Originally Posted by andoboba
Ok, now I feel I must chime in as this so called Dana 10 bolt is not what you think it is. GM made most of their diffs for themselves and called the Corporates. Corporate 10 bolt, Corporate 12 bolt and of course the imfamous Corporate 14 bolt. The 10 bolt being the weakest due to smaller size and axle bearing configuration was used mostly years ago on muscle cars and half ton trucks. Currently GM is still puting Corp Diffs under their half ton trucks, they are just using the Corporate 12 bolt. The heavy trucks and Suburbans of today, mostly 3/4 ton got outfitted with the Corporate 14 bolt. This unit has a full floating axle bearing assembly and is one of the stoutest diffs in this level of service. For one ton trucks GM used Dana 60's and 70's. Now it is these units that I think you folks are confusing for the very light duty Corp 10 bolt. Yes they do have 10 bolts on the cover but they are made by Dana and thus are a Dana 60's or a Dana 70's. You can identify this by looking for a casting number "60" on the lower portion of the housing just to the right of the pumpkin. These are extremely stout units which have twice the load rating of the old 10 bolt. Some people also confuse a Dana 44 which is very common in many trucks, for a Corp 10 bolt due to the fact that all three of these Dana units have 10 bolts in their covers. So be happy, my guess is that you have a Dana 60 or 70 which are GREAT units!!! GOOD LUCK
A. I didn't say anything about a "Dana 10 bolt". That was 87MH the axle pictured is a Heavy truck axle used in the P30 chassis. It does indeed have 10 bolts but you are correct in that it is probably a Dana 70 as the more correct and recognized name but there are some that refer to the bolt count. Because the other axle available under Motor homes is the Sterling and it has a different amount of bolts.
Please do not quote me and then say something posted by somebody else is wrong and mislead folks to think I said it.
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GM trucks and modifying them is my hobby.
I am particularly knowledgeable about the 67-91 Year ranges. I have owned 1970 Suburban, 1975 Jimmy, 1979 Blazer, and 1988 R20 Suburban in the last 5 years. I have a pretty good handle on them and what was available in them and when they had changes both cosmetic and mechainical
I have no problem admitting when I am wrong but I do have a big problem with somebody making a post that appears to give me a tongue lashing me especially when you have wrong info and you’re lashing me for something I didn't say.
they are just using the Corporate 12 bolt. The heavy trucks and Suburbans of today
GM has not made a 12 bolt in 23 years. GM made the last 12 bolt in 1981. They have not made one since. 81 was the transition year where the complete drive train was redone as well as a cosmetic up date. First year for the 10 bolt truck rear, first year for the 700R4, first year for the NP 208 transfer cases. 81 still had some 12 bolts being installed as the axle plants retooled. You got either a 10 bolt or a 14 bolt after 81 for rear axle and a Corp 10 front or D60 front on the 4x4. Some trucks got the Dana 70 rear including the P30 chassis of the vast majority of Motor homes made then.
End of discussion.
C. The picture is not the axle in question.
, mostly 3/4 ton got outfitted with the Corporate 14 bolt. This unit has a full floating axle bearing assembly and is one of the stoutest diffs in this level of service.
In the 70's it is true that 3/4 tons got the full floating 10.5 inch ring gear variation.
In the mid to late 80's when the 14 bolt corporate Semi Floater (C-clip axle like a 10 bolt but a 9.5 inch ring gear) was introduced. It was introduced because GM realized they just shot themselves in the foot with the loss of the 12 bolt. The 14SF is actually stronger then the 12 bolt and rounded out their offering because it could be made with 6 lugs for HD 1500
towing packages. So "through current" is not a true statement. Most light duty 3/4 tons (anything with a 350cid or smaller) after that time frame were equipped with the SEMI floating 14 with the 9.5 inch ring gear. The Full floating only made it behind 454 powered 3/4 ton trucks (concidered the HD) from Mid 80s to current. I own one such truck. I had to search for it.
Just for reference: GM Never made a 1 ton Suburban and suburban 4x4. 2 things make a 1 ton and one is the frame height (to make it stronger) and the second is the front axle. Because of the floor height of the cargo floor GM was restricted on how tall the frame was to give the clearance needed over the axle. Unlike the trucks where there was both metal thickness differences as well as frame height it was not possible on the Suburban to make the frame taller. Just as a little twist to really confuse people they then put a 8600lb GVWR on the 454 Burb. That was to beat emisissions requirements.
The D60 front axle was never available under the Suburban 4x4 even to the Army. So knowing this we also know that a 454 was also never available in a 4x4 Suburban built between 1967
and 1991. GM would not put the 454 in front of the D44 or Corp 10 front axle OR the 14sf rear. GM knew the engine could produce more torque then those axles coule reliably handle. The 454 was available to make the truck a family friendly prime mover for people towing campers.
For fun I like asking people to prove they have a 1 ton Suburban but taking a picture of the RPO sticker in the glovebox. I been at it for 4 years and so far nobody has risen to the challenge and proved me wrong. I have a lot of pictures of 8 lug 10 bolt axles sent to me though.
Those dually burbs that pop up are an aftermarket conversion to a 3/4 ton. I have personally looked at the RPO stickers on 2. They list the truck leaving the plant as such.
The Semi floating 14 with the 9.5 ring gear is available in both 6 and 8 lug variations. GM also did some stupidness by rating Vans as 2500 with a 10 bolt axles. My old Company Van was a 95 Vandura 2500 with a 10 bolt. I broke that axle by 40k on the odometer. Bearing failure as you noted. The 6 lug 14 was used in a lot of 85 up Suburban 1500's with the HD tow package. It is also used in a lot of 88-current trucks with the HD tow package 4x4's like the Z71's.
Also another point of random information if you happen to be axle hunting: Vans run axles 3 inches wider then the rest of the truck line Through 95. The only other truck GM had that did that was some of the pre 71 Suburban Carryalls. It will require welding new spring purches to mount on anything else GM offers. That same time frame the 4x4 trucks tracked 3 inches wider front then rear. The 88 up tracks same front and rear. The new truck is also not as wide as the previous body and uses the same width rear axle as the previous body with a more offset rim to account for the IFS front suspension needs to hold correct steering geometry.
F. GM farms out plenty of their axle manufacturing to DANA. The 10 bolt front axle was built by DANA Corporation. Everything from the knuckle out is interchangeable between D44 and Corp 10 bolt. It you want to you can put a D44 Ford knuckle assembly and stub shaft on a Chevy 10 corp and bolt throw it right under a 70's-mid 80's Dodge 4x4 truck if you like. With the exception of the drag link it would be a bolt on. The Ford uses a Cross over steering to the passenger side and GM and Dodge use a short drag link to the driverside knuckle. GM 10 bolt is a direct bolt in to a Dodge except that Dodge uses 5 lugs.
If you look on the Diff housing you will find a lot of GM axles with the Dana Diamond "<>" cast into them when they manufactured the axle under contract from GM. I know my 79 K5 had it. My 75 Jimmy has had the D44 swapped out for a Corp 10 but I will have to look to see if it was a Dana assembled unit.
G. GM did not use the D44 rear variation to the best of my knowledge in these year ranges (67-current). Before the "Corp" axles they were Using Eaton, NEAPCO axles or the D60 for the rear. The Eaton’s and Neapcos were third member drop out style like a Ford 9 inch. I think 67 was the first year the D44 front was used with the 260 series u-joint. The axle was revised by 74 to use a larger 297 u-joint.
Now this is all off the top of my head so might be a couple discrepancies.