Jump to content
gerg

Falcon Kirby-Bishop Power Steering Box Overhaul

Recommended Posts

Ok after putting up with power steer fluid on my driveway (and on the parking spot at work) for too long, I finally ripped the box out and decided to put a seal kit through it. I haven't done one before, so this will be a tutorial on the fly (I will be learning as we go).

 

V8s are a right pain to do, you have to pull out the starter then either jack up the engine (what I did) or pull the RH extractors off to physically remove the box.

 

The Pitman Arm was buggered (sloppy ball joint), so I needed heat and a puller to remove it. Initially, I wanted to save the arm and try and gently heat it with a heat gun to get it to pop.

 

Put some force on it with a hydraulic puller and that launched itself into the wall behind my bench. So I leant down to pick it up, and didn't watch where my hand was going. It landed straight on the tip of the heat gun I was just using. This is the result:

 

cf871cc9497f40187dab62392cfa967e.jpg

 

This is 3 days later.

 

So first casualty and all i've done is strip the one box plus a spare.

 

Sent from my CPH1903 using Tapatalk

 

 

Share this post


Link to post
Share on other sites

Mother fu$ker that’s a good one.

 

i look forward to seeing how this goes. Are you going to do the roller bearing modification? I have never seen this done before.

Share this post


Link to post
Share on other sites
Mother fu$ker that’s a good one.
 
i look forward to seeing how this goes. Are you going to do the roller bearing modification? I have never seen this done before.
Yeah it fucken tickles, that's for sure.

Both boxes I've stripped already had roller tops on them so sorry no conversion this time. I do believe that the 2 types of bearing housings are different but the bushed one can be converted by machining it out very slightly to take the Torrington race. There is a thread on here from 5 years or so ago, which goes through that process.

One of the boxes is too far gone with the internals, so I pulled down the sector shaft and found some interesting things that I didn't know about before. I'll document them as soon as I can get good pics.

Sent from my CPH1903 using Tapatalk

Share this post


Link to post
Share on other sites

Ouch . They are not an easy thing to just put a seal kit through. To do properly is quite few special tools . The tools are to expand the Teflon seals to fit , then sleeves to reduce them to the bore size so they go in. The tricky part is the input seal . It has to go in from the inside and the tool required presses the seal in from the bottom. That seal is easily damaged plus there is only a very fine lip to press it to so be careful 

 

Then setting up the preloads on assembly is very important 

Share this post


Link to post
Share on other sites

A link to the roller conversion? The top bushes are always worn. I bought up quite a few roller covers many years ago when they were available .  Apparently the company that made them would only do batches of 5000. None are available now . From memory the bearing is the same as the lower sector shaft bearings . I have a few of those . But there was also a washer machined into the top cover to control the sector shaft endfloat .

 

Been considering modifying a few stock bushed covers 

Share this post


Link to post
Share on other sites
Ouch . They are not an easy thing to just put a seal kit through. To do properly is quite few special tools . The tools are to expand the Teflon seals to fit , then sleeves to reduce them to the bore size so they go in. The tricky part is the input seal . It has to go in from the inside and the tool required presses the seal in from the bottom. That seal is easily damaged plus there is only a very fine lip to press it to so be careful 
 
Then setting up the preloads on assembly is very important 
I'll have to suss out that top seal installer. Might have to spin something up in the lathe. The rollers behind the seal would have to come out then, if I'm not mistaken.

Having to stretch the Teflon seals sounds like a real stuff-around. If I can re-use the ones on it, I'll do that instead of potentially stuffing the whole lot. I could pick the worst of the two shafts, try and change the seals on it, then if I screw it up I have a useable set still.

I always wondered what the little Allen key plug was for in the top plate. You take it out, and when you wind the steering over to the right spot, there is another Allen key inside that lines up with the hole. That's an adjuster in the end of the sector shaft that turns a little worm drive down inside it, which then turns a gear that's splined to an eccentric on the sector wheel needle bearing and winds the sector wheel in and out of mesh with the worm gear. So you can actually adjust the mechanical free play with the box installed.

There is another adjuster down in the wheel well that you can wind in and out to take up the piston rack to sector shaft clearance. This takes out any slight delay in assistance from steering inputs. Has a lock nut and Allen key.

Sent from my CPH1903 using Tapatalk

Share this post


Link to post
Share on other sites

Yep you got it for the worm adjuster . It is adjusted carefully on the bench so preload is slightly firmer at centre .

