need to know what years are compatible - gear swap

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arctic388

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I want to change gearing on my 96 Tahoe with 3.42's to 3.73's or maybe 4.11's and need to know what year donor vehicle i need to be looking for? is it 95-99 years?
 

wintercamo

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from my personal experience a 10 bolt chevy 8.5 is all the same just watch spline count of axles/spider gears think its 28 and 31 spline count. I used a 1977 frontend in my 1986 truck for the rear end and a 1995 Yukon rear end in my 1992 YUKON rear end now this was just hoghead swaps with ring and pinion keep as sets and run together and in both cases the gov.loc went BOOM the housings are different with years. on the side note have not had any problems . I think theres not much noticeable difference between 3.42 and 3,73 some but 4.11s better power but worst gas mpg. I think 373 all around gear up to 33 or 35 tire size. like I said this is my experience
 
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arctic388

arctic388

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Had my dad looking for 95-98 front diffs and he just bought me one from a 98 but based on what I'm seeing listed on eBay the 98 is not supposed to be the same. He is on his way now with it. I'm really hoping it will work but if not I will have a 98 3.42 diff for sale. Lol.

He couldn't find a set of 3.73 so I just got him to get the 3.42.

One place he checked told him you couldn't swap to 373 cause it would mess up the computer. Lol.
 
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arctic388

arctic388

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the unit my dad got looks the same as mine and has same 4wd activator so going to swap it in and see if that fixes my roaring.
 
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arctic388

arctic388

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dropped off Tahoe at shop today to have front diff swapped.

but. . . when i was pulling up on ramps at my house in yard i could only get one of my rear wheels to spin. before this my G80 would kick in and hardly spin ever. i tried for 5 mins different things and only the passenger wheel would spin so now i am thinking my rear end might be the problem. i asked my Mechanic to swap front diff anyway since they changed the long tube bearing my 4wd wouldn't engage and then check for roaring after that. if my rear is roaring i am seriously thinking about having my original front diff rebuilt with 3.73 gears and rebuild my rear with 3.73 and then have a tune done for the new ratio


also getting them to check coolant leak. i found it dripping off back of engine on both sides when i was under it the other day. dont have a clue what that would be to fix.
 

wintercamo

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in the front if you had tube off and 4x4wont kick in and aquchurewaiter works check for a washer between the 2 gears it could fall and keep gears from locking in. clutch wear and oil could be rear end problem , could just need a gear oil change with flush make sure no center pin play also
 
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arctic388

arctic388

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i am pretty sure they didn't take tube off just slid axle out. i was thinking that washer would be the problem from a video i saw of rebuilding the diff i don't see how you could remove that axle without taking long tube off so that everything would go back right.

they haven't swapped diffs yet. hopefully today. i am going to get them to do the intake gasket to since i am loosing a lot of coolant and pretty sure the gasket has never been replaced on it. since my dad is retired i am giving him the task of sourcing me used parts. so now i ask him to find me a rear end with 3.42's cause i am almost certain that is my real problem with it roaring. I asked shop to swap in replacement front diff anyway with my goal of taking my original front and rear diff and rebuilding them with 3.73 gears and a trutrac locker in the rear. that is my goal anyways if i dont decide to just buy a newer model all together. i really would like to have one model newer if i can find one at a decent price. but if i cant i will just slowly build this one up and run it till it cant go any more.
 
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arctic388

arctic388

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found a truetrac on Jegs for $388 with free shipping. should be here wednesday.

mechanic has been busy and hasnt even started on swapping front diff and replacing intake gasket. i just hope to have it going and back to me before we get any bad weather. thats the whole reason i bought it was to have 4wd and my luck wont even have it going the one day we do get snow here in middle Tennessee. lol
 

TigerEyz3

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arctic388... you know you don't NEED 4WD for middle TN weather. Folks here forget how to drive when it rains (assuming they ever knew in the first place)... not to mention, we get ICE rather than snow anyway. ;-)
 
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arctic388

arctic388

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you are right. lol

the part that isn't funny is after waiting over 3 weeks and the mechanic not touching it i picked it up and went to another shop and they tell me they are booked up over 3 weeks themselves and that what i am needing done is to much to do all at once. so i asked him to put me on the list but i would keep it until they can get to it. so i decide to drive it down to tire place to have my winter tires mounted and put on then drive it home. on the drive home i decide i am going to swap front diff section myself so i pull up on ramps and get wrenches and climb under it and all of a sudden i am under a rain of dripping oil. i am like what the crap now. checked dipstick and nothing. started it and has 20lbs oil pressure so i dont think i messed up engine. so turn it off and put 3qts in it and started and oil ran down line so i think its the oil cooler line is busted. i cant find my big cresent to take fan off to get bottom shroud out to verify. i am going to auto parts to get a tool for fan and both oil lines. then i will decide if i am going to swap out diff myself. then all i will need is intake gasket done at mechanic. i will just put eaton install on hold till later.
 

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