3.08 to 4.10 first time swap

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dangOl'dodge

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hey guys i want to change the 3.08 gears in my 87 chev r10 truck to 4.10's. mostly for doing brake stands and burnouts.. i have a 4.8/4l60e in it now and as you know i cant use the selector to hold it in 1st gear so it shifts into 2nd while doing brake stands and dies down. i feel with 4.10's it could burn into the power band in 2nd. well im hoping it will anyway! lol

ive never done a ring and pinion swap before been doing a lot of reading on setting the backlash and pinion depth the last few days, one thing im not sure about is spline count? my 8.5" 10 bolt is an 87 and from what ive been hearing that means it would have a 28 spline pinion? most kits i see on summit are 30 spline kits.. what would i need to order for a first time swapper?

Thanks again
 

RangRayy

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28 spline is the axles into the carrier. People tend to beef up while they're there so adding 30 spline axles and matching carrier. Which I would suggest getting a nice posi to throw in with new axles and seals whole changing out the ring and pinion.
 

dangOl'dodge

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Already is posi. Well i cant get it to burn on 1 wheel on pave or dirt so either posi or a proper working lsd.. so i nedd to buy 30 spline axles too if i buy the 30 spline ring and pinion?
 

crazy4offroad

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The pinion will have 30 spline to match your pinion yoke, so that is irrelevant. If you change the carrier to a locker or new LSD you will have to consider 28 or 30 spline.
 

MikeB

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Yeah, pinion spline count is 30. Axles probably 28.
 

HotRodPC

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Ring and Pinion itself doesn't care if the axles are 28 or 30 spline. Spiders or your Locker/LSD unit do care. Point is, Ring and Pinion gears won't matter, so if you've found a used a set from a 28 spline truck and need 30 spline, the R&P should still work so long as you have the correct carrier at the correct ratio break.
 

dangOl'dodge

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Cool thanks. Gonna stick with this unit and just swap ring and pinion as its spinning on 2 tires consistently which is all a guy can ask for from a 10 bolt. Will dump some money into a 14 nolt full floating when i find a nice one.

Any tips on first time swapper?
 

crazy4offroad

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You'll need an impact wrench capable of at least 450 ft/lbs to crush the pinion crush sleeve when setting pinion bearing preload. Re-use your old nut when doing trial/error getting the pinion depth, that way the new one wont be gutted when you go to use it for final assembly since it is a lock nut. Also don't use a crush sleeve at all when trying to get your pinion depth set until you're ready for final assembly.

Did you order a new bearing/install kit? You would need a hydraulic press and a bearing separator to remove the bearings from the carrier and pinion. Whenever you pull the carrier from the housing keep your shims oriented how they came out (left to left, right to right), sometimes you can get lucky and put them back the way they came out and have the mesh pattern set right or nearly right first try. But don't be surprised if it don't work that way since you're changing ratio.

If you ordered an install kit it should have a decent instruction manual about how pinion depth affects heel/toe of gear pattern, and depth of root (how deep the pinion tooth goes into the ring gear valley and vice versa). You'll of course need a dial indicator with either a magnetic or clamp-on stand to set backlash, and your gear set should come with info for the range to aim for, typically 0.005"-0.012" for new gears.

When setting up ring & pinion gears most people only envision the painting of the gears to check mesh pattern. But if the pattern is not right you'll need a caliper micrometer (one of those digital ones do a nice job) to measure your shims and move them from left to right or vice versa of the carrier, and change pinion depth till you get a good mesh pattern centered in the gear, well into the root but not too tight, and come out at the end with the correct backlash. You can also buy some white lithium grease in a spray can and use that to check pattern but the yellow paint in the install kits has the best visibility. Keep in mind you have to check both the "power" and "coast" sides of the ring gear teeth for proper mesh pattern.

And try to get your pinion depth and preload set before you do the final install of the carrier. The impact wrench can chip a gear tooth during that process if the carrier is in there, and it can be a longgg process with a weak impact. You'll have to take a shop rag and reach into the housing and hold the pinion's gear while using the impact, or put a pipe wrench on the yoke to hold the pinion.

Pinion bearing preload is measured in inch-pounds of rotational force of the pinion with no carrier installed. If you don't have an inch-pound torque wrench of less than 30 in/lbs best way I can describe it is spin the pinion yoke with your hand, and when you let go it will stop as soon as you let go but not be difficult to turn. For comparison, twisting off a beer bottle cap takes about 12 ft/lbs, which equates to around 144 inch-pounds. So if the manual calls for 18 in/lbs you can see it wont be much drag.

