What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

SM465 NP208 Shop or Self Rebuild Questions

87K5Newbe said:
Hello all, i appreciate all the support i have recived in the past here. My 87 Blazer has the SM465 and NP208 both of which need new bearings and seals. I was considering doing this myself.

the 208 leaks like a siv and pops out of 4 wheel if i dont hold the stick back somtime, i think mostly in 4L. the 465 shifts ok, somtimes need to drag the clutch to find reverse and of course it leaks as well. need new drive shafts front and rear as well but that i an easy one to solve for me.

first problem i see is tons of cheap chineese bearing and seal kits on Ebay for both transmssion and transfer case. are there good bearing kits out there. it seems the 208 is pretty easy to rebuild acording to youtube, what say you.
second problem is i have heard the 465 if not done properly will pop out of gear. i have never rebuilt a vehical transmission but i am a capable industrial mechanic.

Does anyone have a manuals or guides on rebuilding both units or a weblink they trust.

is there a recomended shop in the west you would recomend. I am In wyoming. just trying to weigh my options here. should i find used 465 and 208 ship them to a shop or ship mine out to a shop or bite the bullet and try it myself? I really dont want to have to park this beast for several months. love driving this thing when home instead of my 2017 Ram.

Any help is appreciated thanks again.

View attachment 514722

View attachment 514723

View attachment 514724

View attachment 514725

View attachment 514726

View attachment 514727
Click to expand...
Just in case it makes a difference in bearings, seals and rebuild parts it appears ( by your pictures ) that your ‘87 model K5 has an older style ( ‘81~’84 K5~K20 ) style long-foot mount adapter and related crossmember - this could mean that your 465 and/or 208 might not be from an ‘87 year model.
I can’t think of any internal rebuild type differences between those years but it might be good to know when ordering parts.

While you are ordering parts for the 465 get the third gear snap-ring replacement sleeve upgrade - it’s cheap and well worth it.


Also, just as mentioned above the shifter tack welding tip will make a huge difference in shifting feel and driver comfort - do not skip that tech tip for it is great advice !

IMG_4088.jpeg
 
tarussell said:
Just in case it makes a difference in bearings, seals and rebuild parts it appears ( by your pictures ) that your ‘87 model K5 has an older style ( ‘81~’84 K5~K20 ) style long-foot mount adapter and related crossmember - this could mean that your 465 and/or 208 might not be from an ‘87 year model.
I can’t think of any internal rebuild type differences between those years but it might be good to know when ordering parts.

While you are ordering parts for the 465 get the third gear snap-ring replacement sleeve upgrade - it’s cheap and well worth it.


Also, just as mentioned above the shifter tack welding tip will make a huge difference in shifting feel and driver comfort - do not skip that tech tip for it is great advice !

View attachment 514790
Click to expand...
Yeah the vehicles that had the 465/208 were all the same from 1981-1988 in 32 spline flavor and tall foot adapter
They were more rare after 1984 though
 
imiceman44 said:
Yeah the vehicles that had the 465/208 were all the same from 1981-1988 in 32 spline flavor and tall foot adapter
They were more rare after 1984 though
Click to expand...
It’s always been my understanding and experience that in ‘85 all adapters went to the short footed type across the board - the 465’s all became long shaft 32-splined ( meaning the K-30 versions dropped the 10-spline coupler after ‘84 ) in ‘85 when the round pattern 205’s with short foot adapters came on the scene to match the ‘81 on up K5~K20 long or short adapters.
For civilian applications the long-foot adapters across the board ended with the ‘84 model year.

Are you say’n that the K5~K20 during ‘85~’88 model years application's used both long and short footed adapters and then switched entirely to short-foot adapters from ‘89~’91 ?
Talk to me about this - never run across a post ‘84 long-foot 465/208 adapter in person or in catalog parts listings ???

The only exception to the post ‘84 model year using a long-foot adapter is the CUCV and related TH400/208 military stuff because they were under contract to keep the supply chain with common parts interchangeability for that model run.
 
Last edited:
tarussell said:
It’s always been my understanding and experience that in ‘85 all adapters went to the short footed type across the board - the 465’s all became long shaft 32-splined ( meaning the K-30 versions dropped the 10-spline coupler after ‘84 ) in ‘85 when the round pattern 205’s with short foot adapters came on the scene to match the ‘81 on up K5~K20 long or short adapters.
For civilian applications the long-foot adapters across the board ended with the ‘84 model year.

Are you say’n that the K5~K20 during ‘85~’88 model years application's used both long and short footed adapters and then switched entirely to short-foot adapters from ‘89~’91 ?
Talk to me about this - never run across a post ‘84 long-foot 465/208 adapter in person or in catalog parts listings ???

The only exception to the post ‘84 model year using a long-foot adapter is the CUCV and related TH400/208 military stuff because they were under contract to keep the supply chain with common parts interchangeability for that model run.
Click to expand...
Just like the CUCV that specific option stayed the same as 84 because there wasn't enough of them to warrant the new design.
IIRC this sm465 was the first 32 spline even though the crew cab was still getting the sm465/np205 in 10 spline until 84.
85 brought the round pattern 205 with 32 spline
 
Never came across any ‘85 on up long-foot K5~20 465/208 adapters but have seen and worked on numerous ‘85 on up short-foot K5~20 465/208 adapters - they are almost identical to the ‘85~’91 K30 465/205 adapters but no provision for the bolt boss for the shifter and no cutout notch on the T-case round pattern for the shift rail that the 205 would require.

