924Board.org

[Patrick]

Hi all! I just got through bringing down my a-arms and had my balljoints "reconditioned" w/ some injectable plastic polymer(i thought it worth a try for the equivalent of $18 for both), time will tell... Anyway i`m now down to finally just adjusting the front wheel bearings. From what i`ve read, their all pretty much the same, though i followed a procedure from rob and daves vw site.
1) Snug the spindle nut(clamp type) down while rotating the rotor in the opposite direction till you feel the rotor just starting to bind.
2) Loosen the spindle nut till the rotor is free, then slowly tighten it up till you cant move the Thrust Washer sideways under the nut w/gentle pressure from a big screwdriver blade.
3) Tighten the spindle nut a bit more, then loosen it until you can just move the Thrust Washer sideways w/ the screwdriver blade using gentle pressure.Tighten the spindle nut allen bolt to lock the spindle nut in place.
4) Test for any kind of play w/ your hands, in-out, top-bottom, side to side. There should be ALMOST no play, very little wiggling if any.

When i finished step 3) "able to move Thrust Washer sideways w/gentle pressure from screwdriver. Tighten allen bolt." I checked for rotor play and found a perceptible amount of in-out play and probably a bit more of side to side play. So i decided to incrementally tighten the spindle nut somemore JUST UNTIL there is no rotor play of any kind, but this resulted in not being able to move the Thrust Washer sideways even by lightly prying or twisting w/ the screwdriver blade(worn bearings?).
First of all, my bearings probably have moderate use but are still usable(no obvious metallic sounds like grinding,etc..). So my QUESTIONS:
1) Is my final adjustment acceptable considering that i probably have moderately worn front wheel bearings, or might i be risking OVERTIGHTENING the bearings? I figured that attaching my wheel would obviously magnify any rotor play, which is a no-no.
2) Is it normal for the spindle nut to NOT screw in smoothly the entire time? Because mine screws in smoothly say a half turn, then tightens up the next half turn and so on and so forth(maybe because its a clamping spindle nut, so its not perfectly round?)

And thats it, i`m waiting for any responses so i can finally put my brake pads in and put the wheels on and ENJOY! THANKS! patrick

[Rich H]

I would go with the first option, being able to move the thrust washer. If its too tight your worn-but-useable bearing will very quickly become a totally-shagged-and-useless bearing.

If the bearing is slightly worn then expect a slight bit of movement, don't compensate by over tightening. BTDT shagged a bearing in about 50 miles.

Curious why you bothered to "recondition" the ball joints they are only about $15 each anyway...
_________________
1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec

[Rasta Monsta]

That sounds correct, but remember not to twist the blade of the screwdriver to move the washer. . .hand pressure only.
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Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[gohim]

After properly repacking wheel bearing the tendency is to adjust the bearings too loose, as the grease fills in space, and provides some friction.

The problem is that when running following repacking and adjustment, the grease is forced out of the bearing, and when the bearings are adjusted too loose, then the wheel bearings become too loose, and unsupported, and fail within a few hundred miles (if that much).

I believe that when it comes to wheel bearings, packing them properly with a good quality grease, and tightening them on the tight side of adjustment range with the understanding that they will loosen up.

The sliding thrust washer method of checking the wheel bearing adjustment only works well with practice. The trick to using it properly is to do the spin, tighten to stop, and loosen at leaset 3 times, to make sure that the bearings are properly seated before making the finally adjustment. When making the final adjustment, I tighten and loosen to achieve a thrust washer that can just barely be moved with two hands on the screwdriver to better judge the effort necessary to move the washer, because I set the adjustment on the tight side.

Make sure that you go back in in a couple of weeks to retest your adjustment, you may have set it too loose, which will cause bearing failure.

[!tom]

Most of the above methods will result in a bearing adjustment that is TOO LOOSE.

There should be NO play in the bearings.

A properly adjusted bearing has pre-load on it, which can't exist if there is play.

You're far better off having a bearing tighter than optimal than looser than optimal.

A bearing without pre-load will, during use, have the rollers contact the race while at the bottom of the rotation, then leave the race at the top of the rotation. This is what damages the bearings, because they are not being held in proper alignment throughout their rotation. A bearing with sufficient pre-load has the rollers in continuous contact with the races through all load ranges.

