Shameless plea for driveline parts & info

[grey beard]

Had all kinds of problems getting my drive line back together. I'm pretty old and fumble-fingered, and lost a few needle bearings - what a cluster.

Finally dioscovered that there is about a 1/16-inch difference in the seat for the U-joint between the two pinion flanges, even though they look identical. Had to swap pinion flanges - which means I had to keep my old Pilothouse flange on the Windsor rear AND use the Windsor axles.

This is good info for you'all to know if you contemplate this swap. Now it's finally back together. Road test is next.

[grey beard]

Look at me, will 'ya, I'm runnin' my own thread - answering myself, as it were. Mebby it's just me out there, and nobody else, what?

Today I finished up my differental swap and road tested the truck. I have to say that with my 30-inch tall rubber and this Windsor 3:73 rear gear, I wouldn't want anything any taller.

The change is amazing, and must be experienced to believe. I now actually drive in first gear, and then shift to second for a good long while. Once in third, I would run out of intestinal fortutude before I run out of engine. I can comfortably do 70 for the first time ever in my Pilothouse. What a change from that 4:56 I had before.

Here's what I have learned, and if you ever contemplate swapping out your rear, you may wish to copy and save this stuff. The shop manual is not wrong, but it makes the sin of a whole lot of ommission. When you attempt to set axle end play, just bolt one axle in place and go to the other side. You cxan set the clearance on one side because the two axles butt ends inside the differential. I needed one thick shim on one side, and this gave me just enough end play to feel on each side. I spent several hours learning this lesson. Your mileage may vary . . .

Also, if you swap a car rear into your Piothouse, please know that the pinion yoke must stay with the drive shaft - not the differential. Also, you will have to use only the center section - not the differential housing, because the spring perches are on the wrong way - unless you want to weld new ones in place and blow the old ones off, which is certainly do-able.

I am pleased with the results of all this work. It was well worth the effort. Anyone need rear wheel seals, I have an extra set of inner and outer from NAPA that I do not need.

Now we all know . . . . . .

Good Luck

[HanksB3B]

grey beard,

Thanks for your input.

Please answer a couple or so questions:

1. I'm assuming you are running the L6 engine?

2. Are you 3-speed or 4-speed transmission?

3. What is the model/yr of your truck?

4. At 70mph, with 30 inch rubber, what rpm are you turning ?

Thanks and Congratulations,

Hank

P.S. I've debated whether to go from a 4.10 to either a 3.73 or 3.54. Some say it'll lug with a 3.54.

[Merle Coggins]

As I've stated here many times, I have a 3.73 diff from a '50 Plymouth in my truck. With 235/75R-15 tires at 29" diameter I can run easy at 65 MPH and can reach 70-75 when needed with room to go. I haven't connected a tach to measure the RPM when driving, but according to Tod Finch's speed calculator I'd be at around 2800 RPM at 65 MPH.

Merle

[HanksB3B]

A local here just bought a 50s Dodge truck for $1,500 and sold the 25" rebuilt engine for $1,600. He's doing the resto-mod thing to the truck so I'm really hoping the differential is the 3.73 and not the usual 4.10 like I already have.

Even if it is a 4.10, if the price is right (under $100) I'll take it because my differential housing looks like someone backed into a tree stump. Although someone tried to fix it, it still leaks.

On my wishlist is replacing mine with a rebuilt, powdercoated stock housing setup with 3.73 gearing.

I would like to know opinions on running the L6 with a 3.54 in a 1/2" ton 3-speed.

Thanks,

Hank

[Merle Coggins]

In my opinion a 3.73 is perfect. Unless you live in the plains, where there are no hills, the 3.54 may be a bit too low.

Merle

[Reg Evans]

Better question is why????

I second that emotion Don. I have no problem adding spacers to get a little better center of gravity and stance but bottoming out on a gentle speed bump or driveway encroachment just doesn't make any sense to me. To each their own. I just hate making sparks on the pavement with my gas tank.

[Reg Evans]

A local here just bought a 50s Dodge truck for $1,500 and sold the 25" rebuilt engine for $1,600. He's doing the resto-mod thing to the truck so I'm really hoping the differential is the 3.73 and not the usual 4.10 like I already have.

Even if it is a 4.10, if the price is right (under $100) I'll take it because my differential housing looks like someone backed into a tree stump. Although someone tried to fix it, it still leaks.

On my wishlist is replacing mine with a rebuilt, powdercoated stock housing setup with 3.73 gearing.

I would like to know opinions on running the L6 with a 3.54 in a 1/2" ton 3-speed.

Thanks,

Hank

I installed a 3.54 ring and pinion in my 49 Dodge Coronet that had a 4.11 in it from the factory. Before the change the car sounded like a truck on the freeway at 55 mph and after it was comfortable at 60. The car did have a well worn 230 under the hood but I never noticed any lack of power so a strong 218 should do just fine. Just my experience and last ditch effort to get you to buy my other set of NOS 3.54's.

[grey beard]

Hank,

My tranny is a 3 speed, my trufk a '48 B1B, engine is a 218. At sixty mph my engine is running between 2600 and 2700 rpm - quite comfortably, I might add.

Does no one around PA need a rear axle/brakes unit for free?

717-354-0276

[HanksB3B]

I saw Paul, the guy that bought what I now know is a 54 Pilothouse. He told me it was a 4.10 and the housing was in poor shape so thats a no-go.

I do live where for the most part it is flat but like to drive into the mountains and secondary roads can be quite steep in California to say the least.

