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Lonnie, if you look at one (or a few?) of Perry's builds you will see that he cut the lower chassis rail below the axle on one side and made a bolt in section. With the bolt-in section removed it must have been easier to remove the rear axle. Perry?

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Warren
Isuzu Pickup/SR20DE, +401 COLD frame
Build Log: viewtopic.php?f=35&t=11601

I was just wondering exactly what that section did, other than a convenient place to mount a panhard bar. A bolt-in section would be a perfect solution IMO. That section was permanently removed on my IRS implementation. Somebody say how it is important.

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Chuck.

“Any suspension will work if you don’t let it.” - Colin Chapman

Visit my ongoing MGB Rustoration log: over HERE

Or my Wankel powered Locost log : over HERE

And don't forget my Cushman Truckster resto Locostusa.com/forums/viewtopic.php?f=36&t=17766

@Warren Nethercote
Hello, Warren;

How is the recovery going?

Yes, I remember that build, and actually having that conversation with Perry. Thank you for the reminder, though.

@rx7locost
The big worry in that solution, Chuck is not knowing what stresses I've welded into the chassis, and where it might possibly move if I cut that lower rail. Mine is truly a one-off and that RHS tube runs almost all the way through the cockpit unlike "The Book" chassis.

But the real problem is in the transmission tunnel tubes. That's where the space issue is. I figured it out once. I'll do it again, but write it down this time [LOL].

Thanks for the interest, gents.

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Damn! That front slip angle is way too large and the Ackerman is just a muddle.

Build Log: viewtopic.php?f=35&t=5886

Lonnie, the happy accident is that any 'movement' post-cut will be seen aft of the cut where it will have no effect on suspension geometry. Perry can probably indicate what, if any, to expect, based on experience.

I am 5 1/2 months after knee replacement and doing well. I am back at summer sailing, albeit not 100 percent agile yet. I ended up with 'foot drop' after surgery because of some nerve damage, but the neurologist says I'm going in the right direction there - just putting up with some foot slap instead of a nice heel to toe roll when walking. And the cataract surgery went well. Today Motor Vehicles gave me the OK to drive without corrective lenses, although I will continue to do so to get that last bit of perfection. But no more need for spare glasses in the car.

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Warren
Isuzu Pickup/SR20DE, +401 COLD frame
Build Log: viewtopic.php?f=35&t=11601

That was on the Chevette build because of the long pinion tube it would have been impossible to remove through frame.
It's about 1/2 way down the page.
http://www.locostusa.com/forums/viewtopic.php?f=35&t=12234&hilit=chevette+horchoha&start=30

_________________
Perry

'If man built it, man can fix it'
"No one ever told me I couldn't do it."
"If you can't build it safe, don't build it."

Perry's Locost Super Che7enette Build
Perry's TBird Based 5.0L Super 7 L.S.O
Perry's S10 Super 7 The 3rd
Perry's 4th Build The Topolino 500 (Little Mouse) Altered
Perry's 5th Build the Super Slant 6 Super 7
Perry's Final Build the 1929 Mercedes Gazelle

@Warren Nethercote
That's good to hear, Warren.

I'm envious with respect to the sailing. About 2 weeks ago, I gathered up all my sailing gear to give a nearby yacht club. It's a great pastime, but I just don't get out there anymore.

@horchoha
Thank you, Perry, I'll revisit the page(s).

Speaking of axles, I'm trying to clean up all the little things I need to do before I remove all the suspension parts. Some time back, I wanted to try out different fender shapes to see what I liked. They are all in foamcore, and use the axle tubes as the place where they rest.

The reason for that is that I generated the shapes based on my 3D models, and using the rear axle center was a repeatable way to generate and compare them. This is the one I settled on. I have to cut out and fabricate the small sliver (bordered in black) this go-round when it's on the rotisserie.

I wanted to see if changes were necessary to the cut out piece, or if it was good to go. It's pretty darn close. I think it looks good, but needs a little refinement, not much.

