Rear wheel Bearing change project
08-05-2017, 03:06 PM
#1
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Rear wheel Bearing change project
I figured id pulll this topic off a Laguna Race result thread as to leave that one about mostly the race. 
Here is what DR Bob and i have been discussing . my main question now, is it really worth it to do the job on the car , or is it possibly easier to just remove the hub carrier off the car. i did the job 10 years ago, and removed the hub and took it to a shop with a press. however, i must say, most of the bill ball video content shows a pretty easy process too for removal, if you have the right tools.
when you remove the carrier, do you need to unbolt the half shaft on the S4? looks like you just unbolt at the lower control arm and upper control arm and it would just pull out (after ebrake cable disconnected)
with the "non -removal" way, do you need to remove the half shaft to move it out of the way to get the jackscrews in there? seems like it.
is the bearing pictured the correct one??
Here is the last notes from Bobs advice to me on the job:
>>>>>>>>>>>>>>>>>>>>>>>>>>
I dont remember having to pull the half shaft out. doesnt it just slide out with the carrier being removed? its been 10 years! good call on the torque wrench rental. however, ive always done the crank nose bolt with a half inch drive breaker bar.... but ball parked the torque. i know what 300lbft is, and i know what 100lbft is... its on the high side of in between.
Ill have to see if Bill is a wrench for hire on this project!
is this the right one? its a big bearing!!
Here is what DR Bob and i have been discussing . my main question now, is it really worth it to do the job on the car , or is it possibly easier to just remove the hub carrier off the car. i did the job 10 years ago, and removed the hub and took it to a shop with a press. however, i must say, most of the bill ball video content shows a pretty easy process too for removal, if you have the right tools.
when you remove the carrier, do you need to unbolt the half shaft on the S4? looks like you just unbolt at the lower control arm and upper control arm and it would just pull out (after ebrake cable disconnected)
with the "non -removal" way, do you need to remove the half shaft to move it out of the way to get the jackscrews in there? seems like it.
is the bearing pictured the correct one??
Here is the last notes from Bobs advice to me on the job:
>>>>>>>>>>>>>>>>>>>>>>>>>>
You'll need to pull the half-shaft out to get the carrier out.
Some parts stores have tool-loan and free-rent programs for stuff like this. Worth a phone call or two to locate one near you. Bill Ball -may- have one in his arsenal, as it's the same setup needed to tighten the crank nose bolt for a timing belt change. Different-size socket, same 3/4"-size drive.
Some parts stores have tool-loan and free-rent programs for stuff like this. Worth a phone call or two to locate one near you. Bill Ball -may- have one in his arsenal, as it's the same setup needed to tighten the crank nose bolt for a timing belt change. Different-size socket, same 3/4"-size drive.
good call on the torque wrench rental. however, ive always done the crank nose bolt with a half inch drive breaker bar.... but ball parked the torque. i know what 300lbft is, and i know what 100lbft is... its on the high side of in between. Ill have to see if Bill is a wrench for hire on this project!
is this the right one? its a big bearing!!
08-05-2017, 07:59 PM
#2
Chronic Tool Dropper
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Mark--
You can let the halfshaft just fall at the outer end if you decide to take the hub carrier to a shop. You'll still need to get the nut off the end to get it out, and wrestle the stub axle back through the bearing when you reinstall the new assembly. Difference: the 6 socket-head capscrews that hold the inner CV joint to the drive flange on the side of the gearbox. On the left side, it's easier at least for me to get the muffler out of the way, so two clamps and two hangers are involved too.
To get the correct torque on the nut, try your body weight MKBW and the required torque, and decide where to put your foot on the bar to generate that.
You can let the halfshaft just fall at the outer end if you decide to take the hub carrier to a shop. You'll still need to get the nut off the end to get it out, and wrestle the stub axle back through the bearing when you reinstall the new assembly. Difference: the 6 socket-head capscrews that hold the inner CV joint to the drive flange on the side of the gearbox. On the left side, it's easier at least for me to get the muffler out of the way, so two clamps and two hangers are involved too.
To get the correct torque on the nut, try your body weight MKBW and the required torque, and decide where to put your foot on the bar to generate that.
08-06-2017, 04:29 AM
#4
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whats the consensus, pull the hub or just do it on the car?
08-06-2017, 06:17 AM
#5
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The mechanic I use ( retired 928 master tech) took the hub to a shop to have it pressed out.
He's the only shade tree mechanic I trust
I would do the same as you need the special puller and installation tool to do it on the car.
He's the only shade tree mechanic I trust
I would do the same as you need the special puller and installation tool to do it on the car.
