I have had a leak out the back of the trans since I got the car. Its a 1968. It seems fairly simple to install the seal. The bushing is a different story. Do I just relpace the seal and see what I get? I will check the yoke to be sure there isn't a groove warn in it. Is it easy to grab the shaft and wiggle it to see if the bushing is shot?

 

Even a new bushing will have some "wiggle". What trans? The TH350 and 400 the tail housing is easy to remove. 4 speed, not so much. That's a full teardown. If the yoke doesn't have a ditch in it, I'd replace the seal.

 

Ouch,,,,,, It's a 4 speed. You are saying I can't replace the rear seal, or the bushing without removing the rear tail housing?

 

The seal is easy. Change that out first. remember to mark your drive shaft before you undo the U joint. You don't want to put it back on 180 degrees out. It's a balance thing.

 

Doesn't matter if you mark the joint, the driveshaft is balanced to itself, not with a trans yoke attached.
Same as the half shafts.
Edit: if you mean mark the front vs rear, yes, probably a good idea, as far as aligning with a particular side of a yoke, not necessary.
Hope I didnt mis-interpret the question.
J

 

A quick tip on the install. You can seat the seal by using a 2 1/2" female PVC coupler you can buy at Ace or Home Depot for about 50 cents. It fits perfectly. I use a block of wood and tap the coupler with a light hammer. Jerry

 

Can you just take the front U joint apart, then pull the yoke out, or do you need to undo both ends of the drive shaft?

 

You could (maybe) ... but don't try it ... lots & lots more work ... maybe you've never removed a u joint? ... u joint R&R should be done on bench.

drop the shaft

 

I ment to say, can I just disconnect the front drive shaft and get the yoke out. OOPS.

 

If your front u joint UnBolts from your front yoke ... then yes. Otherwise, unbolt from differential and drop shaft with front yoke attached

 

Correct. The rear bushing on a 4 speed is in the housing- no access without a big pile of trans parts on the bench. Seal is easy. Pop the old one out an drive a new one in..

 

There's a Kent Moore ("Spent-more") tool that looks like below, which is made for removing/installing rear transmission bushings. It works slicker than calf-slobber on a glass doorknob. I just used one recently for one of my vehicles. 15 min painless job. It's almost worth changing the bushing if your unit's bushing is worn b/c vibration and excess movement can feed back into your transmission and lead to premature tranny failure. These tools come in different sizes for different transmissions/transfer cases applications. I see them avail used (sometimes) on ebay.

The image searches I did of a 4spd Muncie show the bushing going in from the rear. I haven't personally rebuilt a Muncie, but if this is the case, one of the tools like shown below should work. That is ...if your tranny bushing is worn. There will be a little up/down movement, but with a new bushing it would have a minor amount of movement. The tools aren't cheap, but almost worth buying then re-sell to the next guy. Or maybe there are some parts stores that lend common application units out. I was lucky on my job and my small-town chevy dealer let me borrow theirs (they offered to let me use it -- I bought the parts from them). If it's just your rear seal leaking, you can just pull it out with a seal puller and replace and see how that goes (make sure the driveshaft nose isn't scored). I would suggest a GM seal. They are generally a lot better quality than some of the aftermarket ones.

 

I found a Snap-On S-8672D bushing puller for $60 that should be here in a week or so. Made a Bubba install tool for $4,,, I hope it works.

 

i didn't know federal mogul made sink pipes... good looking rig.

 

I guess if the drive shaft is coming out,,, would be best to install new U bolts, and U joints. Might as well over haul the entire driveshaft.

 

Some body off restorations have started that same way... exercise extreme care while proceeding.

 

I'm not sure how well that's going to work hammering the bushing in with a plastic pipe. Drain pipe isn't even full PVC thickness. Maybe if it were rigid plastic IDK. I'm going to say it'll be a no-go. Takes a little hammering force to get a bushing seated. I would get a piece of steel pipe that's the same dia as yer bushing, like a section of exhaust tubing from the auto parts store.


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I changed the rear bushing on my 200-4. I know yours is a standard. I cut a slot I the old bushing with a small air saw. It collapsed and came out pretty easy with some prying. I heated the tail shaft with my electric heat gun. Put the new bushing in the freezer about a hour. Then drove it right in with a short piece of pvc pipe. Just some ideas.

 

I was thinking the same thing so I made another one.... I figure dry ice and some grease will also help. I had to cut off my steering column to fit the Borgenson, this is the left over 1.5 inch end. Thank you your for input.

 

That looks better.

If you're into fabricating tools, you could easily make a pullers like the one I listed. There are ideas on the internet I've seen. Do you have a welder?

1. If so, step one is to buy a new bushing which you already have ...to use as a guide
2. Cut slots lengthwise in a piece of pipe that is about the ID of your bushing ..to make 'fingers' like the tool above has. The pipe has to be long enough to fit from the back of the installed bushing and about 3/4" or longer past the output shaft.
3. Weld a small tack bead at the end of each finger. Build it up high. about as high as you see in the tool I posted.
4. Take a cut-off tool and grind part of the weld-bead flat (so it'll catch on the back of the old installed bushing ..like the tip of the tool I copied above)
5. Bend each 'finger' inwards towards the center some (1/4" - 3/8" will do) .
6. Get a piece of PVC tubing (thin wall) ...maybe your drain pipe will work. You want it so when you insert it INSIDE your metal pipe's 'fingers' it EXPANDS the fingers and holds them tight against the back of your installed bushing (does that make sense?)
7. Weld a nut on the back of your fingered pipe and use a bolt which will pull against the driveshaft as you turn the screw/bolt in.

Then you insert your fingered pipe into the tailshaft so the ground welds will grab onto the back of the existing bushing inside your tail housing. Then insert the plastic pipe to expand the fingers tight against the bushing ...so the welds won't slip. Then 'walk back' the bushing by turning the threaded screw.

It's confusing to write this, I hope it makes sense. but maybe re-read a couple times. Good luck.