# Front diff won't stay engaged



## jeroland (May 29, 2010)

I took my QSW on a mild off-road trail yesterday and was testing out the 4wd and the diffs. The center diff engages and the light comes on in the console but as I was creeping along it kept going out. I could feel slight "clunks" as it disengaged and then tried to re-engage and all the while the light keeps flickering. The road was kind of bumpy and rutty but not extreme. I did notice that it stayed engaged better at higher speeds on the smoother grated dirt roads. The rear locker engages and stays engaged just fine... So, anyone have any ideas? Does this sound like a vacuum line issue or a gear issue in the diff itself?


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## QuantumSyncro (Apr 28, 2000)

Sounds like the vac actuator can't hold because of a vacuum leak. At least that's the first thing I would check since it's the least expensive to resolve. If that isn't the case then move on to the more expensive items.

steve a


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## jeroland (May 29, 2010)

Thanks Steve, my vacuum lines seem to be okay so I think it is the servo that is mounted to the side of the transmission. I'm a bit leery about replacing it though because I have heard that it is hard to remove without breaking the brittle plastic hanger and it has also been hard finding a replacement part... I don't know what to do anymore...


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## QuantumSyncro (Apr 28, 2000)

jeroland said:


> Thanks Steve, my vacuum lines seem to be okay so I think it is the servo that is mounted to the side of the transmission. I'm a bit leery about replacing it though because I have heard that it is hard to remove without breaking the brittle plastic hanger and it has also been hard finding a replacement part... I don't know what to do anymore...


Well you could engage the diff locks and then crawl underneath to see if it's actually holding. Also, you could install a vacuum gauge to make sure that the system is completely tight. Without pulling it I'm not sure what else you could do. Personally I don't think these vac actuators are that uncommon, they appear to be the same as those installed in the doors to activate the locks IMO.

How about the vacuum lines to the manifold and reservoir, everything seem ok? Does it seem to exhibit this behavior at any particular time?

Good luck

steve a


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## eurowner (Jan 26, 2002)

Sounds like the one way plastic white/black vacuum valve is open, lives by the battery tray.


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