Paul's 51 Windsor has the 25" Spitfire engine with a 3.73. I've got to get the story straight, but Paul claims that he can cruise at 70mph and does not have huge tires. Although he knows the L6 peaks at 3600 Paul thinks rpm in excess of 2500 is not a good thing and thinks 2100 is an optimal rpm.

Without the benefit of a tach, realistically I have no idea, but feel as though when I'm driving my B3B 3-speed 4.10, 235/75R-15 anything over 40-45mph is pushing it. My engine has under 1,000 miles on it, idles quietly at what I'd guess is 450-500 and accelerates really smooth and strong.

I'm still sitting on the fence between the 3.73 and the 3.54. 1st gear seems so low most of the time except from a stand still on a hill.

To be continued,

Hank

[lugnut123]

A b1c have the same wheel pattern as a early 80's chevy 5 hole 1/2 ton pickup. Replace your whole rrend with the chevy. Put in a T-5 chevy 5 speed tranny and use the chevy driveline. U mite save some moneys. I ended up spending 200-250$ on a driveline with that special flange that fits the dodge 4 speed. You have to rig a slip joint in your driveline also. With the flange you will use a small GM u joint.

Edited July 25, 2010 by lugnut123

[HanksB3B]

a consideration as welll as some other solutions. Always was impressed with the T-5 solution. A little out of my league but with all the help here might be able to do it maybe this winter. After all it might drop to 60 deg and I can work in that. It's 62 out at 9:29 right now.

Thanks,

Hank

[Jerry Roberts]

.......

I would like to know opinions on running the L6 with a 3.54 in a 1/2" ton 3-speed.

Thanks,

Hank

Hank , That 3.54 will be fine . My truck has a 218 , 28 inch diameter tires , 3 speed transmission , and a 2.94 rear end . I like the set up just fine . I live in the flat lands and drive 70 mph on the highway the motor doesn't lug . I am going up into the mountains tomorrow and I will be shifting down to second gear on the longer climbs , but that is OK .

[John-T-53]

...snip...

Paul's 51 Windsor has the 25" Spitfire engine with a 3.73. I've got to get the story straight, but Paul claims that he can cruise at 70mph and does not have huge tires. Although he knows the L6 peaks at 3600 Paul thinks rpm in excess of 2500 is not a good thing and thinks 2100 is an optimal rpm.

Without the benefit of a tach, realistically I have no idea, but feel as though when I'm driving my B3B 3-speed 4.10, 235/75R-15 anything over 40-45mph is pushing it. My engine has under 1,000 miles on it, idles quietly at what I'd guess is 450-500 and accelerates really smooth and strong.

I'm still sitting on the fence between the 3.73 and the 3.54. 1st gear seems so low most of the time except from a stand still on a hill. Hank

Hank, I've got the same setup (drivetrain and tires) you have, and

45 mph = 2294 rpm

50 mph = 2450

55 mph = 2706

60 mph = 2952

The engine seems happiest between 45 and 50, but over that it's no bueno.

I've been looking for a 3:73 for over a year now, but no luck at all. There was a 3:54 that came up for sale on here last spring, but I thought it was too high of a ratio. With the limited power these flatties have, erring on the side of performance is better IMO.

I've decided to get a T-5 built instead now...with my existing 4:10 rear and new 0.72 5th gear, 65 mph will now be 2300 rpm.

[grey beard]

I'm a retired diesel tech. instructor and college teacher. Since there seems to be serious interest in rear axle ratios on this forim, I'll pass this info along for what it's worth to you. This is also one method whereby it is possible to figure accurately what your engine rpm is at a given speed without a tachometer available.

Tire height in inches times 3.14 equals circumference.

Example: 27 inches x 3.14 = 84.78 inches

Divide this by 12 = 7.07 feet

Divide 7.07 feet x 5,280 feet per mile = 746.82 tire revs per mile

746.82 revs x 4:10 rear axle ratio = 3061.97 engine rpms at 60 mph.

OR

30 inch tall tires x 3.14 = 94.20 inches

94.20 divided by 12 = 7.85 feet

7.85 ffeet x 5,280 = 672 tire rev per mile

672 x 4:10 rear axle ratio = 2757 engine rpms at 60 mph.

IN MY PILOTHOUSE, I HAVE:

30 inch tall rubber x 3.14 = 94.20 inches

94.20 divided by 12 = 7.85 feet

7085 feet x 8,280 = 672 tire rev per mile

672 x 3.77 rear axle ratio = 2533 engine rpm at 60 moh.

Man, I can live with this arrangement.

i like!

[Reg Evans]

Cool Dave ! How does that compare to this RPM calculator ?

http://www.csgnetwork.com/multirpmcalc.html

[Merle Coggins]

I like that formula, Dave. It's much simpler than the one that I was taught in tech school. I don't remember it now but included measuring the tire loaded radius (from the ground to the center of the axle) and plugging that into an algebraic forumla with total gear ratio. I may have to dig out my old school books and look it up again.

Merle

[grey beard]

When you stripped off all the high falutin' titles and such, my job as a public high school teacher was to sell knowledge to unwanting and unwilling customers whwo didn't even want to be in school. I learned long ago that the more simple we can keep things the more easily learned they become - sorta' liike grinding up the stuff small enough that they didn'tknow they were swallowin' it. In a few cases, they even understood. Well, mebby one or three . . .

Why, I even learned how to teach figgerin' out cubic inches of an engine without using any algebraic formulae. Like on the back of a scrap envelope with a lead pencil . . . . go figure!