Independent Rear

[dannyboy3141]

Hey everyone, I am looking to learn how to do an independent rear on a Ranger. Only catch is it can't be links. Don't even bring it up. So with that in mind, how would you guys build an independent rear without links? And...go.

 

[adsm08]

Steal it out of a T-bird.

 

[dannyboy3141]

T-bird? Tell me a little more about the T-bird rear end. Also, what year range of T-bird?

 

[pjtoledo]

one of the TV shows did a full frame conversion a few years ago.
not sure which show, but it had Kevin Tetz on it. Trucks???

powerblocktv.com>trucks>builds>project rolling thunder

2001 Mazda gets a 4.6 and lots of mods, including an independent rear suspension

 

[don4331]

Doesn't the powerblocktv build use a Mustang Cobra IRS?

Advantage of the Mustand IRS - same 5x4.5 bolt pattern. Disadvantage - cost.

T-bird IRS comes from '89 to '97 car. You can get both 7.5s and 8.8s. (There is also the Lincoln version - aluminum carrier). Advantage - cheap compared to Mustang; Disadvantage - 5x4.25 bolt pattern. But you can replace the hubs with the Mustang one for a couple hundred bucks, and have same pattern front and back.

Both the Mustang and T-bird IRS are ~6" wider than stock '92 axle. You can compensate some with Mustang/T-bird rims as the have ~40mm (1.5") greater backspacing, but you will still be a few inches wider...

TruckIRS makes a kit to install it.

I can't remember if '92 has RABS speed sensor or if speedometer pickup is in transmission. I machined a spacer on the rear yoke to get a tone ring. I also used a set of '93-97 front spring/shock mounts versus Dan's solution.

The '03+ Explorer also has an IRS but I haven't seen anyone install it in a Ranger

 

[stmitch]

The Cobra IRS is an improved and strengthened version of the older MN12 IRS that came in the TBird and Lincoln MarkVIII. It has the same bolt pattern as the Ranger. I have one in my garage if you need measurements.

The MN12 has a different bolt pattern than the Ranger, but you can swap to Cobra hubs/brakes if you want. The Lincoln version got the aluminum carrier as Don noted, and also got aluminum lower control arms if my memory is correct. This guy used the truckirs kit with an MN12: http://www.therangerstation.com/forums/showthread.php?t=158351

The Explorer that Don mentioned would be Ranger bolt pattern. Haven't seen it done.

The Nissan 240sx would be the same bolt pattern too. Maybe you can find a drifter or import drag racer that's looking for a solid axle for their 240, and work out a swap.

You're going to have to do some fabbing to make any of them work. You can weld on the kit from Truckirs.com. That will let the whole IRS assembly be bolt in, but it sticks out from the frame a fair bit and limits the wheel offset and tire width you can run.

Or, you can do what they did on Trucks, and do some more cutting/welding to make it bolt in, but narrow enough to allow for really wide rear tires.

Pretty sure that any of the IRS units I mentioned will be wider than your stock rear axle, so keep that in mind. Wide wheels with normal Ranger/Mustang offsets will require the body to be modified if you're planning on keeping the wheels inside the wheel wells.

 

[dannyboy3141]

I like all of those ideas. What would you guys think about transverse leaf?

 

[85_Ranger4x4]

No idea at all how it would fit but the 4dr 02-10 Explorer had an IRS 8.8.

Could probably buy one with a trashed 4.0 Ex cheaper than you could the IRS out of a Cobra and junk what you don't want.

Same bolt pattern as a Ranger but uses the typical later model FWD type offset wheels.

IMO as a truck guy they are kind of oddly designed, changing the rear wheel bearings in mom's '02 was not pleasant. Maybe that is a common thing, it was the only IRS I have really been around.

 

[lil_Blue_Ford]

I like all of those ideas. What would you guys think about transverse leaf?

Transverse leaf (going from one side of the truck to the other) would require links to locate the axle under the truck. Unless you want to build a wacky a-arm setup for it, but it would probably be way more effort than links. About the only way to go independent without links would be an IFS rear out of another vehicle


Sent from my kite using a trebuchet

 

[pjtoledo]

Doesn't the powerblocktv build use a Mustang Cobra IRS?

Advantage of the Mustand IRS - same 5x4.5 bolt pattern. Disadvantage - cost.

T-bird IRS comes from '89 to '97 car. You can get both 7.5s and 8.8s. (There is also the Lincoln version - aluminum carrier). Advantage - cheap compared to Mustang; Disadvantage - 5x4.25 bolt pattern. But you can replace the hubs with the Mustang one for a couple hundred bucks, and have same pattern front and back.

Both the Mustang and T-bird IRS are ~6" wider than stock '92 axle. You can compensate some with Mustang/T-bird rims as the have ~40mm (1.5") greater backspacing, but you will still be a few inches wider...

TruckIRS makes a kit to install it.

I can't remember if '92 has RABS speed sensor or if speedometer pickup is in transmission. I machined a spacer on the rear yoke to get a tone ring. I also used a set of '93-97 front spring/shock mounts versus Dan's solution.

The '03+ Explorer also has an IRS but I haven't seen anyone install it in a Ranger

oops

 

[dannyboy3141]

Transverse leaf (going from one side of the truck to the other) would require links to locate the axle under the truck.

If I used the stock links that came with the axle, I may consider it. What would you say if I just used the stock links?

 

[lil_Blue_Ford]

If I used the stock links that came with the axle, I may consider it. What would you say if I just used the stock links?

The only time I've seen a transverse leaf done, it was on a solid rear axle (like the factory axle), and that required custom links.


Sent from my kite using a trebuchet

 

[stmitch]

Corvettes have used transverse leaf springs in their IRS assemblies for decades, and they do alright. My big concern would be how difficult it would be to change spring rates if the original leaf isn't right. Keep in mind that any donor rear suspension you choose has been designed for the weight and balance of the vehicle it came in originally and your truck will be a different beast altogether. If the spring is too weak, you'll have a saggy rear that bottoms out. If the spring is too stiff, you'll be bouncing all over the road, and the suspension won't be able to articulate as easily, which defeats the purpose of switching to the IRS. With a Traditional IRS, you can compensate for that pretty easily by switching coil springs or tweaking coilovers. It won't be that easy with a transverse leaf setup. All of the factory Corvette race cars over the last couple of decades have coilovers instead of the leaf for what it's worth.

If you're thinking of using a Vette rear, there's also the issue of having a different wheel bolt pattern. It's not too difficult to overcome, but it's not ideal either.

 

[don4331]

The only time I've seen a transverse leaf done, it was on a solid rear axle (like the factory axle), and that required custom links.

I suspect dannyboy is thinking of something like C3 Corvette or equivalent...

Then he could mount the different housing using the Corvette tranverse mount like a frame cross member and use the front leaf spring locations to mount the trailing arms (some vertical adjustment might be required and they may require strengthening...)

The C3 'vette uses the equivalent to drive shaft tubes for axles, one could easily adjust width. (Lots of companies make adjustable track bars so alignment is easily accommodated).

So it would almost be a bolt in...

On the 'vette, the stock exhaust runs under the differential (sports car doesn't have enough space to run high enough to clear axle at max compression and irs/transverse spring prevents running under axle without getting stupid low - which is why you see lots of Corvettes with side pipes - gets them 3" more ground clearance and cools the differential). On Ranger, you have more choices: Go under differential, go over (just under bed), side pipes, or stacks - depending on how low your truck is/personal taste.

 

[dannyboy3141]

I've been studying up on that Rolling Thunder, and I'm thinking the Cobra is the way I should go