changing pinion yoke?
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Well maybe, depends how it was setup. If it was setup with shims yes you can. If it was setup with a crush collar NO YOU CAN"T. But if you are tricky like me you can get away with it by carefully tightening the pinion nut until you are back to where it was and add just a hair more. I've done it many many times.
Last edited by RockinWs6; Apr 2, 2017 at 10:41 PM.
Launching!
Joined: Dec 2011
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From: Alabama
I too have done it with great success . But in your case you cant mark the pinion and nut to put it back where it was because you are replacing the yoke . The measurements will not be the same . Yoke most likely will be of different thickness and the nut rotation will be off if you mark the nut and pinion for reference . It would be best to remove the tires an measure the preload rotation . If it were me I also would stick a screw driver in the calipers to remove the pad pressure or remove the drums . Measure then replace and duplicate the preload rotation . Dont go under , I would do like Rockin said and add 1 maybe 2 inch pounds to you initial measurement , no more than this .
If only a seal replacement you could do like Rockin said .
If only a seal replacement you could do like Rockin said .
you guys are wrong regarding the crush sleeve 
it's purpose is to stretch the pinion shaft,
just like when a cylinder head bolt stretches when you torque it to X lb-ft
the primary purpose here being clamping force, but however much tension the head bolt is under (thousands of pounds) it would take more than that force to further stretch the bolt... resulting in cylinder head lifting and head gasket no longer sealing.
you don't need this kind of "clamping force" on the pinion in the rear axle,
what you need is a specific tightness so the pinion bearings are mated up to their respective races and this is what is called pinion bearing preload, up to about 30 lb-inch.
When you accelerate forward the pinion head is thrust forward, putting a compression force on the pinion shaft and the pinion head bearing and axle housing takes that force. But under a deceleration the pinion head is sucked backward and if this rearward force is greater than any tension placed on the pinion shaft, then that tension force will stretch the pinion shaft resulting in the pinion bearings not riding against their races resulting in the pinion wobbling. From a certain perspective you can say the pinion bearings lose their preload under this condition.
that's why either a crush sleeve, or a solid spacer, is used. And it takes around 400+ lb-ft to crush a crush sleeve which directly correlates to the amount of tension the pinion shaft gets put under. However much tension [preload] the pinion shaft is put under is how much force from deceleration of the car it can handle before it is further stretched- resulting in lost bearing preload and pinion wobble.
the crush sleeve is a one-time use. when you tighten down the pinion nut you must stop once the bearing preload reaches ~20 inch-pounds and in doing so you are not re-crushing the crush sleeve anymore (it takes hundreds of lb-ft to crush it) so there is no stretch happening on the pinion shaft anymore. with no stretch / tension / preload applied to the pinion shaft then any deceleration force will be stretching the pinion shaft, the pinion head bearing will pull away from it's race and cause the pinion to wobble. The exception to all this is if there's a solid pinion spacer then you can re-use it if no other dimensions have changed (i.e. re-using the same pinion with everything the same between the pinion head & tail bearings).
So when you guys say you've done it with great success, what is your metric?
I had my pinion seal replaced at dealer at ~10k miles.
Retired my oem 10-bolt at ~65k miles about 10 years after due to excessive gear noise any speed over 30mph. My car is basically a garage queen... daily summer driver, so i know my failure was not caused by abuse.
it's purpose is to stretch the pinion shaft,
just like when a cylinder head bolt stretches when you torque it to X lb-ft
the primary purpose here being clamping force, but however much tension the head bolt is under (thousands of pounds) it would take more than that force to further stretch the bolt... resulting in cylinder head lifting and head gasket no longer sealing.
you don't need this kind of "clamping force" on the pinion in the rear axle,
what you need is a specific tightness so the pinion bearings are mated up to their respective races and this is what is called pinion bearing preload, up to about 30 lb-inch.
