The 1947 - Present Chevrolet & GMC Truck Message Board Network

The 1947 - Present Chevrolet & GMC Truck Message Board Network (https://67-72chevytrucks.com/vboard/index.php)
-   All 4x4 Tech & Off Roading (https://67-72chevytrucks.com/vboard/forumdisplay.php?f=30)
-   -   T221 assembly issue (https://67-72chevytrucks.com/vboard/showthread.php?t=596913)

mjensen 09-15-2013 11:14 PM

T221 assembly issue
 
1 Attachment(s)
So I was bolting my TCase up tonight, and wasn't really paying attention. Apparently the new bearing for the input shaft is thicker than the old one, because it blew right through the cap on the back. Question 1 is, can this plate be welded? It looks as if it's made out of aluminum, so I'm thinking I can get it TIG welded. Question 2 is whether or not shims are still available somewhere.

Attachment 1152517

'63GENIII 09-15-2013 11:39 PM

Re: T221 assembly issue
 
Yikes that's blows! I bet it could be tig welded or maybe even brazed as long as it doesn't change the tolerances. Does that cap actually hold the bearing or just keep it in the case? That's weird that the bearing was larger than the original
Posted via Mobile Device

mjensen 09-15-2013 11:42 PM

Re: T221 assembly issue
 
It just keeps it in the case. I wouldn't have thought the new one would be thicker, which is why I didn't even think to watch for that. I put the original shims in. Guess that's what I get for assuming.
Posted via Mobile Device

'63GENIII 09-16-2013 12:02 AM

Re: T221 assembly issue
 
I've never been inside a 221 so forgive any stupid questions I may have. If you were to change the shims, would that throw off the gear lash? Or are you looking for a different (thicker) retainer gasket? Is it too late to return the bearing for the right one or too much to take it all apart?
Posted via Mobile Device

swamp rat 09-16-2013 08:35 PM

Re: T221 assembly issue
 
Can you compare the new with the old? or did you toss it? wouldn't hurt to double check that thickness to rule out any possible assembly errors. Of course i have never been inside one so i'm not much help. :)

maxwoof 09-16-2013 10:19 PM

Re: T221 assembly issue
 
My understanding - and you should confirm - is that the star shaped aluminum retainers hold the one piece ball bearings, like the rear input shaft, and only have gaskets behind them. The steel retainers, which use shims, hold the two piece tapered cone/cup bearings, like the idler shaft bearings, and the shims are used to set bearing preload. I believe that the ball bearings need to be driven onto theshaft/bore, and that if the retainer is used to drive them it can crack like yours did.

I have heard of guys fabricating retainers from pipe flanges. You would need to make sure there is a way for the oil from the holes on the case to get to the bearings. You can see how this works by looking at the inside of the bearing retainer.

I would think that if you could weld yours up, and the result didn't leak oil, you would be fine. I don't think that the gear mesh is affected by that beareing because the shaft is fixed in the bore.

There are pdf versions of the rebuild manual including exploded parts diagrams which can be very helpful.

The best advice I can give is to keep the oil level up. The upper bearings can burn out if the oil level gets low. I once saw a "high level oil kit" somewhere. It consisted of a street elbow that screws in before the fill plug. Seems like a good idea to me.

Also, from time to time, I have seen that part for sale on ebay.

Good luck.

mjensen 09-16-2013 10:31 PM

Re: T221 assembly issue
 
Quote:

Originally Posted by '63GENIII (Post 6271224)
I've never been inside a 221 so forgive any stupid questions I may have. If you were to change the shims, would that throw off the gear lash? Or are you looking for a different (thicker) retainer gasket? Is it too late to return the bearing for the right one or too much to take it all apart?
Posted via Mobile Device

There are never any stupid questions...at least that's what I keep telling myself after I post something like this one :lol: The input shaft gear just "rides" on the shaft, there isn't any lash to be set that I saw in the manual that I have. Because the parts are so hard to come by for the T-221, I ended up getting this shaft and bearing from a fellow (awesome) board member that was getting ready to scrap his spares. I didn't think to take careful measurements prior to reassembly because I just made a bad assumption. The large input shaft bearing is somewhat pressed on, so it would be a challenge to remove it. Most research I have found just states to throw more shims at the back plate.

