Rockwell t221 gear slop
 

I've just replaced all the bearings and seals and am getting ready to put this back in. I know there are several on here that have rebuilt these, does this seem right? The low speed gear, spacer and idler gear can move side to side on the idler shaft. It's not end play in the shaft itself, it's almost like the spacer between the two gears has worn. Maybe that's just the way it is made, it was like the before I took it apart also. I tore into it chasing a rattling noise and high speed whine and to stop or at least slow down some of the leaks. I'd hate to put it back in and still have a bunch of noise.

Re: Rockwell t221 gear slop
 

Good to hear about the rock auto bearings. I was going to ask you about that shaft, at first I thought the shaft had a step in it. Then when I took a looked closer at it I can tell it has some wear in it. Dosen't seem that bad though. Attachment 1976876

Re: Rockwell t221 gear slop
 

Mine looks exactly the same, and I thought the same thing that it was made different on each end until i saw that the gears would fit either way and eventually slide over that. I think I'm just going to button it up and throw it back in.

Re: Rockwell t221 gear slop
 

It's never going to be quiet! The gear whine will always be there.

Re: Rockwell t221 gear slop
 

Ya, at this point I am going to rebuild it and put it in also.

Re: Rockwell t221 gear slop
 

I believe the high speed whine may be a normal for its age thing. My T-221 is in very good shape and bxt 48-54 MPH there is a nice high pitched whine. But nothing else. And yes, the bearing and seals are good with no leaks.
Posted via Mobile Device

Re: Rockwell t221 gear slop
 

I know it’s never going to be quiet like a modern one but should the whine be nearing dog whistle levels? That is the speed where I really notice it and the faster the louder and higher pitch. I guess if that’s just the way they are I’ll live with it.

Re: Rockwell t221 gear slop
 

When I had the cover off of mine to inspect I found it to have play like yours but don't remember it as much as yours. But after adding up all the other parts it did need the cost didn't justify repair. I was lucky enough to find a divorced np205 from a international pickup for $100 plus a $50 gasket seal kit. Hope you can make it work. I look forward to watching your progress keep up the good work.

Re: Rockwell t221 gear slop
 

I’ve put it back together and will ignore that for now. I got all the bearing and seals for around $200, and really all the bearings probably didn’t need replacing. I did have to buy an output shaft off eBay but that was purely due to my own lack of forethought.

Re: Rockwell t221 gear slop
 

Id say if it's not leaking, she should be ok. After doing seals, mine held oil for a while but I think it needed bearings as well which led to it leaking after a few months.

I do know that the 221s get a little hotter than say a 205 but I think as long as you're running good fluids and not overthinking it, it should run as it was designed. Long as it has fluid. They're always going to be loud though. Straight cut vs helical cut gears. My '57 Napco had a Spicer 23 or 24. When in 4wd, that thing made a 221 sound quiet.

Again, straight cut gears.

Re: Rockwell t221 gear slop
 

So I got it reinstalled and have been driving it for a bit. The grinding, ratlling dry bearing noise i was hearing is gone. The very high pitched gear whine at 45+ is not gone, but better and I guess tolerable for now. However I've got 2 new (or at least newly noticed) issues. A bad vibration at 50+ mph. I think I've got this isolated to the slip yoke in the rear driveshaft and or a balance issue. There is noticeable deflection in the slip yoke. I took that shaft back off and drove it in front wheel drive only and 90% of that vibration is gone. There is also a rather loud "clunk" when I let out the clutch, or load/unload the drivetrain at speed. Obviously it's not the rear end as it currently is unhooked. I'm wondering if this has something to do with the slop I noticed in the idler shaft and gears. I don't really understand how all that works or what happens when things engage and disengage. Any ideas?

