I have a 37 or 38 banjo rear in my 28 roadster with a closed drive / 39 trans. Everything is hearsay because i bought this car unfinished. The P.O simply stated that he installed a matched set 3.54 ring and pinion in the rear. The ratio appears correct not that it has anything to do with the howl I am experiencing. The rear is quiet under acceleration (running 140w gear oil). It howls under deceleration. The howl is the loudest when i fully let off and the engine is slowing the car to a stop sign. any speed from 20-30 mph on up howls) Up until now i've been shifting to neutral when slowing to keep things quieter (it still howls slightly but better). Does anyone have any suggestions to look at first before i pull the rear out? Not that i have anything to go off of, but i'm doubting that this noise only on deceleration is because of incorrect gear mesh. im wondering if what i am hearing is the pinion walking in and out of the housing. I looked at a few diagrams and i'm thinking perhaps the jamb nuts on the pinion are not adjusted correctly or maybe loose? I'm also new to closed drive units so i'm assuming that the torque tube would stay attached to the trans and i would unbolt the tube from the housing and disassemble that way, thoughts?
I did the same thing, switched an entire 3.54 center section from a 46-48 rear into my 40 rear, and I also had a bit of a whine. When you assemble a banjo rear end, the backlash on the pinon to ring gear is set with the thickness of the gaskets between the bells and the center section. I believe .008 of backlash is the sweet spot. Most likely it was assembled with too much/too little backlash. I tried to do mine correctly, but since it was my first one, I wasn't surprised when mine whined too.
Yes, best diagnostic is to pull it apart and go through all installation adjustments from scratch. re-do mesh, and pinion should of course not be able to move fore and aft. Could be the big nuts on pinion got loose and let everything float!
I know the specs of the "A" rear banjo is different VS the later Banjo. anyone have specs / info setting up the later V8 banjo?
Life with early Fords really needs support from the Ford bulletins! get the set covering 1938 as easiest summary. Load the pinion (I'm betting your problem is thereabouts), set side gear clearance (all these clearances are negative) then shuffle gaskets to adjust ring to pinion location. Basic procedures work the same way '29-48. Model A covered about 1928, V8 stuff covered about 1933 and all changes adapteb in '38. A basic preparation was a very high degree of precision in gear fit, dimensuions and location of pinion, and dimensions of banjo, because these things were bolted together in assemble and sent off down the road. Ford did not put them together six times to check out gasket thicknesses...they were contolled tightly enough that they went together with the .010s and drove away, with survival right into our times. THis potentially means you need to be extra careful in if using modern repro gears to double check fit and clearance and possibly shuffle the gaskets until happy. I say 1938, because there was slight pinion load change from earlier that you probably should use.
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