Converted NP203 grinding sound in 2WD

[coolpup32]

@FitzK25 that Torrington bearing seemed to do the trick. I purchased the 501 kit but could not use the wedges, i cant put my hands on the factory parts at the moment, so i just reassembled the Rancho kit with the new bearing. i also replaced the 307 bearing and seal while in there.

 

[FitzK25]

Well, belated update but I finally tore into it - my problem is of a similar nature, but caused by a different part. It looks like I have exactly the same part time kit in mine. My Torrington bearing looked just fine, but the spacer behind it has been eaten quite substantial by the roller needle bearings behind it. I think this may have been caused by poor shimming when this kit was installed, there was no play at the output shaft. Same result though, the 4wd lock selector has clearly been drifting into the differential housing, the teeth and face are noticeably chewed on mine as well. I can’t find this spacer anywhere - does anyone either have one or at least have the dimensions for how wide it should have been originally?

 

[coolpup32]

I can’t find this spacer anywhere - does anyone either have one or at least have the dimensions for how wide it should have been originally?

Check out the top of page 3 on the 501 kit instructions

https://milemarker.com/wp-content/uploads/2018/04/501_203_Instructions_2017.pdf

 

[FitzK25]

I missed that in there, thank you. it’s specked out to .31 inches and I just measured mine at .28. Not a huge difference but maybe just enough. There’s a clear groove worn in the back side of the spacer and it’s definitely making contact.

 

[coolpup32]

You have the 2 shims / washers around the torrington too?

 

[FitzK25]

Yep, that part all looked fine. I’m amazed it ate the spacer behind the Torrington before it ate the Torrington itself.

 

[cstew47]

Uh.. pretty sure the transfer case calls for 10w30.. its too viscous and not lubricating

you need to run it periodoically engaged to lubricate the front side even tho you overfilled.. im guessing the honey you put in there isnt doing well

I believe the 203 calls for ATF. I have a 205 and the PO put the wrong stuff in it. It requires 80wt diff oil

 

[idahovette]

GM said motor oil back in the day. At the dealership, we put in whatever the customer had in the engine, most of the time 10-40 or 10-30. Always used 10-40 in mine, new since June 1975.

 

[FitzK25]

Final update for me - I installed the mile marker 501 kit, and replaced the differential carrier with one with non-chewed up teeth, and found a replacement spacer at a local trans shop. All back together and filled with 10w30, no more noise, shifts well, and as a bonus the driveline clunk I used to have is 90% gone. As a side note, I talked to the guy at the shop for a while about the old crown gear style part time kit, and he said that because they don’t lock around the output shaft, they constantly build and disperse thrust and destroy that Torrington bearing and/or spacer. His recommendation was to get it out of there and replace it with the 501 kit or the full shaft kit if that could be found.

 

[coolpup32]

Thats great @FitzK25

I tried to use the 501 kit wedges but couldnt get the tail housing fully seated. I assumed it was part of the old conversion kit i was using or i did something wrong... either way i was about 1/4 inch from fully seating. I know where the original parts are but cant put my hands on them at the moment. I need to look at them and see if the kit replaced the spider gear or carrier

 

[68post]

Final update for me - I installed the mile marker 501 kit, and replaced the differential carrier with one with non-chewed up teeth, and found a replacement spacer at a local trans shop. All back together and filled with 10w30, no more noise, shifts well, and as a bonus the driveline clunk I used to have is 90% gone. As a side note, I talked to the guy at the shop for a while about the old crown gear style part time kit, and he said that because they don’t lock around the output shaft, they constantly build and disperse thrust and destroy that Torrington bearing and/or spacer. His recommendation was to get it out of there and replace it with the 501 kit or the full shaft kit if that could be found.

Is the full shaft kit the one that hasn't been made for years ?
GM has been all over for fluid recommendations for transfer case lube but I'm guessing the thinner fluids and ATF were all for fuel mileage concerns. Most don't realize that 80-90 gear oil is equal to straight 30 weight motor oil and 140 equals straight 40 weight.

 

[75gmck25]

I remember when the full shaft-replacement kit was available from multiple sources, but it gradually disappeared. It was supposed to be much more durable, but cost more and was more complicated to install. Most guys took the cheaper alternative.

 

[68post]

I remember when the full shaft-replacement kit was available from multiple sources, but it gradually disappeared. It was supposed to be much more durable, but cost more and was more complicated to install. Most guys took the cheaper alternative.

What I thought. I bought a nice '78 K10 High Sierra shortbed that the guy had drove 250 mi in 4 Hi-lock on the interstate and destroyed the 203.
Almost wouldn't make it 10 blocks home but made him take it back because it was un-driveable and was to be for my wife to drive while her Blazer trans was being rebuilt.
Leaked gas in my drive for two days just because I'd topped it off. Too many projects to buy another, too damn bad too !

 

[AuroraGirl]

Speaking of np203, I just noticed my np203 has a pipe threaded into the rear cover, does that mean someone likely modified it for part time setup the "correct" way to be passively lubed?

 

[Dooley]

When filling a 205 transfer case this link is informative.

Help identifying

I have a picture of my transfer case identification tag, trying to figure out exactly what fluid to run, this is a 1988 square v30 454 4-speed, the Chilton's manual says for 86 to 87 k30 k35 refer to owner's manual, it's hard shifting in and out of 4high I'm thinking of fluid change would help...

www.gmsquarebody.com

The 203 Full time were listed for 10-30 or 10-40. Part timed many, but always used the new machined shaft kits on my stuff.
Never had any problems with oiling.
I still have the T400 and transfer case from my 1979 that spent 18 years pushing an 8.5' Western plow.

You must be registered for see images attach