how much 'end float' in clutch bellcrank?

[J7M46sn]

Hi, 1977 Jeep J20, 360 V8 with a T18 four speed.

My truck was missing all of the clutch linkage pieces between the frame and bellhousing. My truck has the frame mounted ball pivot for the clutch bellcrank, but it's missing the pivot bracket that bolts to the bellhousing. I recently purchased the bellcrank, pn J5354027 that is specific to this truck, and the tube is roughly 8 5/8" long. If I hold it in place, the lever arms seem to line up with the clutch pedal pushrod and throwout lever within reason (I mean it looks to be the correct part). I'm going to have to make the ball pivot bracket that bolts to the bellhousing, and I intend to make one out of angle iron, so it will appear similar to a typical Jeep bracket.

My questions are:
If my bellcrank tube is 8 5/8" long, what should the distance be between the bracket faces be? To put it another way, I know the bellcrank tube ends do not rub on the mounting face of the brackets because there is a rubber seal there, that keeps grease in and dirt out. What kind of gap should there be between the end of the bell crank tube and face of bracket? Something like a 1/4" or 3/8" of an inch seem acceptable? I think this would allow the bellcrank to pivot freely (no binding), no seals tearing up, and no danger of the bellcrank 'falling off' either of the pivots.

The bellcrank should be parallel and perpendicular between the frame and driveline, I just need some idea of what kind of 'end float' I need to establish. If someone could measure the kinds of gaps I mentioned above on their truck, it might give me some more information I can use, before I make my bracket. Thanks!

[Stuka]

I do not have an exact measurement on hand. But I know on my '75 with a 360/T18a, there was some noticeable side to side movement of the bell crank. And there is some play in the engine and transmission mounts. So if you ever replace those, you don't want the ball crank to be so tight that you have to mess with the mounts.

Also note that the transmission side moves as the engine and transmission rotate, especially in low range. Your t-case should have a torque bushing to help limit this, but it still happens.

[tgreese]

I don't own the exact model you have, but my experience with these is they have maybe 1/4"-1/2" side-to-side movement when put together. The bellcrank end movement is limited by the spring clips that go through the bell crank and are under the boots. The rebuild kit for the CJ bell crank has the same parts as a J-truck in this era, though the CJ uses a 1-piece bracket on the bell housing end. Most of the motion is the engine rolling wrt the frame, so the angle of the bell crank changes some.

I would put it all together and see what the range of motion in and out will be. The clips will stop it from pulling apart. Then I would divide that in half when the bell crank is level and perpendicular to the frame, and make the bracket to have that geometry.

My '77 is a 258, which uses a different bracket - otherwise I would measure.

I know that the CJs have a lot of trouble with this setup when one front wheel is stuffed and the other is hanging. There is enough movement so that the clutch pedal no longer works - but the linkage stays together. I suspect that getting the exact left to right measurement won't be very critical.

Also suggest you can replace the low-quality factory ball ends with Heim joint types. The adjustment rod is the most vulnerable to water and dirt. It will fall off and be lost when worn out. https://www.mcmaster.com/60645K451/ Grind out the crimp / spot weld in the rod and thread the end to fit the Heim joint.

[tgreese]

My book shows a 5354072 for some of the V8s in your year range. The 5354027 is for a 258. It'll probably work fine. You may have to modify the length of the adjusting rod.

[Stuka]

I know that the CJs have a lot of trouble with this setup when one front wheel is stuffed and the other is hanging. There is enough movement so that the clutch pedal no longer works - but the linkage stays together. I suspect that getting the exact left to right measurement won't be very critical.

Also suggest you can replace the low-quality factory ball ends with Heim joint types. The adjustment rod is the most vulnerable to water and dirt. It will fall off and be lost when worn out. https://www.mcmaster.com/60645K451/ Grind out the crimp / spot weld in the rod and thread the end to fit the Heim joint.

My Cherokee had this issue too. When climbing steep hills in 1st gear low range, the clutch pedal would move in and out.

What I did on both my Manual trans FSJs was use heim joints with 3/8" all thread. Was way stronger/smoother than the stock setup, and was still adjustable.

[tgreese]

I have equipped both my J10 and CJ-6 linkages with Heim joints. I replaced both the ball joints in the engine compartment, but left the one by the clutch pedal alone - figuring the joint under the dash did not suffer from water and weather. Also, the rods in my CJ are 3/8" diam, and the rods in my J10 are 7/16". I would expect the OP's truck to be the same as mine.

[tgreese]

J10bellcrank.jpg

This might help some -

[J7M46sn]

Thanks for all of the responses, fellerz! I was able to get the correct bellhousing mounted ball pivot bracket from a guy (81nubster) on Ebay. I received his part and installed it, and the bell crank seems to fit/function fine. At this time I have not installed the heim joints, just using the stock pieces/parts for now, to try and get this truck moving again. I do like the idea of the heim's and can see their advantages over the stock linkage, maybe later I will do this modification. Thanks again!