The Stovebolt Site Forums The Shop Area Driveline 1954 Chevy 1/2 tn Truck Torque Tube Bushings O.D.

Hello,

Why do the 1954 Chevy 1/2 ton Truck front and rear torque tube propeller shaft bushings and oil seal have different outside dimensions?
Does the internal dimensions of the torque tube housing decrease or narrow as you go farther down the torque tube housing?

Front bushing: O.D.--1 51/64"
Rear bushing: O.D.---1 49/64"
Oil seal O.D.----------1 23/32"

Spec in Master Cat. 1929-1954
bushings link
oil seal link
Cut away view bottom of page.

The reason I ask is I measured my Okie bushing and it has the same O.D. front and rear.

Any Ideas Appreciated.

Thanks,

Hey Jorb

What exactly are you trying to do?

Hello SWEET

I am trying to to determine what is the best way to go about replacing the torque tube bushings and oil seal.

Some people say to remove the front bushing and slide in a Okie bushing and just push the existing old rear bushing and oil seal farther down into the torque tube.

Some say to use a Okie bushing but you should remove the front, rear bushings and oil seal, by using a long pipe and pounding them out from the pinion gear end of the torque tube.

So I started doing a little research and found out the above outside dimensions of the original bushings and oil seal. The 1954 bushings and oil seal are press fit into the torque tube but as you can see the outside diameters get smaller farther down the tube starting with the oil seal then the rear bushing then the front bushing.

So for the heck of it I measured my Okie bushing and it has the same O.D. on the front and rear end, something seems amiss.

If the tube is tapered or narrows then by pushing the rear bushing and oil seal farther down the tube you would be widening the tube. Thus
causing the rear end of the Okie bushing not a press fit or having a gap between the Okie bushing and the tube. It would be prudent to remove the the existing rear bushing and oil seal.

So I posed the question "Does the inside dimensions of the torque tube narrow as you go down the tube?

The problem is not so much the propeller shaft and rear yoke alignment that the bushings keep in-check,
It is the torque tube oil seal that is most important with a Hydra-Matic transmission, the fluid used in a Hydra-Matic transmission is a lot less thicker than in a manual transmission 90 weight, both lubricate the u-joint and propeller shaft bushings. The thinner Hydra-Matic fluid seeps pass the oil seal easier than 90 weight gear lube. If the torque tube oil seal leaks in a truck with a manual transmission it fills up the rear axle with more of the same 90 weight gear lube, but with a Hydra-Matic truck with a bad torque tube oil seal you end-up with a axle full of 90 weight gear lube and automatic transmission fluid not a good combination.

To make things worst the Hydra-Matic transmission is designed to spray transmission fluid at the u-joint to lubricate it, through the main output shaft front yoke bolt. The bolt has a hole drilled through the center with a pin/nail in it, to meter the oil in a cone shaped pattern. So you could say the Hydra-Matic transmission is spraying lubricant down the torque tube. Where as the manual transmission has a pool of gear lube in the ball housing lubricating the u-joint.
Picture of bolt
picture of Hydra-Matic tail housing

I am thinking of replacing the bushings and oil seal the old fashion GM way, but really do not know where to find the correct rear bushing and oil seal.

I also want to check if there is any scoring and twisted splines on the propeller shaft.
picture of twisted splines on a torque tube propeller shaft
picture of scoring on a torque tube propeller shaft both pictures courtesy cmayna


I recently replace the rear yoke because it twisted off.
picture of busted yoke

While I am at it I was thinking of changing out the pinion and ring gear so I can Cruz at highway speeds.

As you can see I want do it right the first time around so I do not have to do it again.

Thanks

Ok. Now I have a better understanding of the siituation.

If this were my truck, I would do the last thing you mention. Tear it down, clean, and rebuild. The reasons being that you have had a serious failure to rip a yoke like that. I have been rebuilding rear ends for 6-7 years now and I have never seen a failure like that. This makes me think there is something internally wrong and a teardown is in order. At the very least you likely have metal shavings floating around and with the hydramatic fluid mixed with the gear oil, it can't be good for the internal parts in the TT.

