Drill a hole in your strap that the caliper depth rod can pass through. Put the strap on a flat surface and zero out the calipers with the tip of the rod against the flat surface and the caliper body against the top of the strap. So what you've done is zero out the thickness of the strap and what you read is the actual distance the pinion is below the cap parting line. The hole will also give you a flat surface for the calipers to sit on, this will help eliminate any measuring errors from the caliper leaning. One last thing, the parting line on the caps is rarely at exactly half the diameter of the carrier race so you should measure the distance from the parting line to the bottom of the race bore and subtract that from half the diameter of the race and factor that into your math. As you said, that will get you close to distance the manufacturer specs, then you'll have to check the gear contact pattern and adjust as needed. Best regards....
Since you have done this a few times could you give me some advice. I have a 9.75" ford rear end in my 2009 F150 pickup. It has whined for about a year and then I pulled it all apart and the clutches were totally shot and the spider gears were pretty loose with noticeable wear on the spider gear shaft pin. The ring and pinion however don't seem to look that bad. I was not able to find any wear ridges or lines on either the ring or pinion. Should I still replace these or just replace the bearings and clutches and set it all back up again? The one reason I was thinking about reusing the gears is that I won't have to set up the pinion depth again as long as I reuse the old shim and same type of bearings. Please give me your thoughts on this. Thanks.
When measuring pinion depth this way, you can't measure from the bearing cap mating surface. The bearing is not perfectly centered between the housing and cap, due to machining inconsistencies. You must first measure the carrier bearing race and divide by 2. Then, measure the bearing cap depth and either add or subtract the difference (depending on whether the cap is deeper or shallower than half the race) . This will get you the offset, and give a more reliable measurement.
Yes,I agree. The strap isn't exactly in the center. It could actually be way off. I doubt the tolerances were very tight considering it's an American car,manufactured in the 70's. Not to mention that he's measuring it with a wooden paint stick. Aren't you supposed to measure your pinion depth with everything tightened down. It would make more sense to check pinion depth after pinion pinion preload is established. I don't think this guy has any idea how to change a ring & pinion.
I agree. But is the pinion depth THAT critical? I've miked my MB jeep Dana 41 bearing cap mating surface and found that it's .002" deeper than that of the housing. Would .002" cause that much of a problem with the pattern? many of these vehicles have been set up in backyards, barns, etc, by people with rudimentary tools.The diffs have seemed to be pretty silent running, and long lasting.
I use to have a dry ice maker ( it used a siphon carbon dioxide cylinder) Nothing in the world makes a race go in like dry ice. Also used a frydaddy to warm up the bearings, so the inner race would slide on.
Pinion depth measuring off the cap pad centerline is actually not the centerline on every diff I ever built. The carrier bearing will usually sit 20-50 thousand deeper into the carrier bearing cap so if you are measuring off the pads you have to add the 20-50 thousand to the measurements to get true ring gear centerline. Very easy to check with a depth gauge or strait edge and caliper.
This is why it is important to not switch bearing caps around. They aren't the same, and if they are not the same, it is, at best, a ballpark starting point.
I just got doing this with a Chrysler 8.25 and re-geared it as well. I've never rebuilt an axle before. I bought that expensive pinion depth tool that is $400+ and has the pucks to fit in the bearing caps and all that stuff. I did not use "setup" bearings. If I were to guess, pre-loading the bearing is only going to increase pinion depth .002 inches or so. The required amount of shimming I measured was .027 and I used a .030 shim that the original came with, with the anticipation that the pre-loaded bearing will "crush" a bit. Even if it didn't, I would still be within ~1.75 human hairs of where it is supposed to be. I don't know much about rebuilding axles and stuff, but .003 inches sounds like an acceptable tolerance. Also note that it is my belief that the parting line between the bearing cap and the axle housing is not exactly half of the diameter. It could be, but we do not know. That is why it is important to not switch around bearing caps. However, It is going to be somewhere close, and the whole purpose of doing it via this method is to get it in the ball park and fine tune it based on the achieved wear pattern. This way, you are in it for potentially a couple more hours, plus probably $60 or less in setup bearings. The other alternative is to buy the $400+ pinion depth tool and get it right the very first time. Or at least that seems to be the result I achieved.
