Handbrake Tree Removal

[MalcM]

Totally stumped on this one, so before the grinder comes out, can you good people confirm I’m not missing something utterly obvious.

Parts diagram for the tree installation suggests that the tree and spacer slot in to the chassis and then there is a nut and bolt with washers to secure in place and allow a degree of freedom.

Now, it was only after some buffing with a wire wheel I could determine the spacer and tree fulcrum were separate parts, which I think is the nature of the problem. Is the a trick I’m missing to removing this part, or as I suspect, is it just so corroded that the bolt is seized in place and nothing short of grinding will remove it?

I’ve tried 1/4 impact and 1/2in impact guns on the bolt head, neither got any rotation. Also hammering the threaded end to try and push the bolt back out the assembly but that also achieved nothing.

Given one of the pins to hold the handbrake pull rods is also corroded solid in to the tree, I suspect it will need replaced. Does anyone know where these can be sourced, didn’t find anything on the usual internet searches.

[lotusfan]

Parts diagram for the tree installation suggests that the tree and spacer slot in to the chassis and then there is a nut and bolt with washers to secure in place and allow a degree of freedom.

You are correct and it looks more than a little rusty. If you want to try and save it I would suggest cutting with a hacksaw either side within the chassis rails. The bolt head and nut will fall off and you may then be able to drive the remains of the bolt out of the pivot. If you decide to reuse it you could build up the space with washers.

[nomad]

It appears to me that lotusfan's suggestion would be a mistake because the tree rotates on the tube of the tree not on the bolt that locates it. At least that is what the drawing indicates. I would make a single hacksaw cut through the middle of the tube and bolt and reweld the unit after I got the remains of the bolt out. Orrrr, jusst, grind off the head or nut end and move it to the side and extract the unit.

Are those available for reasonable money? Much better design than on the type 26.

Kurt
26/3754

[nomad]

Make that grind off the head of the bolt and remove the nut. Then you should be able to tilt it and remove it. Guess I need more coffee before I post!

Kurt
26/3754

[mbell]

I've done this recently similar but not as bad issues.

The mechanism rotates in the chassis not between it. You need to pull the bolt out, the tube may slide through the chassis with it which is fine. Lots of penetrating fluid on each end and at the join. Hold the tree and rotate the bolt, use grips to the pull the bolt etc. I think I pry'd mine from behind using some metal pieces against body. Or maybe I used the nut and pieces of metal between it and body to back the bolt out a bit.

You need to get the bolt out far enough to split the two pieces then you should be able to get them out.

They need good clean, new bolt and lots of anti seize on refit.

[Donels]

SJS Sportscars have the tree.

[NTG999]

My experience is that the top curve of the chassis stops a socket or spanner fitting over the nut or bolt head so it doesn't undo especially when corroded, a very skinny 1/4 drive socket worked for me

[mbell]

I was able to get a spanner on it the rear nut coming in at angle by the round bar up to the upper cross member. Then 1/4" drive socket on the front, wiggle extension is helpful for that.

[MalcM]

Lidl imitation dremmel dispatched with it in a few minutes. Chopped it just to the side of the tree’s base, as close to the chassis flange as I could.

In no particular order;
- It was installed incorrectly to drawing, hence the bolt head was aft facing rather than the nut. In either case, the flange on the mounting plate with the chassis underneath, remove any possibility of just lopping the head off the bolt or nut off the thread with the grinder. Didn’t fancy my chances of going in sideways on the bolt head and not damaging the chassis plate at the same time

- Basted it thoroughly in penetrating oil over a period of weeks and gave it some serious percussive persuasion with a club hammer, all that achieved was starting to batter the tree assembly through the hole in the chassis

- The nut came off with no real hassle, but the bolt was seized utterly solid. Bracing the tree to prevent it moving and using a 1/2in impact driver didn’t even begin to get it moving (that’s a casual 950Nm / 700lbft!!)

Looking at the replacement parts and spacers on the SJS website, has made me realise how bad the part actually was. The corrosion is quite extreme on this part, one of the pins for the actuating rods is also seized solid. I don’t like replacing parts for the sake of it, but think the whole caboodle will be getting replaced in this instance.

[Quart Meg Miles]

If any of the holes in the tree, rods or cable show any signs of ovality or looseness then drill or ream the pairs of parts together to fit an oversize pin exactly (I custom made mine) and smother everything with grease.

I've had a perfect handbrake for 30 years (nearly 130,000 miles) since doing that with my Type 26 tree using just the standard adjuster to take up pad wear. I change rear wheels (bolt on) using the handbrake to stop the hub rotating with the wheel in the air.

[Bigbaldybloke]

Just for info, there is a technical note from Lotus somewhere that details a modification to the tree to improve the operation of the handbrake, basically it changes the angle between the bar that connects to the handbrake cable and the bar that connects to the rods to the calipers. Replacement ones may already include this. I modified my early Plus 2 one when I replaced the chassis and can confirm it’s worth doing. Haven’t got the details to hand but could probably find them with a bit of hunting.

[mbell]

My plus two had a curved tree. I too found the holes worn and out of round. At the cable connection I added a piece of steel to thicken it, welded up the hole and re drilled it. The aim to restore the hole size and give more bearing surface to avoid future wear.

On the rod connections I didn't do that as they need to be able to pivot for the suspension travel. While the lotus setup works it didn't really match the movements of the rods well. So instead I've made some custom rods, with tie rod ends on the inside and clevis on the out side. The tie rods allow for both rotation and up and down movement that joint sees. Cost is $15 of parts per rod. They are also adjustable so can be adjusted to avoid any slack.

Only just got the car back to together and them adjusted but seems to work well. I was able to make the rear tires squeal when testing it at "speed" and think I could probably get them to lock up if I was really aggressive.