Take a look at my Webshots page. When I did my 3:55 gears a few years ago I tried to document every step so others can see how I did it.

I would at least get the bearings and rebuild kit and start new. I would also HIGHLY recommend the 3:55 gears if your budget allows.

Now, to answer your initial question, the best way to remove the bushing is to insert a pipe up the TT and knock it out. To get mine out I had a buddy fabricate a tool for removal. Here is a pic of it :
Removal Tool In the photo the bushing is on the right, then the tool, then the pipe.

That will get the TT all cleaned up and ready for many years of service. Now for the Hydramatic oil issue, the trans may need rebuilt. At least the rear seal replaced. I have never worked on they type of tranmission, hopefully someone who has will chime in soon....

"I am thinking of replacing the bushings and oil seal the old fashion GM way, but really do not know where to find the correct rear bushing and oil seal."

"While I am at it I was thinking of changing out the pinion and ring gear so I can Cruz at highway speeds."

Jim,

SWEET's advice is excellent. If you are going to get the 3.55 R&P, you will not need to worry about how to get out the old bushing and seal. You will knock them out from the inside (instructions come with the R&P kit). SWEET also has an excellent photo-log of the installation.

There is no need for the "correct bushing and seal". Use the Oakie bushing that comes with the R&P parts. As SWEET suggests, also buy the installation kit.

Call Patrick's directly and ask if he gives a Stovebolt discount. Tell him you have heard good things about him on this discussion board.

Sweet,

The lower section of the Hydra-Matic Transmission tail housing is used as a oil return galley.
As you mentioned I am really concerned about the possibility of metal shavings floating around in the tranny and rear end.

1954 Chevrolet Truck Operator's Manual states: Exercise extreme care to prevent dirt from entering filler tube when checking fluid level.
What I get out of that statement is the Hydra-Matic Transmission is really sensitive to anything floating around in it besides tranny fluid.
Its not cheap to rebuild a Hydra-Matic Transmission. I have been considering dropping the transmission pan to check for metal shavings and magnetizing the drain plug.

The tool you have to push the bushings out gives some ideas on how to make one myself.

By the photos it looks like the torque tube you were repairing, had a Okie bushing installed previously.
On the carrier I see gouge marks are those from the pinion gear?

Is it really necessary to remove the entire axle?

Thanks, The photo log looks great!

Tim

Is there any mismatch gear ratio issue when changing to the 3.55 R&P with the Hydra-Matic transmission shifting, engine bog?

I have not called Patrick's yet but just wanted to know if anybody has changed to 3.55 Ring and Pinion on a Hydra-Matic 1954 1/2 ton truck.

Thanks

Bill Miles has installed and driven his 53 GMC Hydra-Matic and claims that the gearing and radial tires were the biggest improvements he has made to his truck. I have started the 3.55 gears but have not yet installed them to get a test drive.

jorb,

The shifting mph will change with the 3.55, but I am not worried about this. As Greg posted, Bill Miles has a 3.55 set up that works fine.

I think you probably know that the first to second-gear shift takes place anywhere from 3mph to 8mph. After following instructions for from Greg and Bill, I got my 3.90 rear Hydra-Matic to up-shift and down-shift nicely (a 1/16th rotation of the throttle-rod pivot produces a large difference in shifting-point mph). I have no worry about getting it right with the 3.55 rear-end through slow and careful trial-and-error adjustments.

From doing several 3:55 gear jobs I have found two different types of bushings. The one in the photo above is a one piece, I'll call it "long" bushing. The other is a smaller two part bushing. I have never installed the Okie bushing into an already existing system so I can't really say much about it. I have a few of the bushings that I have extracted and have seen the large and small one.

To do the gear swap you do not have to remove the banjo housing from the truck. In my case the pinion bearing failed (from having too much fun with my new 261) so I removed everything for a real good cleaning.