PDA

View Full Version : np205 problem



rdawg_20
08-11-2009, 03:44 AM
i have a 77 3/4 ton and a 81 3/4 ton chevy same motors, tranys same tranfer case problems in 4low i only have front wheel drive no rear wheel but 4 high I have front and rear wheel drive. What could be the problem broken gear?, shaft?, let me know thanks

soylent_green
08-11-2009, 10:59 AM
It's just a linkage issue, mine does that sometimes, and I take it out of 4lo and put it back in, sometimes pushing with a little force, and it starts working. I haven't worried about it beyond that, what's causing it exactly, because I've got a twin stick setup waiting to get put in.

NorthernDrivetrain
08-11-2009, 08:38 PM
Take a look at where your shift linkage attaches to the t-case. The 205 has a pair of shift rods at the end of the linkage. The top rod (closest to input centerline) controls the 2wd hi/low engagement. The rod pulls out to engage 2-hi, and pushes in to engage 2-low, with a neutral in-between. The rod also has an arm that extends towards the front shift pin that helps to control the shift sequence. It could be possible that you have something that is getting between these that is preventing you from being able to push the 2wd rod all the way, or that other debris in the linkage is keeping the rod from going all the way in.

If that isn't it, then there are a couple of shift rail interlock pins that go between the two rods that could be gummed up. These are harder to fix because the lower shift rod has to be removed to get them out (if I remember right)

mudevil
08-11-2009, 09:15 PM
The shift rail could be worn where the interlock pin comes in contact with it.

rdawg_20
08-12-2009, 01:57 AM
could it have anything to do with the fact that there both 4 speeds?

ox_man
08-12-2009, 02:39 AM
i doubt the transmissions have anything to do with it. definitly sounds like the rails are woren or the linkage has readjusted its self.

start with the linkage. the shift rails would be easier to check/replace with the t-case out of the truck

ox_man
08-12-2009, 02:40 AM
ps i have found my np205 rebuild manual disk for anyone that may need or want it pm me for a copy

twoblood
08-12-2009, 12:16 PM
sounds to me like a linkage issue also.......

zodiac
09-09-2009, 12:49 PM
my 205 dose that also i just hit the shift rails with a hammer