| Author |
Message |
Neville Pugh (Nev_Pugh)
| | Posted on Tuesday, September 04, 2001 - 6:40 am: | |
Wow, Bill ! That's epic, thanks for taking the time :-) |
'75 308 GT4 (Peter)
| | Posted on Monday, September 03, 2001 - 9:32 pm: | |
Very thorough description, thanks!
I find their means of locking down the ring-nuts (striking the thin edge down into the shaft cut-out) quite pitiful. A local industrial supplier carries various types/sizes of ring-nuts. They (and other devices I've noticed lately using ring-nuts as fasteners) use a multi-tab lock-washer behind the nut. When the nut is tightened down, the appropriate tab which clears one of the four cut-outs is bent up into it. A much better way of locking the nut in my opinion. I'll find out if they carry some of the Ferrari's metric sizes and use them in the future. |
Bill Sebestyen (Bill308)
| | Posted on Monday, September 03, 2001 - 7:20 pm: | |
Peter and Neville,
I replaced the rear wheel bearings on my 78 308 GTS a while back. The following is how I did it.
The car was supported on jack stands. I found it necessary to remove the rear hub assembly from the car before disassembly of the bearings and axle, as there is just not enough clearance to swing a big breaker bar under the car, because the lower A-arm is in the way.
Dissassembly
I first removed the calipers, brake line, and brake line, mounting bracket, then the entire hub. Once the hub has been removed from the car, I placed 2-studs in the wheel flange where the wheel bolts engage. I then mounted the assembly in a large bench mounted vise by clamping on the studs to secure it from rotation. Once secured in the vise, I used a punch to round out the locking feature of the ring nut. I had to grind the OD chamfer on the end of the Baum Tools socket because the inner taper of the CV-joint flange prevented engagement of the tool with the ring nut. I actually took more material off the tool than necessary, but this didn�t seem to cause any harm. Using a half-inch ratchet and a pipe over the handle to increase leverage, I removed the ring nut. I was able to remove the CV-joint flange using bolts through three of the CV-joint flange holes to a 3-jaw gear puller with the jaws removed. The center screw of the gear puller bore against of the end of the axle shaft. Only a light force was required to withdraw the CV-joint flange (there was no dust seal fitted to my car--hmm) from the axle. I was then able to drive the axle, outer bearing and spacer from the hub with a soft, dead blow hammer striking a block of wood on the end of the axle. With the axle out of the way, the inner bearing plate was unbolted. The inner bearing could now be tapped out with a punch from the wheel side of the hub, being careful not to strike the internal circlip. I was able to remove one outer bearing from the axle using a 3-jaw gear puller. The jaws of the puller were just barely grabbing the OD of the bearing because there isn�t much clearance between the bearing and the wheel flange. I don�t recommend using a gear puller for this. The other was a little too tight on the axle so I brought the axle bearing assembly to a local garage, which had a press and spit bearing puller.
Optional
I replaced one axle because of corrosion on the shaft. A good used replacement was obtained. After both axles were magafluxed to ensure no cracks, I had them sent out for nitrocarburizing to hopefully increase their fatigue strength. Please note that the Lindure process used, will grow the part dimension up to 0.006 inches per surface, but can be held to less than 0.001 inches per surface upon request. Be sure to mike the shaft before and after because local polishing may be required if the fit is too tight. Screw threads will grow more so have this area masked off if you contemplate doing this. New outer bearings were pressed on by another local shop (don�t forget to replace the oil slinger between the wheel hub and the outer bearing).