When you accelerate forward the pinion head is thrust forward, putting a compression force on the pinion shaft and the pinion head bearing and axle housing takes that force. But under a deceleration the pinion head is sucked backward and if this rearward force is greater than any tension placed on the pinion shaft, then that tension force will stretch the pinion shaft resulting in the pinion bearings not riding against their races resulting in the pinion wobbling. From a certain perspective you can say the pinion bearings lose their preload under this condition.
that's why either a crush sleeve, or a solid spacer, is used. And it takes around 400+ lb-ft to crush a crush sleeve which directly correlates to the amount of tension the pinion shaft gets put under. However much tension [preload] the pinion shaft is put under is how much force from deceleration of the car it can handle before it is further stretched- resulting in lost bearing preload and pinion wobble.
the crush sleeve is a one-time use. when you tighten down the pinion nut you must stop once the bearing preload reaches ~20 inch-pounds and in doing so you are not re-crushing the crush sleeve anymore (it takes hundreds of lb-ft to crush it) so there is no stretch happening on the pinion shaft anymore. with no stretch / tension / preload applied to the pinion shaft then any deceleration force will be stretching the pinion shaft, the pinion head bearing will pull away from it's race and cause the pinion to wobble. The exception to all this is if there's a solid pinion spacer then you can re-use it if no other dimensions have changed (i.e. re-using the same pinion with everything the same between the pinion head & tail bearings).
So when you guys say you've done it with great success, what is your metric?
I had my pinion seal replaced at dealer at ~10k miles.
Retired my oem 10-bolt at ~65k miles about 10 years after due to excessive gear noise any speed over 30mph. My car is basically a garage queen... daily summer driver, so i know my failure was not caused by abuse.
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Joined: Mar 2013
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you guys are wrong regarding the crush sleeve
it's purpose is to stretch the pinion shaft,
just like when a cylinder head bolt stretches when you torque it to X lb-ft
the primary purpose here being clamping force, but however much tension the head bolt is under (thousands of pounds) it would take more than that force to further stretch the bolt... resulting in cylinder head lifting and head gasket no longer sealing.
you don't need this kind of "clamping force" on the pinion in the rear axle,
what you need is a specific tightness so the pinion bearings are mated up to their respective races and this is what is called pinion bearing preload, up to about 30 lb-inch.
When you accelerate forward the pinion head is thrust forward, putting a compression force on the pinion shaft and the pinion head bearing and axle housing takes that force. But under a deceleration the pinion head is sucked backward and if this rearward force is greater than any tension placed on the pinion shaft, then that tension force will stretch the pinion shaft resulting in the pinion bearings not riding against their races resulting in the pinion wobbling. From a certain perspective you can say the pinion bearings lose their preload under this condition.
that's why either a crush sleeve, or a solid spacer, is used. And it takes around 400+ lb-ft to crush a crush sleeve which directly correlates to the amount of tension the pinion shaft gets put under. However much tension [preload] the pinion shaft is put under is how much force from deceleration of the car it can handle before it is further stretched- resulting in lost bearing preload and pinion wobble.
the crush sleeve is a one-time use. when you tighten down the pinion nut you must stop once the bearing preload reaches ~20 inch-pounds and in doing so you are not re-crushing the crush sleeve anymore (it takes hundreds of lb-ft to crush it) so there is no stretch happening on the pinion shaft anymore. with no stretch / tension / preload applied to the pinion shaft then any deceleration force will be stretching the pinion shaft, the pinion head bearing will pull away from it's race and cause the pinion to wobble. The exception to all this is if there's a solid pinion spacer then you can re-use it if no other dimensions have changed (i.e. re-using the same pinion with everything the same between the pinion head & tail bearings).
So when you guys say you've done it with great success, what is your metric?
I had my pinion seal replaced at dealer at ~10k miles.
Retired my oem 10-bolt at ~65k miles about 10 years after due to excessive gear noise any speed over 30mph. My car is basically a garage queen... daily summer driver, so i know my failure was not caused by abuse.
it's purpose is to stretch the pinion shaft,
just like when a cylinder head bolt stretches when you torque it to X lb-ft
the primary purpose here being clamping force, but however much tension the head bolt is under (thousands of pounds) it would take more than that force to further stretch the bolt... resulting in cylinder head lifting and head gasket no longer sealing.
you don't need this kind of "clamping force" on the pinion in the rear axle,
what you need is a specific tightness so the pinion bearings are mated up to their respective races and this is what is called pinion bearing preload, up to about 30 lb-inch.
