Doj Dewd

i'll check the lube level and top up if necessary. there is already synthetic in it, and i believe it is 75/90, but not positive . . .

i am sure i used to be able to shift at higher speeds than 30km/h / 18mph. i have always let off the accelerator to shift, and always pulled it in gently.

i see where you guys are coming from in the fact we shouldn't be shifting in speeds that high because you shouldn't be in that situation.

i like the 4x4 on the highway when it is snowy (not icey, just snowy) and i come up to someone who is crawling along well under safe driving speeds because they have no confidence although they might be driving a brand new beamer SUV . . . drives me nuts when i have been doing just fine in my light rear-end truck in 2wd. the highway i drive most have very little safe pasing oppourtunities, so i like to take advantage of them when i can to get the most passing room. if i am in 2wd i either slip or have to SLOWLY build my speed to pass. if i am in 4wd i can get out and past much quicker and then shift back into 2wd.

this is about the only situtation where i would like to be able to shift at higher speeds without having to slow down to 30km on the highway, then build speed back up . . . and i also don't want to drive in 4wd fulltime because i then loose feel of what the roads are actually like . . . and that's when it gets unsafe - people who think 4wd is better for driving poor highway conditions - when in fact it can get you into more trouble than driving in 2wd because in 2wd you would have warnings to tell you it's slippery. in 4wd if you slip, there is little chance of recovering depending on the situation of course.

KATOOM

Very true. Most people think 4wd means "I can drive in any condition as fast as I want". Where in fact, direct 4x4 is not safe on slippery roads. Now "all wheel drive" is different. The reason 4wd seems sketchy on slippery roads is because the front and rear tires are forced to spin at the same speed.....but for optimal traction, they shouldn't. All wheel drive vehicles have vicious couplers or differential transfer cases which let the front and rear tires turn at different speeds. So really that all wheel drive SUV is far less likely to have a problem than our 4x4 trucks in 4wd on the same slippery road.

Doj Dewd

i checked the fluid level and it is fine. i am also now noticing issues with the indicator light as sometimes it comes on, and sometimes it doesn't even though i know 4wd is engaged.

could this be some issue with the vaccum? i will hopefully have a chance to check the lines from the t-case to the CAD tomorrow when the truck is in a warm bay . . .

Doj Dewd

in researching this i came across the posilok system for the front axle. seems like a great option instead of replacing stock parts.

if i were to go with one of these, could the 4x4 shift lever on the floor be removed permanently?

Tate

The posilock just operates the CAD, the lever on the floor you still need for the t-case. You could always just hook a vacuum line to the CAD that keeps it engaged all the time. It would be just like the late '02 and newer with a live axle.

Doj Dewd

haha, oh yeah . . . i take back my last question!!

i came across that vaccum line idea also . . . but i think i like the idea of the mechanical system of the posilok.

pros/cons of one or the other?

KATOOM

This wouldn't be the first time I read that someone was having trouble with 4wd engaging in cold weather. Maybe something to do with the vacuum solenoid on the transfercase or maybe one of the vacuum lines. I'd suggest getting a cheap vacuum gauge tester at the local parts store and chasing all vacuum lines to the transfercase and to the CAD unit. Maybe just a cracked or old vacuum line.

Tallguy67

Doj Dewd,
I put the Posi-Lok CAD in my truck last fall. In fact I did it about 3 days before I bought that track bar from you (which is still sitting in the barn btw). You can get the Posi-Lok from Modern Motors on Barlow for $200. It took me a couple of hours to install but I followed the instructions and it went in perfectly the first time and it doesn't leak or anything. I am really happy with it. When I need 4WD, I slow down, pull the cable, 4wd light comes on, go to 4H on the transfer case and away I go. Those vacuum lines on the CAD are nuts considering the winter conditions and road salt we have. When I am highway driving in bad conditions, I leave the CAD engaged and then you can go back and forth from 2wd to 4wd on the highway at any speed since you already have the front end all spun up to speed. I am really happy with the Posi-Lok CAD replacement. Will answer any questions you have. If you need a warm barn for an install before it gets warm outside, let me know.

Doj Dewd

hey sean,

good info on the posilok. i was gonna call modern motors to see what the price was . . . sounds like it's about as cheap as it's onna get. you mean modern motors on blackfoot?

i was also curious about shifting speeds, i figured if it was already engaged then shifting in and out at any speed should be ok. i also like the fact i can have 2 wheel low if needed . . .

thanx for the feedback on this!

Tallguy67

Yeah - on Blackfoot not Barlow, a few blocks north of Glenmore. Engaging the CAD at any speed above a crawl isn't very nice the way I do it , which is CAD first and the tfer case next. However, once CAD is locked, you can go between 2H and 4H at any speed. The only things you will need that are not in the kit are: good RTV (it comes with a gasket but you need the RTV for a couple of the threaded fittings) and some more diff/axle lube. It is a good solid kit. The hardest part about the whole thing was drilling the hole in the firewall and then threading the cable around the tranny etc to get from driver side over to the CAD on the passenger side. I figure that any good upgrade I can do on our trucks for $200 is about as cheap as it is going to get.

KATOOM

Shifting in and out of 4wd can be done at just about any speed when the front driveshaft is already spinning at the same speed as the rear driveshaft but still I'd rather have a part time system so the front u-joints aren't subject to all the unnecessary wear and tear.

Also, you're right about the 2 lo feature. Its an AWESOME feature to have and its only available on the CAD equipped axles. Its to bad that no manufacture has captivated on the 2 lo feature either simply because of how handy it is for trailering. Anyone who bypasses the CAD unit by keeping it engaged all the time is really missing out.

Tate

Not with manual locking hubs.


You should engage the transfer case first. It has synchronizers in it to bring the driveshaft up to speed, and then the CAD engages. The CAD does not synchronize, thats why you can't engage it above a crawling speed on its own.

KATOOM

True but how many trucks come with locking hubs anymore. Everything is push button this and automatic that. Any longer and these trucks will be driving themselves.