AMC Eagle Den Forum

The Shop => 4X4 and Driveline => Topic started by: johnbendik on August 20, 2014, 04:59:45 PM

Title: Clutch slippage or ???
Post by: johnbendik on August 20, 2014, 04:59:45 PM
I recently did the 'full-time all-wheel drive' mod:

- disconnected the vacuum hoses from both transfer case and front axle shift motor, and sealed off the vacuum canister
- dissembled the front axle, moved the slider over to lock the spines together, and installed a hose clamp to keep it there
  - drove around some, everything seemed to work OK
- used a 9/16 wrench to engage the transfer case in AWD mode
- tested this by jacking one front wheel off the ground and trying to spin it; it had a lot of resistance.

Now, when I drive around, it acts exactly like the clutch is slipping: the engine revs without the car accelerating (unless I accelerate very slowly).   The problem is worse in 1st and 2nd gear.

Normally, I would just assume that my clutch is going out, but it's weird that it started happening right after I manually engaged the transfer case. 

Is there anything I could have done engaging the transfer case that would cause my symptoms?  I've seen references on the den to the dangers of 'false neutral', but I'm not sure exactly what that is...

If anyone has any ideas, I would appreciate hearing them.

JB


Title: Re: Clutch slippage or ???
Post by: Mernsy on August 20, 2014, 05:12:11 PM
When you  moved the lever did you use anything to hold it there? It may have slipped out of 4wd and into false neutral.
Title: Re: Clutch slippage or ???
Post by: Amc1320 on August 20, 2014, 06:37:44 PM
Yep, it actually needs some pressure to hold it into 4 wd, like the vacuum thing would do

I wired mine into 4wd with a peice of bailing wire, worked fine for the last couple years
Title: Re: Clutch slippage or ???
Post by: johnbendik on August 20, 2014, 06:40:12 PM
No, I figured that disconnecting the vacuum hoses would be enough.

But I forgot to mention this in my original post: After driving a few blocks and realizing that something was wrong, I went back under the car and moved the lever back to 2-wheel drive (and verified that the front driveshaft spun freely).

But the roaring noise (and the slippage) is still there.

Can you or anyone else explain what the 'false neutral' condition is?  Or point me to some existing posts that explain it?  I did a search, but didn't find anything useful.

Thanks,
JB
Title: Re: Clutch slippage or ???
Post by: Amc1320 on August 20, 2014, 07:17:54 PM
It needs pressure to hold it in 2wd too

Put it in one or the other and wire it in place good and tight, see if that holds it in place, put tension on it

I hooked the wire to one of the bolts that hold the skip plate on, either front or back depending on 2 or 4 wd mode

I know it sounds kinda redneck, but it works

I also did the front axle thing like you did
Title: Re: Clutch slippage or ???
Post by: johnbendik on August 20, 2014, 09:19:55 PM
Eagle's Den to the rescue, once again.

It was indeed a 'false neutral' problem.  (Once I learned how to spell it, the search worked fine...)

I proved this by shifting it back into AWD, then securing the lever with a method that makes AMC1320's 'redneck' solution look like aerospace engineering: a bungie cord!  I'll go back under there tomorrow when there's better light and secure it properly.  But my quick test drive showed that the noise and slippage was gone.

I awarded thumbs up to both of you (Mernsie and Amc1320), because you probably saved me from spending a boat load of time and money replacing a perfectly good clutch, which would have been just sad.  It's amazing how much the 'false neutral' symptoms mimic a slipping clutch.

Thanks again to both of you, and may all the gods bless this web site.

JB
Title: Re: Clutch slippage or ???
Post by: captspillane on August 22, 2014, 11:45:38 AM
Quote from: johnbendik on August 20, 2014, 09:19:55 PM
It's amazing how much the 'false neutral' symptoms mimic a slipping clutch.

Thanks, that is actually a really clever way to describe it. The reason it is called "false" neutral is because it's never totally disconnected like a real neutral mode would be. It's not a mode you could tow in or anything like that. The car will lurch or barely move and make noises when it is in between the gears, just as if the clutch was totally shot and just barely engaging.
Title: Re: Clutch slippage or ???
Post by: Amc1320 on August 22, 2014, 09:04:47 PM
Good News!
Title: Re: Clutch slippage or ???
Post by: IowaEagle on August 25, 2014, 11:33:50 AM
Darn old false neutral anyway.  You can blame me, I think, for coming up with that term.  I felt it really described what it was doing.  It sure got my attention the first time it happened to me.