Ring and "O"pinion

[topchop]

Think I found the cause of rear end howl between 25 and 50 miles per hour.

Just disassembled the '47 rear end. Gears are 34 and 9 (3.78:1), which surprises me due to the lousy gas mileage.

Quite worn on gear face, raising a nice burr on the outside of ring gear.

Going to be my first banjo rebuild, and I will be replacing everything; Ring and Pinion, bearings, seals etc.

Before I get into it, one question.
For those of you that have done this before, how much trouble should I anticipate achieving an acceptable gear mesh pattern? Reading all the available tech articles on the subject, I know I will be assembling and reassembling a few times to get the correct gear backlash. One article in particular, is the attached .pdf which is for the Model A, but very helpful.

Any tips/tricks/pointers? Thanks in advance.

Jim

 

[edhd58]

I just did this on my 42 Fordor. It's time consuming but very do able. From the time I started the disassembly too the finished re assembly was about 10 hours, but I had no help and even after I thought it was okay once I took it back apart and did it again. It's now quiet as can be. I got my3.54 gears from Speedway.

 

[edhd58]

I have pictures of how I took out the pinion gear if this like it was actually pretty easy used a 2 jaw gear puller from inside the rear end.

 

[topchop]

edhd58, debated about maybe using the 3.54's. Any negative thoughts vs. the 3:78's?

 

[JSeery]

Depends on how and where you drive it. In town or mostly highway? Flat ground or hilly? I would prefer the 3:78.

 

[Tom/SC]

An opinion, We just installed a 3.54 to 1 in a 39 Deluxe coupe. Stock 221 flat head pulls the gear just beautifully no overloading. We are not in hilly country, could make a difference, but it pulls fine around here,SC.

 

[edhd58]

I am in an area of both some hills and a lot of flat ground. I am also out in the country with few stop lights.
I haven't had opportunity to drive it yet, except on our back roads road, I probably only got it to 35 or 40 mph.
It has no interior this week, it is at the upholsterer getting fitted with a new interior and then I'll get it inspected and licensed and be able to open road it.
I have no idea how the taller gears will do vs stock, but it seemed 3rd gear and the motor was up there in rpms just on my road. A neighbor has a 50 Ford P/U and complains about 50 mph having his motor winding up there is why I chose the 3.54 gears.

 

[edhd58]

Here are pics of how i removed the pinion, What it doesn't show is all the propane from a torch I used to heat the banjo part. With the puller in placed and quite a bit of pressure on the pinion I started heating the banjo. it took a good 5 minutes with a propane torch, constantly moving to not create a hot spot. When the pinion broke loose the whole thing popped and jumped and scared the begeezus out of me.
Using the same puller, with washers at the top of the screw and what the screw screws into on the outside, it pushed the bearing out nicely.
Installing the bearings was pretty straight forward again using heat on what ever needed swelling and freezing what ever needed shrinking.
Oh yeah, the engine is a 226 G six cylinder, base HP 90, but bored 0.040 over and the deck and head milled a total of 0.040. I don't know what this may have done to HP

 

[tubman]

I appreciate the title of your thread; I had to think about it for a while before I got it. Thanks.

 

[vilanar]

I did use that tutorial when rebuilding my friend´s broken differential.
Very good information and helpful tutorial.

 

[topchop]

All you guys, thanks. Just the input I needed to help me decide. Western NY has a fair amount of hills and I plan on driving the wheels off this thing when I get 'er done. (Just ordered the 3.78's). Will post progress.

 

[JSeery]

Sounds like a good selection topchop. Everyone is always commenting on the engine RPM on these flatheads. Think the problem is most people are more familiar with the sound (RPM range) of more modern engines. These flatheads were designed to run with the gears they came with! They are 1 to 1 gear ratios and they are going to run at a higher RPM range, just like they were designed to. I like an overdrive myself, but that is a totally different subject.

 

[Drbrown]

I think 3.78 a good choice for your local and region. I'm in a similar topography in eastern NYS and as JSeery mentioned, and although an extended subject, overdrive or Columbia rear end is a nice thing to have with most any flattie. My '47 has 3.78 with a BW OD and although its torque's "sweet spot" is about 55 to 60, it drives comfortably at 65 to 70.

 

[1ton]

If I'm not mistaken, Henry Ford once said "Whether you think you can or think you can't, you're right".

 

[topchop]

Been a couple of weeks now, and thought I’d give an update on rebuild progress.
Not finished yet, but closer.
Determined that it’s not “rocket science”, as long as you do your homework. Having read as much as I can, on here and HAMB, one can pick and choose what is best for you. I just want to post what worked for me so far (not in any specific order).

• Purchase the best bearings (Timken)
• Modify new Ring and Pinion set from Speedway. You need to remove .0010” from diameter for outer pinion bearing to provide a wring (slip fit, - no shake) fit to allow proper preload. Picture below has inner taper bearing pressed on. The exposed diameter has been reduced. Note: the 4 place decimals are U.S. standard measurement.
• Freezing the pinion shaft shrinks the diameter .0005” allowing easier press fit.
• For assembly of torque tube bearing races, putting them in the freezer also shrinks diameter .0008”.
• Leave the torque tube axle seals out until all preloads and backlashes have been finalized.
• I chose to make a bench fixture to stand the rear end vertical.
• Use threaded pins to facilitate shim placement between housing and torque tubes.
• Unless someone has, or made, pinion nut wrenches, you need to get the right tools. Pipe wrenches will only destroy the nuts. Went to the local tool store (Lakeside Tools in Henrietta, NY) and they fixed me up with the correct wrenches for about $30. Now I got ‘em for life.
• DO NOT clean the torque bells tapped holes with a 3/8 – 24 tap. Many have reported leaky bolts after doing so. Just carefully clean the tapped holes and bolts with a soft wire brush.

I’m getting ready to set the “real” carrier bearing preload now. I have only had the bells apart 10 times now, and my arms are getting real big.

More to follow.

 

[42merc]

My question is about the decimal placement of the figures quoted.
Pinion, did you remove .001" or .010" ?

 

[Lawson Cox]

Nice setup you made there.

 

[Mart]

Nice summary and lots of helpful tips. I like the wooden holding fixture, that's a good idea.

Mart.

 

[topchop]

42Merc. Sorry. A toolmaker by trade and we speak in "tenths". That measurement is "ten - tenthousandths" or in laymans terms, one thousandth of an inch.

By the way, just did the carrier preload. The method I am using is, - axles and spider gears installed, and turning both axles at same speed. Using inch-pound dial type wrench, I have shim/gaskets in place that produce 19 in-pounds preload. If I add .0010 (one thousandth) to the right side, it drops the preload to 15 in-pounds. I will be going with the 15 reading. If I reach into the pinion cavity, with the 19 in-pound setting, it seems the ring gear is fairly hard to turn by hand. The 15 In-pound setting is a little easier, but with adequate drag. (Compared to bolts loosened, it freewheels).

Did the comparison twice, and yes, tube-on - tube-off 4 more times.

Anyone have an opinion on 15 vs. 19 in-pound preload?

 

[topchop]

BTW, original untouched'47 banjo gaskets measure .009" both sides, just like Ford says in all the manuals. With all new Timken bearing sets, initial preload to the 15 in-pound settings is .014" left and .015 right. Should give me ample room to set up pinion backlash.