Set your pinion depth to the correct dimension and you are finished with that part...you will not be adjusting any further. Your pattern will be determined by shimming the ring gear carrier.
@@fatstercat Thanks. Mine says 2416 which I assume is 2.416 then -10 etched in so minus .010 from 2.416. I would have to add over .100 of shims to get to that number which seems excessive since I already had .028 in when I measured.
Drill a hole in your strap that the caliper depth rod can pass through. Put the strap on a flat surface and zero out the calipers with the tip of the rod against the flat surface and the caliper body against the top of the strap. So what you've done is zero out the thickness of the strap and what you read is the actual distance the pinion is below the cap parting line. The hole will also give you a flat surface for the calipers to sit on, this will help eliminate any measuring errors from the caliper leaning. One last thing, the parting line on the caps is rarely at exactly half the diameter of the carrier race so you should measure the distance from the parting line to the bottom of the race bore and subtract that from half the diameter of the race and factor that into your math. As you said, that will get you close to distance the manufacturer specs, then you'll have to check the gear contact pattern and adjust as needed. Best regards....
Since you have done this a few times could you give me some advice. I have a 9.75" ford rear end in my 2009 F150 pickup. It has whined for about a year and then I pulled it all apart and the clutches were totally shot and the spider gears were pretty loose with noticeable wear on the spider gear shaft pin. The ring and pinion however don't seem to look that bad. I was not able to find any wear ridges or lines on either the ring or pinion. Should I still replace these or just replace the bearings and clutches and set it all back up again? The one reason I was thinking about reusing the gears is that I won't have to set up the pinion depth again as long as I reuse the old shim and same type of bearings. Please give me your thoughts on this. Thanks.
Thanks this worked for me!
Great video brother! Very informative! Thanks! And remember, as you said: no pain, no gain!
Thanks still hurts lol
When measuring pinion depth this way, you can't measure from the bearing cap mating surface. The bearing is not perfectly centered between the housing and cap, due to machining inconsistencies. You must first measure the carrier bearing race and divide by 2. Then, measure the bearing cap depth and either add or subtract the difference (depending on whether the cap is deeper or shallower than half the race) . This will get you the offset, and give a more reliable measurement.
8by
Yes,I agree. The strap isn't exactly in the center. It could actually be way off. I doubt the tolerances were very tight considering it's an American car,manufactured in the 70's. Not to mention that he's measuring it with a wooden paint stick. Aren't you supposed to measure your pinion depth with everything tightened down. It would make more sense to check pinion depth after pinion pinion preload is established. I don't think this guy has any idea how to change a ring & pinion.
I agree. But is the pinion depth THAT critical? I've miked my MB jeep Dana 41 bearing cap mating surface and found that it's .002" deeper than that of the housing. Would .002" cause that much of a problem with the pattern? many of these vehicles have been set up in backyards, barns, etc, by people with rudimentary tools.The diffs have seemed to be pretty silent running, and long lasting.
@@autophyte .002" may not be a big issue. However, some are significantly more. Could be .030. Then you are in trouble.
@@travism4528 O.K. Thanks.
Watching and learning.
Awesome work. :-)
cecil6711 thanks cecil I'm trying to simplify this as much as possible for my sake and sanity lol
Cool never seen it done that way learn something today thanks
265chevy thanks hanson
265 Chevy, the first Chevy V8 in 55 and 56.
Thank you for this video helped me alot
I didn't see the sound but I heard it... tip: put races in the freezer overnight for easier installation & light coating of grease.
Explained real good
Toss the races in the freezer night before. They slide in easy....good job
I use to have a dry ice maker ( it used a siphon carbon dioxide cylinder) Nothing in the world makes a race go in like dry ice. Also used a frydaddy to warm up the bearings, so the inner race would slide on.
I totally forgot those calipers have that end that measures. Cool! Now I don't have to buy another tool.
