1978 Jeep J10 258 Clutch Problem

[NBD925]

In 4 wheel drive my clutch bell crank keeps dropping off. All clutch components are new. The Motor Mounts are new and the Transfer case mounts are new and match the parts diagram in how they are assembled.

Any ideas here. It seems that the engine moves enough to pop the clutch bellcrank off the ball and then the clutch rod to the throwout drops and the pedal goes to the floor.

Would love to get this fixed. The drivers side bellcrank mount is tight and slid all the way over.

[akguy09]

Can you post a picture of what you have. This will help a lot. Does your bellcrank have a spring on it? most people forget that

[tgreese]

Repaired with the wrong parts? The bellcranks for V8s and sixes are different. You mean the bellcrank or the pushrod? The aftermarket sells repair parts for the CJ that look similar but are not the same.

This is my '77 J10 with a 258. I'm sure this is correct, and it does not come apart.



You can compare. The picture was previously posted in this thread: viewtopic.php?t=22136 Some modifications were made to replace the undependable ball joints.

Note that you can make the clutch stop working by twisting the frame. IME you have to have one front wheel hanging and the other really stuffed for this to happen. The twisting changes the distance between the frame and engine and makes the clutch inoperable. Still does not fall apart though.

[tgreese]

Also, you should have a clip on the bell housing end that keeps the bell crank from sliding off the bushing:

clutchBellcrankClipDetail.png

Look at the '62-73 J-series parts book here: https://oljeep.com/edge_parts_man.html

The clip is the same as the CJ part from the same year and available as part of a kit aftermarket IIRC.

[NBD925]

I just added a file picture of my setup.

Its the Bellcrank that falls off but once it comes off the ball stud then the Clutch Push rod falls off and then bends.

When ever it happens Im in 4 wheel drive and the wheels are in a bind. It seems to move the motor more as you add torque in that situation. As the motor twists to the side it separates the bellcrank from the ball stud.

Is the difference from a stock bellcrank and a aftermarket one noticeable?

[tgreese]

If the bellcrank is chromed, that's not factory. Seems unlikely someone would chrome that part just to be chrome.

Did you look for the clip? It's under the boot on the bellhousing side.

It would help to post a better picture. Too dark, too small.

[Stuka]

The ball studs for the two arms really arent great. Any wear and they pop off. I replaced the linkages on both my FSJs with all thread and heim joints (With teflon bushings). Not only was the linkage movement way smoother, but they never popped off again. Oh, and you get rid of the weak spot in the linkage from the clutch peddle that is prone to breaking.

However, you noted motor/trans/t-case mounts were all new. Did that include the torque arm mount on the transfer case? There is a bracket that comes off near the front output that prevents the whole engine/transmission/t-case from rotating under heavy load. It is separate from trans mount.

I should note there was two styles of mounts. The TH400/D20 mount had a wider mount to alleviate torqueing over. But the manuals had the separate one that I note above.

[NBD925]

The Bellcrank is painted black. I did the best with the picture given the size constraints. The picture shows up well on my end. Is it fuzzy on your end???

The Transmission mount is new and the torque link is new off the Dana 20. There is a stud I believe with two rubber pieces and washers. There is a little slack there that I was surprised by. The two rubber pieces have a cone nose that face each other and that provides some movement. Does that seem right???

The bellcrank pops off only during a bind in 4 wheel drive. Its seems that is when the engine torques over the most in the mounts.

[NBD925]

It looks something like this.

[tgreese]

The parts book is your friend. Cheap on media (CD, USB) from RockAuto.

D20TCMount (658 x 437).jpg

I count 13 different transfer case mount designs 1974-80.

[NBD925]

1978 Jeep J10
258
T-15 Trans
Dana 20

I thought I had the right parts.

That picture basically looks like what I have.

[NBD925]

My Push rod only drops out after the Bellcrank comes off the ball joint. That Bellcrank with the two arms may need to be longer in length or something.

The mount on the Frame is pushed all the way in. Maybe the mount on the Bell Housing could be bent out more.

Any idea on what length the Bellcrank need to be?

This is the Bellcrank Part I bought from Crown J5354027 is this wrong for my jeep??

[tgreese]

Did you read my post above? There should be a clip that holds the bellcrank on the pivot at the bellhousing end.

If assembled with the clip, the bellcrank can only pull off at the frame end. The clip keeps the bellcrank from sliding off of the bushing. The bushing snaps over the end of the pivot. Once inside the bellcrank, the bushing cannot expand and come off of the pivot.

If all the parts are there, the bellcrank is held on strongly at the bellhousing end. It will only come off if the bushing is worn out.

I will measure the length of the bellcrank when I can. You can find the bellcrank length from the picture I posted above. On the photo, measure the size of something you know the actual size of, like the tube diameter. Measure the length of the tube on the picture and convert that to its length in the real world using the scale you found from the picture.

Roughly 9.25".

[pksjeep]

Not really factory, but perhaps a chain to the frame to a bolt on the block would limit the movement and keep the torque tube on the ball studs.