CK5
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Can anyone prove GM used ATF in an NP205?
- Thread starter 82355
- Start date
Strange how this 91 gmc book differs from the Chevrolet version. I do not have those pages or even the same content.
The previous was a unit repair manual. They are always more in depth for individual components.
Better for we hands on people
Better for we hands on people
If an auto tranny seal went bad could fluid from the np205 enter the auto transmission?
Not as likely as the other way, the 205 isn’t under pressure like the trans is
I had a 10 spline SM465/ NP205, when the seal between the two failed, the t case would over fill while the transmission would go low. And that is without any pressure pump like an auto.
What does "synchro" mean in this context and why did GM change to it?
The syncro version of the 205 was used in the auto locking hub trucks to make shifting on the fly easier and at high speeds….I guess they figured if you didn’t have to stop to turn the hubs in you wernt going to stop to put it in 4wd
How did they auto lock, was it a switch, button?
Same type of auto locking hubs that are / were on 80's 1/2 tons, there was a torque sensing mechanism in it that locked. Long term these were not reliable.
Syncro vs non synco 205's can be identified by the front output rear cover, syncro'd versions had smaller bearing with an oiling vein.
(shift fork assemblies are different between these types of 205's)
Non syncro
Syncronized
(shift fork assemblies are different between these types of 205's)
Non syncro
Syncronized
I'll say went dove hunting in 88 with GMC Jimmy auto locking hubs. Going out standard wash here south of town. We were looking for a cattle watering pond, I had a vague location from the 87 dove opener. We ended up in a super sandy wash the K5 kept unlocking and digging the rears to the diff. Plus his tires were worn out nothing special stock size.
Had to pull him out with my little bronco. He got stuck every 1/8 mile or so till we got to some hard pack.
My Bronco was able to dive through the holes. Made the owner of the jimmy mad. Only mod was 31 10.5 15s Firestone .23
Had to pull him out with my little bronco. He got stuck every 1/8 mile or so till we got to some hard pack.
My Bronco was able to dive through the holes. Made the owner of the jimmy mad. Only mod was 31 10.5 15s Firestone .23
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Interesting, when switching from a 203 to a 205 does it matter which 205 you swap to or is one better than the other?
I would stay away from the syncro one as everything on the front output is unique to that case and hard to come by, heck the case itself is hard to come by as it only came on 80s K30s with auto hubs, manual hub K30s got a regular 205 and the 1/2 and 3/4 ton trucks had NP208s by then that were already syncro’d
Imo, the non syncro'd (most common) version is the best one to use because the front output can easily be upgraded to a 32 spline shaft whereas the syncro'd version cannot without a lot of work.
Interesting. I am looking to buy a 205 from a local guy and didn't know there was a difference. Now I'll have to ask him if it's syncro or not
It's really unlikely to be a sycro'd 205, they were very rare - 3 years (82-84, iirc) of K30's with that option only (so not all K30's those years had them) .
Perfect, thanks for the information