Cheers,

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Damn! That front slip angle is way too large and the Ackerman is just a muddle.

Build Log: viewtopic.php?f=35&t=5886

On the drop out brace, as long as you measure before cutting it out, a body jack could be used to spread as needed to compensate for spring back or use an adjustable length brace.

Not trying to slow your roll Lonnie. I'm sure it would take longer than just dealing with the access as-is.

I'll clarify what I was saying before. If you can move the diff back enough to rotate the pinion up and attach the hoist to the pinion flange with a driveshaft bolt, then slide the (lighter than the axle) chassis over to one side so a wheel flange clears the rail on one side, you can lower the axle out of the car with the hoist except for one end.

If you can't rotate the pinion up, make a vee strap/chain around each axle to connect to the hoist. No need to struggle too much.

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Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12

@MV8
Those are some interesting ideas. The hard part is rotating it up. Once that's done, it's just the awkward struggle to get it out of the chassis.

Your idea about hoisting it up by the pinion flange is a good one. I was worried it wasn't strong enough, and I might move a seal or bearing somehow. One you have it with the flange pointing up, it's hard to keep it there as the axle just wants to rotate down due to its weight distribution. The flange lift would solve that problem.

I just spent 3 days repairing my outside irrigation system. It had two failures and a major leak. It would be two weeks before I could get someone out to work on it, so I bit the bullet, and did it myself. The good news is that I can still dig a ditch. The bad news is how much I hurt afterwards [LOL]. I got it done, though.

Cheers,

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Damn! That front slip angle is way too large and the Ackerman is just a muddle.

Build Log: viewtopic.php?f=35&t=5886

Oh man, here we are on page 172 of your build log and I just now noticed you have unequal length trailing arms? This is in reference to the photo that's two posts before this post of mine, and I'm pretty befuddled. What does it look like on the other side of the car? How will you deal with the axle rotating noseward when the wheel comes up from a bump?

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Locost builder and adventurer, and founder (but no longer owner) of Kinetic Vehicles

Sorry to pile on, but Jack speaketh the truth, that one-wheel bumps will cause binding. Due to the differing link lengths, there will be a differential rotating force, with the shorter link pulling the top of the axle forward, while the longer bottom length holds it in place. The side in bump tries twisting the axle tube forward, while the other end tries holding it vertical. The setup essentially uses the axle tube as an enormously stiff anti-roll bar, with the axle tube being the bar. Use a floor jack and lift one end of the axle tube without moving the other side to demonstrate the issue. Worse, raise one side and lower the other. It'll move due to compliance in in everything, but will get increasingly stiff the further it's forced.

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Midlana book: Build this mid-engine Locost!, http://midlana.com/stuff/book/
Kimini book: Designing mid-engine cars using FWD drivetrains
Both available from https://www.lulu.com/

An easy axle design change: Replace the rod end with an OEM type rubber bushing.

I'll second this.

Even if they arms are theoretically equal, it is still a good idea and will help account for build tolerances.

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-Andrew
Build Log
Youtube

Boy, you are a tough crowd! But, that's OK. It has helped me a lot more than it has hurt me, so keep it up.

Here's a little review to get us to common ground.

First, I simulated the rear axle setup full scale. With the trailing arms parallel (my initial setting) it is surprising how little the axle moves, forward, backward, or out of level. Note the pointer on the front of the mockup, which allowed me to see visually, and also measure, how much it tilted when rising or falling. In practical terms, it doesn't matter if the upper arm is as long as the lower one for most things. There are exceptions. I did many simulations manually. The upper arm in this photo is 12" long.


I ended up with an upper 14-1/2" long. That turned out to be close to the 70/100 ratio that old timers said was ideal for a street car. I never could find a reference book with REAL justification for that ratio claim. It also keeps the upper trailing arm inside the rear fender, which I wanted. The setup let me trace from +5" (bump) to -5" (droop), which should never happen, but then I know O'Toole's Corollary, so I take no chances. I also varied the angle of the trailing arms 2 degrees down (upper) and 2 degrees up (lower) in half degree increments. Things varied, but not as much as you might think until beyond 3" bump or droop.


