"Smitty" 5 Speed Clutch Issue

[John Kuzman]

Hi All -

I am close to finishing the installation of the "Smitty" 5 speed conversion kit in my BJ7. Today, I got to the point of re-installing the clutch slave cylinder. I had it zip-tied to the battery cable and safely out of the way during the transmission swap. Once the slave was re-installed with the new pushrod, I could not resist sitting in the driver's compartment and hitting the clutch pedal to confirm clutch fork movement.

First push of the pedal to the floor, clutch fork moved what I thought was the correct amount, but the slave did not retract when I let off the pedal. Pushed the pedal again, and... I wish I could have such a firm brake pedal! The clutch literally pumped up to where the slave was fully extended and would not retract. The clutch pedal was at the top of it's position and rock hard. If I take my foot off of the clutch pedal, I can push the clutch fork and slave back in by hand.

My first thought is that the slave cylinder hose is doing the infamous check-valve routine and allowing fluid to enter the slave, but not exit. This hose, and the slave and master were changed out 4 years ago. Am I on the right path? Any other thoughts would be greatly appreciated. Thanks in advance.

 

[steveg]

I had some issues with my original Smitty setup. I eventually detached the bell housing from the trans and installed it over the clutch on the back of the engine. I could then operate the clutch pedal and observe the full travel of the clutch arm. When you take your foot off the clutch, its springs retract the slave cylinder, pushing the fluid back upstream. If your foot is still on the pedal, slightly, you could be preventing this upstream flow.

From your description, it's not clear whether the clutch is involved or you're just pushing on a loose operating lever.

 

[Patrick67BJ8]

Hi All -

I am close to finishing the installation of the "Smitty" 5 speed conversion kit in my BJ7. Today, I got to the point of re-installing the clutch slave cylinder. I had it zip-tied to the battery cable and safely out of the way during the transmission swap. Once the slave was re-installed with the new pushrod, I could not resist sitting in the driver's compartment and hitting the clutch pedal to confirm clutch fork movement.

First push of the pedal to the floor, clutch fork moved what I thought was the correct amount, but the slave did not retract when I let off the pedal. Pushed the pedal again, and... I wish I could have such a firm brake pedal! The clutch literally pumped up to where the slave was fully extended and would not retract. The clutch pedal was at the top of it's position and rock hard. If I take my foot off of the clutch pedal, I can push the clutch fork and slave back in by hand.

My first thought is that the slave cylinder hose is doing the infamous check-valve routine and allowing fluid to enter the slave, but not exit. This hose, and the slave and master were changed out 4 years ago. Am I on the right path? Any other thoughts would be greatly appreciated. Thanks in advance.

Do you have a little bit of okay in the clutch ideal when it's released? You should. Also try bleeding the clutch again.

 

[John Kuzman]

Steve -

I do not know if I have actual clutch disc disengagement, but the slave pushrod movement is substantial on the first pedal press. I do completely remove my foot from the pedal, but the slave remains extended. I am not quite ready to fire it up and see if I have actual clutch movement. I was going to install the shift lever and driveshaft today and see if I can tell whether there is clutch movement.

Can the clutch system be bled with the slave off of the transmission ussing an Ezzi-Bleed? I need to re-route the bleeder extension and would like to solve this issue first.

 

[steveg]

...Can the clutch system be bled with the slave off of the transmission ussing an Ezzi-Bleed?

Yup.

 

[steveg]

If the bleeding doesn't do it -- when you operate the clutch and it remains in the engaged position, pull back the rubber boot on the MC and operate the pedal with your hand. Do you feel a lot of gap before the plunger engages the piston? Maybe the piston is stuck in the down position because of crud in the cylinder bore. This could be true in either the slave or master. Did you examine both the slave and master to see if the bores are clean?

I had a similar problem 10 years ago after I installed my smitty: the clutch MC evidently wasn't retracting all the way, having the effect of riding the clutch pedal. My disc wore out in a year and started slipping. There may have been a problem with the replacement MC I installed at the time of conversion. Anyhow, replaced the MC again and clutch disc and all has been well since.

New master cylinders are cheap. Slave cylinders are even cheaper.

 

[John Kuzman]

Thanks Steve and Patrick. Heading to the garage this afternoon and will report back later today.

 

[red57]

"I do completely remove my foot from the pedal, but the slave remains extended."

If the slave remains extended then you must not be moving the pressure plate - if the pressure plate is moved, the spring pressure would surely cause the slave to retract when you let up.
Assuming everything is assembled right it sounds to me like the slave pushrod is too short.
Dave

 

[steveg]

The early smittys (like mine) had a number of adjustment issues which may have been resolved by the current owner. At the time, the Toyota ball stud was too short and the operating lever at rest was in the middle of the bell-housing window - a position which didn't give it sufficient travel to fully disengage the clutch. Making a slightly longer ball stud from a 10mm bolt moved the lever forward to the front of the window while at rest.

