[Melrose RS]

I recently damaged my transmission and decided I would try to fix it myself. I've never gotten any deeper into a trans than pulling the side cover off so I knew there would be a learning curve. I found very little help on the disassembly process on the internet and have one printed document but I think a picture is worth a thousand words so I'm posting this so others can work with my photos and be able to disassemble to the point where you can change bearings, sychros and inspect most of the guts. The only special tool you need is a set of snap ring pliers.

Notice I am not calling this thread "how to rebuild a Saginaw" because I claim no expertise at that. Hopefully those who are experts might want to contribute their tips later in the thread.

So here we go...

Get the trans out of the car. Balance it on a 5 gallon bucket and remove the lower tailhousing bolt and the fluid will drain into the bucket.


With the sidecover off you may be able to see what is ailing your trans. There is a magnet affixed to the bottom of the case. Look for broken gear teeth, and metal parts stuck to the magnet. I found a broken tooth in mine.


While the trans is draining, you can remove the 4 bolts holding the bearing retainer in place and remove the bearing retainer. Try to save the gasket.


Now, while it may look like things are going to come out the front of the trans, they are not! Only the bearing comes out the front....

Using your snap ring pliers, remove the snap ring in front of the bearing off the shaft.




Grab the shaft by the splines and yank it toward you. It will move about 1/4".


Next use a screwdriver to coax the bearing out of its seat in the case. The bearing will slide past the splines and off the shaft .

 

[Melrose RS]

Here, Melrose Jr. gets into the act breaking the other four tailhousing bolts loose. We are working on a folding table covered with a shower curtain to help keep things clean.


The speedo bullet will need to be removed. May as well do that now.


Now grabbing the tailhousing and twisting, it will separate from the main case and the mainshaft and gears will come with it out the rear hole of the case.


Unless the input shaft falls off in the process, it will then look like this.


If the input shaft does fall off you will see 14 roller bearings in the case. No big deal, just collect all 14


I can now see the cluster gear(counter shaft) in the case and see where the broken tooth came from. This is first gear. Hard to believe one missing tooth made so much noise.

 

[hpcam]

Need to yank mine out too when the rain starts here... if ever.

Are you doing a complete rebuild?

 

[Melrose RS]

At this point, I could have removed the cluster gear from the case, but my document says that requires a special shaft that you drive in to prevent the roller bearings in the cluster gear from spilling out and I didn't have that tool. I had another case with a healthy cluster gear so I decided I would just swap cases and put my guts and bearings in that main case.

Now is good time to mention that if you identify what the trouble is and have to purchase internal parts, there are many trans shops on the internet and ebay that will sell you new and good used parts.

There are 4 synchro rings(sometimes called blocker rings) in the four speed. This first one will be evident when you remove the input shaft from the main shaft. What to look for in judging the health of a synchro are cracks, worn teeth and worn inside rings. These are like threads on the inside of the synchro ring.


Next, you'll find another snap ring holding the 3-4 clutch hub to the main shaft. After removing that the hub and 3rd gear synchro ring can be removed.


This 3-4 slider had worn teeth on it so I am replacing it with a better-looking used one.


Removing the tailhousing from the mainshaft takes three hands.
Using the snap ring pliers spread the snap ring that holds the rear bearing in the tailhousing. Have somebody pull on the housing while you spread the ring and pull on the mainshaft and the housing will separate.

 

[Melrose RS]

Now you can see the small speedo drive gear and retaining clip. Push down on the clip with a screwdriver and the gear can be removed. Save this gear and the one in the speedo bullet to retain your speedo accuracy.




I bored a 1and 3/4" hole in the table to make it easier to work on the main shaft. This hole is also helpful when working on distributors out of the car.


Another snap ring, then the rear bearing comes off.


Below the bearing is a wave washer and a thrust washer. These come in the small parts kits you can buy.


Now the first gear will come off. Then another synchro. Then the 1-2 slider and another synchro.


Flipping the shaft over, you can work on the 4-3 end of the mainshaft.


Snap ring, clutch hub, synchros(already mentioned above) and third gear come right off.


I believe that is as far as I could go without pressing anything off the mainshaft. Bearings, synchros and clutch sliders can be replaced. Reassembly is just a matter of going in reverse order.
One note, to hold the 14 roller bearings into the input shaft, just use some grease as shown in this photo.


The trans is back together now and working better than ever.
Thanks Brent(67rally) for trading me your old Saginaw for a case of beer!:thumbsup: That really helped with the learning curve and parts.

 

[Melrose RS]

Need to yank mine out too when the rain starts here... if ever.

Are you doing a complete rebuild?

No, my trans was rebuilt when I bought it but I was able to verify that with it apart and reuse most parts. Just like any other bearings you can feel them for smooth operation, inspect all the gear teeth and synchros and look for obvious problems. You can only guess as to the internal condition until you really inspect it closely.

 

[67Rally]

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The trans is back together now and working better than ever.
Thanks Brent(67rally) for trading me your old Saginaw for a case of beer!:thumbsup: That really helped with the learning curve and parts.

Nice work Tom. I really only wanted a 12 pack for it, but since you showed up with a case, what could I do?:beers:

 

[NH69Z28RS]

Nice write-up Tom along with great photos :beers: