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Old 04-23-2002, 02:46 PM   #1
mountainexplorer
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NP205 pops out of low

I have a '78 3/4 ton 4x4 with an SM465 and NP205. The Transfer case pops out of low range, especially when turning while locked in 4wd. What would be the cause?

Also, I have an '80 that has a 205 with the slip yoke. Would it be easier to convert it to a fixed yoke or easier to just use another T-case that already has a fixed yoke?
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Old 04-23-2002, 03:04 PM
Posted in reply to mountainexplorer's post "NP205 pops out of low"
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Re: NP205 pops out of low

I had a problem with flex and the tranny hump would hit the shifter when in 4Lo and cause it to come out. If the clutch teeth or gear teeth are worn it can also cause it to slip out under stress, but I would check for floor clearance first (also it was hard to tell on a level surface that there was interference, I had to manually flex it with a fork lift to figure out what was happening). As far as swapping a complete case or just the fixed yoke tailshaft. You can swap in a fixed yoke tailshaft while the case is still in the vehicle so swapping in a fixed yoke tailshaft is easier. It is harder to find just a rear output but can be done (as I've done it) as opposed to a whole case.
Considering yours is slipping out of gear it may not be a bad idea to find a complete spare and swap it in. Hope this helps.
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Old 04-23-2002, 05:57 PM
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Re: NP205 pops out of low

Theres plenty of clearance as far as the shifter goes. My '78 is completely stock (that is no lift, and little 31" tires). It sounds like something internal. When it pops out, it makes a loud clunk, not as if it were to just slip out. I do know that the clutch in it is pretty worn and bad. Plus now, the tranny jammed in low gear and the shifter is stuck in the position of 3rd. Its always one problem after another.
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Old 04-23-2002, 06:18 PM   #4
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Re: NP205 pops out of low

linkage worn not allowing full engagement
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Old 04-23-2002, 06:32 PM
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Re: NP205 pops out of low

Mine would slip from 4lo to 2lo all the time until I found out that it wasn't fully engaging into 4lo. It was hitting the floor and not fully engaging. I just adjusted the cover forward about 1/2 of an inch.
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Old 04-23-2002, 10:41 PM
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Re: NP205 pops out of low

Pull up the shifter boot and see how close the shifter really is to the edge of the floor when it's in 4Lo. I had a brand new '79 F-150 that would kick out of 4Lo every time I started up a hill. 2 minutes with the tin snip and it never happened again. [img]/forums/images/icons/cool.gif[/img]
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Old 04-23-2002, 11:17 PM
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Re: NP205 pops out of low

I'll double check the shifter clearance again. Although I'm pretty sure it wasnt hitting or rubbing, at least it wasnt when we put the body on the frame. My '78 used to be a 2wd. When we put it's body on a '79 4wd frame, we cut out the floor and used the '79 cab center-hump. That was a year and a half ago since I looked under the boot.
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Old 04-23-2002, 11:22 PM   #8
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Re: NP205 pops out of low

You want to have someone watch it while you drive. A sagging body bushing and/or tired engine/tranny mounts can let the body meet the shifter as torque moves things around.
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Old 04-23-2002, 11:49 PM
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Re: NP205 pops out of low

my buddies did that to but out of high. had a bad thrust washer in it somewhere. he had it rebuild... not a cheap fix.
600 bones later
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Old 04-24-2002, 12:34 AM   #10
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Re: NP205 pops out of low

Yikes, I'm hoping it wont need a rebuild. I paid $600 for the whole running truck, then just put my '78 body on it. It only does it in low. 4-high works fine, no noises or anything. My cab/body mounts are all good, since I made sure I used good ones (I was too cheap to buy new) when I swapped bodies. I'll know for sure or not if it's the floor/shifter clearance in the next few days (the truck is 85 miles away from me right now). I gotta pull the floor pan out anyway to get the tranny shifter un-jammed.

The same weekend my 4spd jammed in low, I also discovered my oil in my '75 Blazer was a sparkling metallic grey color. and I still havent discovered the cause of the mysterious T-case seal leak in my Suburban. I filled it to the full point a month ago. Since then Ive leaked out a good 2 quarts in various places Ive parked. Every time I check it now, it's overfull; but it still leaks everywhere and now clunks like the tranny to T-case sleeve is about ready to sheer off it's splines. My vehicles like to do this to me all at once. 10 trucks and I'm down to one I can drive.
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