When you accelerate forward the pinion head is thrust forward, putting a compression force on the pinion shaft and the pinion head bearing and axle housing takes that force. But under a deceleration the pinion head is sucked backward and if this rearward force is greater than any tension placed on the pinion shaft, then that tension force will stretch the pinion shaft resulting in the pinion bearings not riding against their races resulting in the pinion wobbling. From a certain perspective you can say the pinion bearings lose their preload under this condition.
that's why either a crush sleeve, or a solid spacer, is used. And it takes around 400+ lb-ft to crush a crush sleeve which directly correlates to the amount of tension the pinion shaft gets put under. However much tension [preload] the pinion shaft is put under is how much force from deceleration of the car it can handle before it is further stretched- resulting in lost bearing preload and pinion wobble.
the crush sleeve is a one-time use. when you tighten down the pinion nut you must stop once the bearing preload reaches ~20 inch-pounds and in doing so you are not re-crushing the crush sleeve anymore (it takes hundreds of lb-ft to crush it) so there is no stretch happening on the pinion shaft anymore. with no stretch / tension / preload applied to the pinion shaft then any deceleration force will be stretching the pinion shaft, the pinion head bearing will pull away from it's race and cause the pinion to wobble. The exception to all this is if there's a solid pinion spacer then you can re-use it if no other dimensions have changed (i.e. re-using the same pinion with everything the same between the pinion head & tail bearings).
So when you guys say you've done it with great success, what is your metric?
I had my pinion seal replaced at dealer at ~10k miles.
Retired my oem 10-bolt at ~65k miles about 10 years after due to excessive gear noise any speed over 30mph. My car is basically a garage queen... daily summer driver, so i know my failure was not caused by abuse.
Joined: Aug 2007
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From: Turnin' Wrenches Infractions: 005
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TECH Addict
Joined: Mar 2013
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Likes: 30
I too have done it with great success . But in your case you cant mark the pinion and nut to put it back where it was because you are replacing the yoke . The measurements will not be the same . Yoke most likely will be of different thickness and the nut rotation will be off if you mark the nut and pinion for reference . It would be best to remove the tires an measure the preload rotation . If it were me I also would stick a screw driver in the calipers to remove the pad pressure or remove the drums . Measure then replace and duplicate the preload rotation . Dont go under , I would do like Rockin said and add 1 maybe 2 inch pounds to you initial measurement , no more than this .
If only a seal replacement you could do like Rockin said .
If only a seal replacement you could do like Rockin said .
Unfortunately this is a very critical adjust you should only attempt unless you understand how all these parts interact and will fail rather quickly if over tightened. Feel it before and after how the pinion feels and turns, it should feel the same.
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Verdad Gallardo I got ahold of the guy that built my rearend. He does it for a living and he told me if I check the drag before I take the yoke off I can install the new one if i tighten til i get same amount of drag.
if we were face to face and i had 10 minutes i could explain it on paper.
the principle by which the crush sleeve works is not complicated, but it can be difficult for anyone to understand without having the actual parts in hand to understand everything that is actually happening with the ring & pinion assembly.
fact is
the principle by which the crush sleeve works is not complicated, but it can be difficult for anyone to understand without having the actual parts in hand to understand everything that is actually happening with the ring & pinion assembly.
fact is
- under forward acceleration the ring gear will drive the pinion gear forward
- under rearward acceleration the ring gear will pull the pinion gear back toward the ring gear center line
- you do not need a crush sleeve or solid spacer present between the pinion head bearing and pinion tail bearing to simply achieve an installation having the correct preload of 15 to 30 lb-in on the pinion head & tail bearings. But this does not mean the entire installation is correct for all expected or assumed operating conditions.
- that rearward force by the ring gear on the pinion gear pulls the entire pinion, and it's the pinion nut keeping the pinion from moving rearward thus the pinion is similar to a bolt and nut setup. Now use what you know about basic fastener technology and why you torque a nut and how a bolt/stud then stretches axially within it's elastic range, then into the plastic range, and the reasons why you would want it to do so.
- if the rearward force on the pinion by the ring gear exceeds the tension already placed on the pinion shaft by a crush sleeve/spacer, then the pinion shaft will further stretch and the pinion head bearing would unseat from its race. In principle what's happening is no different than further stretching head bolts because of increased combustion pressures- the force acting on the fastener is exceeding the fastener's capability.
- this simple principle of preload is why we also stretch the axle housing to preload the carrier bearings... youtube and "experts" and the guy who just did it will tell you to just hammer in some shims so it's tight. You want the axle housing stretched and providing maximum preload on the carrier, so when hundreds or thousands of lb-ft of torque is transmitted through the axle housing doesn't flex then allowing ring gear runout or wobble.