Looking good .
wtbm123 thanks terry
Good stuff you guys!
jeff lindsey thanks jeff
well i learned sumdink new...lol. Good well explained video....
Mark Sponge thanks Mark just trying to get r done!!
Great video, thanks
Pinion depth measuring off the cap pad centerline is actually not the centerline on every diff I ever built. The carrier bearing will usually sit 20-50 thousand deeper into the carrier bearing cap so if you are measuring off the pads you have to add the 20-50 thousand to the measurements to get true ring gear centerline. Very easy to check with a depth gauge or strait edge and caliper.
This is why it is important to not switch bearing caps around. They aren't the same, and if they are not the same, it is, at best, a ballpark starting point.
Hello, In the video you gave the width and thickness of the bar to measure pinion depth. What is the length of the bar you used? Thank you!
Great video, hoping for a part 2
thank you
Arent you supposed to preload the pinion to get the right measurement? As in actually assemble it, with a used crush washer or whatever.
Yes..but he's just trying to get close right now.
I just got doing this with a Chrysler 8.25 and re-geared it as well. I've never rebuilt an axle before. I bought that expensive pinion depth tool that is $400+ and has the pucks to fit in the bearing caps and all that stuff. I did not use "setup" bearings.
If I were to guess, pre-loading the bearing is only going to increase pinion depth .002 inches or so. The required amount of shimming I measured was .027 and I used a .030 shim that the original came with, with the anticipation that the pre-loaded bearing will "crush" a bit. Even if it didn't, I would still be within ~1.75 human hairs of where it is supposed to be. I don't know much about rebuilding axles and stuff, but .003 inches sounds like an acceptable tolerance.
Also note that it is my belief that the parting line between the bearing cap and the axle housing is not exactly half of the diameter. It could be, but we do not know. That is why it is important to not switch around bearing caps. However, It is going to be somewhere close, and the whole purpose of doing it via this method is to get it in the ball park and fine tune it based on the achieved wear pattern. This way, you are in it for potentially a couple more hours, plus probably $60 or less in setup bearings. The other alternative is to buy the $400+ pinion depth tool and get it right the very first time. Or at least that seems to be the result I achieved.
No. The bearing rollers aren't going anywhere with preload but be careful because oil can change it.
Heat that housing with a weed burner and pack the race in dry ice it will practically fall into place ( use dry ice not a household freezer)
I put my races in the freezer for 10 minutes they went in a lot easier
I use that trick. its great and easy.
Many supermarkets sell dry ice...works good too.
True
Set your pinion depth to the correct dimension and you are finished with that part...you will not be adjusting any further. Your pattern will be determined by shimming the ring gear carrier.
When driving the inside race hold that driver with channel locks bent about 45 degrees sideways instead of with your hand.
slide a longer pipe over the handle
So you don't have to put a preload on the pinion to get a measurement?
The pinion is just laying in there without a preload correct?
Yes it's just to get me in the ballpark
Cool accent...you a jersey boy?
Lol no from Massachusetts I get asked that alot
Great vid Can you tell me by deducting 5 thousands on pinion dept ,How many thousands would it add or deduct on backlash ?
You set backlash with the carrier shims not the pinion.
@@jnotah pinion shims are for positioning the pinion in the correct spot (in or out) where it meshes with the ring gear.
@@frankpaya690 You are correct, but that wasn't his question.
what tool was used to measure the depth? with the block?
Digital calipers
A 71 SS should have come with a 12 bolt not a 10 bolt diff as far as I can remember.
No 12 bolts came factory installed in a camaro after the 1970 model year ended
What was your callout labeled as on the pinion? Was it a 4 digit number with no decimal?
yes I called the company to confirm and that was it
@@fatstercat Thanks. Mine says 2416 which I assume is 2.416 then -10 etched in so minus .010 from 2.416. I would have to add over
.100 of shims to get to that number which seems excessive since I already had .028 in when I measured.
:)
I dont have any shims on and my pinion sits too high what do I do
Did you have shims below the race? Some are shimmed that way