Changing Front Wheel Bearings On an 80 308

Back in the day of ball bearings we were told that proper adjustment was critical. Tapered bearings lube better and have greater surface area and we were always told they were not as sensitive to adjustment or lubricant for that matter. At the beginning of my career I was shown by a few old timers how to do it and I have to confess I have never used a torque wrench to do it nor for that matter have I ever read that chapter in any Ferrari manual. What I do know and I can convey in the written word is that in the perfect world they will have a little preload to keep them from skating or sliding and flat spotting the rollers. Having said that in a wheel bearing application I have never seen that happen and I have run across all manner of ill adjusted bearings. I do subscribe to the notion of overtightening them to start with. I was always told that this squeezed the grease out from between the rollers and races. In the old days good wheel bearing grease was very thick and so this was a real concern. I would say that if you have a slight amount of preload on the bearings and feel no drag attributable to that it will be just fine. The wheel bearings on the front of a rear engine Ferrari are designed to carry several times more weight than they do. And that does not take into consideration the miracle lubricants we are using now.

As an example how good our modern lubricants are we have gone back to the evil ball bearings and they last a good long time. Still doesn't make them any good, just tolerable.

The pictures of your steaking job on the nuts will work fine. All that is required is to deform enough metal into the groove to prevent the nut from rotating off and there is really no force to speak of trying to make it turn.


As far as the brake line fittings go one of the worst inventions ever is the flare nut wrench. It makes it possible to overtighten the bejesus out of a fitting. If it cannot be removed without a flare nut wrench (assuming no rust) it was over tightened to start with. If it requires more force than available with a good standard open end wrench the line or fitting is in some way damaged and should be replaced anyway. Chances are that it was damaged by a prior assembly with a flare nut wrench.

 

Brian,

Thanks so much for your input. I just got off the phone from my brohter-in-law who has been a drag racer for 30+ years. He really has been freaking me out as he says the top fuel cars have up to 1/8" of free play and said if I tightened it up too much that I could melt my spindle, spin the outer or inner races etc. I was so concerned that I backed my wife's car out of the garage tonight and jacked up the drivers side just to check for free play. I could feel the smallest amount of free play after about 10-15 miles of driving yesterday. I called him back to tell him this and he was concerned that as the spindle and bearings when heated up would expand and remove any free play and end up freezing the bearings and or spindle!@#$%@#?

As I said I turned the nut until I could feel the smallest amount of free play and then turned it tighter the smallest amount until the free play was gone (maybe 1 or 2 minutes of a clock), then set the nut. The reason I did this was because I was told that they will loosen up after driving and of course like the dummy I am, I figured hell, I will tighten them a little so that when they loosen up they will be just right like "The Three Bears"! I also figured that since the inner bearings just slide on the spindle that a small amount of preload would lock them in so to speak so that the inner bearing could not rotate on the shaft as it would be pushed up against the shoulder it rides against. I see now that the inner races are held in place by the load of the car.

I love my car like a family member and shudder at he thought that I would melt a spindle and of course end up in a ditch or worse. Your explanation gives me some comfort but I am still concerned about what will happen as they heat up and expand. I do believe that the free play I felt was what the WSM suggested even though it was after the car is driven. I hope I am not wrong......

Thanks for all your advice,

Rob

 

The races will expand more than the bearings so heat will give them more play, not less. Slight play is ok. Slight preload is ok. Shoot for somewhere in the middle. If it was as critical as your brother in law says, with the UAW being what it is cars would be littering the road with wheels falling off.

 

Okay Robert. Im 47, soon to be 48. Maybe for my birthday I will be able to go drive MY FERRARI? But, anyway, back in the day...

I owned this cool little MGB/GT, and after two years of hard driving finally succeeded in wearing out the clutch. You know you have to pull the motor out of those to do the job. But after growing up on crude American cars, I always loved and was amazed at the quality of engineering on that little bundle of joy. So there it is with its poor little heart ripped out, sitting on the garage floor in a puddle of oil and coolant, and the car with its heartless engine compartment. So before I could put the car back together I had to crawl in there to change over the throwout bearing. Yuck the filth. But I got my butt down in there. So this one night some goofy friend I knew back then gave me some of that funny weed.

So picture this 18 year old kid, hair all frizzed and greasy and clothes all oily and dirty, sitting in the engine compartment of a MGB playing with the clutch mechanism, at 4 O clock in the morning! I think I was out there like that for hours just amazed at that stupid lever. My point is that by the time I had the car back together I was really freaked out about every little thing. Did I do this right, did I do that right. This crap can wake a guy up in a cold sweat in the middle of the night if you dont get a handle on it. There is an old saying with airplanes, that if it looks right, its probably right. Same goes for cars. No offence to your racer friend, but everybody in the world has something they dont know. Could be the greatest racer in the world, but he, nor I, nor you, nor anyone here, knows it all. Just keep this knowledge. Old worn in bearings that are working well now, will continue to do so almost indefinetly. New bearings will always be an unknown until they have "time" on them. Don't freak out my friend, just relax and keep an eye on everything as you go. Most times everything will offer a warning of impending doom if your alert and paying attention. Unless its those lead plugs in the crankshaft galleys of a 300 HP Continental airplane engine. Glad to see Enzo thought to install screw in plugs.

 

Breda is an Italian company that makes trains and heavy equipment.
Washington DC Metro trains used to be made by Breda. Their logo is actually very similar to Ferrari.
I would trust a Breda bearing 100%

Gianluca

 

Thanks, didn't know that.

 

Coming in a bit late, but anyway ...