The front bushings are semi-rigid poly. The rear axle end is highly compliant in everything but forward or backward movement of the axle. So if something is wonky on a bump, it can move pretty easily with the front semi-rigid bushes being the anchor of the trailing arm.



I can't say that I've tested the jacking up one wheel thing yet, but here's what I believe based on having the same rear axle in my much heavier, midsize truck. If I hit a one wheel bump of real significance, the car is going to move before the suspension has time to react. The car is very light, and the axle is pretty heavy. That's what the truck does anyway.

Now if all else fails, I can replace the rear axle rod end with a squishy, mushy OEM rubber bushing setup. I don't anticipate that will be necessary, though.

Cheers,

_________________
Damn! That front slip angle is way too large and the Ackerman is just a muddle.

Build Log: viewtopic.php?f=35&t=5886

Boy, you are a tough crowd! But, that's OK. It has helped me a lot more than it has hurt me, so keep it up.

Here's a little review to get us to common ground.

First, I simulated the rear axle setup full scale. With the trailing arms parallel (my initial setting) it is surprising how little the axle moves, forward, backward, or out of level. Note the pointer on the front of the mockup, which allowed me to see visually, and also measure, how much it tilted when rising or falling. In practical terms, it doesn't matter if the upper arm is as long as the lower one for most things. There are exceptions. I did many simulations manually. The upper arm in this photo is 12" long.


I ended up with an upper 14-1/2" long. That turned out to be close to the 70/100 ratio that old timers said was ideal for a street car. I never could find a reference book with REAL justification for that ratio claim. It also keeps the upper trailing arm inside the rear fender, which I wanted. The setup let me trace from +5" (bump) to -5" (droop), which should never happen, but then I know O'Toole's Corollary, so I take no chances. I also varied the angle of the trailing arms 2 degrees down (upper) and 2 degrees up (lower) in half degree increments. Things varied, but not as much as you might think until beyond 3" bump or droop.


The front bushings are semi-rigid poly. The rear axle end is highly compliant in everything but forward or backward movement of the axle. So if something is wonky on a bump, it can move pretty easily with the front semi-rigid bushes being the anchor of the trailing arm.



I can't say that I've tested the jacking up one wheel thing yet, but here's what I believe based on having the same rear axle in my much heavier, midsize truck. If I hit a one wheel bump of real significance, the car is going to move before the suspension has time to react. The car is very light, and the axle is pretty heavy. That's what the truck does anyway.

Now if all else fails, I can replace the rear axle rod end with a squishy, mushy OEM rubber bushing setup. I don't anticipate that will be necessary, though.

Cheers,

_________________
Damn! That front slip angle is way too large and the Ackerman is just a muddle.

Build Log: viewtopic.php?f=35&t=5886

Sunday morning I was itching to get back working. I didn't want to wait until my neighbors were up to help with removing the big Ford 7.5" live axle, so I thought I'd try getting it out on my own.

Armed with my trusty Chinese shop crane, and a lot of stupidity, I gave it a whirl.


It got pretty awkward, but manageable if I went slowly.


As I mentioned a while back, there were big issues getting it in place, way back when. It has been so long that I forgot I solved the problem by grinding off the overhang of one of the emergency brake cable brackets, giving about 1/4" extra clearance when rotating the differential out of its running position to vertical when getting it into, or out of, the chassis.

Going back in, I'll use helpers. There was one small casualty, which could have been avoided with helpers.

So, the rear axle is happily at rest, looking for a chance to attack my shins.


I also got the old, junk rotisserie rehabilitated, and ready to go once I replace the plastic collars that kept the shafts from moving out of the square tubing of the stands. They had broken down from being in the sun for years. And, I have once again proved my basic tenant of operations, "Too dumb to fail."

Cheers,

_________________
Damn! That front slip angle is way too large and the Ackerman is just a muddle.

Build Log: viewtopic.php?f=35&t=5886