Pleas help, which way do the perches go?

[morrow_jacob]

Possibly a dumb question, but I need help as to which way does the square hole on the perch go? towards the front or back?

All the the pics I took I cannot get a close look, all the pics I find online are too close to see the orientation. This is a Bbody Dana 60 I scored off of craigslist that I'm moving the perches back to stock.

Thanks again you guys!

 

[mopar 3 B]

That is strange the FSM shows round holes. Wonder why the square hole for a round bolt? Is there a difference in hole spacing from the alignment pin hole to the outer holes? Will measure my Dana in the morning.

 

[HEMI-ITIS]

The preferred method would be with the diff in the car so you could measure the trans and driveshaft angles so you don't need wedges to correct the final pinion angle.

 

[badmopar67]

I do not believe it matters the only hole that matters is the center hole which the spring nipple fits into other than that The u bolts don't go through those holes.
The only time I've seen those offset holes be used is when you're lifting a 4x4 truck by lengthening the rear shackle the axle tends to come towards to the front of the wheel well slightly the guys will drill out the front hole to offset the axle on the spring to make up for this distance
Ask me how I know

 

[morrow_jacob]

I do not believe it matters the only hole that matters is the center hole which the spring nipple fits into other than that The u bolts don't go through those holes.
The only time I've seen those offset holes be used is when you're lifting a 4x4 truck by lengthening the rear shackle the axle tends to come towards to the front of the wheel well slightly the guys will drill out the front hole to offset the axle on the spring to make up for this distance
Ask me how I knowView attachment 279017

I was thinking this was true about it not technically mattering, but I just wanted it to be in the correct stock orientation. Thanks for the reply though, sweet Ranger, I drove an edge the Navy, love em

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The preferred method would be with the diff in the car so you could measure the trans and driveshaft angles so you don't need wedges to correct the final pinion angle.

I agree completely, that is why I am going to only tack them in place for now. My original axle, which is now sold so now I dont have a reference , had a 5* from ground angle.

I plan on going with the RMS 4 link rear, I called them and they said they go from the stock angle, which he agreed was 5* from ground. Any pinion angle adjustment can be made with the control arms from there, and adjustments would need to be made since there wont be leaf springs and leaf spring wrap.

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That is strange the FSM shows round holes. Wonder why the square hole for a round bolt? Is there a difference in hole spacing from the alignment pin hole to the outer holes? Will measure my Dana in the morning.

Yup, I checked that out too but couldnt find a definitive answer, thanks for checking!

 

[Cranky]

That is what you get when you order new perches these days. IIRC, they are what the Iso clamps used? Also, the center hole is larger on those cars and you will need to tack in a bushing get a snug fit on the older style alignment pins. And too bad you are over 200 miles away. I have an alignment shaft for checking that stuff. Chances are the ends will move when you weld them up....at least they always have when I welded them.

 

[badmopar67]

I believe the angles are not from the floor to rear but between the rear and the driveshaft probably not supposed to be not more than 3° difference between the two.
but no less because you do need some variance for proper universal wearand this needs to be done with full weight on the suspension

 

[Cranky]

I've found perches from 3 to 5 degrees nose down from the factory measured from the housing opening. Now what it is once it's mounted on the springs can be a different story. Thing is to weld them both at the same angle. Some will tack them on once the rear end is sitting on the springs and that's not the right way to do it as that can vary a lot depending on the type of springs used.

 

[badmopar67]

On a car that might be true now I think about it's possibly compensating for spring wrap, cranky have you ever check the drive shaft angle with the full weight on the suspension just to see the different degrees angles between both.I haven't checked my car which is completely stock suspension but I might slide under there just to see

 

[badmopar67]

Just crawled out from under my car completely on the suspension the rear is 2° towards the ground and the driveshaft is on an angle of 4° towards the rear The only differences I am running at 275/60/15 on the back never really checked it but it's definitely a factory set up. but this is in my garage which does have a slight slope to the garage door which I would think would change both numbers a little bit but the difference between the two should stay the same

 

[Cranky]

On a car that might be true now I think about it's possibly compensating for spring wrap, cranky have you ever check the drive shaft angle with the full weight on the suspension just to see the different degrees angles between both.I haven't checked my car which is completely stock suspension but I might slide under there just to see

With the full weight on the suspension is how you are supposed to check it. And you can still get the correct measurements on a garage floor with an incline to it. You're measuring relationships with the parts in the car and not the earth......

 

[badmopar67]

10/4

 

[Cranky]

But the perches do not come from the factory set at 0 with the pinion if that's what you are thinking. Have never found one to be 0 but are always welded in with the nose down a few degrees and the spring where the rear end sits usually has some angle too. You might be surprised to see how much the angles change when the car is under acceleration vs deceleration. Load up a stock factory car with a family of 4 and luggage in the trunk makes a big difference too. Add that to a 440 powered New Yorker and things can get kinda crazy looking when dad hammers the throttle doing 30 and the car downshifts into 1st and goes blasting past the moron doing 30 in a 50 zone. Don't know about others but my dad did stuff like that with the car full lol

 

[morrow_jacob]

That is what you get when you order new perches these days. IIRC, they are what the Iso clamps used? Also, the center hole is larger on those cars and you will need to tack in a bushing get a snug fit on the older style alignment pins. And too bad you are over 200 miles away. I have an alignment shaft for checking that stuff. Chances are the ends will move when you weld them up....at least they always have when I welded them.

Dang, that is too bad you are that far, thanks for the offer though! There is a shop in Fort Worth that can check and bend em back if needed thankfully. I will weld them nice and slow and hope for the best.

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I believe the angles are not from the floor to rear but between the rear and the driveshaft probably not supposed to be not more than 3° difference between the two.
but no less because you do need some variance for proper universal wearand this needs to be done with full weight on the suspension

Correct, thats what the angle I will try to achieve once the rear 4 link is in the car through adjustments

My goal while its out of the car though was to make the dana match the 8-3/4 perfectly, which while sitting on the floor, is 5* down (or up since its upside down) for welding. The best I can figure is make it match whats on the original axle and hopefully there will be enough adjustments with the RMS. With that I have to actually match the tranny because there will be no movement when the gas peddle is mashed, the axle should be "locked" at that pinion angle. Or as I understand it.

Thanks for your time!