Clutch pedal mechanical linkage (XK 140 DHC LHD)

Hello Jaglovers,
Question:
I Overhauled the clutch linkage, new spherical bearings, spring etc.
Is it normal that by operating the clutch-pedal the shaft/spherical bearing moves about 0.2 inch horizontal?
It’s the spherical bearing that moves in de chassis because it’s conical, or did I something wrong?
(The car is LHD so the clutch linkage is different than RHD)

Thanks for tips, ideas

.

Best regards,
Teun

From your pictures, it looks to me like the 140 LHD is the same principle as LHD 120 and Mark V. The big compression spring is between two big flat washers, is compressed and held with a split cotter pin, so it holds the spherical bearing in place against the cup welded into the chassis.
Did you leave out or lose the second flat washer inside the chassis?
These pics are of my Mark V. There are 2 rubber o-rings around the spherical bearing to hold the grease in.
PICT0035
PICT0001

Hi Rob,
The second washer is in the frame, I had to sanded a little because it didn’t fit through hole on the inside of the frame.
Your spherical bearing is way more in the chassis as mine, can do anything with the cup in the chassis but can sanding the spherical bearing, so it will deeper in the chassis.
Don’t know if that’s the right way to do?

Maybe there some more colleagues on the forum that have some ideas?

Teun

Hi Teun,
My LHD 140 does the same thing, too much axial movement of the clutch pedal shaft.
I think that I only put one of the big C.3295 washers inside the frame, but the parts manual specifies that the 140 LHD DHCs used TWO of these washers inside the frame.
Using two washers ( or even 3) instead of only one, would seem increase the compression of the spring, thereby exerting more inward axial force on the shaft and hopefully pushing the spherical bearing into its cup in the frame rail slightly more.
Maybe you might consider trying this.
Also, perhaps adding the outer and inner o rings, shown in Robs picture, would help too.

Hi Gary,
Thanks for thinking with me!
I have only 1 instead 2 in it, the washer is 0.12 inch (3 mm) that does not (maybe a bit) take the different with the force that’s pulling him out.
I think the spherical bearing in the frame-cup is the problem, it has no radial base, the force is pull it out of the frame-cup. (the frame-cups is possible not correct/suits for the spherical bearing)
I will try to give it more radial base in the frame-cup by filling (JB Weld?) the frame-cup and modify the spherical bearing.

Ore maybe there some more colleagues on the forum that have some ideas?

Teun

I’ve just set up my 120 roadster RHD. There’s about the same amount of horizontal movement as you have described. The clutch seems to work well enough. Either it’s normal or I’ve made the same mistake as you. Kind regards
Iain

Attached is the drawing for the clutch pedal shaft. This is how I reassembled my 140 DHC with no problems.

Gary,
Thanks for sharing that drawing! Where is it from? I
am doing battle with my clutch. Do you have any idea how long the distance piece is? Part number C7588? Mine is missing. A PO cobbled something together out of aluminum. In looking at the distance piece on one of the vendors sites it appears to be steel?

Thanks

Wes Keyes
York, Maine

That C7588 distance piece is only on 140, not 120. The drawing is from Viart’s 140 book.
Here is a LHD 120.
clutch linkage 001
The big compression spring on the main shaft is supposed to prevent lateral movement.

Hi Rob,
OK this is helping me out immensly seeing that photo. No distance piece makes more sense. So I am looking at the diagram F in the parts manual for a 120 and parts numbers 50, 52 and 53 plus the cotter pin. Are those all between the clutch petal and the outside of the chassis? Also my shaft doesn’t have a hole in it for cotter pin. Could you enlighten me?

Thanks again.

Wes Keyes

Hello Folks,
After putting everything back together I am finding that when I puch on the clutch petal the shaft moves to the left so much that it pulls out of the bronze bearing in the bell housing. Upon examining the lever on the operating shaft (the one the fork is mounted to) I find it is angled back at about a 45 degree angle. I bet it is supposed to be more vertical but would love to hear from some one on that issue. I suspect that the throw out bearing is worn out and that is why it is angled. I is just a theory but I may be in for pulling the transmission?
Any thought? BTW can the trtanni be pulled with the engine in place?
As always , many thanks.

Hopefully the pic will appear?

Wes Keyes
York, Maine

IMG_2590.JPG.pdf (2.1 MB)


Yes, your lever on the clutch shaft is angled too far back. Two possible causes are worn throw-out bearing and sheared off screw pin in the fork.

It should look like this.
clutch linkage 004

Time to pull the trans. The trans can be pulled without pulling the engine; pull the seats, floors, tunnels, support the engine on wood blocks at the rear of the oil pan.

Part 50 o-ring is between the spherical bearing and the cup in the chassis, fits into a groove there, and parts 52 o-ring and 53 flat washer are outside of the bearing. They should hold all the grease more or less on the bearing. The big washer protects the o-ring from damage by the motion of the pedal arm.

I can’t guess why you would not have a hole for the cotter pin. It should be about here.
clutch linkage 005


If that big spring is not compressed you will certainly get lateral movement. The flat washers on either side of the spring prevent one end of the spring from digging into the inside of the chassis frame, and the other from cutting the cotter pin.

Often the one flat washer falls off inside the frame when the shaft is pulled out, i.e. the remover not knowing it was there to catch it.

I wonder if you have the wrong clutch pedal arm?


There are quite a few varieties around for different models.

