1967 Chevy CST aka "the loud truck"

[Ol Blue K20]

Rick, I'm not a diff builder but...don't worry about the axles worry about the gear mesh and wear pattern. the axles will fall in after...

[phaus01]

Always a lot of good information available at www.ringpinion.com

[67chevy1series]

Sorry didn't see the comments were on the last page

[67chevy1series]

Originally Posted by Ol Blue K20

Rick, I'm not a diff builder but...don't worry about the axles worry about the gear mesh and wear pattern. the axles will fall in after...

well that's what I thought... I went to go put my rear calipers on and I noticed the caliper wouldn't go on the passenger axe unless I moved the bracket towards the differential about 3/4's of an inch... That means my axle shaft is moved wayyyyy to far to the left

Originally Posted by phaus01

Always a lot of good information available at www.ringpinion.com

Thank you I will check that out right now

[67chevy1series]

Found out the problem... The carriers are different I need to get a special ring gear and pinnion to fit my axle and posi

[Ol Blue K20]

That's not good... good luck Rick...

[Ol Blue K20]

I was talking to a buddy and he thinks they make a spacer to adapt your ring on that carrier..

[jbclassix]

The spacer would work if he was putting 4.10s on a 3.73 carrier.

Rick. Can you return your carrier and get the 3 series carrier? That would be your best route cost wise. If you wanted to replace R&P you will have to set pinion depth on your new gears as well as pinion pre-load. that's time, money, and tools. (and my favorite part) hit me up if you have any Q's

[Ol Blue K20]

Originally Posted by jbclassix

The spacer would work if he was putting 4.10s on a 3.73 carrier.

Rick. Can you return your carrier and get the 3 series carrier? That would be your best route cost wise. If you wanted to replace R&P you will have to set pinion depth on your new gears as well as pinion pre-load. that's time, money, and tools. (and my favorite part) hit me up if you have any Q's

Thanks JB for clearing that up, I learn something new here all the time...thanks again...

[jbclassix]

Any time!

[67chevy1series]

Yikes... Well I don't think ill be getting rid of that 4 series posi carrier anytime soon... Unless somebody wants to trade posi carriers? Do you know who sells or where I can buy a ring and pinnion to still use my 4 series carrier and have 3.73's? Let me know what it's called or where ill buy it. I have access to a lot of tools ( I'm in diesel mechanics in college) so that's not an issue and as for labor and time I think my labor is worth having a posi in there and ill save up money for it, and you guys could help me and walk me through the process. And with this new ring and pinnion will the carrier be centered in the differential housing?

[jbclassix]

I'll check rick, but I think they only sell "thick" sets of lower gears and not "thin" sets of high gears. Which posi do you have (hey you could post a picture since you haven't in a while). You may be able to score an empty carrier for dirt cheap and swap the guts.

[67chevy1series]

Originally Posted by jbclassix

I'll check rick, but I think they only sell "thick" sets of lower gears and not "thin" sets of high gears. Which posi do you have (hey you could post a picture since you haven't in a while). You may be able to score an empty carrier for dirt cheap and swap the guts.

i see.. well hopefully they make a 3.73 r&p that has the same configuration of the 4.11 just with the teeth count of a 3.73, if thats possible.

anyways i finally have a computer at my dispsoal so i will post some pictures of the posi and some other random pictures of the truck here some of the rear disc brakes and one of the new fender for the passenger side. the picture of the fender is of when i sanded it to bare medal and then primed it as you can see its a straight clean fender i got lucky there!

[67chevy1series]

heres the posi carrier next to the original non posi carrier from my truck

[jbclassix]

Originally Posted by 67chevy1series

Well the posi install isn't going so smooth.. This is what I have and what I think I know:
The posi carrier is from a 67 12 bolt and was 4.11 gear ratio.
My rear axle is a 71 12 bolt and is a 3.73 gear ratio. Now from what I understand the 3.73 and 4.11 gear ratios both use a 4 series carrier.

