Front Disconnect AWD Sleeve / Grease Fitting / Poor Mans Mod

[dvanbramer88]

I was unaware people wanted 2lo.... interesting idea though, especially for someone's first post (i smell a lurker).
Where's our EEs for this one? The theory is good, but I would imagine that the motor would only activate for when the signal is sent from the selector. So there would be no way to go from 2lo to 4lo. it would have to be 2lo, back to 2hi, (flip switch) then back to 4lo. Not entirely sure of the use of 2lo, ultimately. ALSO not sure what, if any, wear/damage would occur to xfer case/front diff/disco by not having the front engaged in 4lo. If my mental flow of tq is accurate, wouldn't in a way put the drive train essentially in 3lo?

2lo is good for parking a heavy trailer or on a steep boat ramp where you still need tight turning abilities on pavement, but a little extra torque would be nice. Or just otherwise running in low gear. Like a lot of the switchbacks on TECORE, the only reason we run 4LO is for the LOW not the 4.

With an open front diff, it would be "intermediate shaft lo"

[DirtyBacon04]

Yea, thats why I said essentially 3lo. As in if the vehicle was on a 4pt lift... 3 tires would turn. Never thought of that need for a 2lo... interesting...

I'm in FL.... so, uhhhhh whats a switchback?! Some kinda snake or something? Is it poisonous?

[dvanbramer88]

Yea, thats why I said essentially 3lo. As in if the vehicle was on a 4pt lift... 3 tires would turn.

Yes. But I don't do too much of my driving on a 4 point lift.

I'm in FL.... so, uhhhhh whats a switchback?! Some kinda snake or something? Is it poisonous?

They live in the mountains, usually on the side of big forested hills. Not native to Florida.

[DirtyBacon04]

Yea, thats why I said essentially 3lo. As in if the vehicle was on a 4pt lift... 3 tires would turn.

Yes. But I don't do too much of my driving on a 4 point lift.

Ha! Pussy.

Thats the ultimate "off-road"

[BlackLT]

I was unaware people wanted 2lo.... interesting idea though, especially for someone's first post (i smell a lurker).
Where's our EEs for this one? The theory is good, but I would imagine that the motor would only activate for when the signal is sent from the selector. So there would be no way to go from 2lo to 4lo. it would have to be 2lo, back to 2hi, (flip switch) then back to 4lo. Not entirely sure of the use of 2lo, ultimately. ALSO not sure what, if any, wear/damage would occur to xfer case/front diff/disco by not having the front engaged in 4lo. If my mental flow of tq is accurate, wouldn't in a way put the drive train essetially in 3lo?

Hmmm, not really a lurker - just kinda!
I'm from back in the trailvoy days (like 2007!) - then GMTNation. I am lifted, but don't do much off-road. Searching for why my 4WD didn't work I found the diagnostic flow chart on here as well as this thread. I do wander over here from time to time but never had a need to post.

I knew my version of the poor mans mod works and thought it may be useful to someone else.
I figured people such as yourself and others, that know more than I, would know if it would work for the 2 lo thing.

I don't know exactly how all that works, but you say about 3lo. Without the disconnect engaged my truck was only 2WD even when the selector was in 4Hi. So how would it be different in 4Lo? I'm probably just not following what you mean by 3lo.

[DirtyBacon04]

meaning it would only be "3lo" if you had a front locker. but since MOST of us don't it would just drive like a 2lo... i suppose i shouldn't have mentioned it. it's just confusing people

[Trail X]

Indeed Bacon, 3lo is a confusing term, and only applicable with a front locker.

Nelson, I had done something similar at one point, except I don't like cutting wires. You can get the same effect if you extend the actuator, and then just unplug it's electrical connector and cover them up to keep them clean. I see clipping wires as a recipe for potential electrical malfunctions in your future.

You say that clipping this wire does not cause a 4WD error light to illuminate? I find that surprising. What is the function of the wire that you cut? Does it not give an error light in any position?

[BlackLT]

I don't get a warning light in any position. Well, not in 2hi or 4hi - didn't check the others.
I took a guess at the black wire being the negative for the motor. The sensor to tell if it's extended must be 2 of the other wires and evidently the sensor doesn't check if it retracts in 2WD??
Duly noted on the wire cutting possibly being bad. I do plan to fix it right - at which time I will solder the wires back together.
I don't have a garage - we had a good bit of snow and single digit temps - till I diagnosed what was wrong, I drove my 95 Camaro in the snow storms - not fun. Cutting the wire seemed like a small thing at the time!!

[Trail X]

The TCCM watches the feedback signal from the actuator to make sure the actuator engages fully. If the signal on the feedback doesn't go from hi to low after it sends the "extend" signal, it should report a problem. I don't understand how cutting the wire bypassed all of that. Is it possible that your service 4WD light is burned out?