Re-assembly
After everything was cleaned up, the axle/bearing assembly driven into place again using a soft dead blow hammer on a block of wood centered on the wheel flange. It might be helpful to gently heat the hub and chill the axle/bearing assembly prior to performing this step. The inner bearing was then drawn most of the way into the hub and over the axle by carefully tightening the six bearing plate nuts. Again, gentle heating of the hub may facilitate installation of the bearing. Final seating of the bearing was accomplished by again clamping the 2-studs in the wheel flange with a bench vise to prevent rotation. The CV-joint, flange was assembled onto the splined axle and the washer and nut added. Using the Baum tool and a half-inch torque wrench, the old axle nut was tightened to the prescribed setting (a lot). I then removed the old axle nut, washer and CV-joint flange to fit a dust seal and reassembled and retorqued the assembly using a new retaining nut. The retaining nut was locked with a punch. After remounting the hub to the car, two of the inner bearing, retaining plate bolts will have to be removed to refit the brake line mounting bracket. These 2-nuts were tightened by feel on the car using a box wrench, as I was unable to get to them with a torque wrench. Bill |
Steve Magnusson (91tr)
| | Posted on Monday, September 03, 2001 - 12:38 pm: | |
Neville -- I didn't mean to imply that you couldn't have a legitimate problem at <50K miles -- just that, IMHO, a 308 Owner needn't put the same priority on following the "recommend service" interval here (as say for timing belts). Even though your miles are lowish, you are still at 2 +/- decades of age so I'd still consider it not unreasonable to refresh the rear of any 308 (including a little lubricant work on the outer A-arm bushings). Interesting comment in that other thread about only restored cars or risky garage queens being available. Eventually, "untouched" service-wise becomes a liability so on a 308 I'd put "having the rear wheel bearings done" on the "+" side of things with a weight like "fresh clutch" -- JMHOs. |
Neville Pugh (Nev_Pugh)
| | Posted on Monday, September 03, 2001 - 7:04 am: | |
The car has done 30,000 miles BTW |
Neville Pugh (Nev_Pugh)
| | Posted on Monday, September 03, 2001 - 7:03 am: | |
Thanks for the feedback people .... definately sounds like it's worth getting some prof. help.
Magoo .... no, I'm not sure it's the bearing, just an (un)educated guess. It only happens whilst going round left hander bends however. And the oil in the gearbox was (alledgedly) replaced by the Ferrari specialist I bought her from 2500 miles ago (service included as part of the sale), but I couldn't tell you what make / type of oil ....
Thanks :-)
Nev |
'75 308 GT4 (Peter)
| | Posted on Friday, August 31, 2001 - 3:09 am: | |
Both of those numbers appear in my SPC (172/79. Yes I know that's a later SPC for my '75 car, but I haven't had a problem yet getting parts for my car by using it).
From the people posting on the FList about this, it sounded like they were dealing with a ~'77 GTS, so I imagine it was the later type of flange (but don't quote me on that). |
Steve Magnusson (91tr)
| | Posted on Thursday, August 30, 2001 - 3:13 pm: | |
Peter -- As my previous message suggested, I let a pro (Tony P.) do the upright/bearing work so I don't know. The '78 SPC (161/78) shows an early flange 104604 and a later flange 111521 so this could be the difference (but I don't know for sure) -- do you have a different PN in your SPC? |
'75 308 GT4 (Peter)
| | Posted on Thursday, August 30, 2001 - 2:52 pm: | |
Steve, there were a few messages on the FList awhile back, that the ring-nut socket had to be machined to match the taper of the drive flange. Just before I bolted-on my drive-shafts, I took a look at that, seemed to me there was enough room around the ring-nut to get a socket on. Did you have any problems like that when you serviced yours? |
Steve Magnusson (91tr)
| | Posted on Thursday, August 30, 2001 - 10:45 am: | |
Neville -- Too much labor cost in that project not to invest in the new parts (bearings & seals) IMHO. There's not much "official" documentation other than the cross-section drawings in the WSM and the exploded SPC drawing (the few sparse words in the WSM just say to replace the rear wheel bearings every 40,000-50,000 kilometers, which is way conservative, but at a mileage of ~50,000 miles or beyond I think this can be done with no regrets on any 308. I did mine at ~90K miles, but it probably should have been done a little sooner.)
I consider myself a fairly serious DIYer, but I think this is a project best done (value-wise) by splitting the work between the DIYer and the professional by taking your rear uprights to a qualified F shop for the actual spindle/bearing/seal R&R (unless you're like Peter, and you like doing �little� things like building a hoist in your garage) -- three special things required for this project: the ring-nut socket, a hefty impact wrench, and a serious (not tabletop) press with the right �donuts� for the presswork. |
magoo (Magoo)
| | Posted on Thursday, August 30, 2001 - 7:27 am: | |
Are you sure it's the bearing? When did you change your gearbox lube last. It could be your limited slip differential clutches causing the noise. When and if you change it be sure you use a gear oil that is limited slip compatible. Mobil 1 synthetic seems to be a good choice. Just a suggestion before you replace the bearing. |
Neville Pugh (Nev_Pugh)
| | Posted on Thursday, August 30, 2001 - 6:37 am: | |
Anyone got a description on how to remove and replace a 308's rear wheel bearing(s) ?
I think mine's on it's way out .... when I've been driving hard (i.e. everything's hot) and I take a sharp left hander I get a low moan from that rear quarter.
Think I might just strip and regrease the bearing first (just to help stretch things a bit further) .... is that easier ?
Thanks ! |
|