Automatic bell housing bushing

[DMC5738KC]

If you have an automatic transmission fluid leak coming from the bell housing you might be interested in this information.

After a lot of searching to replace the bushing that the torque converter's hub rides on in the bell housing, I finally have a part number for the community.

If your torque converter hub to bushing clearance exceeds .004", and the bushing is scored, worn, or just plain bad, you will want to replace it. You will also want to inspect the hub shaft of the torque converter for any scoring or wear. It should measure 1.874" to 1.875". Rob Grady confirmed to me that this bushing, which is pressed into the bell housing, was not a "serviceable part" from the factory, and therefore not listed in the parts book.

The common cause of this bushing's failure is grit in the transmission fluid (which indicates other bigger problems with the transmission itself). The torque converter's hub is lubricated with pressurized transmission fluid and when the bushing and hub are exposed to contaminants the surfaces wear, which in-turn, allows fluid to pass through the bushing.

The transmission (as you probably know if you are an automatic owner) is a Renault 4141-80. There are apparently parts that interchange with some GM transmissions which is the only reason this bushing is available.

The part number is:

SONNAX 54253-01

The bushing, that was removed from the bell housing, dimensions were:

2"OD (50.84mm OD); 1.879" ID (47.74mm id) x 0.554" wide (14.07mm).

It was scored and had some wear areas around it.

The torque converter hub diameter is 1.875" (47.62mm)

The new bushing has been upgraded to have a tighter tolerance of .002" and may require honing after installation to achieve an acceptable fit. Proceed with caution and keep the tolerance less than .004" - measure twice - hone lightly!

The new bushing came from:
Oregon Performance Transmission
P.O. Box 6137
Salem, OR 97304

They have an online website and I'm sure there are other suppliers that carry the same part. With shipping it was about $15.

I hope this information can benefit other owners with a similar leak.

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[David T]

This is great reference info and as years progress and the fleet gets older this will become more and more relevant. Another thing to check to make the bushing last a long time is that you have both hollow locating dowels in the bell housing. They locate the housing accurately to the motor and if you don't have both dowels the motor and bell housing will be mis-aligned increasing the wear on the bushing. The surfaces of the bell housing and motor must be clean and flat too. BTW, by the time you have worn the torque converter bushing out from the grit you will have long ago worn out all of the seals and the transmission will be leaking all over. When you check your fluid level you should put some on your fingers and feel it. If it is gritty it should be changed. If the fluid is dark and thick (not translucent red) it should be changed. If you wore that bushing out the torque converter should be rebuilt. There is a plastic washer in there and best practice is to replace it with a bronze one. It is also good to get it open and get all of the dirt and grit out or you will just further contaminate the transmission.

[DMC5738KC]

David, Good follow up information. I had the torque converter rebuilt at Precision of New Hampton. I communicated with Maury there, and they did a great job and had quick turn around. $175 for a complete overhaul and new hub shaft welded on. I saw the old white plastic washer that you mentioned floating around at the bottom of the torque converter when I sent it in to them, but did not see it when it came back, so I'm assuming it got replaced. Precision of New Hampton is located in New Hampton, Iowa and they have done a lot of high end work for a variety of vehicles including for Jay Leno and his jet powered car. I have no doubt they have done an A+ job on my TC.

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