James_Douglas

It looks like I bought myself some time. I picked up a pumpkin from a 1946 Desoto Limo that appears to be in OK shape. I cleaned it good and stuck it in yesterday. I ran Sondra to work this morning and at boulevard speeds like 35 to 40 it seemed fine. On flat level ground at 35 and with a light throttle I could just barely hear it. With the engine going good, I could not hear anything. This unit is a 4.3 to 1 unit. The contact patch looked good and the teeth had no pits or hard shinning spots. The bearing sounded ok when I had it on the bench but without a load...I did nothing but clean it inside and out and painted the thing. I did not even change the seal. It does move out from a traffic light much better in Second Gear with the 4.3 set from the old 3.91 set I have been using. We shall see after a freeway run or two. ********** I talked with some folks about the issue of all these units have torque issues with the ring gear bolts. Including ARP. The consensus is that it is possible that the steel bend over locking tabs that MOPAR used could "cold flow" after a load of 50 plus years and/or 75,000 miles. That would allow the bolt to loose its bolt stretch. That is why, in addition to galling, ARP uses those hardened steel washers on the hardware and locktite. This is a very plausible explanation and I may well just use ARP lube on the top of the bolts and Locktite Red on the threads when I rebuild the new unit. Now if this rear end is good for the time being, I can take a few months and rebuild the pumpkin slow with attention to detail. I may also send the NOS 4.3-1 ring and pinion out for super finishing. Has anyone every found some of these bronze cupped spider gear (pinions) thrust washers that go between the gears and carrier case? The ones that one side look like a moon crater. Best, James

I would have to check a Plymouth Parts Book, which I do not have being a Desoto guy, but I suspect that it is possible that the Auburn Clutch used a different fork that the Borg and Beck. Someone may need to check that for him that has a 1950 Plymouth Parts Book. James

I disagree. It is not the engine HP it is the speed down the road for a sustained time. Case in point is my bad ring and pinion gear in the '47 Desoto. I can run it for short amounts of time here in San Francisco and it is fine. After about 10 minutes running down the freeway it heats up and starts to howl. It is function of the cars speed. I run my flathead for hours at 65 on the freeway.

It did not have anything to do with V8's. The tech note, the best I remember, said that due to the New Interstate Highway System that sustained higher vehicle speeds were causing the heat in the axles and they elongated. This caused them to bind on the stop or rubbing block in the differential. Therefore they added more end play. It is function of sustained speeds not engine type or size. I know we all run out flathead six's down the freeway at 65 and 70 all the time and that would have been very unlikely in the late 1940's. James

I use about .010 on the Desoto Suburban as I drive at 70MPH on long freeway runs. The axles grow at higher speeds and I do not want them bottoming out on the block in the rear end. Like I said, I read it in a manual from the mid-1950's years ago and noted it in my service manual...I just cannot remember which of my 100 car books it was in or perhaps it was in one of the hundreds of pages of factory service bulletins I have from 1946 to 1957. James

One of the things I always do on my old cars, 6v or 12v, is to use a long screw on one of the headlight bucket screws. I then attached a ground wire to it on the backside of the bucket and run them up to the battery cable (Positive or Negative as the case my be). This way the head lights have a direct ground path. This helps a lot as it bypasses all the sheet metal connections. James

I have found the the balking gear and rings can be hard to get. Used ones all day. New ones very very hard to get. The balking gear and ring are critical for the proper operation of the OD. It works on a friction principle and after years of use the ring digs a groove into the gear. Once it wears enough the unit starts to not shift "sharply" and reliably. One part that is hard to get is the little bronze thrust spring that slows down the main shaft. If one is using fluid drive it is of particular importance as the weight - momentum of the unit really needs it. The other issue I have seen is the three speed main shaft, which is different for overdrive applications, tends to wear on the face where the 2nd gear rides. This is at the edge of the fluted section. Even with an NOS second gear that wear can be such that you cannot get the second gear end play within specification even when using the largest snap ring that will fit. I had to have the rear of my second gear Industrial Hard Chromed on the rear face to make up for the main shaft wear. It has been quiet for over 50K miles. Last year, after 10 years of an ebay search running, I found an NOS main shaft and am saving it for my second unit I will rebuild in the next year. Now I use my car all the time, it is not an occasional thing, it is out daily driver so I want and expect all the transmission parts to meet the factory specifications on a rebuild. I had to pay Frank Mitchell a small fortune for an NOS balking ring and gear. I probably spent about $1500 on NOS parts plus my labor to build an as good as new three speed and BW overdrive. The actual work on it is not very difficult. It is however a lot of little things that all need to be done correctly. Of course one can use what appear to be good used parts and do it for less cost. But then one takes a chance that something will make some noise or not last 50K miles. James

