73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => 73-87 Chevy & GMC Trucks => Topic started by: Ronno6 on April 16, 2018, 04:33:21 PM
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I sure wish something,ANYTHING on this truck would make sense.
1984 C10 Stepside
Differential is 8.5", 2.73 ratio near as I can figure.
Code stamped into the axle tube on front of passenger side about 3" from center casting:
BR3 G299 1
I have searched the web for info, but I have not found anything which directly relates to this code.
Anyone decipher it??
I am not certain how this ratio would perform with a Muncie M20 with 2.52 first gear.
What information will I need to get 3.43 posi setup for this critter??
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The 2.73 would have been a common rear end ratio with a 350/4 speed in '84, but the truck transmissions had a 6.55 super low, and 3.58 1st gear. It sounds like you want to swap in a car transmission, so you have lost the low end ratios.
The 6 cylinder trucks had 3.42 and 3.73 as common axle ratios, and it was optional on the automatics. It should not be that hard to find an entire axle to swap in. Its probably better to buy an open differential axle, and then add in a locking differential from Summit or Jegs. Most of the aftermarket limited slip or locking differentials I've looked at are designed to swap into an open axle.
The trucks with factory limited slip differentials probably had the GM gov-lok, which is not a great axle if abused with burnouts. Its designed to help get traction in a work truck, so they never expected someone to be trying to burn rubber with it.
Bruce
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BR3 2.73 Non Locking, G Framingham plant, 299 day of the year, 1 shift.
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Assuming the original gears are in there.
Best way is to remove the cover, the ring gear should be stamped with the ratio. Or count the ring teeth and divide by the pinion teeth.
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I am indeed desiring to swap in an car Muncie M20 with a 2.52 first gear.
I have done the spin the wheel and count driveshaft revs and determined that mine in a 2.73.
I think the 3.42 diff would be a good ratio, but I do want posi.
Now that blazer74 has given me the info, I can move forward when I get to that point.
I have seen references to "series 2" and "Seriies4" in relation to differentials.
What is that all about, and what is mine?
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What manufacturer are you looking into?
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What manufacturer are you looking into?
Don't know as of yet.
Any recommendations?
Is mine most likely 28 or 30 spline axles?
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Most likely 28 spline. I do not like lockers and prefer LSD. Auburn Gear makes nice cone style differentials. Strong and smooth, some guys say they don't like them because they aren't rebuildable. My argument to that would be that if you trash one the whole thing is probably trashed anyway and if yours needs rebuilding it was probably weak to begin with. I have an auburn pro behind my big block and it has held up nicely. Hopefully I didn't just jinx myself :) I would say shop around and see who has good deals going on inclusive of all of the components and installation material.
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Most likely 28 spline. I do not like lockers and prefer LSD. Auburn Gear makes nice cone style differentials. Strong and smooth, some guys say they don't like them because they aren't rebuildable. My argument to that would be that if you trash one the whole thing is probably trashed anyway and if yours needs rebuilding it was probably weak to begin with. I have an auburn pro behind my big block and it has held up nicely. Hopefully I didn't just jinx myself :) I would say shop around and see who has good deals going on inclusive of all of the components and installation material.
I have looked into them, and seem to be solidly built units.
Only problem is, being a 'BAMA fan, I could never tell anybody what posi unit I have............
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2 things are extremely evident after a short tool around the yard:
1. 2.73 way too high....3.42 definitely in the offing
2.LS or posi for sure......I kept 1 wheel spinning quite a bit of the time ( of course, the 2.73 didn't help...)
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Yeah ditch the 2.73:1, LSD is Posi, one in the same. Just remember to factor in your tire size and transmission ratios before you buy a gear set. There are many calculators online you can use to help you better pick the perfect final drive ratio.
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I have found a differential from a 1987 C10 for sale, supposedly with a 3.42 ratio.
I hope to look at it on Wednesday.
What will the stamped codes will be stamped on the passenger side axle tube if it is posi and 3.42??
Is posi indicated by a letter at the end of the sequence?
I search for this stuff online but never seem to find what I am looking for........
Hmm, I had been thinking 3.42 because I had a 79 Z28 w/4 speed and 3.73.
I had thought my tranny was a 2.20 1st gear, and the 3.42 in the C10 with the 2.52 M20 1st gear woulda been lower overall.
BUT ...the Z-28 had a 2.64 1st gear..............
I just really didn't like the 3K rpms @60mph.........
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Where can I find a list of stamped rear axle codes for the 84 to 87 vintage??
It gotta be out there, but all I find are RPO codes and diagrams of the
stamped codes indicating the first 2 or 3 letters indicate the ratio..............
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Do not rely on any markings on the axle housing. You need to remove the cover to determine the gear ratio accurately.
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The current owner may not approve.....
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You should never buy an axle without removing the cover and inspecting anyway.
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Good advice! Thanks.
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Is this type of posi setup any good??
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What's going on in this pic? I see bearing caps removed. It's a clutch type LSD, better than open differential but you need to either count the teeth on the ring and pinion or look for the stamp on the ring gear to figure out the ratio.
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I am just concerned as to whether this type of LS diff is any good.
This is not my part, nor one that I am looking at.
I have found one for sale out of a Buick Grand National that is of this style,
and want to know if it is decent.
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You know a truck and a car axle aren't the same right?
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Obviously I have much to learn.
That is why i seek knowledge on this forum.
Are posi carriers 410408N and 410409N not compatible with truck axles??
84 C10 8.5" diff 28 spline
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I think the carrier will interchange but don't quote me on it. I never swap in used parts and always go with a quality aftermarket carrier, ring and pinion with all new accessories.
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Again, good advice. Thanks!
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You know a truck and a car axle aren't the same right?
How do they differ (for sake of education...)?
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Spring type (leaf or coil) and mounting location, axle length, backing plates, brakes, drums, axles, wheel lug pattern, companion flange etc. several variables. There were lots of trucks made from 73-91 which will bolt right in. No need to go Frankenstein unless you are building a custom setup, then who cares at that point.
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Spring type (leaf or coil) and mounting location, axle length, backing plates, brakes, drums, axles, wheel lug pattern, companion flange etc. several variables. There were lots of trucks made from 73-91 which will bolt right in. No need to go Frankenstein unless you are building a custom setup, then who cares at that point.
Those appear to be pretty much external differences (Xcept axles.)
Carrier, ring & pinion, bearings and shims shouldn't care if car or truck. No?
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You asked how the Axle's differ. Don't get terminology confused:
Axle (whole assembly), Axle shaft -drives the wheels, Differential (carrier, differential gears, etc), final drive (ring and pinion). So yes, they are external differences. If your goal is to source used internal parts then yes you can try and gut another 10 bolt.
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You asked how the Axle's differ. Don't get terminology confused:
Axle (whole assembly), Axle shaft -drives the wheels, Differential (carrier, differential gears, etc), final drive (ring and pinion). So yes, they are external differences. If your goal is to source used internal parts then yes you can try and gut another 10 bolt.
Yup. Swapping used internals was the thrust of my inquiry.
As you had indicated that car and truck axles differed, I was uncertain if you referred to the internals I was citing as opposed to the entire rear end assembly.
Hence my query..........
Thank you as always for your response.
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What do the members think about Yukon Dura Grip??
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