- The most preload you can apply directly results into how much force something can handle before it further stretches or distorts- provided it's properties follow hooke's law and this applies to the pinion shaft and the axle housing.
- rockinws6 does not own a bridge
Last edited by 1 FMF; Apr 7, 2017 at 01:05 PM.
the real proof is you simply do not need a crush sleeve or anything between the pinion head and tail bearings to achieve pinion bearing preload. That happens when you tighten down the pinion nut pushing the yoke and tail bearing inward.
So then ask yourself - why even install a crush sleeve?
And because a service manual or some guy who rebuilds them for a living said so is not a valid answer.
So then ask yourself - why even install a crush sleeve?
And because a service manual or some guy who rebuilds them for a living said so is not a valid answer.
Joined: Aug 2007
Posts: 24,241
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From: Turnin' Wrenches Infractions: 005
the real proof is you simply do not need a crush sleeve or anything between the pinion head and tail bearings to achieve pinion bearing preload. That happens when you tighten down the pinion nut pushing the yoke and tail bearing inward.
So then ask yourself - why even install a crush sleeve?
And because a service manual or some guy who rebuilds them for a living said so is not a valid answer.
So then ask yourself - why even install a crush sleeve?
And because a service manual or some guy who rebuilds them for a living said so is not a valid answer.
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Crush sleeve is there to keep the inner race from rotating and to insure proper torque readings when checking rotating preload, it also holds the nut tight against the bearing assembly. Without the crush collar there is no force against the nut, think about it. This is a precision setup assembly, wheel bearings are not.
Wheel bearings you mentioned are not torqued to such a spec and don't require precision set up BUT they do require a lock of some type to retain the adjustment nut.
I have something else to mention, when you go through engineering school and are hired to design such a assembly and are qualified to make such statements DO SO. Till then please don't sway anyone to follow you into HELL.
Wheel bearings you mentioned are not torqued to such a spec and don't require precision set up BUT they do require a lock of some type to retain the adjustment nut.
I have something else to mention, when you go through engineering school and are hired to design such a assembly and are qualified to make such statements DO SO. Till then please don't sway anyone to follow you into HELL.
you crack me up.
post #12 you say I say to install it and THAT is enough for ALL to comply..
post #14 you say when you go through engineering school and are hired to design such a assembly and are qualified to make such statements DO SO. Till then please don't sway anyone to follow you into HELL
you may subscribe to the mentality that a [specific] degree, or ASE certification, or some bunch of diplomas on a wall is required to qualify someone as credible and that's your problem...
2x2=4 sqrt(81) = 9 and I don't have a math degree does not mean i am wrong?
hope you have a mechanical engineering degree then, from a reputable school, and that is pertains specifically to rear axle repair... I won't even go so far to say it has to be specifically for repair on the GM 12-bolt which is the axle in question... because if you don't you just won the hypocrite of the year award with your statements.
post #12 you say I say to install it and THAT is enough for ALL to comply..
post #14 you say when you go through engineering school and are hired to design such a assembly and are qualified to make such statements DO SO. Till then please don't sway anyone to follow you into HELL
you may subscribe to the mentality that a [specific] degree, or ASE certification, or some bunch of diplomas on a wall is required to qualify someone as credible and that's your problem...
2x2=4 sqrt(81) = 9 and I don't have a math degree does not mean i am wrong?
hope you have a mechanical engineering degree then, from a reputable school, and that is pertains specifically to rear axle repair... I won't even go so far to say it has to be specifically for repair on the GM 12-bolt which is the axle in question... because if you don't you just won the hypocrite of the year award with your statements.
wow this post escalated quickly lol. i did put the 1350 yoke on. i made the dumbass mistake of not taking one brake drum off before i took a preload measurement,haste makes waste. so i was screwed on what to tighten the preload to. my torque wrench only goes to 150 ft/lbs and i went well past that to get about 8 in/lbs preload. i felt like my 1/2 drive and persuader where about to break if i went any further.
just so i am clear the preload should be measured as the pinion is turning and not what it take to start rotating?
just so i am clear the preload should be measured as the pinion is turning and not what it take to start rotating?
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Yes turning torque not break away but there are specs for both. As long as it turns smooth and easy without play you are fine. I always remove the wheels brakes and rotors if I'm taking a pre measurement which I should have mentioned. Sorry I just know what it should feel like before it turns the ring gear. The proper way to do this is to pull the carrier then measure the torque BUT If everything is in good condition you can get away with a lot as long as you don't go too tight. Loose is better than too tight, bearing die quickly if run too tight but trust me if you had it tightened too tight it would be hard to turn.
