[El Jefe]

After much searching and posting elsewhere to no avail;


Where do the differences that account for the WMS to WMS measurement discrepancy between a GM and Dodge Dana 60 occur (GM and Dodge kingpin front axles approx. 78-91 or so)? I have researched this at length, and cannot seem to find the answer to this; the GM is roughly 1.5 inches wider WMS to WMS, yet the inner and outer shafts between the two axles are interchangeable. According to the BillaVista writeup, the caliper brackets, calipers, hubs, and spindles are all interchangeable, so does this leave the sole burden of difference upon the rotor itself? That being asked....can I swap GM brake parts onto a Dodge Dana 60 front? This application is in an 85 Chevy truck, but that nonwithstanding, the GM parts are about half the price of the Mopar.


Edit: The axle in question is of the external hub 79-91 variety, which differs in some internal dimensions from the 92-93 internal hub axle.

 

[dorfs]

The Dodge short side shaft is about 1 1/2inches shorter. When I shortened my GM 60, I used a Dodge inner.

 

[El Jefe]

The Dodge short side shaft is about 1 1/2inches shorter. When I shortened my GM 60, I used a Dodge inner.

Did you use the short side inner from the external or internal hub axle? From what I understand, the short sides on those two are roughly 1.5 inches in difference (internal hub is 15.98", external is 17.67")? I took this info from the BillaVista writeup and from a D60 book I have at the shop. Of course, no other dimensions listed.

 

[bad76ih]

I've got an external spline Dodge D60 and some GM D60s I'll measure the difference tomorrow. But I am almost positive that all the Dodge D60s had the same dimensions.

 

[BillaVista]

Here's my guess, from the research I did.

It seems there are reports of 69.5" wms Dodge's, but most appear to be 67.5".

I only listed 67.5"wms in one table, as I got no reliable source confirmaation of a 69.5.

BUT, as you pointed out, for Dodge inners, 660182-5 is 17.67”, same as a Chevy, while 660182-1 is 15.98" and won;t work in a Chevy.

My guess is, there are 67.5" wms axles, and they are the ones that use 660182-1 15.98" inner, which would make the width difference in the tubing itself.

I suppose one could do some rough calcs using the length of the inner and outer shafts and the width of the carrier (if one knew that) and see how the 2 differ.

I shall watch this thread for info to update the article.

 

[DRM]

I have a 78/79 Dodge 60 front tore down right now in the shop. I would be more than happy to help in measuring parts if I can.

 

[El Jefe]

I have a 78/79 Dodge 60 front tore down right now in the shop. I would be more than happy to help in measuring parts if I can.

Since this is the external hub version of this axle, can you verify the lengths of the inner axle shafts (specifically the short side)? I will get a definite WMS to WMS on my 85 Dodge 60 today. Does someone have the dimensions of the Dodge or Chevy rotors (diamater, thickness, backspacing, etc.)? Thanks for the info/help!

 

[DRM]

I can have pics and measurements of the inner shafts, and any other parts thet are separate by Wed. night

 

[bad76ih]

We'll see if DRM's measurements are the same as mine. I compared a dodge'80 dual wheel front to an '84 single wheel GM.

1) Measuring housings. The short side was about 1.5" shorter on the dodge.

2)Rotors: Dia. , Thickness, hieght (mounting surface to back side of Rotor). (with a tape measurer).
GM- 13, 1 9/16, 3.
Dodge - 13, 1 1/4, 2 3/4.

I've had about 6 dodge D60/D61s in the last 2 years. Ranging from '79 to '92. They were all narrower than the GM. Anyone ever noticed the tie rod mounting point on the dodge knuckles is about 1.5" higher than a GM.

 

[El Jefe]

We'll see if DRM's measurements are the same as mine. I compared a dodge'80 dual wheel front to an '84 single wheel GM.

1) Measuring housings. The short side was about 1.5" shorter on the dodge.

2)Rotors: Dia. , Thickness, hieght (mounting surface to back side of Rotor). (with a tape measurer).
GM- 13, 1 9/16, 3.
Dodge - 13, 1 1/4, 2 3/4.

I measured my Dodge SRW 60 today (external measurements only), and came up with basically the same dimensions that you did;

WMS to WMS- ~67.5"
Rotor Diamater - 13"
Rotor Thickness - 1.25"
WMS to rotor face - 2.625"

I also measured the axle tube from the inside edge of the knuckle (on the tube) to the inside edge of where the tube presses into the center section-
Short Side - 3.5"
Long Side - 23"

No time to pull out the shafts, but I will be interested to see if DRM's measurements of the external housing match up with ours, and the actual measurement of the shafts themselves.

With the measrement of the rotors, is it still possible to run a GM rotor/caliper/backing plate on a Dodge axle? Will the extra .25" of depth cause a misalignment issue with the caliper/backing plate?