So this is what I've done: I took the non posi 3.73 carrier out, and I left the pinnion in I didn't even touch it, then I took the ring gear off and installed it on the posi carrier I bought new bearings and installed them they went on just like they should of I also bought new races to go with the bearings when I went to go install the posi I ended up breaking one of the shims that came in my axle so I bought a shim kit so I set the carrier in and shimmed it almost every way possible I put equal amounts of shims and I couldn't even turn the differential it wasn't even budging so finally I got the differential to spin somewhat easily but that was with the shims on the passenger side and no shims on the drivers side... And if the carrier is moved to the drivers side then the axle shafts are going to move to the right..
So please somebody help me and tell me what I'm doing wrong I'm burnout on what to do.. :/

www.ringpinion.com

ok.... going back and trying to sort this out..

first, there is a passenger car 12 bolt and a truck 12 bolt axle. If your posi came from a truck 4.11 then it should fit your 3.73 gears. The carrier break is 3.42/3.73. If it came from a car, sell it and put your non posi back in.

2nd, I don't see anything about contact pattern in anything you posted so far, so...

Assuming you have a truck posi, Here is my advice..

Remove your ring gear from your carrier. This will prevent contact interference between ring and pinion while establishing carrier pre-load.

Set your carrier up with enough shims so that you have 0 end play. For the garage install, your carrier should go in "snug" since you aren't using a spreader, but should turn freely once installed and caps torqued.

Once you have your total shim pack thickness established for 0 end play, you can remove the carrier and re-install the ring gear.

Now, I recommend recording your total shim thickness for reference. You can now establish your CONTACT PATTERN. judging from what you are saying, I would start with all the shims on the passenger side of the carrier. If you have questions about which way to move the ring gear, I can get into that if you need.

In reference to you talking about the axle shafts moving right or left, you could shim your carrier all the way to one side and it wont move your axle shafts any significant amount. you do need to ensure that the spline count is right between your shaft and the side gears.

One more thing that I highly advise is inspect or replace your axle bearings, and replace the axle seals no matter what.

Another thing you can do while you are into your axle is check pinion pre-load. You don't want to allow a failure to ruin all your hard work!

[67chevy1series]

Originally Posted by jbclassix

www.ringpinion.com

ok.... going back and trying to sort this out..

first, there is a passenger car 12 bolt and a truck 12 bolt axle. If your posi came from a truck 4.11 then it should fit your 3.73 gears. The carrier break is 3.42/3.73. If it came from a car, sell it and put your non posi back in.

2nd, I don't see anything about contact pattern in anything you posted so far, so...

Assuming you have a truck posi, Here is my advice..

Remove your ring gear from your carrier. This will prevent contact interference between ring and pinion while establishing carrier pre-load.

Set your carrier up with enough shims so that you have 0 end play. For the garage install, your carrier should go in "snug" since you aren't using a spreader, but should turn freely once installed and caps torqued.

Once you have your total shim pack thickness established for 0 end play, you can remove the carrier and re-install the ring gear.

Now, I recommend recording your total shim thickness for reference. You can now establish your CONTACT PATTERN. judging from what you are saying, I would start with all the shims on the passenger side of the carrier. If you have questions about which way to move the ring gear, I can get into that if you need.

In reference to you talking about the axle shafts moving right or left, you could shim your carrier all the way to one side and it wont move your axle shafts any significant amount. you do need to ensure that the spline count is right between your shaft and the side gears.

One more thing that I highly advise is inspect or replace your axle bearings, and replace the axle seals no matter what.