[bartonmd]

I was unaware people wanted 2lo.... interesting idea though, especially for someone's first post (i smell a lurker).
Where's our EEs for this one? The theory is good, but I would imagine that the motor would only activate for when the signal is sent from the selector. So there would be no way to go from 2lo to 4lo. it would have to be 2lo, back to 2hi, (flip switch) then back to 4lo. Not entirely sure of the use of 2lo, ultimately. ALSO not sure what, if any, wear/damage would occur to xfer case/front diff/disco by not having the front engaged in 4lo. If my mental flow of tq is accurate, wouldn't in a way put the drive train essetially in 3lo?

You're likely right about having to go from 2LO to 2HI back to 4HI or 4LO to get the motor to engage again.

However, there's nothing wrong with running the T-case in 2LO. I used to do it on my CTD to back heavy trailers up steep pavement, where you want the low range, but don't want the 4WD scrubbing tires. Even current Ford trucks can use 2LO, because they still have lockouts at the front hubs.

Mike

[Steeda]

Since everyone in this thread has exploded the front Disco numerous times.... i have a question:

Has anyone that has 4wd (2wd/4hi/4lo/auto) seen any additional wear or damage from doing the sleeve mod?

I ask, because I don't know if our Transfer case is designed to have the prop-shaft spinning all the time.

I read over on GMT that someone lunched their transfer case running it in AUTO for a year- and I wanted to make sure that the sleeve wouldn't produce the same results.

Oh- and I am asking because mine went boom. Thanks everyone.

[v7guy]

I know there are no shortage of guys here running the AWD sleeve for years with no issues. I don't know that it's been discussed from a transfer case stand point, but as far as the front axles it provides more support and is likely much easier on the bearings in the outer disconnect.

I would say that it's likely a non issue.

[DirtyBacon04]

I've been running the awd sleeve for several years, however have yet to crack it open to inspect internals... I guess that should be on my to do list, eh?

[Trail X]

The only real additional wear is on the seals of the prop shaft. This goes for the one on the back of the front diff, and the front prop shaft seal on the transfer case. The clutches in the transfer case actually get reduced wear when the front end is sleeved. My diff pinion seal is leaking, and I'm betting its because of the sleeve.

[cpyonker]

Has anyone had any issues with the awd sleeve yet?

Also, do you need the zerk?


Sent from my iPhone using Tapatalk

[Laxman33]

I need to repair the disco on my wifes trailblazer. I am very interested in the awd sleeve mod, but still a little confused on how it all works. Once installed you will be in AWD full time. So will there still be 4hi and 4lo? Will there every be any need to use the dash selector anymore.

[DirtyBacon04]

I need to repair the disco on my wifes trailblazer. I am very interested in the awd sleeve mod, but still a little confused on how it all works. Once installed you will be in AWD full time. So will there still be 4hi and 4lo? Will there every be any need to use the dash selector anymore.

A little more reading would've answered all this for you. The sleeve does not make your rig AWD. The difference between AWD and 4WD systems lies within the transfer case. A change to the splined disconnect (aka disco) will not affect your transfer case.
GM originally designed a disconnect between the intermediate shaft and passenger CV shaft to reduce wear and drivetrain drag, thus preserving MPGs. This disconnect has proven to be a weakness in offroad usage. Therefore we discovered that using the sleeve that is found in AWD versions of the 360 will mitigate that weakness. The sleeve invalidates the term "disconnect" as it is no longer disconnecting. All the sleeve does is permanantley connect the intermediate shaft to the passenger CV shaft, and in no way affects your transfer case or 4hi/4lo ability.

Functionally, you will still drive the same. You still need to use the dash switch to engage A4WD,4hi, and 4lo.

When you switch into 4hi/4lo, two things are occurring. 1) the transfer case is engaging the front prop shaft and 2) the disco motor engages, locking the intermediate shaft to the CV shaft.
What this mod does, is eliminate the second step by remaining connected at all times.

[Laxman33]

I need to repair the disco on my wifes trailblazer. I am very interested in the awd sleeve mod, but still a little confused on how it all works. Once installed you will be in AWD full time. So will there still be 4hi and 4lo? Will there every be any need to use the dash selector anymore.

A little more reading would've answered all this for you. The sleeve does not make your rig AWD. The difference between AWD and 4WD systems lies within the transfer case. A change to the splined disconnect (aka disco) will not affect your transfer case.
GM originally designed a disconnect between the intermediate shaft and passenger CV shaft to reduce wear and drivetrain drag, thus preserving MPGs. This disconnect has proven to be a weakness in offroad usage. Therefore we discovered that using the sleeve that is found in AWD versions of the 360 will mitigate that weakness. The sleeve invalidates the term "disconnect" as it is no longer disconnecting. All the sleeve does is permanantley connect the intermediate shaft to the passenger CV shaft, and in no way affects your transfer case or 4hi/4lo ability.

Functionally, you will still drive the same. You still need to use the dash switch to engage A4WD,4hi, and 4lo.

When you switch into 4hi/4lo, two things are occurring. 1) the transfer case is engaging the front prop shaft and 2) the disco motor engages, locking the intermediate shaft to the CV shaft.
What this mod does, is eliminate the second step by remaining connected at all times.

I did some searching but was still a little confused. But you cleared everything up for me now. Thanks for taking the time and going into all the details. I really appreciate it. Now just need to get my parts ordered.