08-06-2017, 01:48 PM
#6
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Doing it on the car means you don't have to disconnect all the suspension. Taking it off means you get to inspect and service/replace the worn suspension parts on the way through. Doing it on the car means much less chance of messing with current alignment.
Way back when, the labor cost of having the bearings replaced at a local expert was about the same as the cost of the Sir Tools B90 Porsche sub-kit. My idea was to have it for clinic cars and for other locals to use it when needed. Bill borrowed mine and later found one of his own. You could help him justify that purchase.
Way back when, the labor cost of having the bearings replaced at a local expert was about the same as the cost of the Sir Tools B90 Porsche sub-kit. My idea was to have it for clinic cars and for other locals to use it when needed. Bill borrowed mine and later found one of his own. You could help him justify that purchase.
08-06-2017, 02:15 PM
#7
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The nice thing about the dual axial ball bearing is that tightening the big nut puts zero pressure on the actual ball bearings. The two piece inner races set the preload !!!
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08-06-2017, 03:19 PM
#8
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Actually you can slide hammer the old bearing out and use a piece of treaded rod for a hack to pull the new bearing into place. Heat the carrier freeze the bearing for install. Use the stub axle to full seat the bearing.
The nice thing about the dual axial ball bearing is that tightening the big nut puts zero pressure on the actual ball bearings. The two piece inner races set the preload !!!
The nice thing about the dual axial ball bearing is that tightening the big nut puts zero pressure on the actual ball bearings. The two piece inner races set the preload !!!
how does the stub axle used to "seat the bearing" thats the part that makes me worry i cant do it. the tool set makes sense........plus , the trade off seems to be unbolting the CV axle, vs the two bolts.. (loower and upper control arm) (and some small work to get the ebrake cable out.) sounds like a trade off, no? i guess you save the time of driving to the shop with the press.
(and the cost)Doing it on the car means you don't have to disconnect all the suspension. Taking it off means you get to inspect and service/replace the worn suspension parts on the way through. Doing it on the car means much less chance of messing with current alignment.
Way back when, the labor cost of having the bearings replaced at a local expert was about the same as the cost of the Sir Tools B90 Porsche sub-kit. My idea was to have it for clinic cars and for other locals to use it when needed. Bill borrowed mine and later found one of his own. You could help him justify that purchase.
Way back when, the labor cost of having the bearings replaced at a local expert was about the same as the cost of the Sir Tools B90 Porsche sub-kit. My idea was to have it for clinic cars and for other locals to use it when needed. Bill borrowed mine and later found one of his own. You could help him justify that purchase.
sounds like , borrowing both Billl and the tool would be a good route if he is game . BIll, you out there?
Ill gladly pay for part of this tool and his time!! thanks for input... got to get that thing done..missed the POC laguna race this weekend, but certainly dont want to miss next months PCA Cal speedway event , or the big laguna event here in September!
08-06-2017, 08:03 PM
#9
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I just tried to "break" the nut loose... no way, it made a 25" breaker bar at 1/2" , look like a piece of spaghetti. i was jumpoing on it with a shield incase it broke.. it must have been bent 45 degrees with no budge. (and im 200lbs).
I left Bill a message.. lets see if he is around and wants to give me a hand. otherwise, plan B... drive to shop, crack, go home and dissemble, return to R and R bearing and then repeat.
I left Bill a message.. lets see if he is around and wants to give me a hand. otherwise, plan B... drive to shop, crack, go home and dissemble, return to R and R bearing and then repeat.
08-06-2017, 09:40 PM
#11
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My tool arsenal includes a 3/4-drive adapter that used to have a slide-through "breaker bar". With the bar removed, I can use a larger/longer 5'-long demolition bar (home store tool) to easily walk the axle and crankshaft pieces out. I still use a torque wrench to tighten on both. I'm sure there are other options, just sharing the one that works for me.
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Take a socket and a long bar (like the demolition bar) to a local welding shop and join them together permanently. Never worry about this stuff again. You'll still need a torque wrench or some math skills to get the tightening torque correct.
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Take a socket and a long bar (like the demolition bar) to a local welding shop and join them together permanently. Never worry about this stuff again. You'll still need a torque wrench or some math skills to get the tightening torque correct.
08-07-2017, 12:34 PM
#13
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Thanks!
Now i was thinking last night.. how do you remove that big nut, if you dont have the tire and wheel on the car to counterhold.. better yet, how do you break it free if you have removed all the brakes too! rattle gun? I tried a rattle gun at 400psi and it didnt budge it either.
mk
Now i was thinking last night.. how do you remove that big nut, if you dont have the tire and wheel on the car to counterhold.. better yet, how do you break it free if you have removed all the brakes too! rattle gun? I tried a rattle gun at 400psi and it didnt budge it either.
mk
08-07-2017, 12:59 PM
#14
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Get a bigger rattle gun. Breaking the axle nut free is step one on this job, before any other disassembly.
