1967 4x4 excessive transmission/transfer casewhine?

[amoscl]

I am in the process of getting a 1967 Chevy 4x4 roadworthy. I have tuned the engine, replaced the u joints, serviced both axles, and changed the fluids in the transmission and transfer case. When taking it out for a spin it seemed like there is an excessive whine coming from the transmission or transfer case. I have never owned an old 4x4 so I am not sure what is considered excessive. I have read that both the SM420 transmission and T221 transfer case have a whine to them. After returning, I pulled the top plate off the transmission and the gears look like they are in good shape. Here is a video I captured after the initial drive. I did have the transmission access cover pulled when I shot the video in an attempt to better locate the whine.

Any assistance is appreciated.

Here is the video

http://youtu.be/gqOaGsegl9E

Thanks!



1967 4x4, 292 ci, Muncie SM420, Rockwell T221

[Redcap]

That is quite a bit of whine, but it doesn't sound quite to the territory of 'excessive' yet. I'd drain and change the fluid in both trans and transfer-case.

[odog]

That sounds just like my 420/221 combo. I just put new output shaft and bearings in my trans, and checked over the tcase and it still sounds that way. It always has. I think it is the way the gears are cut, straight, not helical, or something like that. I am glad somebody else's sounds like mine. I think it is fine, but thats just me.

[SunSoaked]

Yep-

Sounds just like my 69 with same trans/T case.

[snj8198]

yep, sounds like it's working!

[amoscl]

Thanks everyone for your feedback! I knew that these old 4x4s were noisy but I just wanted to make sure nothing sounded abnormal. I am pumped about getting it running. It was in pretty bad running condition when I bought it in October and it hadn't been tagged since 2007. This is my dream project. I always wanted an old 4x4 and love this body style. Now I need to find some dirt trails!

[vectorit]

My 68 SM465/T221 sounds similar, but not as loud?
Hard to tell though.
T221's do have a whine.

Here is a video I did of mine a long time ago.
For mine, I put down Dynamat and jute padding under the carpet which has really dulled the whine.

Taking the burb out for a spin around the block ...

[amoscl]

I am getting ready to start working on the interior so will definitely put in sound barrier to dampen the sound in the cab.

[69GWC]

What is the best product to help with the sound.? I have the sm465/T221 as well and its alittle loud as well.
Posted via Mobile Device

[vectorit]

In my case.
I sprayed the trans cover underside with a thick coat of bed liner stuff, you know that spray can version you can get at Napa for PU bed protection.

Then I put two layers of Dynamat on the trans cover, and a single layer of Dynamat, and jute padding with heat barrier on the floor. The carpet is from ACC with the thick rubber base.

All that really toned down the noise, and I only hear it at low range. At highway speeds, it's really nice inside the cab even though I hear it since I know it's there. Others don't seem to notice now.

I feel it doesn't matter what you use, be it Dynamat, Fatmat, or any other similar stick on stuff. It all seems to kill noises coming through sheet metal pretty good.

[amoscl]

Well I decided take out the transfer case and transmission to check them out, clean and paint. It looks like I will need to replace the output shaft and transmission/transfer case coupler. The gears in the transmission and transfer case look good but the output shaft from the transmission is shot. I guess I will give Novak a call and see if I can get the parts.

[snj8198]

PM Odog on this. It wasn't too long ago he went through the same ordeal with that combo. Maybe he can help ya a bit with what he found for parts availability and prices or so.

Nice truck.

[amoscl]

Originally Posted by snj8198

PM Odog on this. It wasn't too long ago he went through the same ordeal with that combo. Maybe he can help ya a bit with what he found for parts availability and prices or so.

Nice truck.

Thanks! I will send him a PM.

[69GWC]

Let us know if you find a place tp buy parts from to repair that 221.
Thanks.
Posted via Mobile Device

[Redcap]

Might be better off finding another trans/t-case rather than sinking a bunch of money into that T221. They are a sturdy unit, but from what I've seen...parts, when you can find them, aren't cheap.

[61K10]

this might help some looking for parts--never dealt with them---

monstertrans.com/store

[odog]

rebuilding the trans was cheap compared to a new one. I rebuilt it myself, and I am not overly mechanically able. Just take your time and when you pull something off, set it out in order so that you can put it back on the same way. I talked to Eric at Novak, he was REALLY knowledgeable and knew right what I needed. Make sure to specify that you need a shaft for a 4x4 as it has a groove milled into it on the end for a snap ring. I went ahead and put all new bearings in the trans while I had it apart, just cause I didnt want to do it again later. I think I tore it down, cleaned it all up, painted it and reassembled in a day. While you have the tcase out, check the bearing covers on the back, mine leaked 80-90 so I took them off and resealed them with RTV.