Here’s a picture of one:
Note - there’s no notch for the 205’s shift rail as this is for a ‘85~’88 208 case & ‘89~’91 241 case.
1759752122340.png

1759752728052.png

1759752799620.png
 
Last edited:
What's leaking? That's normal seepage by my standards :D, not to discourage you but don't be surprised if both are just as leaky after the rebuilds.
 
tarussell said:
Never came across any ‘85 on up long-foot K5~20 465/208 adapters but have seen and worked on numerous ‘85 on up short-foot K5~20 465/208 adapters - they are almost identical to the ‘85~’91 K30 465/205 adapters but no provision for the bolt boss for the shifter and no cutout notch on the T-case round pattern for the shift rail that the 205 would require.

Here’s a picture of one:
Note - there’s no notch for the 205’s shift rail as this is for a ‘85~’88 208 case & ‘89~’91 241 case.
View attachment 514795

View attachment 514796

View attachment 514797
Click to expand...
Well I guess some assembly locations had more leftovers then because they used them beyond 84.
And by the way, and I will go and confirm today by measuring both, but the 208 adapter is shorter than the 205 by I think an inch.
I wanted to use my 465/205 adapter for a 208 but the splines wouldn't reach, so I found the right adapter.
I have a few of the 205 adapters sitting here
 
imiceman44 said:
Well I guess some assembly locations had more leftovers then because they used them beyond 84.
And by the way, and I will go and confirm today by measuring both, but the 208 adapter is shorter than the 205 by I think an inch.
I wanted to use my 465/205 adapter for a 208 but the splines wouldn't reach, so I found the right adapter.
I have a few of the 205 adapters sitting here
Click to expand...
I wasn’t indicating that the 465-208/241 short-foot adapters were the same length dimension's as the round pattern 465/205 adapters - just pointing out the quick and easy visual differences for reference and that the 465/208 short-foot adapters were indeed made as the picture proves its existence and use.

I’ve never taken the time to compare the lengths of each - I’ve got a 465/208 long-foot adapter and a 465/205 short-foot round pattern adapter that I can measure too if needed.

It makes sense that the 208 input splines came up short when trying to use the 205 adapter as those round pattern 205’s all used the long/deep snout input gear that reached into the adapter for spline engagement as the 208’s did not protrude as far.

As far as the long-foot adapter being used after 1984 I can’t find any parts listings for the dual isolator mounts for that adapter and crossmember but rather it all changes over to the short-foot type one piece mount that is used on the 1985~1991 type crossmembers.
All the listings show a clear cut off point of 1984 model year for the old style mounts and the newer style mount solely being used from 1985 model year forward.
Seems like GM would have listed both type mounts in those years if they were both being used simultaneously - oh well, stranger things have happened…
All is well
 
Last edited:
Don't forget CUCV's are the wild card. They are all '84 spec. My '85 M1009 has the dual isolator tall foot adapter for the TH400/NP208.
 
tarussell said:
Just in case it makes a difference in bearings, seals and rebuild parts it appears ( by your pictures ) that your ‘87 model K5 has an older style ( ‘81~’84 K5~K20 ) style long-foot mount adapter and related crossmember - this could mean that your 465 and/or 208 might not be from an ‘87 year model.
I can’t think of any internal rebuild type differences between those years but it might be good to know when ordering parts.

While you are ordering parts for the 465 get the third gear snap-ring replacement sleeve upgrade - it’s cheap and well worth it.


Also, just as mentioned above the shifter tack welding tip will make a huge difference in shifting feel and driver comfort - do not skip that tech tip for it is great advice !

View attachment 514790
Click to expand...
Thank you. I am researching the 3rd gear now.
 
Chickntrk said:
What's leaking? That's normal seepage by my standards :D, not to discourage you but don't be surprised if both are just as leaky after the rebuilds.
Click to expand...
That's a good question. My power washer died and I dint live near a high pressure car wash. The 208 has to come out it pops out in low. Slip yoke is supper loose. So I gotta pull that off. Then I thought might as well seal up the 465.
 
HankScorpio said:
View attachment 514772
1. The "Ball" is tack welded to the shaft. Check it, the welds can crack and get sloppy. 2.The "Snout" is often 2 piece with a roll pin holding the lower half in. It also wears and gets sloppy, you can weld it together. 3. the "Roll pin seat" can wear and you can put a little weld in there and file the slot back to size. Do all 3 and it makes a huge difference.
Click to expand...
I second this. I welded mine and put “rebuilt” shift forks back in because some of the nylon pads were cracked or missing. Huge difference in how much general “slop” the top of the shifter has. When I’m bouncing down a rocky trail, getting violently rag dolled inside my blazer, the gear shift is much less likely to knock itself out of gear and/or murder my knee cap now.
Cleaning before welding was a major pain in the ass because everything was permeated with gear oil… and a little careful dremeling was needed to make sure the welds didn’t interfere with the way the ball rolls around in the top cover. Totally worth it though.
 
87K5Newbe said:
Hello all, i appreciate all the support i have recived in the past here. My 87 Blazer has the SM465 and NP208 both of which need new bearings and seals. I was considering doing this myself.
Click to expand...
There’s nothing in the transfer case you can’t work on.

HOWEVER! Where’s the leak happening? If it’s just out the rear where the driveshaft goes, you can pull off the rear output shaft housing, and replace the bushing that supports the driveshaft, and the rear seal… there’s a nice rear seal out there that has an accordion boot/dust seal attached to it.

Also! When my 208 started leaking- I just swapped a 241C in. It’s a direct replacement and a hell of an upgrade. Just a hint lower gearing, stronger, and has an internal oil pump circulating the lube.

Might be getting harder to find a passenger drop 32 spline NP241 these days? Good option though. They were found in the 2500 suburbans 1987-91 behind the 465, and also the 400 automatics (with different adapter)
 
Last edited:
You must log in or register to reply here.

Latest Posts

Top Bottom