these - consider a CV, many don't like them because it's one more part to break, more complex, more moving parts to wear...

2) it depends, if you're planning on going skiing and driving this, then you need the yoke/pinion perpendicular to each other. OTOH, if top speed is going to be 30 or 40 mph in 4 wd, close counts. Harmonics start at about 50 mph (rule of thumb)

positive caster keeps the rig going straight down the road, and that tends to be the most important issue - it's why people cut n turn because making an old rig handle better aims the pinion at the ground and causes clearance issues.

 

[aandy767]

Thanks, stretching the frame 18" and my nv4500 and np205 move the front drive flange rearward. And the rear driveshaft should be plenty long also. So both drive shafts should be long enough. I put an angle finder in there months ago, and it looked like I wouldn't have too much angle on the drive shafts. Just don't remember what it was.

Main question was on the front pinion, don't want it to steer poorly. Should be able to fine tune it with threaded links.

 

[SuperBuickGuy]

most cut and turn toyota axles because they handle so poorly - that said, stretching the wheelbase should help a lot. You can cheat a little by aiming the pinion just less then perpendicular with the ground but it's a tradeoff. why are you concerned about cutting and turning the axle? you're halfway there with the 3 link.

Any rear driveshaft about 18" long in the rear is adequate - but more is better to reduce driveline angles.

 

[aandy767]

Not scared of the cut and turn, would do it if i need to. Just want to get the caster correct.

My front shaft will be pretty long, so I think I'll be okay on the drive shaft angles. I think my front driveshaft will be about 6" longer than stock(not here to measure).

Lift is planned at 4-5 inches, we'll see. There is a lot of room for adjustments. Would like to lift as little as possible an not have any tire contact issues (would like to retain a somewhat stock looking rear quarter panel). I'm sure I'll have to trim.

I would think cut and turn is for a SOA 6" plus lift, with a factory length front driveshaft. That's of course why I have asked. And appreciate the responses.

 

[SuperBuickGuy]

getting the yoke further away from danger and getting 5-7* of positive caster are the reasons most cut n turn.

 

[aandy767]

It's a slow go
Looks like i'll have to relocate the AC compressor

 

[aandy767]

As far as the engine height, I used the crank pulley bolt. Lined it up just above the front bumper. After searching for how hight to mount it, tons of head scratching, it dawned on me that they came with a hand crank in the 2f's. and it seems to be just above the front bumper.

Maybe most people just know where to put it.

About an inch to an 1.5 between the radiator and the fan.

 

[aandy767]

working on engine mounts now

 

[aandy767]

That AC compressor and tensioner sure look like they are going to contact the diff.

 

[Mace]

How much hood clearance do you have? if there is sufficient room, you can always mount the motor higher.

Having a bit of a slope of the motor will allow the tranny/tcase to fit better as well.

 

[aandy767]

I think I could go higher, but there's only about 2 - 2.5" to that tensioner. Would need to move the engine up maybe 3", I think the hood would close.

The body and frame are about 75 miles apart. I've got a note pad full of measurements.

They make a relocation bracket to move the compressor up high to the passenger side.

Will remeasure today.

 

[aandy767]

Made some progress on the Transmission mount. Used the cross member that came in the one ton Chevy the NV4500 came out of. It hangs about as low as the transfer case so it should be easy to mate a skid plate.

 

[aandy767]

Okay question
Does my engine look too low?
It seems like the SBC and LS fans sit a little low, But does this look right?
I'm jonesing to burn in the engine mounts, but I think I'll have time. I guess I'll tack in the four link, and three link next.

 

[Mace]

I would personally see if you have clearance issues at "full stuff" before I change anything. Keeping the motor low has benefits.. Course it also depends on how low the tranny/tcase sits under the frame and what you want to deal with.

 

[aandy767]

I need to be patient. My first thought was to finish the mounts, but I have a lot more to sort out before all is set.

 

[Mace]

MUCH Easier to be patient and do things once. Hopefully