So....I am in town for the weekend and I started to trial fit the 4.3 ring gear. I drilled the cracked carrier (for testing) to .003 over the ARP bolt shaft size. Just enough so it will slip through the hole. I then tried to mount the ring gear. No Joy. I then took one of the carriers that I had not drilled and measured some of the holes. They are all about .010 over the shaft size of the factory bolt. Ok, they used 10 thou clearance. So I drill the holes out on my test carrier so I have 10 thou of clearance over the ARP bolt shaft size. They go in but VERY tight to turn. So tight it will affect the bolt torque. Now I am wondering what the hell is going on. Is the new ring gear threaded holes not EXACTLY perpendicular? So I mount it on the carrier I have not drilled yet (the one I will ultimately use) and it fits and the factory bolts go in without it being a chore. So, what IS going on? After studying it for a while I figured it out. It also may explain why, if you have followed my thread, why the factory bolts were not tight on all three of the units. The factory bolts have a very small shoulder that is not threaded. In fact that shoulder is so small it may not even index much into the carrier when the steel locking plate is on the thing. So, the threaded section is what is "indexing" in the carrier hole. Threads are notorious in such situations as pounding down with the loads and a close look at the old bolts shows this is what is going on. It is on the order, the best I can tell, of .005 to.009 or so. I used a new bolt by comparison. So, what this means is the ARP bolts with a deeper shoulder that index fully with the carrier hole do not want to "move" to deal with any ring gear threaded hole alignment issues like the factory bolts did. So, I will have to drill or ream in .001 increments until the bolts will go down without creating any side loading that would toss off the torquing of the bolts. Now that brings up the first issue...the factory bolt failure and the loose bolts on the other units. I suspect that the ring gears are moving due to the threads pounding down over time and if it goes on long enough...loosening of the ring gear and then failure of the bolt. I can tell you that Winters Performance has two bolts with two different shoulder lengths that exactly match the hole in their carriers and I know that Currie has special bolts for their 9 inch Fords. I suspect that a fully indexed ring gear bolt is a good thing and one in which the threads are in the mating hole is a bad thing. A long wonky post for sure. I will be back at it next weekend and see what I get. James

The new cars. There was an article on this some years ago I read. The candle power keeps going up and those of use with old PAR lights even at 12 volt are going to be blinded by the new ones.

On the fronts could one not drill out the rivets and swap the drums? I would have to look and see if the rivet holes are in a different pattern...the bolt pattern would be an issue but one MAY be able to weld the old holes up and drill new ones for the smaller pattern... A backing plate can be welded and modified easy enough to fit if it clears the uprights... I would just change the front to discs and if one needed the 12 inch on the rear just swap and entire big 8 rearend. James

I have been running a 6 volt POS ground alternator for 15 or more years. I have a six volt electric pusher fan that I use now and then. I have never had a problem with it in 15 years and about 70K miles. I strongly recommend an alternator if you are using an Optima Battery. See my posts from 17 years ago or so to read up on that. James

If you want the 12 inch brakes, just do get a 1946 yo 1948 Desoto Suburban/Limo or big Chrysler 8 rear-end and swap the while thing. James

I am out of town this week and next. While I am out send me a private message with your phone number and I would be happy to help in 2 weeks when I am back in home. The 1949 and 1950 Chrysler Windsor is mechanically the same as the 1949 and 1950 Desoto convertible. I did a near concourse restoration on one. So, I know then too well. James

