# 4 low won't engage...



## bstarling (Apr 24, 2005)

..all the time. It will bang...bang but stay in 4 high on my 98 Suburban. I have the 4 option transfer case that includes all time as well as conventional 2, 4, and 4 low WD. I was thinking it was binding up but have had difficulty even after backing up and coasting to a stop in neutral. It sometimes catches and most of the time doesn't. Anyone got any ideas.

Bill:fishing:


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## F I LetsGoFishin (Apr 24, 2007)

I sometimes have a simular problem with my old cherokee. When the tranny mounts go bad I can not get out of 4wd and if the motor mounts go then I can not get into 4 low . mine is an 83 with the linkages conected to the frame and yours my be different but it worth looking at.


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## To0C0oL (Jul 17, 2007)

Check the fluid level in both the Transfer-case and Transmission..

It could be differnt on Chevy's, but on Ford 4wd models, after time, the seals keeping the Transfer-case fluid away from the Transmission fluid wear out and the fluid will drain out from the trans and overfill the transfer-case..

If you've never flushed the fluid out before, it might be a good time to do it now..


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## narfpoit (Jun 16, 2004)

First question is are you in Nuetral when trying to engage it? You probably already know that it needs to be in Nuetral but just Checking. If so the the next step could be the (tccm) Transfer Case Control Module. To Check try disconecting the Battery for 30 minutes and retrying this can sometimes reset the TCCM. If that doesnt work then it may be the encoder motor. I think it is posible to turn the encoder motor by hand to see if it is binding. Have you had it scanned to see if any DTC's are listed that would indicate a problem. Also when you push the Button for 4 lo does the indicator light flash like it is trying to go into for lo, if not then it may just be the switch. 

Anyway I hope at least some of this helps.

John


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## bstarling (Apr 24, 2005)

*Thanks to all...*

...for their sugestions. I haven't had time to mess with it yet but will next week. I am still trying to understand what was wrong with the old floor mounted lever. You pulled the sucker and it worked, none of this switch crap.

John, I know you have had right many experiences with GMC 4 WD at least down this way. Did you get it straightened out? 

Anyone have any other ideas?

Thanks, Bill:fishing:


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## narfpoit (Jun 16, 2004)

bstarling said:


> I am still trying to understand what was wrong with the old floor mounted lever. You pulled the sucker and it worked, none of this switch crap.


Yeah they went through all that trouble to so some pansy wouldnt brake a nail trying to engage the 4x4 and ended up with four extra parts that can, and enevatably will brake when you need them.



bstarling said:


> John, I know you have had right many experiences with GMC 4 WD at least down this way. Did you get it straightened out?


Anyway I found my problem. It was the Vacuum Actuator. I ordered a knew one and hope it will get here by next week. The annoying part is that it is located under the battery tray. If it had been somewhere that I could reach it then I could have engaged it manually. I am still looking for somewhere else to mount it but there isnt very much space under the hood of a blazer.


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## Ryan Y (Dec 1, 2005)

*John, One idea, serves two purposes.*

WHat I did was....

My batteray tray was somewhat similar. Take out your battery tray. Cut the bottom out a little smaller then the battery itself and bolt it back in. THat way it will keep the sand out and you can get to what you need to.


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## narfpoit (Jun 16, 2004)

Firespyder7 said:


> WHat I did was....
> 
> My batteray tray was somewhat similar. Take out your battery tray. Cut the bottom out a little smaller then the battery itself and bolt it back in. THat way it will keep the sand out and you can get to what you need to.


Thanks for the tip Ryan. My part came today so I will check that out when I put the new one in.


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## free spool (May 15, 2006)

theres a vaccume line that runs to the drivers side of the front diff. make sure it is pushed on the end all the way and that it has no splits in it. my buddy has a 97 chevy that he had similar problems with i checked it for him and he hasent had any problems since


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## bstarling (Apr 24, 2005)

*Thanks to all...*

for the sugestions. The problem was two fold. Firstly, the transfer case was low on ATF, secondly it prefers to be shifted while slowly rolling. Smooth as silk now.

Bill:fishing:


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