Axle Question

[ng19delta]

I'm going to throw this up here, and on a couple other Dodge forums, but I have a question regarding the rear axle... My truck is an Oct 42 production, by serial number, and originally had the small differentials. At some point, someone swapped in the large differentials... The rear cover has a 3/8" spacer for it(welded to the cover), but I noticed something else lately. I did not notice when I took it all apart, but on reassembly, the left driveshaft has about a 1/8" gap between it and the hub... I can tighten it up, but then it presses against the box in the middle of the 4-pinion differential, and makes the diffy VERY tight... Were there different axle shafts for the different differentials? I am thinking best bet would be to make a spacer, and let all be... I checked the splines against a brand new side gear, and there is no binding, so I know it is not hanging up there. The gaskets I have for the rear seal are paper thin(!) and the hub seal is M-37...

Scott

[Gordon_M]

Scott, you need a copy of this:

TM 9-1808C Power Trains and Interchanges, Military Civilian Trucks 1941 - 1971 (Dodge) Paperback – 1981 by by John H. Zentmyer

John covered all the shaft, transmission, and axle interchange stuff in great detail, including the small modifications made between series and so on. It's worth having for anyone interested in any of the 4 x 4 Dodges from the '40s onwards.

[ng19delta]

I've had a couple people mention cutting the end of the axles by 1/16", which makes perfect sense, but reading through the interchange manual(I had to find it in a .pdf online- i have NO idea where mine is) I also found that there should be a 1/16" spacer behind the third member itself: The axle line is 1/16" farther to the rear with the larger differential: I'm glad I discovered this NOW, and not after the diffy got eaten... But I realize I will also have to pull & reset the front third member as well! (Although I had no problem with the axles there...)

Since I have to pull the pumpkin again, I am going to tear it down & replace the side gears- I have a NOS rebuild kit- may as well...

Scott

[Kaegi]

I've had a couple people mention cutting the end of the axles by 1/16", which makes perfect sense, but reading through the interchange manual(I had to find it in a .pdf online- i have NO idea where mine is) I also found that there should be a 1/16" spacer behind the third member itself: The axle line is 1/16" farther to the rear with the larger differential: I'm glad I discovered this NOW, and not after the diffy got eaten... But I realize I will also have to pull & reset the front third member as well! (Although I had no problem with the axles there...)

Since I have to pull the pumpkin again, I am going to tear it down & replace the side gears- I have a NOS rebuild kit- may as well...

Scott

on the diff mounting you use 3 gaskets on a housing that has been converted. always use NOS gaskets as the new ones are NOT the correct thickness. no need for a 1/16 spacer with 3 gaskets.

[ng19delta]

I found my copy of the interchange book, and looks like I have a couple things to do: Grind back the axles by 1/32nd each side(although 1/16 as recommended won't hurt); add a spacer of 1/16" between the third member & axle housing; convert to the 7/16 studs... The larger ring gear diffy has a 1/16" difference in the axle line, which is why it requires the spacer: It can cause failures at the hub end. Now I have ANOTHER question: Given that I need to put the spacer on BOTH axles, do the front axle shafts ALSO need to be trimmed? I can't find a reference for that...

Kaegi- I may just make the spacers, as I am not sure I'll be able to always find NOS gaskets...

Scott

[Kaegi]

NG delta, there are a zillion NOS gasket packages for about 10 bucks each that come with 3 gaskets inside. jobrated.com, VPW and Midwest I believe all have them I don't think we will run out in this lifetime. the NOS are so well made they can be reused usually. the NOS package also has trunion bearing gaskets, axle flange gaskets and cork gaskets for the felt seal but the cork is usually bad

[ng19delta]

NG delta, there are a zillion NOS gasket packages for about 10 bucks each that come with 3 gaskets inside. jobrated.com, VPW and Midwest I believe all have them I don't think we will run out in this lifetime. the NOS are so well made they can be reused usually. the NOS package also has trunion bearing gaskets, axle flange gaskets and cork gaskets for the felt seal but the cork is usually bad

Cool- Thanks!
Scott

[ng19delta]

I found my copy of the interchange manual last night: I read through all the info on the issue, and it says, other than the forward shift of the larger differential, that 1/32" needs to be removed from each axle- I'll measure them to be sure of the start length(I have a suspicion one may already be shorter) then trim them down. I was also wondering about the front axle: but from what I see, there is no need to t rim the fronts: apparently both large & small use the same axles in front...