400 psi? What kind of compressor do you have?
400 psi? What kind of compressor do you have?
08-07-2017, 01:07 PM
#15
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Rattle gun is really tough on the differential. And where did you find 400 PSI or a rattle gun rated for that much pressure?
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Put the wheel(s) back on and put the car back on the ground. For those playing along at home, the nut on the stub axle is the second thing you remove when you attack this project, right after the center cap on the wheel. The center cap isn't an issue on Mark's race car, so the nut moves into first-removed, last-torqued position on the project steps list. A combination of transmission in Park or fifth gear and car on the ground with parking brake set is usually enough. Add an assistant's foot on the brake pedal if the nut is really stubborn. Then a LONG bar stiff enough for the forces needed will walk the nut off like buddah. 1/2"-Drive sockets and breaker bars do not come close to meeting this requirement. There's also a reminder in here somewhere that you really need to use a torque wrench or calculated force when reinstalling the nut. Too loose, and the bearing gets extra clearance and fails quickly. Too tight, and you risk stretching the stub axle and/or distorting the threads in the nut. Plus getting the nut off next time can be a real b!tch.
Reminder: the axle nuts are sacrificial, and get replaced after each use. Especially if you've accidentally tightened them blindly to "that's not going anywhere!" tight.
----
Long ago on a at-the-time interesting car (now very collectible as luck would have it), I was having trouble keeping the stub axle nuts tight. This car had two small single-row ball bearings in the carrier, with a spacer in between. With wider wheels, more offset than original spec, along with sticky tires, rear wheel bearing replacement was a monthly duty during the almost-year-round SoCal race season. I thought I was helping hold things together by over-tightening the nut, but the bearings still came apart with extra clearance. Finally the stretching stub axle gave out as I was over-tightening it (fortunately), leaving me with a non-rollable car and a couple really expensive axle pieces. The only difference between that setup and the 928 is the way the bearings are made as one in the 928 vs. the separate bearings with spacer in the Lotus.
The solution for the Lotus was a bunch of welding and machining of the rear carriers so I could fit tapered roller bearings with new custom better-alloy stub axles. That added almost a pound(!) of unsprung weight to each side with the sleeves, bearings, and the sturdier axles, but I never had to replace a rear carrier bearing set again in half a dozen race seasons following.
-----
Put the wheel(s) back on and put the car back on the ground. For those playing along at home, the nut on the stub axle is the second thing you remove when you attack this project, right after the center cap on the wheel. The center cap isn't an issue on Mark's race car, so the nut moves into first-removed, last-torqued position on the project steps list. A combination of transmission in Park or fifth gear and car on the ground with parking brake set is usually enough. Add an assistant's foot on the brake pedal if the nut is really stubborn. Then a LONG bar stiff enough for the forces needed will walk the nut off like buddah. 1/2"-Drive sockets and breaker bars do not come close to meeting this requirement. There's also a reminder in here somewhere that you really need to use a torque wrench or calculated force when reinstalling the nut. Too loose, and the bearing gets extra clearance and fails quickly. Too tight, and you risk stretching the stub axle and/or distorting the threads in the nut. Plus getting the nut off next time can be a real b!tch.
Reminder: the axle nuts are sacrificial, and get replaced after each use. Especially if you've accidentally tightened them blindly to "that's not going anywhere!" tight.
----
Long ago on a at-the-time interesting car (now very collectible as luck would have it), I was having trouble keeping the stub axle nuts tight. This car had two small single-row ball bearings in the carrier, with a spacer in between. With wider wheels, more offset than original spec, along with sticky tires, rear wheel bearing replacement was a monthly duty during the almost-year-round SoCal race season. I thought I was helping hold things together by over-tightening the nut, but the bearings still came apart with extra clearance. Finally the stretching stub axle gave out as I was over-tightening it (fortunately), leaving me with a non-rollable car and a couple really expensive axle pieces. The only difference between that setup and the 928 is the way the bearings are made as one in the 928 vs. the separate bearings with spacer in the Lotus.
The solution for the Lotus was a bunch of welding and machining of the rear carriers so I could fit tapered roller bearings with new custom better-alloy stub axles. That added almost a pound(!) of unsprung weight to each side with the sleeves, bearings, and the sturdier axles, but I never had to replace a rear carrier bearing set again in half a dozen race seasons following.