Tailshaft bushing removal/install

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pearljam724

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I’m getting prepared to freshen up my 904 transmission. Is the tailshaft bushing easily removable/easily installed once the tailshaft housing and seal is removed ? I understand it might be packed in there tight. Has anyone ever done this without a special tailshaft bushing tool ?
If so, how and what did you use ? I was think of heating the case or hoping to find a washer the same size to drive it in. But, probably won’t be able to find one the perfect size.
 
pearljam724 said:
I’m getting prepared to freshen up my 904 transmission. Is the tailshaft bushing easily removable/easily installed once the tailshaft housing and seal is removed ? I understand it might be packed in there tight. Has anyone ever done this without a special tailshaft bushing tool ?
If so, how and what did you use ? I was think of heating the case or hoping to find a washer the same size to drive it in. But, probably won’t be able to find one the perfect size.
Click to expand...

It's not a big deal with the tail housing off. (especially if you get the seam in the bushing started first)
I have a chisel I modified when I was in the business that I ground to have a V in the end 90 degrees to the original edge.
When you get ready to take it out note where the oil hole in the bushing is and put the new one in the same way.

I cut the chisel kind of like this.
It's not critical, but just needs to be able to get under the edge of the bushing and lift it.
This tool is actually for cutting bushings, but the tail shaft bushing has a seam you can get under and pop up pretty easy.

Untitled.jpg
 
TrailBeast said:
It's not a big deal with the tail housing off. (especially if you get the seam in the bushing started first)
I have a chisel I modified when I was in the business that I ground to have a V in the end 90 degrees to the original edge.
When you get ready to take it out note where the oil hole in the bushing is and put the new one in the same way.

I cut the chisel kind of like this.
It's not critical, but just needs to be able to get under the edge of the bushing and lift it.
This tool is actually for cutting bushings, but the tail shaft bushing has a seam you can get under and pop up pretty easy.

View attachment 1715438270
Click to expand...
Thank you. I know the oil hole alignment. I have a very similar looking tool that I fabricated from 1/2” rebar to remove hood springs on my 1950 Chevy.
When you say pry it up ? Do you mean you have to pry it up from the yoke end, before you can push it out from larger end of the case in order to remove it ?
I was thinking I could just tap it out from the larger end of the case with maybe 2 long 1/4” ratchet extensions attached together for a far reach. Or the tool I have similar to yours. Is there a lip somewhere on the yoke end of the housing that requires lifting the bushing as you explained ? My tail housing is about to come off. The next time I go at it and remove the bearing clip.
 
pearljam724 said:
Thank you. I know the oil hole alignment. I have a very similar looking tool that I fabricated from 1/2” rebar to remove hood springs on my 1950 Chevy.
When you say pry it up ? Do you mean you have to pry it up from the yoke end, before you can push it out from larger end of the case in order to remove it ?
I was thinking I could just tap it out from the larger end of the case with maybe 2 long 1/4” ratchet extensions attached together for a far reach. Or the tool I have similar to yours. Is there a lip somewhere on the yoke end of the housing that requires lifting the bushing as you explained ? My tail housing is about to come off. The next time I go at it and remove the bearing clip.
Click to expand...

The bushing is just a tube, so what I meant was to start folding it in on itself at the seam in the bushing.
The seam will give and the bushing will slide out mostly intact instead of having to cut all the way down through it.
I always stood the housing with the small end up and knock it down till it falls out and onto whatever surface I am working on.
 
TrailBeast said:
The bushing is just a tube, so what I meant was to start folding it in on itself at the seam in the bushing.
The seam will give and the bushing will slide out mostly intact instead of having to cut all the way down through it.
I always stood the housing with the small end up and knock it down till it falls out and onto whatever surface I am working on.
Click to expand...
I got it now, that’s a good tip about the seam. I was under the impression that it won’t come out toward the big end. If it can. What keeps it from going in further than it needs to be when you install a new one, nothing ?
 
Anyone want to share their experience using a tailshaft bushing removal tool (allows removal of the tailshaft bushing without removing the tailshaft housing from the transmission)? Where one might find one and if it was worth it?
 