Hi Rob,
I will pull the tranni tomorrow. Thanks for your pics. My pedal arm looks like your pic so I think I am OK there.


The cotter pin I was referring to is part number 54 in the parts manual. (Hopefully my screen shot comes through). It is the location in the diagram that confuses me. I guess it is referring to the cotter pin on the inboard end of the spring. I have that one like in the picture you sent. Originally the washer you refer to as sometimes missing was missing when I took my mechanism apart. The spring was actually poking through the hole in the outboard side of the chassis!
I think the fact that the lever is so far from the shaft is causing the shaft to pull away from the bell housing. I think once I solve the issues and the distance is shortened the shaft will stay put.
Thanks for hanging in there with me.

Wes Keyes

The Plate F in the parts book is of the RHD setup, which is not a mirror image of the LHD, thus the parts are assembled in a different order.

Rob,
Thanks for clearing that up.

Wes

Hi Rob,
I pulled the tranni today and what a mess I found. The throw out bearing was almost down to bare metal. The bolt in the fork and the one in the lever are broken off half way in so those will be fun to drill out. The fork is cracked as well. Hopefully I have everything I need from a sedan bell housing and fork. I might as well go thru the tranni if I have gone this far. Do you happen to know if a synchro box can b e substituted or is the rear mounting too much of an issue to deal with?
Thanks for your expertise.

Wes Keyes

Those sheared off square head fork bolts and broken forks have been up for discussion here before. Incidentally though we started this thread with XK140, both 120 and 140 share a lot of the clutch linkage design and thus problems.

I don’t know anything about swapping all-synchro gearboxes; I try to stick with what was original. You need something with a 4 bolt rectangular mount on the tail case, prefix letters SH, JH, SL, JL or OSL. Mark V and early Mark VII had it. But I bet your trans is fine, just get reverse unstuck.

I have several videos on YouTube regarding the shaft /pins . I have converted to RHD . This one may be useful ?

I thought I’d revive this thread as I noticed I have the same problem as the original poster: the clutch pedal shaft moves horizontally towards the outside of the car – but only about 0.1". Pulling everything apart, I found the two washers to be missing on each end of the spring (XK120 LHD OTS car) and the oil holes on both the clutch pedal arm base and clutch shaft firmly plugged up. Side note: does anyone ever oil these?? Anyway, I searched the inside of the chassis box section with a coat hanger wire and magnet and came up empty for the washers. Also, there was only one o-ring: the outside one. I’ve already placed an order for these small sundry parts, but the big question is this:

Can I save the clutch pedal shaft for reuse? There’s wear on the pedal arm end from where it was starting to bear against the bearing hole opening in the chassis box section. Looks to be about 3/32" in depth (sorry Metric-literate readers). Also another shallower one from the spring wearing in to the shaft – but it’s minor. I’d like to reuse it because replacements are semi-pricey and a check of all the states-side usuals shows it to be currently out of stock.

On another side note, I don’t think I have any other problems with the clutch mechanism – at this time. The angle of the arm protruding from the bell housing is just like in Rob’s photos so, hopefully all is still well with the throw-out bearing shaft internals. I did notice that someone brazed the external arm on the throw-out bearing shaft (this is the arm on the outside of the bell housing) so, obviously there was an issue once before with this whole assembly.

In order to save the clutch pedal shaft I’m thinking of building up the worn area(s) in question via my MIG welder with inert gas shielding, running as fat of a bead as possible on its highest setting (though this welder was only made for, at most, running a bead on metal no more than 1/4" thick). I’d follow this up by chucking the shaft on my lathe using a 4-jaw and dial indicating it to within 0.001" runout. Finish by turning the welded area down to the outside diameter of the unworn parent metal.

Does this sound do-able or am I wasting my time by introducing possible warpage of the shaft along with possible inadequate weld penetration by filling the worn divoted spots?

Here are two pictures of the shaft in question after a light emery cloth cleaning:


Thanks.

Addendum: I so wish this Rube Goldberg set-up could have been made more simple like the slave cylinder assembly I once had on a long departed MGA…

Hi Christopher:

Having had the mechanical linkage apart on my XK last year I found similar scoring on the shaft. Not having welding skills or equipment (we’ve talked about this!) I opted for a new shaft from S.N.G.Barratt. I also found the oil passageway clogged, as was the one drilled through the pedal boss itself, indeed, it was a kind lister on this Forum who set me straight as to what the holes were for as I had speculated after cleaning them out! As to, “does anybody oil them?”, I am ashamed to admit that I never had up until replacement, they will now get a regular oiling (Castrol lubrication chart I have suggests every 5,000 miles and yes, even with the chart I missed doing it!). The washers were present on my car and not inside the frame rail, in fact it was Rob’s warning in an earlier post that prevented me from letting that happen on disassembly. I think the wear on my shaft came from years of no lubrication with the shaft chafing against the insert in the frame. Not sure what that insert is made of, but after putting everything back together and adjusting the clutch I noticed I am still seeing a very slight degree of movement at the outer end of the shaft leading me to think that perhaps that insert also got worn a little. The lubrication chart specifies engine oil for the shaft, however, I also covered that insert with a good coating of chassis grease. By the way, I found with a little careful trimming to enlarge it that a brake wheel cylinder dust boot will do a perfect job of sealing off the inner end of the shaft where it enters the bell housing.

Chris.