The bolts I got from Winters Performance are made for them by ARP. I have to decide if I want to use the bend over metal locks or use locktite on the threads or both. ARP told me to use their assembly lube on the upper shaft and special washer and snug them down. Then one at a time in a cross pattern remove a bolt and put a couple of drops of locktite on the threads put it in and torque it. The pull another one and do the same...until done. The bolts are 12 point and I will need to get a 3/8 inch 12 point for my 1/2 inch drive torque wrench. Also, a 9.7mm drill bit (3.818) is on its way to open up the holes in the carrier from .375 to .381 which these bolts require. The stock 3/8 bolts are a little sloppy in their holes, not much but not a precision fit. Let hope I can do better. James

A little more detail would help to answer your question. Assuming that you are telling us that you need to replace the front floor pan, the rear floor pan and the trunk floor pan then the procedure is something like this: 1. Get everything out of the car that would be a problem with welding sparks flying around. 2 Take the doors off the car and take the trunk lid off the car. 3. Weld a series of 1x2 steel tubing in an "X" pattern to the center pillar from side to side to stabilize the body left to right. 4. Weld a 1x2 steel tube from the bottom of this "X" to the front door hinge area and the same thing on the rear door. I like to go from low in the center to high on the door areas. 5. Weld two 1x2 steel tubes from the trunk rear lip (under it) to the wheel well arch top. Now you have everything stable. Pull the body from the frame and place it on saw horses or a rotisserie. Have someone come by and blast the body and while at it have them blast the now free chassis. Then you can start on the body reconstruction and in parallel work on the chassis and power train. James

On three different cars... The rear-end pumkins were in fact made by Dana. I do not know if Dana made the entire rear-end and just delivered them or if they delivered parts like full pumpkins and Desoto assembled the rear-ends. In any case, I suggest that people may want to check the ring gear bolts at their next opportunity. If the ring gear shifts even a very little bit...it will toss off the ring and pinion mess. The MOPAR service books state that "as little as .002" will cause the rear-end to make noise and wear prematurely. James

Interesting... So, I got my 4.3 to 1 ring and pinion NOS set and they look fine. I wanted to get one more carrier, the thing the ring gear bolts to, as one of mine is bad as I said above and the other is for the 3.3, 3.5 and 3.7 gears. The 3.9, 4.1, 4.3 and 4.5 use a different one. What is interesting is that I called up to my bone yard guy and he is pulling one off of a Limo in the yard and it is 4.3 to 1. What is odd is that a 4.3 does not show up in the Desoto Master Parts Book. It does on the 1946 Chrysler Master Parts book, but not the 1946 to 1948 Chrysler roll up nor the 1954 roll up. *********** The thing today is that my bolts came in from Winters Performance. The ring gear uses a 3/8-24 right hand thread that is about 1 inch long. I called ARP and they said they make a bolt for Winters Performance that is 3/8-24 right hand thread for their fancy rear-ends. I confirmed the length as they make two bolts one a hair longer then 1 inch and one a little shorter. I ordered both and they both come with the ARP washers with the cut side for the curved root of the bolt shaft. I had to order through Pete and Jakes as Winters does not process via CC over the phone or internet. What did bite me in the ass this morning when I has the bolts on the bench is that their shaft is NOT 3.75 but .381 inch...urgggg So, I had to order a 9.7MM (.3818 inch) drill bit and will have to drill the 12 holes in the carrier for the bolts to slip through. So much for getting it done this weekend and I busy for the next week. As a caution to everyone. A factory bolt in my Suburban that was 4.11 failed. When I took it apart a couple of weeks back it only had 4 or 5 bolts holding it on. All the rest had failed or were failing. When I took apart the 3.91 that I have been using the last 6 years the bolts WERE NOT PARTICULARLY TIGHT. Also, I stripped the 3.36 rear-end and their bolts were not very tight. All these rear-ends came from different cars and I can tell by the bend over tabs they had not been touched since the factory. What this means is that these bolts get loose with time and/or the bolt material was not up to the torque needs. In any event, I do not know off the top of my head if the regular rear ends used the 3/8-24RH one inch bolts; but if they do then all are suspect with age. I will swing back when I get the thing together in a couple of weeks and post the result or any issues. James

So, what is the after the new head compression test versus the old one?

