I have a Brookville Model A frame with the parralel 4 bars kit from Pete & Jakes. The instructions are of almost no help to me. They just give you a diagram. I can figure out where the brackets weld to the 9" housing but how do yoy mount them to account for pinion angle? Or do I just them as even as possible and adjust the angle with the bars?
Set the pinion angle BEFORE welding the brackets to the 9"housing. I think its 13-15 degrees on the snout u-bolt flange.
When you are unsure how something you bought works just call the manufacturer and ask them. I'm not sure whether you are trying to weld the brackets to the housing on a bench or in place under the car. I would have the frame supported at the desired ride height and the housing centered in place then set the pinion angle at about 3# down. Then set the brackets in place and tack weld them. When you are sure all the angles and bars are where they should then finish the welds.
Just be careful putting too much heat one side of your housing because if you are not careful you can warp it. Currie Enterprises always recommends that when ever they build a rear to let them do all the welding.
What he said, except unless you are building a drag racer, the pinion should be about 3 degrees up -- assuming the engine / trans is 3 degrees down (i.e. the angles should be equal and opposite).
I am just learning to mig weld. My plan was just to tack the brackets and take it to a local tig welding guy who does it professionally. I havent purchased the housing yet. I was going to order one of the housings from Speedway but now I may call Brookville and see if they sell the housing with the brackets already welded up. Its for one of their frames so they may be jigged up for it?
Don't worry about warpage, burn those bastards on there good! (what the hell are you supposed to do, turn the heat down so you don't get any penetration?) If it is warped straighten it by applying heat of the opposite side of the tube.
No matter who welds it, with good weld penetration and the resulting heat, it's almost guaranteed that the housing will have to be straightened afterward. I don't think that it's a really difficult or sophisticated process. I used to work for Ford Motor Company, running an automated rear axle housing welding machine, and every single housing was straightened at the end of the line. As far as I saw, the housing was inserrted into a simple checking fixture consisting of two V-blocks to support the housing...one at each end. They would take a measurement, (I'm somewhat unclear on that part...I think it was just from the outside of the housing) and rotate the housing so the bowed side was up. Then they would apply pressure from above to the protruding portion with a press...take another measurement, etc. Set your pinion to the same angle as the engine and trans. Not on the same plane...but parallel.
If you buy a housing from Brookville, they have them welded up at the right angle for their frame with their motor and trans mounts. They will also weld them onto your own housing if you send it to them. If you want to do it yourself, Get the frame set and the ride height that you are going to run with the rake you want. Check the angle on the motor and trans. It should be about 3° down in the rear. Then put the front of the ladder bars on the front crossmember mounts. Position the rear end in place and set to approx. 3° up at the pinion. Now position the brackets, with the ladder bars attached and bolted up in the front, tot he axle housing. I make sure the adjusters are in about the middle of the available thread for fine tuning later. Now tack them to the axle. CAREFULLY pull the ladder bars off the brackets and remove the rear end. Be sure you don't bump or bend the tacks or break them loose. Now I put it on the welding bench and weld about 1/3 of the radius of the bracket where it meets the housing. I then move to the other bracket. Let them cool, go back to the first one and weld the opposite side and opposite end of the bracket from the first weld the same way, then again to the other bracket and so forth until you are done. This keeps the heat down with good penetration. I have done dozens this way and only one was warped when I was done
Thanks guys for the info. This sounds like something I would in all probability not do right myself. I will be calling Brookville this week. The frame already has all their brackets on it so if they can sell me a housing ready to go I am ok paying extra for it over the Speedway housing.
I set pinion angle on all race cars & street rods in the following manner. Set your car to height front & rear. Measure angle of drive shaft near rear pinion then measure angle of pinion. On a 4 link run 3° on a ladder bar i run 4°. Ladder bars have more flex so add a degree. U want the pinion down not up. The rear end at the pinion tries to climb up under load so u want it angled down so under load the pinion & driveshaft are almost straight. This will give max bite to the tires minus wheel hop. Wheel hop on race cars can be traced to pinion angles being off most times
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