new axle

[bob69m]

hello everyone

I got a posi rear axle today from a relative of mine. I dont know what year truck it came from but he said that its a stock positive traction axle. This is what it says on the tag on the axle. I hope someone knows what it all means I just want to make sure it is same gear ratio as whats already in my truck.

3L55 8 8 9L27

this is what says on the one thats in the truck now 3L55 8 8 5F19

 

[Rons beast]

Hey Bob,

That should be a 3:55 locking diff. with 8.8" ring gear. The 5f may be the date of manufacture, and the 19 the # of axle splines...or the plant # that I'm not sure of.

There should be a series of numbers and letters, ( ex. S832E ) that would code the axle.

This site would give you the info...http://www.fordification.com/tech/rearends_ford15.htm

Good Luck

 

[bob69m]

So the L stands for Limited Slip right? but the axle thats in the truck isnt a limited slip axle.

 

[Rons beast]

The L stands for "Equa-Lock". "3L55" Fords version of limited slip, or "posi" and yeah I know it's and L not an E.....I'm just repeating the info sheet. I don't write em'.

 

[bob69m]

so limited slip and a posi are same things right? I can spin the wheels on the new axle and they both turn same direction, the ones on the truck spin oposite so the one on the truck isnt a posi, but it also has a L in the code, what the ****?

 

[Rons beast]

Yes they are the same. I can't say that the spinning wheel test is the defining method of determining a "posi' or LS aka EL rear axle. The axle has to allow the right and left sides to turn independent, for the purposes of navagating a turn. ( the outside wheel has to make more revolutions than the inside wheel.) The limited slip..."posi" comes into effect if one side looses traction. In that event the torque is applied to the opposite side. This is done by a series of plates or cones and springs.

So I guess the only way to be absolutely sure the axle is "posi" "Limited slip" "Equa-lock"...etc. is to open the cover and look inside.

That all said, If you are turning one axle with the pinion hooked to a drive shaft, and the other not, the wheels will do different things.

 

[Krafty]

you could always just put an air or electronic locker in the new axle if you wanted.

 

[Seabronc]

Pull the cover and take a picture of the carrier, they look differently inside. If I had my camera, I'd show you a picture, just take a picture and post it.

Good luck,

>-

 

[Bully Bob]

"so limited slip and a posi are same things right? I can spin the wheels on the new axle and they both turn same direction, the ones on the truck spin oposite so the one on the truck isnt a posi"

Your above statment is all true.... >< <'>

Lock/block one wheel on the new axle. Try to turn the free wheel. This should be difficult to do, or a lot of resistance. (indicates posi)

Should you swap the complete axle, or just the gear-set, put in new gear oil & the posi additive in either case.

You can rotate the (1) wheel & count the rotations of the yoke to get the ratio. i.e. one rotation of the wheel gets 3 1/2 yoke rotations = 3:50 or 3:55's

However, like Seabronc says, you can discover a lot with the cover(s) off... count the teeth. etc.

BTW, rule of thumb is NOT to trust the factory tags when making changes. It's not uncommon for someone to change gear-sets & fail to remove the tag.

 

[bob69m]

so this is whats inside the new axle

 

[Rons beast]

That is a posi/ equa-lock/ limited slip....rear.

 

[bob69m]

Equal-Lock

This was the first design limited slip used by Ford in both the 8 " and 9" rearends. Except for new clutches, there are only used parts available now. This design is not aggressive and does not lock-up harder when more power is applied as most every other limited slip design does. Ford built two different Equal- lock designs. One uses four plain steel plates, three fiber lined plates, and one Belleville spring for preload. The other uses only three plain steel plates, two fiber-lined plates, and two Belleville spring plates. The design that uses two spring plates can only be converted to the single spring design with more clutches if the appropriate clutch hub is used to accommodate the higher number of clutch plates. Can be identified by five tab clutches (Ford Traction-Lock for the 8" and 9" use four tab clutches). (factory)

So having this isnt really as awesome as I thought, acording to what I found on the internet this isnt very desireable. any opinions?

 

[Bully Bob]

Depends on your intentions.... what might they be..???

Posi is OK.., lockers are better., Air or elect. lockers are the best. (for street-n-dirt)

What's wrong with what you have now..?

It takes some knowledge & exp. to swap a 3rd member.

Posi won't hurt things but some folks break related driveline parts once lockers are installed.

There's a bit more homework needed B4 these changes are made. >< <'>

 

[Rons beast]

IMHO..That rear is a great option for everyday driving, and some light offroad driving. It would be pretty good in snow too, but not the best if you are agressively involved in trail or bog driving, or rock climbing.