3/4 ton axles onto my 1/2 ton K10

[fallguy]

Ok guys, rookie here needing help. I currently have a 1986 k10 with 3.42 gears and with my 33" tires its always shifing going down the highway when i hit an incline.

I found a set of 3/4 ton k10 axles with 3.73 gears from an 84 in a yard.

Direct swap or not?

i have asked to harvest everything from the shackles down (to get the leaf springs), but really i will probably put 4" lift springs under it.

other than pulling the covers and putting in new oil any thoughts or recommendations? i am going to head down the road of having 35's with my new rims.

Will i be ok with existing drive shafts? will this work relatively easily or do i need to do a bunch of fabrication or buy a ton of new parts???

THANK YOU!

 

[Kapdin]

yes sir, just did this my self. they only thing is some 3/4tons came with 56" rear springs and all halfs have 52", i got lucky and the 3/4ton had 52"s so direct swap. The rear drive shaft was the only tricky part, if you can get the 3/4ton do it other wise you just get a combo joint were it connects to the rear diff. the front is direct bolt.

 

[smurph20]

The rear springs are actually 52 inch rears on 1/2's but can also be 56 on either 3/4 and 1/2 ton trucks and all trucks had 46 inch fronts.

 

[MrMarty51]

The rear springs are actually 52 inch rears on 1/2's but can also be 56 on either 3/4 and 1/2 ton trucks and all trucks had 46 inch fronts.

So,the springs are`nt the same widths ??? so that the 3/4 ton diffs wont uclamp to the 1/2 ton springs.
The reason I`m asking is Ricky{a friend} wants to put the 3/4 ton diffs under His 1/2 and I was`nt wanting to pull them springs.

 

[Mattchu60]

I thought about doing this as well, I think instead I am settling on finding a 9.5" 14 bolt semi floater. Its a good upgrade over the 10 bolt and I can keep my 6 lug wheels. They both would use a 10 bolt front (1/2 or 3/4) so I feel like its a good way to upgrade without having to change everything from 6 to 8 lug.

My understanding is that they should bolt right in, you probably do not need to swap springs unless you want stronger 56" 3/4 ton springs. I have stronger 52" springs on mine, that is always an option as well.

If you just are swaping for different gear ratios, I guess then you can just swap everything to 3/4 8 lug, maybe you could find a package deal with wheels and tires as well.

 

[WVscottsdale]

combo joint is 1350 from napa for the rear just completed the same thing width of springs are the same just need to make sure of the rear. brakes rotors should be the same on the front and of course drums are different but you can reuse the calipers if you are going with a lift then you will need extended brake lines raised steering arm and i also have to get a longer draglink that should be about it

 

[MrMarty51]

I thought about doing this as well, I think instead I am settling on finding a 9.5" 14 bolt semi floater. Its a good upgrade over the 10 bolt and I can keep my 6 lug wheels. They both would use a 10 bolt front (1/2 or 3/4) so I feel like its a good way to upgrade without having to change everything from 6 to 8 lug.

My understanding is that they should bolt right in, you probably do not need to swap springs unless you want stronger 56" 3/4 ton springs. I have stronger 52" springs on mine, that is always an option as well.

If you just are swaping for different gear ratios, I guess then you can just swap everything to 3/4 8 lug, maybe you could find a package deal with wheels and tires as well.

OH thank You.
Well,a bit of a misfortune.I did`nt leave a message on Mikes phone that I had unbolted the diffs. on the scrapper pickup,He was`nt going to haul it off until next week,I leave a message on His machine this morning,this after noon My son comes by to change oil in His car,after He is done I go for a test ride with Him,We go by Mikes and the trailer is gone,out to the scrap yard We go,Mikes pickup/trailer is ther but no Mike.
I talk to the yard owner and Mike dropped off the pickup this morning to let them unload it.the diffs. are gone,I have to go back about eight in the morning to see if maby the yard manager did`nt get them cut up into four foot pieces.
I`m bummed,now not only with working in some very cold and very windy weather of pulling twisting wrenching and even having to drag the torch set for two blocks because two U bolt nuts would`nt come loose I now have to pay scrap prices for the differentials.
I did`nt have the heart to tell Ricky that the diffs were gone so I`m just hoping I can get them hauled home before He knowa what happened.
I could say screw it,it`s not for Me,but,Ricky has been through a lot in his life,served His dutys worth,come out of that a bit messed up and on SSI so He gets about enough money to pay His rent and utilities and barely enough for groceries.
I have a couple of stripped radiators and a heater core along with some other scrap that I`m hoping might come kind of close to the differences of what I have to pay them and what they will pay Me,I do`nt have much for money either.
I was bummed to say the least but I`m past that now and am happy joyous and free man again.

 

[fallguy]

yes sir, just did this my self. they only thing is some 3/4tons came with 56" rear springs and all halfs have 52", i got lucky and the 3/4ton had 52"s so direct swap. The rear drive shaft was the only tricky part, if you can get the 3/4ton do it other wise you just get a combo joint were it connects to the rear diff. the front is direct bolt.

Thanks! Any reason to keep the 3/4 ton front drive shaft too? Meaning are the 3/4 ton shafts of better quality or something?

 

[Green79Scottsdale]

One other thing you might want to consider is the gear ratios. If you don't like the 3.42's with your 33's, you most likely are not going to like 3.73's with 35's. I would think at least 4.10's, and 4.56's would be even better for you.