 

[DRM]

No time to pull out the shafts, but I will be interested to see if DRM's measurements of the external housing match up with ours, and the actual measurement of the shafts themselves.

You will have to suffer some there - as my long side housing has been narrowed a few inches

But I can still get stock shaft measurements, external housing measurements on the short side too.

 

[BillaVista]

With the measrement of the rotors, is it still possible to run a GM rotor/caliper/backing plate on a Dodge axle?

I am almost completely certain it is. I believe the caliper piston has enough travle to just take up the difference with no ill effects.

 

[El Jefe]

I am almost completely certain it is. I believe the caliper piston has enough travle to just take up the difference with no ill effects.

I wasn't as concerned with the caliper (since the Dodge and GM are the same) as I was with the rotor's proximity to the caliper bracket, due to the larger dimensions of the GM rotor (depth, specifically).


May have to get off my lazy ass and do the 'trial and error'. Dammit.

 

[BillaVista]

Oh, I see now, I wasn't paying enough attention. You're talking about what a roundy-round guy would call "hat depth" I believe?

I wonder how much difference there is not just between GM/Dodge but between different rotor manufacturers?

Hmmm....looks like you may have to try it and let us al know so I can put it in the "bible"

 

[DRM]

I believe there *are* rotor hat differences between Dodge and Chevy. The guy (David Lepp @ www.metalfusionfab.com ) who made my 3/4 ton dick brake conversion brackets for the front ran through all the options when he was trying to find out what would work.

I will try to lick his brain this week to see if he has the differences written down somewhere.

I took a few measurements tonight, so here is what so got so far:

78/79 Dodge 60 front axle
Spindle height (total) = 7 7/16"
Long side shaft (joint center to end) = 35 1/4"
Short side shaft (joint center to end) = 15 15/16"
Stub shaft (joint center to end) = 12 1/8"

Housing has been narrowed somewhere around 3 3/4" on the long side.
Knucke casting to diff casting short side (exposed tube length, stock) = 3"
Knucke casting to diff casting long side (exposed tube length, narrowed) - 19 1/8"

I can try to get some hub/rotor measurements this weekend if it helps

 

[DRM]

Did you use the short side inner from the external or internal hub axle? From what I understand, the short sides on those two are roughly 1.5 inches in difference (internal hub is 15.98", external is 17.67")? I took this info from the BillaVista writeup and from a D60 book I have at the shop. Of course, no other dimensions listed.

From my measurements tonight on an external hub style Dodge 60 front, I get the 15.98" measurement... So this may need to be edited on BillaVista's page.

 

[DRM]

btt for day crew

 

[El Jefe]

From my measurements tonight on an external hub style Dodge 60 front, I get the 15.98" measurement... So this may need to be edited on BillaVista's page.

I removed the short style shaft after reading your post to measure, and I come up with the 15.98" as well (on an external hub style). Thanks for the time in measuring!:beer:

 

[DRM]

I removed the short style shaft after reading your post to measure, and I come up with the 15.98" as well (on an external hub style). Thanks for the time in measuring!:beer:

It was cold out there at 10:30 last night, so I only got a few measurements before I went back inside to warm up I can get more by this weekend if needed...

 

[Lloyd]

I've got a '90 axle (all stock) disassembled in the garage now. I'll try to get all these measurements this evening as well and see how it all compares. It's a 61 but aside from the pinion offset that shouldn't matter.

I have a different version of the same question - I'd like to know if I can use my existing rotors with the new internal-spline hubs; when El Jefe's question is answered so is mine.

Bill - after digging through your excellent page, the Dana website and various books, it appears that thick D61 gears (4.10 is deepest available) will work with a 4.56-up D60 carrier/locker without any spacer. This has been verbally confirmed by several different sources - I'll find out for sure soon and let you know. Spacer thicknesses: standard (thin) D60 4.30-down gears in a 61 - 0.210"; D60 carrier break - 0.160". Ring gear pilot height on 60/61 carriers ~0.300", ring gear bottom bevel ~0.100" so a 61 spacer leaves NO useful amount of ring gear pilot (and is therefore useless IMO, without a pilot spacer ). 61's with 3.33 and 3.07's used a regular 4.10-down 60 carrier. There is/was a special open carrier made for the 61 to use regular thin 60 gears in 3.54-4.10, and some evidence suggests that '75-79 Ford 61's may have had a Trac-Loc with this offset as well but I haven't been able to confirm that. Also a unique entry in the '80s Ford listings is either a misprint or a combination of part numbers that don't seem to add up.

And another useful bit of information - for external hubs, the distance from the flange mounting surface to the inside of the stub shaft outer snap ring is 0.75" - an important number if you want to make 35-spline drive flanges. Conveniently, side gears for a D70 Powr-Loc have this dimension from the thrust face to the end of the splines, allowing the flange to be made from flat stock. I'm planning to mount mine with studs and cones.