Changing ring and pinion gears?

[liftedchevys87]

1987 Chevy V10 4x4 (1/2 ton, 350ci, 700r4 tranny)

I have a Chevy with a 6 inch lift and 37 in tires. It has stock axles with 3:46, I checked the G code for the rear end ratio I know it's around 3:40.

I want to change the gear ratio to somewhere in the mid 4:00's to compensate for the big tires so It don't lug so bad and it runs the proper rpm on the highway. I didn't want to swap the hole axles so my question is....how hard and realistic is it to just change the ring and pinion gears. Anyone know of any problems to look out for? Just wondering about people's experience with axles. Thanks

[choptop]

I'll be following you here. I need to change the gears in my red truck. I have swapped the axles in my truck do to the rear self destructing and a gear swap has got to be easier in my opinion, unless you have a shop with a lift.

[VileZambonie]

Unless you are experienced at it don't attempt to do it yourself unless you are prepared to use it as a learning experience. It's really not a DIY job unless you're equipped with the means. If you search you'll see several threads on this subject. If you do decide to take it on yourself I'm happy to help with your questions. 4.11:1 should get you where you want to be and your stock ratio is most likely a 3.42:1

[liftedchevys87]

Yeah, 3:42 is what it is. Yeah I've never done it before but I gotta learn some day so I'll go after it myself lol. Thanks

[VileZambonie]

You're in CT too so if you need help I'm not too far

[Irish_Alley]

have to say I'm with vile again on this, not a diy job unless you want to have someone do it again for you. I've done ping and pinions well just rings on a 14 bolt (changed lockers out) not hard but you don't deal with shims just two nuts you unwind or wind up till it all matches up

[liftedchevys87]

Thanks Vile

[zieg85]

Yes, bringing it up again...Directed to Irish and Vile... 14 Bolt Full float in my 1985 C30.  I am wanting to do a gear change.  To hear Irish say it isn't bad at all.  Vile what do you think?  I just picked up a series 3 Gov-loc for 4.10 and below.  My truck has, or it is suppose to have a 4.56 according to the code on the sticker in the glove box.  Still trying to find the right deal on 3.42 gears so I have time.  I wish the aftermarket had the stock 3.21 like my C20 has in it now.  I am going to see if there are any YouTube how too's as well later this evening.  Thanks in advance guys.

[bake74]

     Once again to state that vile knows what he is talking about.  You need the right tools, the guessing game gets frustrating to say the least.  The best thing to do for your first time is pay someone to show you and teach you.  It is not impossible to do, the first set I ever did, well lets just say they did not last all that long, then I got smart and had someone teach me. 
      You-tube does have some great tutorials on setting ring and pinions.

[zieg85]

     Once again to state that vile knows what he is talking about.  You need the right tools, the guessing game gets frustrating to say the least.  The best thing to do for your first time is pay someone to show you and teach you.  It is not impossible to do, the first set I ever did, well lets just say they did not last all that long, then I got smart and had someone teach me. 
      You-tube does have some great tutorials on setting ring and pinions.

I agree but if the 14 Bolt full float is easier because of what Irish has eluded too???  It doesn't cost anything to ask...

[bake74]

     I have never tore apart a 14 bolt before, hopefully they are easier.  If that is the case let me know so I can put 14 bolts in my truck.   

[MMiller]

14 bolts are easier to setup backlash, because it has adjuster nuts.  I don't know what a 10/12 bolt diffs have for adjustment.  If they are anything like a Dana you better have a pretty good toolbox to get bearings off and on the side of the carrier.

In all reality a 14 bolt will not be much easier, its still the same steps.  Setting up preload on the pinion bearings, and getting backlash and preload right on the carrier.  And that doesn't even take into account of getting the pinion depth right, so the wear pattern is correct.

I know lots of guys that will rebuild a V-8, can make a carburator run, but refuse to work on differentials.  I don't particularly like to do diffs, but I can.  I've done JD farm tractors, Cat farm tractors, Dana 44, 60, 70, 80, and 14 bolts.  It takes patience, and the ability to keep taking it apart and putting it together until its right.  Its best to find someone that has done a bunch successfully to help you through the first time, and maybe watch you do the second one.  Or at least check your work.

Michael

[VileZambonie]

There are a lot of shops that can't even do this right but if you're smart and determined you can do it. I say if you believe you can achieve. The adjustable collar on the carrier is nice and makes setting preload and backlash much easier than dealing with a housing spreader and aftermarket shims.

Let me ask a few ?s

Why do you want to do the swap? Do you have access to a dial indicator, pinion depth gauge, in lb dial torque wrench, hydraulic press, gear marking compound, pry bar and a means of fabricating or obtaining a pinion flange holding fixture?

[zieg85]

There are a lot of shops that can't even do this right but if you're smart and determined you can do it. I say if you believe you can achieve. The adjustable collar on the carrier is nice and makes setting preload and backlash much easier than dealing with a housing spreader and aftermarket shims.

Let me ask a few ?s

Why do you want to do the swap? Do you have access to a dial indicator, pinion depth gauge, in lb dial torque wrench, hydraulic press, gear marking compound, pry bar and a means of fabricating or obtaining a pinion flange holding fixture?

I just don't have anyone I know and trust to do it and have heard horror stories about local shops doing it.  I am not opposed to buying the tools needed to do the job and can make most anything.  I have access to a hydraulic press, and I have the in lb dial torque.  Bottom line I want it done right and I have all winter to get it done as it was officially taken down to Comprehensive insurance till spring.  I am on a fishing expedition for information.

I am going to check with a 4x4 shop I know of that has been in business for a long time and see what they charge.

[bake74]

     Hey zieg, if you end up doing it, take a lot of pics, I bet there will be people following your progress.  Good luck with your search.