2nd Gen Non-Engine/Transmission D70 to a D80 swap

[Nate]

Does a disc break SRW D80 bolt right into place where a D70 once was?



Just wondering if I need other parts and pieces.

 

[zstroken]

Possible new u bolts depending how long yours are.

Need the axle cradle and the plate that goes on top of the springs.

Also need to shorten your driveshaft.

 

[Nate]

Any sources for the plates other than the dealer?



I doubt I'd be able to find them at a junkyard unless I would find a truck and have them pull the axle and parts off for me. Most of the yards around here are inventory setup with the parts already pulled from the truck.



My U bolts should be fine since they are longer than stock. I have about 1. 25" of threads after the nut and I never trimmed it figuring I could use that for traction bars or a D80 .





To go from drum brakes to discs, do I need to use a different master cylinder or proportioning valve?



I have a few axles in mind, around $1200 seems to be the going rate for a D80 disc brake and 4. 10 gears.



I was thinking of putting the D70 under my Jeep, but I'd need to change the gears... and the Detroit. . and disc brakes, so I may be better off selling it.



I'm setting up the truck to do occansional sled pulling if your wondering why a D80. Plus I'm hoping disc brakes will help out my weak brakes.

 

[Nate]

No sources on those plates other than the dealer?

 

[Nate]

Dealer gave me these part #s after being on the phone for a good 20 mins. He was pretty confused for some reason.





52038459 is the spring plates, $25. 45 each



52038311AB is the little plates that are on top of the spring in between the U bolts. $11. 35 each for those.



That sound about right??

 

[Extreme1]

It the tubes are the same size, I'm guessing the mounting plates between axle and the springs would be too. (Note, this is a guess)



If the tubes are different diameter, you'd need new u-bolts too. You might want to compare to truck at a dealership when they are close to confirm.

 

[Nate]

D80 tubes are larger.



Why would I need new U bolts, they don't go around the axle tube.

 

[AMikesell]

I am doing this every same thing on my dads truck but it is just swapping a D70 with disc to a D80 with disc and you may get away with using your u-bolts but you will need the cradle and the backing plate and all of the hardware that goes with the disc brakes since they are different bolt patterns and size. Also as stated above you will need to shorten your drive line some, if you have a quad cab short bed it will be about 1 1/2 inches but not sure on a long bed. Hope this helps, Andrew

 

[Nate]

I'm not sure what you mean by hardware for the disc brakes because it's a different bolt pattern?



Dana axles that are used under Dodges, and Chevies are all 8 lug x 6. 5" as far as I know.

 

[csutton7]

I slapped a 2001. 5 d80 (drum brakes) into my 99(d70 w/drum brakes) with no issues except for the parking brake-- I had to do some jerry-riggint where the cables meet at the frame--but I did take the plates and u-bolts with me---chris

 

[Extreme1]

D80 tubes are larger.



Why would I need new U bolts, they don't go around the axle tube.

Doh! That's right, they go around the springs.

 

[Nate]

The yard I checked for the axle has them on a rack, so I don't know what happens to the "accessory" parts.



The U Bolts I have on the turck aren't stock, and have about 1. 5" of thread past the nut. I never trimmed them knowing I may need that length for traction bars or a different axle

 

[SnoKing]

I slapped a 2001. 5 d80 (drum brakes) into my 99(d70 w/drum brakes) with no issues except for the parking brake-- I had to do some jerry-riggint where the cables meet at the frame--but I did take the plates and u-bolts with me---chris

2001. 5 had rear disc brakes! SNOKING

 

[csutton7]

SNOKING----these didn't---that doesn't mean that they weren't mismarked from the yard I bought them from--they're more likely an '01, but they were marked '01. 5-----chris

 

[AMikesell]

The hardware is the backing plate and the e-brake assembly on the backing plate along with the calipers and rotors.