Remember that as you load the bearing, the components (rollers and races) will deform as they take the load. This is why pre-load is necessary -- a bearing with continuous contact un-loaded will no longer have continuous contact while loaded if there is insufficient pre-load. And, a bearing adjusted so you can wobble the wheel doesn't have continuous contact at any time.

Much of the advice on these forums advocates for wheel bearings to be too loose. Snug 'em up and you'll be far better off.

The hub must still be able to turn, but with a properly adusted bearing with a fresh re-pack, you won't get more than a 1/2 turn rotation out of your hub after giving it a good spin.
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78 924 NA
5-lug

[Rasta Monsta]

Uh-oh, we have had this conversation before. What you are saying is contrary to the FSM. . .wheel bearings are not supposed to be preloaded.
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Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[Slam]

Local-ish Porsche guru (944/924) says finger tight plus 1/4 turn. Of course, finger tight can mean anything, depending on whose fingers they are. I tend to err on the side of tightness and haven't had a front wheel bearing failure in over 14 years, FWIW. In that time I have changed them about 3 times just because I felt I wanted to.
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'88 944 Auto - may or may not resurrect

[Mike924]

Hmm - I always thought front wheel bearings on RWD cars needed a tiny amount of clearance/play - i.e. no pre-load. That's for FWD and rears on proper cars.
_________________
1985 Porsche 924 'Lux', Kalahari Beige (my ex)
1993 Porsche 968 Coupe, Midnight Blue, 6 spd

'There is no substitute for a little grease under your fingernails.' - Chrenan, 924board.org

[Mike924]

Edit : Ooops - triple post
_________________
1985 Porsche 924 'Lux', Kalahari Beige (my ex)
1993 Porsche 968 Coupe, Midnight Blue, 6 spd

'There is no substitute for a little grease under your fingernails.' - Chrenan, 924board.org

[Mike924]

Edit : Ooops - triple post. Sorry
_________________
1985 Porsche 924 'Lux', Kalahari Beige (my ex)
1993 Porsche 968 Coupe, Midnight Blue, 6 spd

'There is no substitute for a little grease under your fingernails.' - Chrenan, 924board.org

[Patrick]

THANKS for all the replies! I just did some reading and also found out that generally RWD cars with TAPERED ROLLER BEARINGS do need some perceptible END PLAY, about .001-.005 inch. Also, because the car has not been driven much since the front bearings were regreased, i opted NOT to regrease them. So i suppose i shouldnt worry about some grease initially being forced out of the wheel bearings(and ending up with a loose wheel bearing after some driving) as the grease has already been forced out. I guess i`ll go for Rich h suggestion of not compensating for a slightly worn wheelbearing by tightening excessively, although not as loose as the standard method of thrust washer movement w/a gentle push from the screwdriver. After tightening and backing out the spindle nut several times to seat the bearings well, on the last try i will just try for the LEAST amount of perceptible play(just short of NO perceptible play), using only my hands of course on the rotor. I will then re-check the adjustment after a few runs.

So let me ask you guys that do the standard thrust washer method(LIGHT pressure on the screwdriver), do you get any kind of play w/ both hands manipulating the rotor? Wont the magnified play when the wheel is on mess up any ALIGNMENT values? I plan on having my alignment checked and dont want to encounter aligning problems due to the play.

Oh Rich H- i opted not to buy new balljoints(even if their only$15 each) because; 1) i`m on a REALLY tight budget (the word CHEAP is relative to how much a person earns, depending on his job and which part of the world he practices his job) 2) It`s $30 for both balljoints + shipping and handling to these islands(i could have it shipped to my sister in CA where my mom is visiting and have my mom take it home, but she`s not coming back till end of July- DOWNTIME that i`m avoiding. 3) Its worth trying out this "reconditioned" balljoints for $18 for both, probably wont last, i`ll find out... cheers!

Oh, any replies for my 2nd question about the Spindle nut NOT screwing in smoothly during about 1/2 of EACH full 360 degree turn it makes? Is this normal? THANKS AGAIN! patrick

[Rich H]

Fair enough, I hadn't considered the difficulty of actually getting the ball joints!

The nut is not 100% round because of the split, I wouldn't worry about it. Just go easy on the allen bolt as they are very soft metal and round easily.

Just keep an eye on the bearings and check them after a few drives, then again after a few '00 miles. Will be fine.
_________________
1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec

[Patrick]

Okay, thanks Rich h!