Fishing68 said:
Anyone want to share their experience using a tailshaft bushing removal tool (allows removal of the tailshaft bushing without removing the tailshaft housing from the transmission)? Where one might find one and if it was worth it?
Click to expand...
No special tools are needed. If the tailshaft housing is removed. It’s an extremely simple process. I used a flat head screwdriver to pound it out and a very large socket to install it. Leaving the tail shaft housing installed requires special tools. Do the simple thing and remove the housing.
 
Thanks pearljam724.
I am thinking of replacing the yoke as well since the worn tailshaft bushing was worn by the contact with the yoke. Would you replace the yoke whenever you replace the bushing?
 
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Fishing68 said:
Thanks pearljam724.
I am thinking of replacing the yoke as well since the worn tailshaft bushing was worn by the contact with the yoke. Would you replace the yoke whenever you replace the bushing?
Click to expand...
You’re welcome, bud. I just finished completely rebuilding my tranny about a month ago. I knew nothing about transmissions prior. They are as easy to rebuild as a carburetor is. Don’t be intimidated. Mine is working flawlessly now. I would only replace the yoke if I could visibly see wear on the splines or where the u joint c—“clips butt up against the yoke. I had minimal wear on my rear yoke where the c—clips butt up against the inner part of the yoke. It caused vibrations over 60 mph. I had a machine shop fix the wear with a special machine. That fact removed all vibration. A driveshaft balance job, will tell you if your yoke is good or not too.
 
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Fishing68 said:
Thanks!
Click to expand...
Definitely, have your driveshaft balanced. After you install new u-joints. Remove the rear yoke too and take it with you to give to the balance shop. They will need both yokes to balance the driveshaft. Only cost me, 60 bucks. Well worth it. I chased a small vibration in my driveline over 60 mph for nearly a year. The driveshaft balance and rear yoke repair removed all vibrations.
 
Fishing68 said:
Sounds like familiar symptoms. Thanks for the advice. What bushing/supplier did you go with?
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I believe all the kits available probably use the same manufactured bushings, seals,etc. I used a kit from a company called Phoenix Trans Parts. I have a 1969 - 904. I chose them because they were the only place that included the correct housing seal with dust boot for my year transmission. I’m happy with the kit, it was cheaper than anything else available. But, didn’t include correct size accumulator seals for my year. No big deal. I bought an aftermarket accumulator piston with seals for around $18 and it was perfect. And it still equaled less than competitor kits. It cost about 70 - 80 dollars into completely rebuilding it, total. I also bought a new larger capacity pan with a drain for another $50.
Total cost, $130 compared to a professional transmission shop would have been between 1000 - 1200. I probably invested 4-8 hours of total time over a week. Cleaning valvebody, etc included in that time.
 
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Man I have got some things to learn....
Accumulator piston?..., first time hearing that term/name/part.
-Thanks for the info./ advice.- will do some independent studying
 
Fishing68 said:
Man I have got some things to learn....
Accumulator piston?..., first time hearing that term/name/part.
-Thanks for the info./ advice.- will do some independent studying
Click to expand...
Yeah, study the transmission for a couple weeks prior and save pictures on your phone. Particularly the valve body check ball locations. And valve/spring orientations. It’s a piece of cake. If you can rebuild a carburetor. You can rebuild a transmission. Air tests will tell you everything that’s wrong or not concerning bands being applied correctly or not in reference to shifting problems. If you have slippage problems. Your clutch packs need replaced, bands need replaced or adjusted. Also fluid level may be incorrect.

Shifting problems are related to line pressures not being correct. Due to seal wear or incorrect adjustments. Shifting problems are also due to valvebody valves or governor weight needs cleaned by very lightly polishing them. People don’t change tranny fluid often enough. Tarnish or wear particles in fluid. Causes valves or governor weight to stick. They will also stick due to very slight wear from slight abrasions or slight oxidation. When this happens your transmission won’t shift correctly at certain times. All of this is very easy to address and fix.
 