Another thing you can do while you are into your axle is check pinion pre-load. You don't want to allow a failure to ruin all your hard work!

the posi was pulled out of a 67 suburban so according to what you said it should work. when i put the posi in my axle shafts were able to go in and at one point i did have it in and fully working the problem was that i had no shims on the left side and a bunch of shims to the right, now i know you said it wont move my axle shafts in the axle but i have to disagree because when i set it all up and put the shafts in with the pin thought the carrier my driver axle shaft was approx. 1'' out and on the passenger side it moved it in approx. 1'' and it was a sombi*** to put the c clip on the passenger when i went top mount me rear caliper brackets i had to install 6 washers just to bring the bracket inward so my caliper would align with my rotor on the axle shaft... now i didn't install it wrong so i don't see any error in what i did except installing all the shims to one side, but that was the only way i could move the posi freely and everything still be hooked up. as you can see in the picture my carriers are different and the "offset" (for lack of a better term) is off a pretty good amount. i completely understand what you are saying and im not trying to aggravate or confuse you but for some reason what you are telling me is correct and i did the correct work but even after all that the posi just doesn't want to cooperate lol

[67chevy1series]

this is what member "1774btcrew" stated in the thread "I have a very clean 12 bolt spring type posi with 4:11 removed from a 1967 Suburban with low miles." the for sale thread is called "12 bolt posi carrier with 4:11 gears" and is in the classifieds section for 67-72chevrolet & gmc pickups

[jbclassix]

No arguing going on... just problem solving! Are tour axle shafts different lengths?

[67chevy1series]

they are the same length. and as for teeth contact i did establish gear contact pattern and the contact was even across when going forward and for reverse the contact was towards the outer portion of the tooth.

[jbclassix]

I take it this was the FS thread? Several weird things, one, the case for the lower gears should have the ring gear flange furthest to the right. So, your new posi should SHOULD be right! Looking at the pictures in the FS thread, it almost looks like the the 4.10s have the aftermarket spacer between the ring gear and the carrier.

So the basic design of the diffs, the higher the gear ratio, the larger the diameter of the pinion gear, the lower the gear ration, the smaller the diameter of the pinion gear. A 3.08 pinion gear is larger than the 4.10 pinion gear. So the carrier for the 3.42 and down gears would have the ring gear flange further to the left to make room for the larger pinion. I almost wonder if your 3.73's are aftermarket "thick" to fit a higher ratio carrier? But your pictures don't look like it was a thick ring gear, and if it was a "thick" set, and you truly were not using the spacer, then it should fit!

have I confused you yet?

Lets start over, are there any part numbers or markings on the posi carrier? What are all the part numbers on your Ring and Pinion too? Let's see what we have to do to get this thing set up.

[67chevy1series]

yes! exactly! thats why i bought it i thought it was what i needed and your correct my ring is not spaced and is factoery what GM put in for 71 now i have come across and idea what i i could get a 3.73 ring and pinion but instead of it having a large pinion like the 3.08 and whay my truck hasd maybe i could get a 3.73 gear with a smaller pinion and thicker ring gear? because i have noticed that the pinion in my truck is a lot bigger then the one shown in the for sale thread

[jbclassix]

They dont make different size pinions because that would be altering the tooth size, which would not mesh with the ring teeth then.

Grab all the numbers off the parts you have, maybe something is askew. GM truck and passenger 12 bolts both used different carriers and different ring and pinion sets.

Unfortunately, I cant find Build sheets like Dana axles, so you are stuck to checking your existing part numbers and making sure they are correct for the application.

By the way, congrats for not being out partying on a Friday night.

[67chevy1series]

ok well ill try to figure out what i all have. im going to double check and make sure my gears are 3.73 maybe i was lied to by the PO of the frame and suspension about the gear ratio... we shall see when i get back home. and haha thanks i must be a weirdo because i really just don't have any pleasure in going to parties and being the age of 18 that's i guess not "normal" i would gladly stay at home and wrench on my truck then go to a party.

[67chevy1series]

jeremy just out of curiosity if somebody was trying to install a 4.11 posi carrier into a 3.07\3.08 ring and pinion axle would they have the same problems as me?

[jbclassix]

Originally Posted by 67chevy1series

jeremy just out of curiosity if somebody was trying to install a 4.11 posi carrier into a 3.07\3.08 ring and pinion axle would they have the same problems as me?

Yes. This would explain your problem. 3.42 and higher gears use a different carrier. The ring gear flange will be further to the LEFT of the axle for 3.42 and higher. My guess is you have 3.08 or 3.42 gears... not 3.73.