Having adjusted the ball stud, I made an adjustable pushrod out of a piece of 10-24 allthread, a nut with jam nut and a scrap of 1/4" steel tubing. I adjusted the two to give me the complete travel of the clutch operating lever. Once the pushrod length had been established, I replaced the adjustable one with a permanent one made from 1/4" drill rod.

If adjustments like these are necessary, it's easier to detach the bell housing from the trans and not mount the trans until after they're resolved. It may be necessary to position the bell housing more than once to get these items resolved.

 

[John Kuzman]

SUCCESS!!! While sitting there staring at the slave, I decided to take the rubber boot off of the clutch fork and run my WiFi endoscope in through the bellhousing to see what was going on. The scope showed that the slave pushrod was only taking up most of the free play and when I pumped up the clutch pedal, I was simply running the slave cylinder to it's limit. That's why I had the rock hard clutch pedal after two pumps. Short answer: pushrod was too short.

The pushrod supplied with the kit was about 2-3/8". I played around with washer stacks, and finally put a 5/16" nut on the end of the pushrod and that did the trick. I then made a 2-7/8" pushrod out of a 5/16", grade 5, bolt. Same diameter as the supplied pushrod.

Fired up the BJ7 on the jackstands and ran it through all gears without any problems. I ran out of time, but I will hopefully put it on the ground tomorrow and give it a good shakedown run.

I am considering making an adjustable pushrod similar to the set up used in the 5 speed conversion kits for the midget/sprites.

Thanks all for your excellent guidance.

 

[steveg]

Excellent, John - thank you for the followup!

Wouldn't think you'd ever need to adjust the pushrod once you've settled on a length that works.

One of the issues has always been that the 3 different clutches used on big Healeys are of varying thicknesses, hence the pushrod-length issue.

 

[Michael Oritt]

Congratulations on finding the problem and as Steve says the length and sometimes alignment of the pushrod has been a known issue for many years. Just google "Smitty's five-speed transmission pushrod length" and you'll find a lot of similar experiences. I bought my kit from Smitty's and installed it at his shop. I remember we had to make a trip to a hardware store to buy a bolt of the proper length so we could cut off the head and threaded section.

 

[Patrick67BJ8]

The early smittys (like mine) had a number of adjustment issues which may have been resolved by the current owner. At the time, the Toyota ball stud was too short and the operating lever at rest was in the middle of the bell-housing window - a position which didn't give it sufficient travel to fully disengage the clutch. Making a slightly longer ball stud from a 10mm bolt moved the lever forward to the front of the window while at rest.

Having adjusted the ball stud, I made an adjustable pushrod out of a piece of 10-24 allthread, a nut with jam nut and a scrap of 1/4" steel tubing. I adjusted the two to give me the complete travel of the clutch operating lever. Once the pushrod length had been established, I replaced the adjustable one with a permanent one made from 1/4" drill rod.

If adjustments like these are necessary, it's easier to detach the bell housing from the trans and not mount the trans until after they're resolved. It may be necessary to position the bell housing more than once to get these items resolved.

I had similar problems with my Smitty conversion. That Toyota ball pivot is definitely a problem. When I pushed down the clutch pedal the clutch operating lever was doing the pivoting and it was very hard to operate the clutch. I just put a 3/16" washer under the Toyota ball stud and it was enough to make it work. Nothing like hearing "yours is the first one to have this problem" when you're troubleshooting the issue.

 

[steveg]

I had originally put some washers under mine, but decided making a longer stud out of a bolt was easy enough.

 

[steveg]

I feel a little for Smitty on this. He built a Good Thing, but installing it is a "fiddle" as the late Ron Phillips said. Some of us (including me) tend to focus on the issues rather than the big picture. It's a good setup once the issues get sorted out.

 

[Patrick67BJ8]

I had originally put some washers under mine, but decided making a longer stud out of a bolt was easy enough.
View attachment 50035

When I bought my Kit I'd have expected that the Toyota ball piece to have been removed and a correct fitting ball piece installed. Nothing like having to pull and install the transmission twice.

 

[steveg]

It would at least be helpful if alternate - for each of the 3 different clutches - ball stud and pushrod length info were shipped with the kit so one would be able to set it up without the rework.

This is the reason IMO it's useful to bolt the Smitty bellhousing up and observe the operation of the clutch before putting the car back together.

 

[Patrick67BJ8]

It would at least be helpful if alternate - for each of the 3 different clutches - ball stud and pushrod length info were shipped with the kit so one would be able to set it up without the rework.

This is the reason IMO it's useful to bolt the Smitty bellhousing up and observe the operation of the clutch before putting the car back together.

I agree with you about the trial run first. There's always enough time to remove and reinstall the transmission twice.