| Author |
Message |
William Hubbell (Countachxx)
| | Posted on Wednesday, February 28, 2001 - 12:08 pm: | |
Apart from the 308 & its siblings, Do any other Ferraris have weak axles ? |
Craig Dewey (Craigfl)
| | Posted on Wednesday, February 28, 2001 - 12:01 pm: | |
I'm glad you came with your facts about the axles. My only further comments are that most problems that I have heard about are with cars in racing/high speed situations. Anyone racing their car or competing in any other speed events owe it to themselves and the spectators to have their stub axles checked and/or replaced. Later type tire improvements will also tax the strength of stub axles when used in high performance situations. Those of us who drive their cars on the street in a "regular" way shouldn't need to worry about fatigue of these axles -- which I suspect is why Ferrari refused to replace your parts. (Obviously it is questionable because of the high performance nature of the vehicle.) |
Jhann2 (Jhann2)
| | Posted on Wednesday, February 28, 2001 - 11:35 am: | |
I have considerable information regarding failure of GT-4, 308 and 328 rear stub axles. 348 axles and later are of a different design. As a professional Engineer I became involved after I broke a left rear axle at speed on turn 1 of the Mosport track in my 1989 328GTS. Laboratory analysis disclosed a fatigue failure at the junction of the axle to the flange. Ferrari refused to replace the part (as warrantee) claiming that I had used slicks. In fact, the tires I was using were Goodrich R-1. We also discovered that the O.E. axles were not heat treated (Rc around 20). As a result my company Stainless Steel Brakes Corp. produced 6 experimental axles from Corvette forgings using proper radii at the flange and case hardening in the transition area and up the flange. Two axles were installed on my car and will never break but were found to be too expensive for small production runs. Ferrari has since corrected the radius problem but still never heat treated the material. In my judgement track tires will shorten axle life as stated by Craig but eventually all the early axles will tend to break due to fatigue. A periodic check of high mileage axles would be prudent. As of this date we have information about axle breakage all over the world including Australia, Japan and the US. |
Craig Dewey (Craigfl)
| | Posted on Saturday, February 24, 2001 - 7:55 pm: | |
William...
That could be true but as an engineer, I was taught that "normal" loads on parts should theoretically never cause fatigue failures- which is essentially what you are talking about. Only when the load exceeds this design load should you experience this kind of cracking and failure(It can be cumulative). I would suspect the factory used some pretty severe loading when designing these axles since they know the type of usage their cars receive. I am also sure that they do not account for the loads that are experienced during racing street cars, especially with wide sticky tires. |
William Hubbell (Countachxx)
| | Posted on Saturday, February 24, 2001 - 8:54 am: | |
I am sure that running hard on the track & or throwing on slicks or very sticky modern tires will only make the failure come sooner. However to be safe, realizing that the last 328 was built like 11 years ago, I would suggest that every1 check their axles cus I am sure that 11 or 15 or 20 years of normal road driving also takes its toll |
Craig Dewey (Craigfl)
| | Posted on Saturday, February 24, 2001 - 7:03 am: | |
Ifrgt... I am only somewhat concerned with mine. I would suspect that a problem will not exist until excess cornering loads are put on the stub axles. If your car is used for daily transportation and not "events", I would think the life would be long. Cars that use special tires at ferrari events can generate cornering forces many times that of "normal" loads. I almost bought a 328 that was extensivly used for events... I'm glad it didn't happen. |
Herbert E. Gault (Irfgt)
| | Posted on Saturday, February 24, 2001 - 6:36 am: | |
Could this be a problem on street cars? Has anyone had such a failure on a daily driver? This is a little concearning to me as I do not like the idea of being passed by my own wheels. My belief is that this type of failure should not be occuring unless the car is being subjected to several times it's ability. |
William Hubbell (Countachxx)
| | Posted on Thursday, February 22, 2001 - 5:55 am: | |
in order to propely inspect the stub axle you have to remove it & have it magnafluxed cus the cracks may be too small to see or they may start inside |
rocco solmito (Rock)
| | Posted on Wednesday, February 21, 2001 - 8:13 pm: | |
It also happens on series three 328's, with the use of slicks. With street tires the car will
slide,reducing the chance of breakage.
The rear hubs have to be dismantled in order too
inspect the axle,while in there change the bearings |
William Hubbell (Countachxx)
| | Posted on Wednesday, February 21, 2001 - 8:05 pm: | |
http://www.performancess.com/strange.html
Try the address above. It seems that Strange also sells parts through many distributors. I'll ask my mechanic how & where he bought my stub axles from Strange Engineering |
William Hubbell (Countachxx)
| | Posted on Wednesday, February 21, 2001 - 7:23 pm: | |
Strange engineering may have a web site, I'll ask my mechanic for their #. I think they advertise in Hot Rod magazine & maybe u can reach them through 1-800-555-1212 & ask for them.
to be more specific about this cracking problem, the stub axle looks like this capital T , on its side when installed in the car.
the problem with the factory axle is that where the horizontal & vertical surfaces meet it is shaped like this an L, all straight lines, it should have much more of a radius so that where the stock axles crack , the Strange axle has a lot more metal there & less of a 90 degree angle thus it is able to withstand higher G forces without craking. Last time I checked they were about $1,000 for 2 axles, I dont think the instalation is particulary labor intensive as although u Might have to remove the suspension upright to access it better. It would b a good time to redo the bearings & replace worn axle boots as well |
'75 308 GT4 (Peter)
| | Posted on Wednesday, February 21, 2001 - 6:58 pm: | |
More importantly, how do we reach Strange Engineering? Web site, email, phone, etc...? |
Rob Lay (Rob328gts)
| | Posted on Wednesday, February 21, 2001 - 5:14 pm: | |
About how much do Strange stub axles cost to buy and install?
Thanks |
William Hubbell (Countachxx)
| | Posted on Wednesday, February 21, 2001 - 5:01 pm: | |
Rob, I would suggest u ask your mechanic or find a 308 stub axle & compare the 2. If u have or about to get some super sticky tires upgrade the axles beforehand |
Rob Lay (Rob328gts)
| | Posted on Wednesday, February 21, 2001 - 12:41 pm: | |
Thanks very much for the FYI. I assume that this applies to 328's as well. |
William Hubbell (Countachxx)
| | Posted on Wednesday, February 21, 2001 - 12:29 pm: | |
I drove my 308 quite a lot at Lime Rock & Watkins Glen & other NE tracks. Ive had 2 stub axles snap on me, once at Laguna Seca CA when the car was being towed off the track when the engine mysteriously just stopped
& again, much more dramatically at Lime Rock in the corner before the downhill, I was doing about 70 when I feel the tail slide, I think to myself "WTF, I never slide here" Then I see a tire flying about 100 ft in the air over my head & the corner worker doing the Macarena & I realized whose tire that was sailing so gracefully over head.
Since then I have switched to Strange Engineering stub axles.
The factory design has a too abrupt radius which causes it to fail under repeated high G loading, so if u have a 308 & run her hard I would HIGHLY advise u swap your stub axles or at least have the current ones magnafluxed to insure they r not cracked. Good Luck & be safe |