 

If you like I can measure up the tool I have for that seal . Basically it is exact O.D of the seal , then has a large land at the bottom of the case so as to guide the seal in dead straight. The seal is tapped in very careful so it just touches the very small step in the case 

 

The seal expanders I made up out of exhaust tube years ago , basically tapered enough to expand them over the lands where they fit . Then there is a tapered sleeve bit like a ring compressor that is the bore size the Teflon seal runs in. That shrinks the seal after being fitted a while so they slip easy into place 

Share this post


Link to post
Share on other sites
Yep you got it for the worm adjuster . It is adjusted carefully on the bench so preload is slightly firmer at centre .
 
If you like I can measure up the tool I have for that seal . Basically it is exact O.D of the seal , then has a large land at the bottom of the case so as to guide the seal in dead straight. The seal is tapped in very careful so it just touches the very small step in the case 
 
The seal expanders I made up out of exhaust tube years ago , basically tapered enough to expand them over the lands where they fit . Then there is a tapered sleeve bit like a ring compressor that is the bore size the Teflon seal runs in. That shrinks the seal after being fitted a while so they slip easy into place 
Thanks Greg that would be awesome if you could do that for us. I haven't cracked open the seal kit properly yet, is that input seal metal-backed? If so, I will have to push out the top roller races down through the casing to get the new seal in, right? Are they in tight (ie I'm not going to fuck them by getting a soft drift on them)?

Sent from my CPH1903 using Tapatalk

Share this post


Link to post
Share on other sites

So here's that sector shaft I mentioned. This is the stuffed one that had a seized roller. I found out why when I stripped it..... The sides of the wheel that runs on the thrust races had indents in it from the needle rollers. This thing has copped a big hit at some point and damaged the Torrington race.

Roller: c5306f900615ce7d67625fc5ea06b954.jpg

Retainer:
47fac571f5e8b7abbfc27046f109f072.jpg

Here's how the roller and retainer sit in the shaft:
d045fc07f3b51f82436fa0489075ee7a.jpg

And the worm adjuster:
37ed462c79d86a47d06e920e06a01fdb.jpg

And thanks to@gregaust for the heads-up, this is how the top seal comes out, it pushes down through the housing quite easily with a socket. The needle race and bearing holder come out the bottom together. It would be really easy to mistakenly try and knock the seal out through the top, you wouldn't see that tiny lip under a bit of grime, the protrusion would only be about 10 thou.

Socket:
9a3f6fa5e5f8f4dbcf15ddadf3755c37.jpg

Seal and bearing holder:a223d9d5c57f4543b20f380fdef1fe9e.jpg

It's hard to see in that shot but the holder has two notches cast into it to allow the oil to get past from the reaction valve (in the worm shaft) back to the return port in the housing. With this in mind, the holder effectively forms part of the valving, so I assume should be treated with care so as to not damage it.

Sent from my CPH1903 using Tapatalk

Share this post


Link to post
Share on other sites

And she's home, used the same tool to tap the bearing into place as well. Used a bit of Loctite 518 flange sealant around it to make sure no oil gets past the outside. It's only return pressure behind it but still, no harm in sealing it off.

 

Took me 30 min to make the tool, 30 seconds to use it fb00fb9f6887ef5dbd38d6599c3b3de0.jpg

 

Sent from my CPH1903 using Tapatalk

 

 

 

 

 

 

Share this post


Link to post
Share on other sites

Ok now for the dreaded Teflon seals

 

Based on advice from[mention=124]gregaust[/mention] , I installed the seals by gently stretching them around the valve assembly. I wasn't as gentle with them as he suggested, ended up with a twist in each one. It took some careful coaxing with a small flat screwdriver to get them squared up again, then I compressed them by using a quality hose clamp and using the solid part of it (not the punched thread bit) to compress the Teflon down to the right diameter. The housing doesn't have much of a taper into the sealing area, so this step is crucial for getting it to sit home without damaging them.

 

 

Clamped up:

1ec1229737d848f4e913321c64b11a7a.jpg

 

See the difference between clamped (left) and not clamped (centre)

cba3c732380f3ecaecf81979b17c6dac.jpg

 

Now on to the piston seal. This is a bit easier to get on than the valve seals as it's a larger diameter. The o-ring goes in first and acts as a rubber spring to force the Teflon out against the bore. Instead of trying to shrink the Teflon down, I will have to come up with a way of collapsing the seal (sort of like a ring compressor) while installing to get past the threads at the start of the bore. Something like sticky tape or celluphane might do the trick.

 

c9d2cab139098ef4929c25b79770e415.jpg289b7fe6ca0ff359ac1fea29ce399dc0.jpg

 

Seal protrusion 3074edcd370a73727f539496c1c25d8b.jpg

 

And she's in. Used a bit of sticky tape wrapped tightly around the seal and piston, but I would suggest an alternate method because the tape was really difficult to get off once the piston is in.