So much fun...

Scott

[Kaegi]

another thing to consider too is even if you made a 1/16 spacer for the diff, and used an aftermarket gasket, you still would be off because the aftermarket gasket is not the correct thickness and that is in the math when using a spacer

[ng19delta]

OK... Just took a serious look at things axle wise, and found somethings out... lol... Since I found my interchange book, I looked over the axle shafts a bit more closely. The one which fits OK is a 1/2 ton WC shaft- 915249, and it is 36 7/32" long, so no wonder it is ok... However, at 1 1/8" dia., it is smaller than it should be for a 3/4 ton WC.

The OTHER axle is the problem child: It is 36 7/16"- about 13/64" too long... But that is easy to explain, because Bubba threw in a 1194067 axle, which I looked up, and is for a mid to late (54-60) 50's D series, W100,200, or 300(all depending on the years) In any case, NOT the correct axle. It IS 1 1/4" in dia, so that is good, but I'd have to hack a bit off to get it to the right length- but it should still work ok if I did.

Either way, I have a mis-matched set of axles, so I'll be looking for a pair of correct 921659 axles... If I can trade for them so much the better...

[ng19delta]

THANKS to Ernie Baals for his help! Ernie had a spare set of axles he let me have a deal on, and a set of proper gaskets, so I'll be able to get everything axlewise fixed up this week...

Now to just do the work over the next couple days...

Thanks Ernie!

Scott

[ng19delta]

Over the last couple nights I readjusted the backlash on the rear differential(I decided not to change the side gears in the diffy- at some point I will be looking for a new ring & pinion due to old damage, but currently operable, so I'll do it then), installed new adapter studs I made on the lathe, 3 gaskets (as stated by the interchange manual)and installed the rear differential; removed the outer ends(wheels/tires, drums, hubs, spindles & axles) on the front axle, pulled the differential & checked its backlash, put in the new adapter studs, 3 new gaskets, and reinstalled the front differential & reassembled the front end, installed the "new" rear axle shafts (Thanks again, Ernie!), and drained the transmission so I can reseal the side plates... Last night I ended up closing the shop at 10:15 PM or so- and I'd only been up since 4 AM(and was again this morning)... And to make it really fun, the Dodge lives just about against the wall- so that the TR6 fits in on one side of it(I need to open my bigger doorway just a little...), so to get all this done without taking her outside, I had to get under both ends, and put her on the car rollers I have, and then push & pull her away from the wall... And then push her back when I was finished. I forgot how much fun it is to move 2 1/2 tons of Dodge when you have no power assistance... Or ANY assistance... lol... But I CAN... And when I moved her back, of course I managed to push her off the car dollies when I got her against the wall- so I have to reset them, and move her back to the middle of t he floor, so I can take her off the dollies & pull her out.

Oh yeah- once the rear axles were fully in place & tightened down, I reached under and found I had the play I needed in the pinion Before it was solid like concrete because I had one axle too long, which was jamming the pinion block...

Tonight will be the easy work- make one adapter stud with long 7/16 threads, to replace the one holding the front brake tee onto the diffy, install & seal the rear differential cover, remove the tranny side covers & reseal them, and take a nap... Tomorrow I'll refill everything, check the alignment(set toe in), and take her for her first actual test run- I hope!

Yes, it is THAT much fun... Then I get to build 2 wooden Ben Hur trailers... One will most likely be for sale...

Scott

[Kaegi]

making fast work of it all! did you make a spacer for the rear diff cover or get the rare 9 5/8 bolt on diff cover?

[ng19delta]

making fast work of it all! did you make a spacer for the rear diff cover or get the rare 9 5/8 bolt on diff cover?

The front & rear diffys came with a home made spacer which seems to handle the job nicely... I modified the rear one by welding it to the cover, so I only have one gasket back there to worry about. I have to do the front one yet...

Scott