1. Re tightening torque, 18ft-lb is pretty light. It's 18 lbs on the end of a 1- foot socket bar, or 2 house-bricks. 10ft-lb is about 1 brick, so that's pretty loose! Is that what you're applying?

2. Packing bearings by hand is one of life's real pleasures - the feel of all that grease oozing between the fingers will stay with you a lifetime

3. I'd say you heaved way too hard on the rigid brake line, hence the leak. The end fittings can distort pretty easily, and will never ever seal properly again. You need to treat the solid lines with care, and always use fingers to start the threaded fittings back into their holes, not a wrench. They can be damn easy to x-thread due to the tube's stiffness. I would have just taken the old one down to a brake shop & get them to bend-up a replacement. Common exercise.

4. FYI you can seperate the top balljoint from the upright by using 2 hammers after undoing the nut. If space permits, place one hammer against one side of the casting where the (tapered) bolt goes through, abd give a hefty whack to the opposite side of the casting. You need a small amount of vertical load acting to pull the components apart (gravity, small jack, etc), and with practise you can usually pop the joint in 1 or 2 goes. Basically you are just elastically deforming the bolt-hole just enough to allow the tapered-fit to release.

5. I wouldn't pack the inter-race space inside the hub with grease, just in the around the brgs themselves. First, the grease is usually HTB non-melt, so it shouldn't flow, but if it does it may go places you don't want it (brakes).

6. Finally, re pre-load, I'd just do them up tightish initially just to seat them, spin the wheels a little, then back right off and re-spin. Finally torque to spec or until no free-play. Drive the car for a few days/week, then recheck for any play. If suddenly you've got lots then retorque. Chances are you wont.

HTH

 

That makes me feel better since I probably over tightened them!!

 

I'm inclined to agree that it's just as easy to open up the brake lines... besides, isn't it about time for a complete flush of the brake fluid anyways?

But there's no need to go through the "pull like Hercules" routine. Pop off the little flat spring clip that secures the hose to the bracket, and then the hose and its female fitting come out the bracket - unlike the S-line, the hose is flexible.

 

I didn't see this little tip in this thread, though maybe I missed it. Installing new races is easier if you pop them in the freezer for a few minutes before installing them in the hub PB : )

 

Holy Thread Revive Batman!!!

 

Looks like Eric either just woke up from a very long, deep, Rip VanWinkle-esq sleep, or he's been trolling the archives looking for something to comment on and found one of the longest dorment threads possible to bring back to life. LOL

And the oddest part is that when this happens there is usually an opening line like "gee, I was searching for information on xxxxx and came across this thread...." But here, he just launches into commenting on what someone wrote over 5 years ago. Nicely done, Eric!!!!!

 

Robertgarven sweats the details like no one else.

Good also to see the wisdom of Rifledriver, and even HE didn't know of that alternate Italian bearing maker.

Good times.

 

A bit less odd if you know that there's a link to this thread in the DIY sticky right at the top of the 308 sub forum.... So no searching, no trolling, no archive mining, this thread was right at the top begging for an update

I wouldn't be surprised if this thread comes back to life every five years or so until there is really truly absolutely nothing more to say about 308 front wheel bearing replacement. And that might not even a bad thing - all else being the same, we might be better served by one DIY thread than the same information scattered across a half-dozen threads.

 

Dear Friends,

My memory is going so good thing every once and a while someone post to an old thread so I can remember how to do it by reading the thread again! HA.. I just checked my bearings and almost no play, so I think I did OK! Its been so long I forgot to worry about the wheels falling off!



Rob

 

Hate to say I told you so....OK maybe I don't hate to say it......Told you so!!

 

I worry about my wheels falling off CONSTANTLY!!!

Which is rather odd because never in my life have I had one fall off.

I DID have a 20' sailboat I was towing pass me on the highway, but then on the next part of the spin my Pontiac Firebird was BACK in the lead!!!

 

Reminds me of a story my Dad tells from his youth. Was riding with an uncle towing a trailer. He looked over and there was a tire and wheel heading by them at a high rate of speed. His uncle said, "hmm I wonder who lost a wheel" just before his trailer leaned to one side and ground to a halt!

 

Hello everyone, re-reviving this thread with a couple questions, as I'm about to do the front wheel bearings myself. First of all, I really appreciate all the effort that went into this thread.

From the 308 GT4 workshop manual, page F8 (I have a GTS but that section doesn't exist in the copy of the QV workshop manual I have), it says to "introduce in advance gr. 120 of AGIP F1 33 FD grease in the space between the two bearings; grease should be spread on the hub inner surface."

Is the 120 gram figure important, or is there a simpler rule of thumb, like just pump the hub full between the bearings?

Secondly, it describes using a dial indicator to check for axial play after torquing 2.5kgm / loosen / 1.5 kgm (18 and 11 ft-lbs). I quote, "the resulting axial play should be as near as possible to 0.06mm, not less." However, most of the advice I've seen here seems to suggest shooting for zero play, plus no or a tiny bit of preload, rather than having play from the start. Also, my front bearings right now appear to have never been touched from the factory and have ZERO play (repacking because sticking brakes liquified my grease, not because of wear). If anything they still have a tad of preload. Any thoughts on the 0.06mm play figure from the workshop manual?

 

LOLOL!

Good to revisit an old thread now and then, for pearls of wisdon like THIS!

Roll on...

 

Indeed! I just finished the job, and kept that advice in mind. The 120 gram figure was either another example of a Ferrari doc giving a grossly inaccurate number, or synthetic grease weighs much less now... I just filled the inner hub about to the level of the bearing race diameter. As for preload, the prescribed 0.06mm of play corresponds approximately to "finger snug," about 1/6 of a turn below 11ft-lbs. I went to "finger tight" and called it good.