Be sure to use red Loctite thread locker on the pinion nut, carrier bearing cap bolts, and ring gear bolts which I think may be left-hand thread. Also put some silicone sealant on the pinion splines before assembly and you should have a rock-solid install.

Sticker shock I know, but here's some tools that I use or recommend:
Starrett dial indicator kit
https://jet.com/product/detail/1d0b...gtrPtANfdHIHbbepBtjkqRoClAXw_wcB&gclsrc=aw.ds

Digital caliper micrometer. One of these work surprisingly well:
http://www.homedepot.com/p/Carrera-..._6VV-yfy3EGgnIraKBRDNxoC-37w_wcB&gclsrc=aw.ds

NAPA 550 ft/lb impact:
https://www.napaonline.com/napa/en/p/NPT6767/

Proto bearing separator:
https://www.zoro.com/proto-gearbear...MkL8V1RFpv1fdKapP-QPSBoC-Qjw_wcB&gclsrc=aw.ds

This is a decent press for the price, may need to drill some holes further up the rail closer to the ram so the carrier can fit underneath. Shipping is HIGH so you may find something as good elsewhere. Of course ALWAYS use safety glasses and extra caution when using a press:
http://www.grizzly.com/outlet/10-To...hPouQoJNmOEpqESe5VdIFT3C1nLXgfOTvxBoCNeXw_wcB

Inch pound beam style torque wrench:
https://www.amazon.com/Performance-...0436&sr=1-4&keywords=inch-pound+torque+wrench

And of course you'll need a large impact socket for the pinion nut if you don't have one already but that can be picked up at a local parts store. You may be able to rent or borrow the precision tools for the job, just be very careful with them. Personally I would never loan my precision tools to anyone lol.

As with anything, shop around, try to find discount codes, etc and you can save a lot of money. Hope something here helps, good luck and post how it goes.
:cheers:
 

MikeB

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You'll need an impact wrench capable of at least 450 ft/lbs to crush the pinion crush sleeve when setting pinion bearing preload. Re-use your old nut when doing trial/error getting the pinion depth, that way the new one wont be gutted when you go to use it for final assembly since it is a lock nut. Also don't use a crush sleeve at all when trying to get your pinion depth set until you're ready for final assembly.

Have you ever used spacers instead of a crush sleeve? I'm planning to change my truck's 8.5" 10-bolt 2.73 gears to 3.23 or 3.42 soon, and was wondering about using spacers.

BTW, a trick when trying to determine the proper pinion shim thickness is to use the old pinion bearing, but hog out the ID slightly with a sandpaper roll so you can easily tap the bearing on and off the shaft. Then when you've got the proper shim size determined, press on the new bearing. And don't forget the shim(s)!

Also, I've successfully used an Ingersoll Rand #231 1/2" impact wrench on three crush sleeves. I'm not sure what it's rated at, but I doubt it's over 350 lb/ft. I'm not saying it's quick, but it does work. Also it let's me creep up on the proper rotation TQ instead of going right through it!

I also have a 24" pipe wrench and a section of water pipe that I use to hold the yoke (by using a frame rail, trailing arm, or whatever) while torquing the nut.
 
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crazy4offroad

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The Dana 60 and 14b ff on my mud truck had spacers, it is the best way to go but I think it took more tries to get preload right. But there's nothing like tightening down that pinion nut all the way and preload is set. Only bad thing is as the bearings wear, if you had to tighten up the pinion it would require disassembly unlike a crush sleeve.

And yes that is a good way to get the pinion bearing shim thickness without a lot of pressing. It's also helpful to have a carrier bearing modified like that for pressing on new carrier bearings. Usually the snub of the carrier will still catch a normal bearing if you're using one to press with and be a bitch to remove.
 

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Good tips. Thanks.
 

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I had mine done, from 3:08 to 4:10 I had to get a different carrier, the 3:08 is smaller.
 

HotRodPC

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I had mine done, from 3:08 to 4:10 I had to get a different carrier, the 3:08 is smaller.

Do you know which carrier you had? I was fairly certain the 10 bolts were 2.73 and up numerically which means your carrier should have worked. Maybe different if it was an LSD unit. :shrug:

He needs to find out which carrier he has anyway to make sure. If he's keeping the same carrier and it's an LSD or Locker and breaking point is say 3.73 and down numerically for example, then I'd go with the 3.73. Not worth that extra $500-$600 to buy a new LSD or Locker for just over 1/4 turn especially for his purpose of wanting to do a gear change.
 

crazy4offroad

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You can buy a "thick" gear set for the 3 series carrier, just don't get the Motive Gear ring & pinion with the spacer.
 

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