Re: Rockwell t221 gear slop
 

Been going through some of the same issues with my x-fer case as well. Original case in truck sounded like it was going to explode over 50mph. Tore it down and found badly rusted and worn parts, plus a few installed wrong. Basically took best parts from 3 different cases and all new bearings and seals. Now had totally different noises, but maybe a little quieter. Knew parts weren't going to self destruct, and figured noises were from mismatched gears. Shortly after found another case that looked to be in really good original shape, so put it in as is. Sounds much better, but suspect maybe could use a bearing or two. Will investigate when I have more time.
As for your gear slop, I noticed on mine the same wear on half of the idler shaft. I put it together with the worn splines on the low range gear as I recall, so that would be tight in 2hi. I think that helped on mine.
Once I determine that my noises aren't a bad bearing, then will start in with sound proofing the cab floor.
While most everybody I've talked to with a 221 complains about the noise, there is another guy in town with a 65 and his is as quiet as my old 2wd. Would have never believed it if I hadn't heard with my own ears, but there is at least one quiet Rockwell out there.
Keep us posted on your progress,
Tom

Re: Rockwell t221 gear slop
 

What did you get for end play when you shimed the two adjustable shafts.

Re: Rockwell t221 gear slop
 

I got one down to almost zero (by removing almost all the shims) and the other was around .015". I was worried about the amount of shims I took out, but I read elsewhere others have done the same. The service manual says under .015 or as close to zero as possible, so I'm not sure why the shims were ever there to begin with.

Re: Rockwell t221 gear slop
 

Yeah, I'm kind of of the same mind. Once I'm satisfied it's not going to grenade itself I'll start insulating and ignore the rest.

Re: Rockwell t221 gear slop
 

I also way overfilled it before I put the top cover back on and added an elbow to the top plug.

Re: Rockwell t221 gear slop
 

Something I forgot to mention that you might find interesting. While I was doing all the above mentioned swapping and fixing etc, I ran the truck for quite a while without the x-fer case installed. Figured I'd check the gas mileage and then compare when the case went back in. Believe it or not it averaged 13mpg with or without that crazy inefficient counter shaft style case. Go figure.

Re: Rockwell t221 gear slop
 

I'm more surprised you were getting 13mpg at all. ;)

Re: Rockwell t221 gear slop
 

Finally got it back together jd. I did run into one problem. Had a ticking noise in it and finally realized I had the smaller gear on the idle shaft in backwards. Cost me a new bearing for that mistake, but i got it flipped around and it is nice and quiet now. Maybe i can get it sitting back in the frame in a couple of weeks so i can get the rear drive shaft in and set the rear pinion angle so we can finish the 14 bolt swap. Now I have to look into going through the 4 speed tranny. Thanks again for your help. Attachment 1988412

Attachment 1988413

Attachment 1988414

Re: Rockwell t221 gear slop
 

Looks great. I did the exact same thing with the idler, but I caught it in time. One side has a bevel and one doesn't. I figured the bevel needs to face the gear its going to mesh with. Good work.

Re: Rockwell t221 gear slop
 

Man nice paint job 👍
I overhauled mine a year ago, the noise has been the same. I just took a 450 mile trip this weekend to Bakersfield CA to watch the races, cruising 65-70 down highway 5. She was loud, I need to insulate the cab. Also i think the urethane mounting bushings l bought for the transfer case might also be magnifying the sound thought the frame. Other than the noise she ran great. I've put over 9k miles on her since the rebuild.

Joe
1963 K10

Re: Rockwell t221 gear slop
 

Urethane mounting bushings make them noticeably louder!
Been there done that.

Re: Rockwell t221 gear slop
 

Dieseldude4bt, where can you get a set of the rubber bushings?

Re: Rockwell t221 gear slop
 

I could not find any, that's why I know the difference in noise transference.

Re: Rockwell t221 gear slop
 

Wow, never heard that before, but makes sense. I think I may have some usable Rubber ones on a shelf somewhere, so will see if I can swap them out and see if it helps. Will let you all know if/when I get this done. Anybody else out there noticed this?
Thanks for the post, Learn something new every time I check out this forum.