With the wheels brakes and rotors removed that pinion should feel like it has a slight drag with no play up and down. One hand should turn it easily.
Let me explain how turning torque feels 5inch lbs< easy to turn 10inch lbs<firm to turn 15inch lbs< stiff to turn 20inch lbs getting very stiff to turn 25inch lbs<getting hard to turn 30inch lbs very hard to turn.
On used its always better to stay on the light side. Be sure to use some kind of thread locker on the threads and seal the yoke splines with silicone. I run a small bead inside the yoke splines towards the outer end so as you slide the yoke on the silicone seals the splines. Wipe off and silicone that comes out of the splines then put your washer in thread locker on the threads and tighten the nut with a standard 1/2 drive ratchet and socket till it stops turning. This will be the point where you were before you started. It will be very hard to turn at this point, feel that the pinion turns easily without any play up and down. Now mark the nut and pinion thread with the edge of a small file. This will be your reference point. Now turn the nut 1/16 of a inch more past your mark. The nut should turn very hard so be careful because it will break away and turn too much. Just bear down on it and as soon as you feel it move let off. At this point the pinion should turn free with slight drag and smooth. Good Luck
With the wheels brakes and rotors removed that pinion should feel like it has a slight drag with no play up and down. One hand should turn it easily.
Let me explain how turning torque feels 5inch lbs< easy to turn 10inch lbs<firm to turn 15inch lbs< stiff to turn 20inch lbs getting very stiff to turn 25inch lbs<getting hard to turn 30inch lbs very hard to turn.
On used its always better to stay on the light side. Be sure to use some kind of thread locker on the threads and seal the yoke splines with silicone. I run a small bead inside the yoke splines towards the outer end so as you slide the yoke on the silicone seals the splines. Wipe off and silicone that comes out of the splines then put your washer in thread locker on the threads and tighten the nut with a standard 1/2 drive ratchet and socket till it stops turning. This will be the point where you were before you started. It will be very hard to turn at this point, feel that the pinion turns easily without any play up and down. Now mark the nut and pinion thread with the edge of a small file. This will be your reference point. Now turn the nut 1/16 of a inch more past your mark. The nut should turn very hard so be careful because it will break away and turn too much. Just bear down on it and as soon as you feel it move let off. At this point the pinion should turn free with slight drag and smooth. Good Luck
Last edited by RockinWs6; Apr 16, 2017 at 08:23 PM.
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you crack me up.
post #12 you say I say to install it and THAT is enough for ALL to comply..
post #14 you say when you go through engineering school and are hired to design such a assembly and are qualified to make such statements DO SO. Till then please don't sway anyone to follow you into HELL
you may subscribe to the mentality that a [specific] degree, or ASE certification, or some bunch of diplomas on a wall is required to qualify someone as credible and that's your problem...
2x2=4 sqrt(81) = 9 and I don't have a math degree does not mean i am wrong?
hope you have a mechanical engineering degree then, from a reputable school, and that is pertains specifically to rear axle repair... I won't even go so far to say it has to be specifically for repair on the GM 12-bolt which is the axle in question... because if you don't you just won the hypocrite of the year award with your statements.
post #12 you say I say to install it and THAT is enough for ALL to comply..
post #14 you say when you go through engineering school and are hired to design such a assembly and are qualified to make such statements DO SO. Till then please don't sway anyone to follow you into HELL
you may subscribe to the mentality that a [specific] degree, or ASE certification, or some bunch of diplomas on a wall is required to qualify someone as credible and that's your problem...
2x2=4 sqrt(81) = 9 and I don't have a math degree does not mean i am wrong?
hope you have a mechanical engineering degree then, from a reputable school, and that is pertains specifically to rear axle repair... I won't even go so far to say it has to be specifically for repair on the GM 12-bolt which is the axle in question... because if you don't you just won the hypocrite of the year award with your statements.
Launching!
Joined: Jun 2014
Posts: 204
Likes: 8
From: Houston
When tightening up the yoke for the install, you say to have the wheels/tires and brakes off the rotors. How are you locking down the yoke to tighten the nut? Or am I misunderstanding? Do you tighten the nut with the wheels on the ground?