Clutch Pedal Lever Bolt/Lockwasher

[lyle11]

I am replacing my clutch pedal. It is the new style with the slotted free play adjustment on the pedal. My topic is with regard to the part inside the torque tube that links the pedal to TOB.

After the clutch pedal lever slides over the cylindrical part of the pedal assembly it is secured with a 3/8” bolt that goes through a divot that keeps it in place. It calls for a 3/8” split lock washer.

When I first removed the bolt, I noticed that the lock washer was distorted. It was flat and the hole was spread open. I, of course, planned to use a new lock washer. After I slid the new clutch pedal assembly into place I used a Grade 8 split lock washer. I tightened it and never really got that feeling that this is snug. I shined a light in and, my new Grade 8 lock washer looks just like the old rusted one I removed. It is distorted. Spread out and flat. It is located about 1’ into the casting so you can’t really see the lock washer compress.

I’m probably just over-tightening the bolt. I’m thinking that the surface of pedal lever just doesn’t have enough contact with the washer so it spreads after it is fully compressed.

I didn’t see any torque spec for it in the service manual. I put a torque wrench on it set to 20 ft-lbs and it never clicked so it’s less than that. I am using the original bolt with the threads chased with anti-seize.

It doesn’t seem like this is a bolt that would be prone to loosening. Maybe I should clean off the anti-seize since it’s in a protected area. Maybe use a toothy type lock washer. Probably I’m okay with a slotted washer once it’s closed. I just don’t get that solid snug feeling and I’m thinking I won’t get that based on the contact surface. It’s just one bolt, but obviously hard to access so I’d like to feel good about it before I re-couple the tractor.

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[Glen]

Hi,
Maybe the surface under the lock washer isn't flat, or is rough.

You could take the lever it is called out and look at it, remove the bolt and if the surface where the lock washer goes isn't good, file it flat with a good file, unless filing it would cause a problem.
I wouldn't want to make the metal thinner by filing it much.

I don't know what the experts think of that idea.

Below is a pic from TM Tractor of a lever.

[lyle11]

Hi,
Maybe the surface under the lock washer isn't flat, or is rough.

You could take the lever it is called out and look at it, remove the bolt and if the surface where the lock washer goes isn't good, file it flat with a good file, unless filing it would cause a problem.
I wouldn't want to make the metal thinner by filing it much.

I don't know what the experts think of that idea.

Below is a pic from TM Tractor of a lever.

Thanks Glen. My plan was to remove the lever and replaced the clevis pin and cotter key but, it’s hard to reach and I couldn’t get that cotter key to bend at all using a needle nose plier. I managed to get the clevis pin and cotter key replaced on the other end at the TOB holder but had better access. That cotter key was really hard to straighten and get out too. I think it’s a 1/8” cotter key and very short so there isn’t much sticking out to get a grip on. So, in the clutch end I just figured that if it’s in there that tight and the yoke pivots I’ll just leave it.

I actually put a flat washer under the lock washer and that seemed to work. My only concern was the flat washer is a larger diameter and I wasn’t sure if it would rub on the casting as it pivots.

[SamsFarm]

I would say with proper manufacturing, the surface where the lock washer and screw head make contact should have been spot faced perpendicular to the screw hole.

That clamp looks to be a casting or forging, that would need machining to make a functional part!

On a side note I understand the misery of getting at this part, and I have never had to work with one! (Yet!)

[tst]

todays washers are graded, and a lot of import junk, the silver are the standard cheap low grade material, gold is a high strength, rated a 5-8 depends on who is selling it, also check the hole to make sure its not all oblong distorting it

[Dale Finch]

My plan was to remove the lever and replaced the clevis pin and cotter key but, it’s hard to reach and I couldn’t get that cotter key to bend at all using a needle nose plier. I managed to get the clevis pin and cotter key replaced on the other end at the TOB holder but had better access. That cotter key was really hard to straighten and get out too. I think it’s a 1/8” cotter key and very short so there isn’t much sticking out to get a grip on. So, in the clutch end I just figured that if it’s in there that tight and the yoke pivots I’ll just leave it.

Rather than a cotter pin, perhaps you could use a hitch pin...no bending required. They make all different sizes...this is just to show you what they look like. You can get them at most hardware stores.
https://www.amazon.com/Fastener-Assortment-SDTC-Tech-Retaining/dp/B07V7SXGW7/ref=asc_df_B07V7SXGW7/?tag=hyprod-20&linkCode=df0&hvadid=459638773866&hvpos=&hvnetw=g&hvrand=9744632487243058147&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1021047&hvtargid=pla-945153259111&psc=1

[lyle11]

Thanks for all the ideas. I realize, as Tim said, that there is a lot of junk hardware made now. But, the old rusty washer I removed, which may have been original, had the same distortion as my new washer. So, I looked at the bolt which is a dot head bolt, and it looks almost certain it is the source of the problem. Under a bolt head (might be called a cap screw), there is typically a round flat area that matches the lock washer so it doesn’t move and compresses evenly. In the case of this dot head bolt that area is mashed up around the shaft. So, as you tighten it, it wedges against the washer and spreads it out.

So, I found an old Grade 5 bolt about 1/8” longer than the dot head, used a small diameter, thin 3/8” flat washer just to give a nice flat surface on the pedal lever and a shiny plated Grade 8 lock washer from a different source from what I used before, although as stated I don’t think it’s the problem.

I tightened it and now get a nice firm stop on the socket wrench that feels normal to me. It’s hard to see but I think you can see what I mean under the head of the faulty bolt. I’m thinking the bolt was bad from the manufacturer and should have been rejected. Not sure what would make a bolt head distort like that in use. The lock washer now compresses normally without a big gap between the ends.

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[tst]

also a drop of red locktite and it will not come out