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Fishing68 said:
Man I have got some things to learn....
Accumulator piston?..., first time hearing that term/name/part.
-Thanks for the info./ advice.- will do some independent studying
Click to expand...
A good manual is hard to beat and Tom Hand wrote a nice one a year or so back. You can get it here on Amazon

https://www.amazon.com/dp/1613253354/?tag=joeychgo-20

BTW: I don't see a lot of worn yokes unless they have a ton of miles on them. The bushing is soft so it wears out first and is much cheaper to replace
 
It’s extremely common for the ears to be slightly bent or tweaked from someone incorrectly installing or removing u-joints at some point in time. This creates an unbalanced driveshaft and vibration also. The yokes can also have minimal wear grooves from u joint c-clips rubbing up against the inside walls of the yokes. All it takes is a millimeter or two of wear to create vibrations.
 
I picked up a tailshaft bushing removal tool.
Replaced the tailshaft bushing with a new bushing.
The old tailshaft bushing shows minimal wear and slip yoke also shows minimal wear.
I also checked the play between the slip yoke of the old tailshaft bushing and the new tailshaft bushing and there is no noticeable difference. Both have a little (same amount of) play.
Noticed the drive shaft is not original and the slip yoke was exposed for the first two inches when installed and the suspension fully loaded. I have read and am told by a driveline shop the recommended exposure should be about 1" to 1 1/4".
So decided to order up a longer driveshaft from Drivelines NW to get the recommended slip yoke position relative to the end of the transmission tailshaft. Not sure if it will fix the vibration problem but I am hopeful given all the info I have found.
The quotes for just going with all new driveline parts was not much more so decided to go with new u joints and a new slip yoke and have the whole unit high speed balanced.
Should have it back and on the car for a test drive this week.
 
Fishing68 said:
I picked up a tailshaft bushing removal tool.
Replaced the tailshaft bushing with a new bushing.
The old tailshaft bushing shows minimal wear and slip yoke also shows minimal wear.
I also checked the play between the slip yoke of the old tailshaft bushing and the new tailshaft bushing and there is no noticeable difference. Both have a little (same amount of) play.
Noticed the drive shaft is not original and the slip yoke was exposed for the first two inches when installed and the suspension fully loaded. I have read and am told by a driveline shop the recommended exposure should be about 1" to 1 1/4".
So decided to order up a longer driveshaft from Drivelines NW to get the recommended slip yoke position relative to the end of the transmission tailshaft. Not sure if it will fix the vibration problem but I am hopeful given all the info I have found.
The quotes for just going with all new driveline parts was not much more so decided to go with new u joints and a new slip yoke and have the whole unit high speed balanced.
Should have it back and on the car for a test drive this week.
Click to expand...
Listen to my advice. Triple check the wear on the inside of both yokes where the u-joint C clips butt up against the inside of yokes. It doesn’t take a lot of wear where I’m referencing. The c clips leave grooves on this surface. It may look like minimal wear. But if both sides have grooves hardly noticeable. Its enough to cause problems because you have to figure if there’s minimal wear on both sides of yoke. That can add up to a 1-2 millimeters of wear. The smallest amount of groove from C clips will cause vibration. Look them over very closely.
 
Today I picked up the new driveline (new longer driveshaft, u-joints, slip yoke - all balanced) and got them installed. Vibration problem completely solved!
Thanks to the folks at Drivelines NW.
 
While chasing a high speed driveline vibration(dead smooth below 98 mph with dramatically increasing resonance above that), I bought the tool to change the bushing in the car without disassembling the transmission. It works like a charm.

However, even with a brand new installed bushing and yoke, the clearance between the two parts is excessive on my stuff. A buddy of mine is making oversized bushings to reduce that clearance, but having the yolk plated and ground to a larger outside diameter is another option.

I've yet to do either so far, as I can't figure out how to measure the inside diameter of the installed bushing with the output shaft in the way.
 
jbc426 said:
While chasing a high speed driveline vibration(dead smooth below 98 mph with dramatically increasing resonance above that), I bought the tool to change the bushing in the car without disassembling the transmission. It works like a charm.

However, even with a brand new installed bushing and yoke, the clearance between the two parts is excessive on my stuff. A buddy of mine is making oversized bushings to reduce that clearance, but having the yolk plated and ground to a larger outside diameter is another option.

I've yet to do either so far, as I can't figure out how to measure the inside diameter of the installed bushing with the output shaft in the way.
Click to expand...

Just remove the tail housing to measure it. What the hell are you worried about vibrations over 98 mph for, lol ? Unless you race ?
 
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