One big thing to look at it the front bearing retained on the input shaft. MAKE SURE THE SEAL IS GOOD AND THE COVER ISNT CRACKED!!!! WHEN TIGHTENING IT DONT GET GORRILLA ARMS LIKE I DID AND OVERTIGHTEN IT, YOU WILL BE TAKING THE WHOLE THING OUT BECAUSE YOU BROKE IT. If it looks cracked or broken anywhere, get the billett piece from Novak as well, its solid and you wont break it.

There is really nothing to these transmissions. There are some rollers that go into the cone on the front of the output shaft, make sure to get them all when you take it out, they will probably fall out and into the case, but take the PTO cover off and fish them out with a magnet. Put some grease on the nose of the new shaft to hold those rollers in when you goto reinstall, otherwise it will be a pain.

I took everything out through the top, Really just need a bearing puller, a deadblow hammer and some sockets and wrenches and a snap ring pliers and a small flat head screw driver. Some of the snap rings are the ones that have no "ears" on them if you follow. They are the kind you get under with a screw driver and just work off the shaft. Not a big deal though.

The shaft on the bottom of the trans will want to fall out, so when you get the trans to tcase adapter off, put a bolt and washer back into one of the lower bolt holes to hold that lower bearing in place, other wise you will fight that shaft falling out of position everytime you move the case.

As for the collar on the tcase. It is held in place by 2 thick seals in the adapter. One on each side of the collar. The parts store hear cross referenced the seals and I guess they dont have those thick seals anymore??? Anyway, they gave me 2 thinner ones that butted together to make 1 thick one, all they are ofr is to hod the collar in place and keep oil in the rans a tcase and out of the adapter.

Check the splines on the tcase, but if its like mine, they are fine.

Good luck and feel free to pm me if you need any thing.

Erik

[amoscl]

Originally Posted by 61K10

this might help some looking for parts--never dealt with them---

monstertrans.com/store

Thanks for the site.

[amoscl]

I am going to follow Odog's path and try to get the parts from Novak. They definitely have the shaft and I will call them tomorrow and see about getting the coupler. I inspected the transfer case this evening and it looks really good. If I can get the SM420 whipped into shape I should be good to go.

Everyone, thanks for all your help.

Amos

[amoscl]

Just an update on my progress. I ordered the mainshaft from Novak which should arrive tomorrow. Novak currently does not have any couplers for the t221/sm420 so I am deliberating on my next step with the adapter. I think I will talk to a couple of machine shops and see what the possibilities are. In the meantime, I disassembled the transfer case and did find that one of the idler shaft bearings was in poor shape but other than that the transfer case looks really good. I decided to go ahead and replace both bearings on the idler shaft and on the rear output shaft since I had it apart. I was able to get the bearings at Advance Auto.

If anyone has a spare coupler I am definitely interested.

For anyone wanting the part numbers to the bearings for the T221 here they are:

Front idler shaft bearing - Timken/National 02476
Front idler shaft bearing race - Timken/National 02420
Rear Idler shaft bearing and rear output shaft bearings - Timken/National 15126
Rear Idler shaft bearing and rear output shaft bearing race: Timken/National 15245
Output shaft oil and adapter oil seal - 472164 (As Odog stated they don't make the thick oil seals anymore so one needs to double up this seal.)

[69GWC]

Great info thanks for posting it up.
Posted via Mobile Device

[snj8198]

good to hear its coming together for you.

[amoscl]

Well, I finally found time to work on the transmission and ran into a problem. The first/reverse gear will not slide over the mainshaft I received from Novak. Definitely put a damper on my Saturday as I was hoping to have the transmission ready to go. I guess I will have to give Novak a call on Monday. Shouldn't all SM420 mainshafts be the same? Here are some pics. The grooves for the first/reverse gear in the mainshaft appear too small to accommodate the gear. Other than that everything else is identical.

On a positive note the transfer case is cleaned up and ready to go and since I had the floor mat out of the truck I took the time to sand and repaint the cab floor and also cleaned up and painted the transmission/transfer case support.

[amoscl]

Well, I finally finished rebuilding the transfer case and transmission and the truck is running again. The new bearings reduced the whine substantially. I had to have the mainshaft Novak sent me modified since it was out of spec. I ended up having it modified at an industrial machine shop.

Here is a video of the truck after the rebuild.

http://www.youtube.com/watch?v=zhshF...ature=youtu.be