Dana 70 to 80- questions

[dpuckett]

I have recently acquired a complete- drum to drum, shocks, swaybar, and p-brake cables included- Dana 80 Dually axle to go under my 92 D350. I know I'll have to change or at least alter the spring mounts/ u-bolts, and p-brake cables, along with maybe the yoke on the driveshaft. But what else will I have to do? I sent a PM to RonA, but figured others may be able to use this onfo as well, so here I post.



ALso, where can I get the parts needed? SOrry for the lack of thoroughness, but I am in a rush, and can edit the post later to further explain stuff.



Thanks a lot,

Daniel

 

[R C Cola]

Axle change ? ?

I did this complete change. Not bad. You pretty well have it. Here is the write up I did on it.

http://www.tdr1.com/forums/showthread.php?t=108520&highlight=axle Hope this works and you can just clik on it. The shocks are easy if you use the shock mts from the old axle on the new one and cut off one shock mount that is in your way. Let me know if you need more info. R C

 

[bgilbert]

RC, wow, you can use a dually D80 on a srw 250 pickup?? Now that I have to look into. Wheels/tires track the same, sweet. I can deal with the hub sticking out if it does, but does it ? Daniel how about a backing plate to backing plate measurement?

 

[R C Cola]

Axle swap

Bill-- Yep . . axle sticks out much like the front on my 4x4 dosen't bother me at all. People told me it would not work. It fit beautiful. If I do decide to go with dually's all I have to do is bolt the wheels and fenders on. The brakes are wider so you might want to measure hub face to hub face. I just changed to spoke wheels 17" recently ( to save money on tires) and the chrome cap fit over the axle hub just fine. Now the whole thing looks nice.

R C

 

[Sri Ram]

Stomp has an 80…

A couple of weeks ago I saw Stomp's truck had an 80 on it. Maybe he could chime in here, or you could pm him…

 

[dpuckett]

Thanks.



I got a reply from RonA, and he said to weld up some half-moon inserts onto the d70 shock mounts, and I asked for further clarification on that. Does anyone else have any other ideas? What did you do, RC? Stomp?



-DP

 

[tugboatphil]

Here are some pics that Ron sent me when I was considering this swap. I didn't have the money at the time, so repaired my 70. They are for the shock mounts being moved and the E brake cable. It's all I have.

 

[RonA]

I modified the bolt holes on the shock mounts in a milling machine. You just have to slot them a bit so the wider u bolts will fit. I think I made a different spacer plate for on top of the springs also. I'll have to look. I do miss the 70(at least the limited slip part) at Christmas time. It is almost a tradition now to get stuck at the Christmas tree farm. I've thought about adding a power lock, but I like going straight on wet roads even if it means having to get out and lock the hubs once in a while to get unstuck.

 

[dpuckett]

Ok, Ron, disregard my request for pics, as I now see the pics tugboat posted.



I measured the axles, and there is about a 1/4" difference in diameters. Funny, the 80 LOOKS a lot bigger than that. So that will make it easier to bore the holes out with a die grinder and shim up.



Thanks for your input, guys. Just have to get the u-bolts and lug nuts.



-DP

 

[R C Cola]

On myswap for shocks

Took the bottom plate from the 70 axle and used it on the 80, this provided a place to bolt the shocks. Factory shock mount on the 80 on the drivers side was in the way, so trimmed with a torch. RC

 

[dpuckett]

Update

Got the axle swapped out last weekend- prep took a lot longer than actual install with an underpowered die grinder. I (for now) bored out the stock plates to take the wider axle of the D80 and used the stock u-bolts. I had to take a torch to the corner of the spring holders on the axle so the u-bolts would fit down the axle tube- the 99MY springs are apparently about 3", while the 92My springs are ~2-5/8 or 2-3/4"



Ujoints were a direct fit.



Shock mounts fit without triming any of the 2nd Gen shock mounts. Guess it has to do with spring holder width. I could squeeze the old shocks like an accordian, so I didnt even bother putting them in.



Driveshaft has 1/2" slack- I'm getting it shortened (so it'll have 1-1/2 to 2" slack) and rebalanced next week.



I had to move the e-brake mount up about a foot to accomodate the "new" cables. It is SOOO neat to have a parking brake now- they had been unhooked in the D70 for some reason.



I plan to get some new u-bolts made up. I think I am going to go with round u-bolts under the axle, and put a piece of 1/2" plate steel on top of the spring mount and torque 'er down real tight. With the springs being narrower than the stock D80 mounts, I think this is the best route for me, plus it keeps it all in line with the K. I. S. S. principle, on which I base my life.



It was a little more work (ok, mainly time) than I anticipated, but nothing unexpected. We used my buddy's font end loader to lift the heavy stuff- axles on and off the truck, back end of the truck itself. I had to use 2 Ford wheels for the time, along with 2 Dodge wheels I got with the axle, and I have a HORRIBLE vibration/ shimmy between 45-70mph. I figure it is one of the Ford wheels (my 90 D350 has a Ford rear axle) bent, or the fact the center hole is a little larger, and may not be lined up perfectly with the center of the axle. but I live 8 blocks from work, so it isnt THAT big an issue at the moment, though I am on the lookout for 2 more Dodge wheels, maybe 3. All in all, I'd do it again. The wheels track is about 4inches wider than the D70 C&C axle I took out, which makes me think it is a D80 C&C axle.



One more question- would it be possible to take the 5/8 lug bolts off the front and put in some 9/16 lugs to match the rear? I realize that would mean 2 more wheels, but at least they'd all match then.



-DP

 

[JCronnelly]

DP,



What gears do you have in the D70? What condition is it in? I ask because I want to know if you are willing to sell it?



John