When to lock hubs or not

[Roonie]

According to the ATLAS II manual most noises are caused by improper driveline angles. If there is any vibration at the shift levers the pinion angle needs attention.

My shift levers do vibrate!

[TroySmith80]

Hmm, so it's generally the short front driveshaft that is making the noise? I guess they figure for as little as it's used, it's not worth making it work smoothly?
Engineer: "we need CVs"
Bean-Counter: "you can't have 'em"
Marketing guy: "We'll just say not to drive fast in 4x4 and call it a day!"


RE: Atlas. If it has synchros, i would imagine it should shift well at speed. 'Course i don't know a damn thing!

[carringb]

Originally Posted by TroySmith80

Hmm, so it's generally the short front driveshaft that is making the noise? I guess they figure for as little as it's used, it's not worth making it work smoothly?
Engineer: "we need CVs"
Bean-Counter: "you can't have 'em"
Marketing guy: "We'll just say not to drive fast in 4x4 and call it a day!"

Pretty much sums it up. Ford and Dodge make CV driveshafts for dealers to install if a customer complains. QuadVan installs the Ford CV driveshafts standard (instead of shortening the U-joint stock driveline). I'm not sure about the others up front.

[geoffff]

Originally Posted by Roonie

AUTOMATIC TRANSMISSION; While the vehicle is slowly moving forward, place the transmission into neutral and engage the front or rear control into Low. The Atlas is a synchronized shift design, which means synchro sets have been added to SPEED MATCH the gear and shaft relation. If you are stopped with no forward motion and the unit will not shift, place the transmission in Drive or Reverse then back to neutral, then attempt to shift the Atlas.
DO NOT FORCE THE ATLAS INTO GEAR.

I usually have a go trying to shift rolling slowly forward in gear (<5 MPH) and if that fails I stop the van and switch off the engine. In that case, it works best if I'm somewhere I can get the van rolling just a bit in neutral.

-- Geoff

[oldfart3]

Unfortunately, it seems like most of the times I need to lock the hubs and engage the front axle, I'm already stuck. Like the manual says, the Atlas can be challenging to shift unless you're moving. I've had pretty good luck by shifting the transmission back and forth between neutral and reverse or drive, but it still takes some coaxing.
John T

[Bones_GSXR]

I was talking about engauging speed. It is the shifting that causes issues not once it is shifted.

When shifting into 2WD or 4WD LOW, REMEMBER the following: The vehicle should be at a slow roll forward, NO FASTER THAN 5 MILES AN HOUR! Speeds faster than recommended could cause personal injury (like unloading the rear payload into the front seats!), or damage to the drivetrain (which is not only embarrassing but expensive!). The Atlas has the unique feature of 2WD low with the rear axle or the front axle. At any time while driving
in low ratio, you can disengage either the front or rear by shifting the respective handle into neutral.

Sounds like you can put it in 4WH at any speed (not that I'd try it) you just can't take it out!

[jage]

Originally Posted by Bones_GSXR

Sounds like you can put it in 4WH at any speed (not that I'd try it) you just can't take it out!

Sure, out to 2wd, out to N just not 4lo or 2lo...

[daveb]

I engage my atlas in and out of 4H while moving all the time. I also can go in and out of 2WD to 4WD in low range while moving but I'm not driving at high speeds. I always make sure there is no load on the drive train during the switch. When shifting from Lo range to Hi range, I'm slowly rolling.

I feel for the synchros, like shiftng a manual transmission without using the clutch. I also use the forward/reverse trick if necessary for moving between Hi & Lo range. I never read the Atlas instructions so I can't say if that's correct, but I've been shifting these same types of transfer cases on heavy equipment for 30 years. Hope it's OK.

I usually engage the hubs before I need them.

Dave

[vandiesel]

I know this is an old thread but finally got to use the van and the atlas today going over Santiam pass. I missed winter last year from an achilles injury. The reason for the post is this: once I locked the hubs at home I noticed an immediate vibration. My last van was a 7.3 quadvan and the new to me rig is a 6.0 SMB 4x4. Can anyone chime in on SMB smoothness with locked hubs? After reading the thread it sounds like I don't have CV driveline joints like my quadvan. Can I take mine to 6 states and have it done? Just curious as I intend to have a blast this winter in the van. I also noticed some mild rattles from going from under load to coasting. I may throw a go pro down there like shuttlepilot did that convinced me to get sulastic shackles.