Front differential won't engage

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highperf4x4

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My truck is a 1990 GMC k1500 with the floor shift 208c transfer case. Everything worked fine before I started my most recent upgrades. I pulled the front differential to install a 6" lift kit. While I had it out I took it to the shop and had new gears, bearings, seals installed. I also pulled the transfer case with the factory 5 speed to install a th400. After putting everything back I'm having trouble getting the front differential to engage. I've checked all the harness connectors and I've replaced the actuator. When I shift the transfer case into 4h or 4l it takes forever to engage if it engages at all. Most of the time it doesn't. When it does engage, it won't stay. Once the truck starts moving it disengages. Any suggestions about what I can check and how to test the components involved in 5th member actuation?
 

chevyman98

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When you saythat it takes forever to engage are you talking about the 4x4 or the tcase. The way its worded sounds like the tcase taking a while to engage but I seen you said you have a floor shift. It could be something inside the differential no mating correctly or just the new parts are tight not letting it engage or possibly a defective new accuator
 

chevyman98

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Why did you swap out the 5 speed. If your close in Texas I'd be interested in it
 

highperf4x4

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I needed the th400 for mud bog racing. I put a 383 Stroker motor in it and 4.56 gears front and rear. 2000rpm stall and stage 2 shift kit. The 5 speed worked fine just not good for racing and that's all this truck does anymore. I'm selling the tranny with the clutch kit, slave cylinder, master cylinder and shifter for 600. I'm in Norman Oklahoma. It's 4 hours from here to Dallas.
 

highperf4x4

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My transfer case shifter engages fine. The panel on the floor board lights up when the front differential engages and sometimes it will light up eventually but it won't stay. When I drive around for a minute the lights go out again and stay out.
 

highperf4x4

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This turned out to be the switch on the transfer case. Quick and easy fix. A crescent wrench and 5 minute job. Sorry it took me so long to update. Forgot all about it.
 
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