Hello

I have a 77.5 f250 with married trans case. I can put it into 4H and the 4wd works but when i put it into 4L it goes into low but stays in 2wd. Any idea what could be wrong with my trans case that would cause it to do that? Thanks

 

What t-case is it? 203 or 205?

 

It is a 205

 

Guess I will bring it in for a rebuild.

 

Have you verified that the front driveshaft isnt turning?

 

Yes,front driveshaft does not turn in 4L.

 

Any grinding noise fron the xfer case when you are in 4L?

Is this a new issue or a new truck for you? Meaning did you just buy it and it wont work or you have had it a while and it use to work?

Have you unloaded (had it in the air) the front end with it in 4L recently? If it works as it should in 4H and not 4L sounds like a internal xfer case issue, rebuild time....

 

No grinding it all, it must have been like this when I bought it. This is the first time I have ever tried using 4L. Its weird it doesn't work. Must be a shaft,gear or key broken somewhere inside of it.

 

Try putting the rear axle up on jackstands with the front axle hubs-lockouts disengaged/unlocked in the free position, and with someone watching put truck in gear while t.c. is in 4low and see if front drive shaft turns

Before you do this double check your t.c. shift linkage to make sure the shifter is pushing both shift rails all the way into the t.c.

 

Did you not ck the 4L when you were test driving it? Lesson learned now.... it is what it is. Sorry moving on....

Ok since there is no grinding, are you sure the xfer case lever is going into the full fwd position. Nothing in the way, speaker box, CB, dash because some crazy shift **** thing hits it ect....

Have you insp and lubed the linkage and made sure it tight, the main mount nut can loosen up.

Also does it have a body lift, sometimes the floor can be the culprit causing this?

Here is the guts, some say 10 hrs to rebuild, if you know what you are doing.......

 

I bought it not running so I could not test it.

You can buy full rebuilds for $690 at broncograveyard,maybe that would be cheaper then rebuilding mine.

Like I said 4H 4wd works and low range works, just not 4wd in Low. I will check linkage. Thanks!


The beast.

 

I would think and hope a trans, GB, or 4x4 shop place could rebuild it for alot less than $690.

Especially is you only need a shaft or one gear since it works in all the other modes?

Keep us posted on what you get worked out, I am curious now.

Your avatar rig and the yellow one are both sharp rides.

 

Sounds to me like an issue with the shift rails, one rail controls the Hi/Lo range and the other rail controls the 4wd/2wd.

I'm guessing when you engage low range, the 4wd shift rail isn't fully engaging.

You might try to put the t-case in 4Hi and crawl underneath and spray both rails with some WD-40 and run the t-case through the ranges a few times.

 

Other than bearing and seals wearing out its very hard to hurt the np205 unless its been neglected since day 1 and your truck does not look neglected at all.
Beautiful truck man!!!

 

ditto the above, 205's just very rarely break, its probably a shifter issue with the rails not both moving. If it is broken, I'd buy a used on for $50-100 before I'd buy a rebuild, since they break so rarely.