51db4343f41579fa58628279248ec797.jpg

Share this post


Link to post
Share on other sites

When at a workshop and doing alot of these quite a few years ago, we compressed the seals much the same as you have Gerg and then put the whole shaft in the freezer for a few hours.

You wouldn't believe the difference it made in reassembly. Great work on the seal installation tool.

Share this post


Link to post
Share on other sites
When at a workshop and doing alot of these quite a few years ago, we compressed the seals much the same as you have Gerg and then put the whole shaft in the freezer for a few hours.
You wouldn't believe the difference it made in reassembly. Great work on the seal installation tool.
Thanks mate, regarding the shaft... You mean it shrunk the Teflon a lot more after freezing?

Sent from my CPH1903 using Tapatalk

Share this post


Link to post
Share on other sites
A link to the roller conversion? The top bushes are always worn. I bought up quite a few roller covers many years ago when they were available .  Apparently the company that made them would only do batches of 5000. None are available now . From memory the bearing is the same as the lower sector shaft bearings . I have a few of those . But there was also a washer machined into the top cover to control the sector shaft endfloat .
 
Been considering modifying a few stock bushed covers 
Sorry mate missed this one

http://www.ozfalcon.com.au/index.php?/topic/2988-needle-roller-bearing/&do=findComment&comment=69889

Sent from my CPH1903 using Tapatalk

Share this post


Link to post
Share on other sites

Some baby steps today...

 

Power Rack:

 

Power piston rack adjuster screws in from the outside, onto a swiveling button that runs on a polished section on the back of the rack. The button can be held in place initially with some grease or Vaseline. Leave it wound out for now.

e195e8e9dc025dd8d2d456fa90fc2bcf.jpgef12f7de76f278c17ee140530d7bf467.jpg

 

Worm Shaft Bearing:

 

Firstly, you should adjust worm shaft bearing preload by winding it up without the sector shaft installed. This allows you to feel the bearing drag without any other friction in the system. I aimed for a light, consistent drag without any "graininess" to the movement of the shaft.

 

I adjusted that threaded alloy end plug with a pair of multigrips. There's a seal that goes inside between the plug and the bearing cup. Tighten locknut once done.

21a58edca578275abd1aaac50f35d667.jpg

 

Sector Shaft:

 

As mentioned, make sure the rack adjuster is backed off all the way to allow clearance between the teeth as you feed the sector shaft down into mesh with it. The teeth on mine needed some burrs taken off to slot into mesh correctly.

 

Now that it's in, to adjust properly you really need to pop that Allen key plug out of the top plate and adjust the worm follower wheel (if that's what it's called) with the Allen key adjuster. I couldn't get that plug to budge out of the housing and didn't want to break anything. So decided to adjust it with the plate off, then pop the plate into place to locate the top of the sector shaft and give a more accurate roller clearance. The roller clearance always gets tighter when you install the plate. If installing new seals in the box, I would leave the o-ring out of this top cover until your adjustment is done (to prevent o-ring damage)

 

You need to make sure your follower is in the middle of the worm shaft, as the straight-ahead position is the most critical point for adjusting free-play. It appears that the clearance gets much looser as the wheel travels to each end of the worm (ie: at the end of each steering lock) I suppose this is to allow for greater wear occuring in the middle of the worm shaft and when this wear is taken up by adjusting, the additional clearances away from centre (where much less wear occurs) prevents binding once adjusted.

 

This extra clearance toward each end doesn't affect steering free-play in operation as the built-in castor and self-centering effect always has steering load taking up the slack, trying to push the steering back to the centre where the load is neutral.

 

This adjustment can be a trap on manual boxes: adjust for wear and get the clearance nice in the middle and it can lock up as soon as you wind the steering off centre.

 

It took a few goes, but I reached a compromise. There is a little bit of play in the follower wheel that I can't do much about.

 

The shaft is pretty much in the right spot here, as it lines up roughly with the plug in the bearing plate. You should adjust it right up till it's tight, wind it through a few locks each way, and try and find any tight spots or notchy feeling through the input shaft. You will likely feel them just either side of straight ahead. Back off the adjustment till no tight or notchy spots can be felt through the full movement of the input shaft lock-to-lock.98d6e82912eb788e5124cfa1cc7fb53c.jpg5cf264d0359fd52580368638422cc138.jpg

 

EDIT: more pictures added above

 

Sent from my CPH1903 using Tapatalk

 

 

 

 

 

 

 

 

Share this post


Link to post
Share on other sites

How did you retain the roller cross-shaft in position (originally held in with the ball bearing)?