I cannot address Plymouth and Dodge, but I can Desoto and Chrysler. The one item that I would change, and did on my '49 Desoto and will on the '47 Desoto is the rear cross member. These things are flimsy and worthless. There only job is to keep the side frame rails at a specific width and to hold a couple of body bolts. What I did was build a thick wall tube to replace it that had holes drilled in it and the holes had thick wall round tubes welded in. This created a place to bolt in a custom designed hitch. I would think about it. James

https://www.allpar.com/d3/cars/desoto/suburban-1951.html The answer.

One could in theory drill and tap an aftermarket axle for lug bolts. The issues are the depth of the flange and the material. When I talked with a couple of the after market axle folks none of them were willing to do it as none of them thought the flanges were deep enough to deal with the fulcrum length of lug bolts. The studs have the flange on the back which distributes the loads over a larger area. I also thought about making a threaded ring of the appropriate steel material for repeated lug screwing but it may get in the way of breaks or other things. Again a lot of engineering after I have spent the money on a rear end and not knowing it will all work before I spend the money. In the end, a $4K custom ring and pinion gear would be a better bet... As an aside, on the rear disc conversion on the '49 I machined a nice little mounting stud that went into one of the removed drum rivet holes and bolts in place. Works nice. James

I would have to go digging in my notes as it was 15 years ago. But, as I remember these were not the same for some reason. James OK, So I pulled my notes. They have a used one, but it is used, they have no new ones. If you look down that list they do not have much is the way of NOS/NORS hard parts. What happens is the large outer ring that looks like a very big snap ring digs into the balking ring and creates a groove. Now this part works by friction. Too much and it does not shift right or at all and too loose and it does not shift right or at all. The problem is that there is no way to measure the friction on the bench. One could take a used one and have it hard chromed to fill the wear, but this is not possible for the big outer ring. You would also have to worry about the surface roughness as if it is not the same as the factory then you end up with the same problem. I looked at all the options before I spent $400 for a NOS balking ring from Frank after it was apparent that the one in the unit I purchased from George was junk. My point is that there are a few key parts in these units that are VERY hard to get and unless they are near perfect you run the risk of having a unit that either does not work quite right or will not last for years. Now, if it is a weekend toy probably not an issue. if you are going to drive it 100K over 10 years it will be sooner or later be a problem if these parts are not in great shape when it was installed. James

Thank you, I have had that chart for 15 years or so. But, if you read my comments you can see that the issue is studs versus bolts and no wiggle room to move the flanges in to account for studs. A rear end swap will do nothing to solve that problem. James

Marc, Something is not right. I just checked my Hollander Interchange Book and it shows 1938 to 1950 Desoto ALL interchange. Are your springs new? If not, then what is happening is that your suspension is hanging down lower as the spring are worn. That makes one think that the expanded length is longer than what was designed by the factory. Since the roll up 1954 Master Parts Book shows that they are the same and Hollander show they are the same and my actual factory original shocks lengths are documented. I would just use what I did. James

The largest issue with these is the balking ring set. If worn they never work quite correct or start acting up in due course. I purchased the last NOS one Frank Mitchell had some 15 years ago and it cost a lot. Go see my very old posts for the issues around my "rebuilt" OD. I have not seen a NOS balking ring set since and I have been looking as I have a spare I need to rebuild. The sun gears are also VERY hard to find and it the unit was ever run with low oil these are junk. So, unless it came out of a car that is running and you can hear it, I would not pay more than $500 for a unit or a seller has to warrant that the sun gear and balking ring is usable or take the unit back with a full refund. Anyone who pays more than $500 is playing Russian roulette with their money. James