10 bolt and 12 bolt differences

[chvymudin3388]

every freaking rear end ive found has 3.08's ive found two 12 bolts both 3.08's. whats the differencs between a 10 bolt and 12 bolt if i get the 12 bolt is it gonna bolt in place? is the ujoint different? backing plates? i need to know all the differencs that might keep me from doing this swap

 

[dremu]

every freaking rear end ive found has 3.08's ive found two 12 bolts both 3.08's. whats the differencs between a 10 bolt and 12 bolt if i get the 12 bolt is it gonna bolt in place? is the ujoint different? backing plates? i need to know all the differencs that might keep me from doing this swap

U-joints are different, IIRC ... one is 1310 and the other is S44, maybe?

As long as they're both off Blazers (1/2 ton trucks, Burbs, whatever) the perches will be the same, shocks should be.

Backing plates ... I donno. I suppose if they both had the same size brakes you'd have a better chance ... why not just get one complete, drum-to-drum?

-- A

 

[NoReGrEtS]

every freaking rear end ive found has 3.08's ive found two 12 bolts both 3.08's. whats the differencs between a 10 bolt and 12 bolt if i get the 12 bolt is it gonna bolt in place? is the ujoint different? backing plates? i need to know all the differencs that might keep me from doing this swap

they both suck, you want to find a 6 lug 14bsf or swap to 8 lug and get a 14bff

 

[pauly383]

Early ones had smaller rear drum brakes . But you can use your existing brakes . When my 10 bolt broke , we undid the backing plates ( after axle removal ) and suspended my brakes above the axle , slid new axle under , and attached my brakes without even opening a a fluid line at all . No bleeding

Had to do the conversion u-joint for awhile . Have a new shaft now thats already set for 12 bolt on the axle end , and 10 bolt joint cv on transfercase end .

I took the axle itself off a 2wd truck , and the 5 lug shafts slid out and 6 lug shafts slid right in . The shock mounts are a little off I noticed with the shackle flip I have , and one shock has to be upside down to clear tube .

I have a 4x4 12 bolt now , changed the other 12 bolt out to go with lower gears , well a little lower . Went to 3.73's over 3.08's , but hey it was dirt cheap. Now I have 4.56 to go on the 3.08 axles ( put under my project ).

 

[BL1TZKRIEG]

how much stronger are the 12b compared to the 10b ?

 

[pauly383]

Not much if at all . Its a trade off , smaller pinion for 12 bolt with bigger ring gear , larger pinion for 10 bolt with smaller ring gear . I like either axle up to 35 or so with open carriers and lockrights . Its all about finesse , they can live for a long time . Most of the broken ones you hear about are either beat on , too damn old , or have new gears/diffs installed and not broken in right

 

[jdemaris]

Info on semi-floating 14 bolt cover rear?

every freaking rear end ive found has 3.08's ive found two 12 bolts both 3.08's. whats the differencs between a 10 bolt and 12 bolt if i get the 12 bolt is it gonna bolt in place? is the ujoint different? backing plates? i need to know all the differencs that might keep me from doing this swap

I'm looking to beef up the weight carrying capacity on my 83 K5. Does anyone out there have the load-carrying ratings for the different axles? My K5 has a Chalet motorhome on it - so when loaded an it has an extra 1300 lbs. - at least - all of the time. It now has the 10-bolt cover, 3.08 rear. I'm thinking of taking the rear out of an 89 3/4 ton Suburban that's up in my field and putting that into the K5. It has a 14 bolt cover, 12 bolt ring gear - called the "9.5" by GM - with 3.73 gears and much larger brakes. I checked part numbers for axle-bearings and they are different - so I assume bigger and better for more weight. The axle weight rating tags are missing on the Suburban - but even if it had the tags they would depend on the spring-package.
It looks like it will be a bolt-in swap - but I'd like to know the different weight ratings for the 10 bolt, 12 bolt (14 bolt cover), and the larger 3/4 unit with full-floating axles - themselves - not accounting for the springs.

 

[dyeager535]

The apps with big 13" brake 14SF (the 9.5") is rated over 8000#GVW, but there is no difference between it and any other 14SF. You can do a search for a thread started by me and titled "14SF tech" for a whole bunch of info on it.

Only one I know off the top of my head.