Spindles done?

[Michael M.]

What do you guys think of these spindles? They are off my 66. 75,000 miles. Are they salvageable? The caliper shows 1.249 inboard and .749 outboard (+ or- .001). Some of the black is where the bearings were riding above the surface. The hubs are fine, races are still tight in the hub. Thanks for any opinions you can offer.

Mike


pass spindle 1 (2).JPGpass spindle 2.JPGdriver spindle 1.JPGdriver spindle 2.JPG

[Duke W.]

Re: Spindles done?

It's common to see this type of galling wear on the front spindles. One thing you can do is measure the diameter of the unworn portions to determine their as-machined diameter. If it's .750" and 1.250", then nominal wear is only .001".

My recommendation is to polish the wear surfaces with #400-600 wet sandpaper wetted with mineral spirits or paint thinner to knock off any high spots.

They may still look somewhat knarly, but I think they are serviceable.

Use a full synthetic base NGLI #2 EP grease that states suitable for disk brakes.

I also like to dress the washer to get end play in the range of .001-002". I have found this improves steering precision over the OE range of .001-.005", which is due to the thread pitch, hex nut, and choice of two perpendicular cotter pin holes.

My '88 MBZ 190E 2.6 has a pinch nut that can be set and tightened at any clock position, and the end play spec is .0004-.0008"! That may be one reason why the steering (recirculating ball gear just like C2/3 Corvettes) is so precise.

Duke

[Russ S.]

Re: Spindles done?

I agree with Duke. They should be just fine.

[Michael M.]

Re: Spindles done?

It's common to see this type of galling wear on the front spindles. One thing you can do is measure the diameter of the unworn portions to determine their as-machined diameter. If it's .750" and 1.250", then nominal wear is only .001".

My recommendation is to polish the wear surfaces with #400-600 wet sandpaper wetted with mineral spirits or paint thinner to knock off any high spots.

They may still look somewhat knarly, but I think they are serviceable.

Use a full synthetic base NGLI #2 EP grease that states suitable for disk brakes.

I also like to dress the washer to get end play in the range of .001-002". I have found this improves steering precision over the OE range of .001-.005", which is due to the thread pitch, hex nut, and choice of two perpendicular cotter pin holes.

My '88 MBZ 190E 2.6 has a pinch nut that can be set and tightened at any clock position, and the end play spec is .0004-.0008"! That may be one reason why the steering (recirculating ball gear just like C2/3 Corvettes) is so precise.

Duke

Thanks Duke and Russ. I'm a pretty good mechanic, but I'm not sure I have the correct instrument to measure the endplay. Duke, do you measure the endplay with a dial caliper against the rotor or hub or can you measure it with a feeler gauge between the nut and washer? I normally tighten and loosen the nut by hand or with a channel lock several times, as I spin the rotor, to be sure the bearings are seated and the excess grease is forced away from the spindle. Then, I tighten the nut until the rotor starts to bind and hang up and then I back off enough to insert the cotter pin. It's kind of a feel thing and hard to explain. If I have to back off too much I start over until I'm comfortable with it. The only other thing I do is check them for excessive heat after a short drive. It's kind of imprecise but it has worked for me in the past (and no, I didn't tighten these bearings, they came that way) but I'm all for a better way and I like to learn as much as possible. i wouldn't mind learning how to get the endplay to a better spec. The parts themselves aren't that precise so it may not be so easy.

Thank you.

[Timothy B.]

Re: Spindles done?

Michael,

As far as the end play I think the GM book say's tighten the bolt to 12 inlbs then back off one flat. That will get you in spec.

[John H.]

Re: Spindles done?

Michael,

As far as the end play I think the GM book say's tighten the bolt to 12 inlbs then back off one flat. That will get you in spec.

Tim -

It's 12 ft-lbs.

[Duke W.]

Re: Spindles done?

Thanks Duke and Russ. I'm a pretty good mechanic, but I'm not sure I have the correct instrument to measure the endplay. Duke, do you measure the endplay with a dial caliper against the rotor or hub or can you measure it with a feeler gauge between the nut and washer? I normally tighten and loosen the nut by hand or with a channel lock several times, as I spin the rotor, to be sure the bearings are seated and the excess grease is forced away from the spindle. Then, I tighten the nut until the rotor starts to bind and hang up and then I back off enough to insert the cotter pin. It's kind of a feel thing and hard to explain. If I have to back off too much I start over until I'm comfortable with it. The only other thing I do is check them for excessive heat after a short drive. It's kind of imprecise but it has worked for me in the past (and no, I didn't tighten these bearings, they came that way) but I'm all for a better way and I like to learn as much as possible. i wouldn't mind learning how to get the endplay to a better spec. The parts themselves aren't that precise so it may not be so easy.

Thank you.

I think you understand the "feel" of it. You can use a feeler gage or dial indicator to measure end play. It takes a little experience, and making mulitple measurements that are consistent means you probably have it.

Oh, the feel of precision measurements. I love it, and it pays dividends for sensitive drivers.

Once you're done, grab the top and bottom of the tire and wiggle it. You should feel ever-so-slight play.

Duke

[Tom L.]

Re: Spindles done?

A little off topic but I replaced the bearings on my car a while ago and followed the procedure you list. One flat seemed to be too much since I could feel movement in the bearings once I backed off. I felt it when rocking the tire at 12 -6 o'clock and 3 - 9 o'clockThis was without any measuring tools. Thanks for any input!!

[Duke W.]

Re: Spindles done?

After you've "tightened" the nut - 12 lb-ft - but I just usually snug it with a 10-12" crescent wrench and spin the tire a few times, back off the nut until you sense that the preload is gone. Back off enough to insert the cotter pin, but don't spread it. Wiggle the tire at 12/6 o'clock and you should feel play.

Now remove the cotter pin, advance the nut 1/12th turn and install the cotter pin in the alternate perpendicular hole. Feel for play as above. If play can be felt advance another 1/12th turn. Repeat until you cannot feel play, then back off 1/12th turn, and install and spread the cotter pin.

I think most guys end up with too much clearance. Each 1/12th turn of the nut takes up about .004".

I learned how to do this as a teenager working in a gas station. The boss was a good teacher.

Duke