In the ones I've played with, I tapped and threaded/loctited a tiny allen key grub screw, in place of the ball.

 

I found that if they're still running the bronze top bush, the worm drive follower/roller bearings are usually gummed up solid,

with tiny bronze chips, from the worn bush - stopping the roller from rotating.

I've never been successful freeing them up, without fully disassembling the sector shaft as you did.

Share this post


Link to post
Share on other sites
How did you retain the roller cross-shaft in position (originally held in with the ball bearing)?
In the ones I've played with, I tapped and threaded/loctited a tiny allen key grub screw, in place of the ball.
 
I found that if they're still running the bronze top bush, the worm drive follower/roller bearings are usually gummed up solid,
with tiny bronze chips, from the worn bush - stopping the roller from rotating.
I've never been successful freeing them up, without fully disassembling the sector shaft as you did.
Luckily Dave, I had a second box to play with (I wish lol) so I was able to pull the siezed one apart to see how it all works. Mine was siezed from a little bit of rust but mostly impact damage (presumably).

I tried to push the good one apart too, to see if I could shim to take up a bit of slack. But it wasn't cooperating, so I left it alone before I broke something.

I don't see any problem drilling, tapping and grub-screwing that shaft into place. The manufacturer probably just peened the ball in there for cost reasons. I would first try re-doing it and if that didn't work, then grub screw it.

Sent from my CPH1903 using Tapatalk

Share this post


Link to post
Share on other sites

The sector shaft seals go in like this, but the last one, a dust seal, goes in smooth side down. If you put it in the other way, the lip runs on the splines. 17e5ceb337e80347ce9b8986fc7b4e38.jpg

Pitman Arm pivot: it's not a ball joint but a straight pin that runs in a nylon bush encased in a tapered rubber outer bush. You open up the peened edge around the joint and push the pivot out the bottom.

This pivot was pretty corroded so I gave it a linish, cut a slot down the nylon bush (so it collapses down and takes up the slack) and re-assembled the lot. I drilled and tapped for a 6mm grease nipple in a section that I reckon wouldn't take much load. The problem with this joint is that it faces upwards and collects water with no outlet, so it chops out due to corrosion. If it was greasable from the word go, it would never wear.358111d80168a5a63a8dcb7c48f6a108.jpg1500c44bf4084a22082a6c3333ffa3d1.jpg

Sent from my CPH1903 using Tapatalk

Share this post


Link to post
Share on other sites
Any more pics of the pitman arm reco?
 
Btw, I like the offset bench vice!
very cool.
Yeah sorry mate, just doing this in dribs and drabs while I have a spare moment at work each day. I pulled the most buggered one apart first so I knew what to avoid buggering. So I'll grab some pics Monday.

Sent from my CPH1903 using Tapatalk

Share this post


Link to post
Share on other sites

I ground the peened-over base off this one, as I'm not re-using it.

872c8009f662dd84a86b78929ff6e75e.jpg

Note pintle on the end of the pin that locates in the dimpled plate

cd08dd36ea503f7428b690f166932634.jpg

Slice down the side of the bush
7e96448a70bfa21c4529634b02bce602.jpg

Installed7ba570e0e5037dbf7219f89e368e9dcc.jpg

Dismantled
b5c05fdf77adcff0441a5974f13c9dec.jpg

Sent from my CPH1903 using Tapatalk

Share this post


Link to post
Share on other sites

So I fucked up with assembly....

Installed the box, had to jack the engine up and tilt it sideways to get it past the extractors. Hooked everything up, started the engine, then my boy looked under it and said "daddy there's blood coming out"...

Looked under, it's coming out of the sector shaft. I'd put the shaft pressure seal (the one above the Pitman Arm) in backwards, after deliberating on which way to do it. I have no exploded view or instructions and couldn't remember how it came out. I guess I had a 50% chance and I lost.

I managed to pop the arm off, push the shaft up (after taking the top plate out) dig out the dust seal, remove the circlip and seal all with the box in place, which saved a shitload of work pissfarting around with jacking up the engine again, etc.

The seal actually goes in with the "cup" section facing upwards toward the pressure side, with the oil pressure forcing the inner and outer lips to seal on their respective surfaces.

4661cb58f07cb30ca4ac5fce242d729e.jpg

The dust seal goes in backwards to the way a normal seal goes in: the lip goes facing inwards. If you put it in like you would normally with say an axle seal, the lip will run on the splines.

20d0390601c8094c562ab983f69fc07c.jpg

Sent from my CPH1903 using Tapatalk

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×