Quote:

Originally Posted by swamp rat (Post 6272608)
Can you compare the new with the old? or did you toss it? wouldn't hurt to double check that thickness to rule out any possible assembly errors. Of course i have never been inside one so i'm not much help. :)

Ha...sure didn't. I put the TCase back together and threw the old parts away without really checking the fit with the trans adapter bolted on.

Quote:

Originally Posted by maxwoof (Post 6272852)
My understanding - and you should confirm - is that the star shaped aluminum retainers hold the one piece ball bearings, like the rear input shaft, and only have gaskets behind them. The steel retainers, which use shims, hold the two piece tapered cone/cup bearings, like the idler shaft bearings, and the shims are used to set bearing preload. I believe that the ball bearings need to be driven onto theshaft/bore, and that if the retainer is used to drive them it can crack like yours did.

I have heard of guys fabricating retainers from pipe flanges. You would need to make sure there is a way for the oil from the holes on the case to get to the bearings. You can see how this works by looking at the inside of the bearing retainer.

I would think that if you could weld yours up, and the result didn't leak oil, you would be fine. I don't think that the gear mesh is affected by that beareing because the shaft is fixed in the bore.

There are pdf versions of the rebuild manual including exploded parts diagrams which can be very helpful.

The best advice I can give is to keep the oil level up. The upper bearings can burn out if the oil level gets low. I once saw a "high level oil kit" somewhere. It consisted of a street elbow that screws in before the fill plug. Seems like a good idea to me.

Also, from time to time, I have seen that part for sale on ebay.

Good luck.

Thanks! Yeah, I took good pictures of how this came apart and had the pdf that details ripping it apart. The shims went in just as they came out, but with the "new" input shaft, I should have measured against the old...instead of with the size of the cracks in the retaining plate :lol: I'll keep my eye out on eBay to see if one comes up. On another note, I emailed a guy at work to see if he had any scrap 221's laying around to which is response was "no, but I have two 205's". Maybe if he has the trans adapter I'll switch to the easier to find parts for 205. Of course that's going to open up a few more issues that I'll need to deal with.

JPBrecheisen 09-17-2013 12:45 PM

Re: T221 assembly issue
 
I would think you could get that thing welded up. I'm pretty sure you can get custom shims made. Not sure what it would cost, but I'm almost certain it can be done. Just depends on how bad you want to keep the Rockwell unit.

Here are some links that might help on the shims possibly.

http://www.aloma.com/custom.aspx
http://www.metalshims.com/c-26-custom-shims.aspx

argonaut 09-18-2013 01:02 AM

Re: T221 assembly issue
 
I need to check but I didn't think you need to shim that rear cover for the input shaft. I thought it required a thick gasket.
But i could be wrong. I'll check the book.
Posted via Mobile Device

Yukon Jack 09-18-2013 02:49 PM

Re: T221 assembly issue
 
Mike, I still have my old T221 that got damaged when I got low on gear oil and toasted some bearings. My retainer cap got torn up and I took this as a good opportunity to swap in an NP205. Looking at my old pictures, my T221 did have shims under that cap and I should have those still. If you need them, send me a PM.

pheengurs 04-14-2019 03:14 PM

Re: T221 assembly issue
 
3 Attachment(s)
I know this is an old thread, but for those of us still running the T221, I had my brother fab up a replacement solution...

I took some measurements of the old retainer, and how the bearing behind it apparently needs some play and butts up against the retainer (which is probably why they fail?) and then my brother made up a new one and welded it up.

I later ground the oil passages into the retainer before rtv and install.

I've been running this piece for roughly 5 years and it works great.


here's some pics:

'63GENIII 04-14-2019 03:37 PM

Re: T221 assembly issue
 
Pretty creative fix for a fairly common problem with the 221.

For a lot of the 221s, a cracked bearing retainer is its death sentence.

This kind of ingenuity is what keeps our trucks on the road long after many newer disposable vehicles are sent to be recycled.

Good job on the fix there!

68GMC2500 04-21-2019 10:14 PM

Re: T221 assembly issue
 
1 Attachment(s)
When I bought my truck my transfer case was making a lot of noise. I found torque King had all the parts I need. Check them out.


All times are GMT -4. The time now is 07:55 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com