208 help

[ftcjimmy]

I just swapped out a bad np208 for what i thought to be a good one. I start it up, go to put it in drive. Nothing . Reverse...Nothing . I go to put it back into park and i get a grinding noise . I disconected the transfercase shifter from the case and make sure its in 2 high because the shifter wasnt putting it all the way in.....the linkage needed adjustment. Still nothing. When i put it into reverse and drive the motor idles down a bit just as if i was sitting there holding the brakes when putting it into drive. thats normal. Anybody have any ideas as to what my problem is before i have to drop it again? thanks -DJ

 

[pauly383]

Put it in 4 low and see if it grabs , maybe bad shift fork on the range selector .

 

[ftcjimmy]

nope. shifted through all the ranges. nothing.

 

[dave_90_blazer]

were the splines ok on the input sleeve of the t-case? if they are stripped, it will do what you are experiancing

 

[ftcjimmy]

just kinda threw it on....not sure. looks like im droppin it again tonight

 

[pauly383]

Don't be scared to take the case halves apart . Its easy to tear into this , just need an exploded view and pick up the needle bearings to reassemble . There is a post with the guts pic on here , have to dig it up .

Loved to know what happened to it !

 

[norville]

Please let us know what happens. I'm looking at sub with a 208 and a "tranny problem". When I looked at it it was in 4 low. I'm thniking it has a bad fork in the TC . And the PO thought the tranny was shot.

thank
bob

 

[ftcjimmy]

WEll my DD just lost its brakes so i probly wont get around to the case till late tommorow morning. ill post up as soon as i figure it out

 

[resurrected_jimmy]

Is there any reason not to think it might be the tranny?

 

[fordtruggy]

If the T case is in nutral it will do exactally what you are saying.But I dunno what else it could be doing other than the splines not being wright...?

 

[diesel4me]

mismatched>???

Maybe he put a TH400 style 32 spline NP208, on a 700R4 tranny with 27 splines about 1/4" smaller in diameter????..that would make for some slippage..

 

[rooferbret]

Bingo!

Thats exactly what happened when i installed one for a sm465 instead of for my 700r4.

 

[79k20350]

that does seem very plausible...

 

[dave_90_blazer]

that does seem very plausible...

yeah, I thought of that last night when I was drunk

 

[ftcjimmy]

And that was what it is, wrong spline cout. The input on this new case was bigger. But hey on the plus side, ive cut my case swap time down to about an hour and 15 min., with simple hand tools! Never know, this may come in handy on the trail someday.

 

[diesel4me]

keep that case??

I'd keep the "wrong" NP208 in case you want to upgrade to a TH400 or SM465 someday(you'll need the adapter that goes to them too though)..Either that or maybe you could sell it..possibly to ME!..but I do have 1 "spare" already..

I bought a NP208 and a TH400 adapter at Thompson Speedway's swap meet last year for 30 bucks..I'm hoping its a good one,(feels ok turning it by hand,and it shifts ok)--the one in my 82 K20 doesn't come out of 4wd anymore,so I just unlocked the hubs this summer,and didn't use it too much anyway(mostly I just plow with it and use it in poor weather)..

Once you do a R & R of a T-case,you find its not that difficult really..other than a few hard to get a wrench on bolts,lifting it up and getting it in is the hardest part of the job..A NP208 is easy compared to the NP205 cast iron case!... about 100 lbs easier!. .

 

[roadnotca]

I posted the Xplode of the NP208, from the '85 parts book. Let me eat breakfast, and I'll post again.
PC problems here, it won't upload.
Tried again at 15:00 PST with "pictures", maybe not my PC.

 

[WarrenLovell]

Sounds like what mine was doing...and I drained the fluid and out came white vinyl shifter fork covers!...Now it only does it when I slam on the brakes.

Warren