Technical How to "make" a poor-man's posi......

Sometimes referred to Down Under as a "CIG locker"... Commonwealth Industrial Gases used to supply welding gear and consumables locally.

Cheers,
Harv

 

I have done the extra shim behind side gear poor man posi on a 8.2 ten bolt, ford 9 inch and currently in my 63 pontiac which I have yet to drive. The 8.2 blew normal gear lube out of vent so i refilled with posi lube and all was good. Ran 12.50 with that for part of a season with no problems. Ford rear end went a few seasons running mid elevens with a sub 1.50 sixty foot by the time it started to slip I was tired of replacing 28 spline axles and could afford a spool and 35 spline axles. All were street driven so I thought I may as well try it with a big Pontiac

 

Just remembered that shot peening the shim and the shim surface of side gear works as well so I've been told.

 

Here's what I recommend:

 

On the stock cars with the jacked springs and tire stagger, I could push the car in the pits myself, going left. To go right it took 4 or 5 of us.

 

Positively wrong.

 

Now that's a LOCKED rear. LOL

 

The PowerTrax

 

A locked rear end is preferable in a lot of Road-Racing .

Aussie V8 Supercars and NZV8 Touring cars had a spool as a controlled component.
TransAm cars also run them.
I also ran a locked rear in my under powered Lotus Cortina and my Big Block Corvette [with IRS]

In this type of racing it is all about cornering.

So "Solid rears don’t like to turn corners" with amateur chassis tuners

It is very easy to set up a locked rear for "corner entry" and also give excellent bite out of a corner.

 

Maybe the parking brake broke?

 

I think what everyone was talking about was a locked rear end on the street! Trying to ease around a corner on a dry street or gassing it on a dry street can give you problems.
Sliding around a dirt corner or going into a sweeping curve on a race track at speed, no problem. For these you need both wheels pulling!






Bones

 

It is very easy to set up a spool for the street
The slip angle of most tyres exceeds the radius differential of tight corners.

For a carpark queen, all you do is stiffen the rear [roll stiffness] and soften the front.
The soft front allows the body to roll more ,but the stiff rear tries to prevent it rolling [so it unloads weight off the inside tyre]

For high speed cornering, this tuning can usually be done with 2 way adjustable shocks .
You soften the compression [jounce] and stiffen the extension [rebound]
This allows the rear to roll and unload weight off the inside tyre, And it also allows the rear to squat out of the corner.

I've used a locked rear on the street. A locked rear will only aggravate an already understeering car.
A stiff rear anti roll bar is preferable in wet conditions because it transfers weight at slow speeds

Locking the rear end without suspension tuning can be dangerous.
Most people are totally out of their depth with suspension [which is why the locked rear end is blamed , and usually outlawed]

 

Let’s lock this thread before we get any further down the rabbit hole of locked rears on the street. Yes, of course we are talking about street only here. I won’t argue on the internet. I’ll just tell you about my friend in high school that welded his spider gears, then went out and ruined a nice car, almost got himself and a carload of kids killed. Bad idea. End of story.

 

Why don't we totally wipe this thread off the internet, So we can all live in ignorant bliss.
The whole point of this forum is to gain knowledge and swap ideas.

You want this thread locked because it doesn't agree with your opinion or limited knowledge
So it is NOT "end of story!"

 

I've driven several rowdy cars on the street with a spool, they behaved exactly the way I expected them to. Quite fun, even (especially) in the rain. I'll say that they aren't for everyone and they will end up twisting axels... An example is when pulling to a parking spot and then using your hands to bounce the back of the car and watch the inside tire 'unwind'. Point being, welded spiders or a spool, or even a nice tight locker will not change the fact that the driver needs to be aware of and capable of handling the new character of the vehicle.

 

skinny rear tires…

 

Did this a couple of times. Just make sure to get ALL of the grease and oil out of the carrier before pouring molten lead into it. Wrap the carrier with a steel can or scrap of sheet metal, held on with hose clamps, remembering to leave one side open, warm it up to 350-400 degrees and melt a bunch of old school tire weights in a plumbers pot.

Pour the molten lead into the carrier completely filling it up. Then go drink a couple cold ones and wait for everything to cool. If it's filled correctly it'll be locked up, but with a little cushioning effect.

Not for the street IMHO but oval track or drag racing...

 

Re: the lead thing, I need to see a pic. Lol. Would the lead stick on the ring gear, lock up then on the pinion?

 

"Lincoln Locker"

 

The worst part of a spool is when your car breaks down ( it will at some point) and you have push it around a corner you need 2-3 burly guys to push the darn thing. Wheel dolly's would be handy in some cases.

 

That's from the early 70's. I don't have pictures. The lead is only in the carrier where the differential gears are. Oh and you have to keep the lead out of the side gears so the axles will slide in, unless you can figure out how to get the lead in with the rear all together. I did it to a 57 Chevy rear, and that's how I learned what happens if there's any grease or oil in the carrier...

I was lucky that the job was done out in the dirt driveway. My mother and older brother would have killed me if I managed to burn the garage down!

 

lol. I’d imagine molten lead hitting oil would surprise the hell out of you!

Be like casting something in wet sand.

 

Yes, but it includes fire! Much better

 

kids in high school usually can't drive very well, especially when not used to the car they are driving. A proper Locker, will behave completely differently to that of a welded diff. If done properly, welded gears aren't that dangerous, as long as you know what to expect.

 

Hey, Mimi;
Thanks for the comments. Most don't know - or care - that 1 mod will require others to work effectively. Requires thought beforehand, & afterwards, usually. More effort than available from most. Also requires personal responsibility, which is long-ago-lost.
Marcus...

 

Thanks!
One adjusment I didn't mention is "More Positive Caster" [which has other consequences]
This causes lift on the inside front and diagonal weight transfer which unloads the inside rear.[more ideal for a "Carpark Queen"]

Racing Karts use this^^^ and they also stiffen the twist in the rear frame with the rear bumper.

But too much caster can trigger "death wobble" in a lightweight vehicle.

Apart from sharing knowledge ,this whole thread is a moot point.
The total cost of doing all these suspension mods would far exceed the cost of buying a "Tru-trac" or "Detroit Locker"