Hey Mel that picture of the tool in the last photo looks just like a hub bearing removal tool. I have a couple of those already. Can you tell me the size? Mahalo!
exact one of these tools mel showed here you need. I will look later in my toolbox what sizes they are thanks for the diff picture. could be it is broken because of the bad alignment? I´m no engineering to know how to calculate such load. but when the alignment is not correct the load to this diff-case is not as it has to be. may be others here have more knowledge and can tell us why those diffs mostly break at this same location? I wonder because on this part of the diff there is nearly no load on, except the bias of the limited slip diff
Allowing the F pimp to work on my car again?? I'd rather slit my wrists. The last time I let one of those knuckle-heads touch my car, it almost blew up!
Qwaz... When looking at your pics in post 12, I see the result as circled in the chart. This would seem to infer a correct backlash and therefore a pinion in the correct position (in/out, fore/aft, front/back) relative to the crown. This is confirmed by your measured .005 value. The diff may needs to shim left/right rather than the pinion fore/aft. What exactly are you trying to change? There has been so much discussion, perhaps I am missing your key concern. In post 26, you had said: ___________________ Orignal installed shims were: 2.7mm left and 1.7mm right. - (perfect preload but gears bind) Current installed shims are: 3.2mm left and 2.2mm right Current backlash is .003" or .07mm ___________________ Once the preload is correct with a given total amount of shim (2.7+1.7=4.4mm), as I understand it, that total of 4.4 should remain unchanged as the diff is shimmed left/right. Mathematically, 3.2+2.2=5.4, when it should have remained at 4.4.... no? When you say, “perfect preload but gears bind” it sounds to me like a left/right diff adjustment (move the crown away from the pinion) rather than an in/out pinion adjustment. If the preload is right, the 4.4 total amount of shim is correct. Perhaps I’m missing something… but it is still preferable to re-hash the issue than tear into the case in error! For what its worth - it seems to me a diff shim issue rather than a pinion height issue. Rgds, Vincenzo Image Unavailable, Please Login Image Unavailable, Please Login
This does look a bit scary. Iterative adjustments with a chunk of work between iterations. Something to be proud of when done. Hopefully the tranquil Maui setting will help keep the hobby in perspective. With regard to figure 43 of the WSM - What is wrong in those figures where it says, "incorrect"? Looks like the gears are lines up, and the wear is well centered, or not terribly off.
This may help- it seems to me that #1 is your solution: 1) With no change in backlash, moving pinion further from ring gear moves drive pattern toward heel and top of tooth and moves coast pattern toward toe and top of tooth. 2) With no change in backlash, moving pinion closer to ring gear moves drive pattern toward toe and bottom of tooth. 3) With no change in pinion shim thickness, an increase in backlash moves ring gear further from pinion. Drive pattern moves toward heel and top of tooth, and coast pattern moves toward heel and top of tooth. 4) With no change in pinion shim thickness, a decrease in backlash moves ring gear closer to pinion gear. Drive pattern moves toward toe and bottom of tooth, and coast pattern moves toward toe and bottom of tooth. Rgds, Vincenzo
the tools for the 2 nuts: the diameter for the pinion shaft is around 57 mm, for the other shaft around 43 mm ( left thread ). I made such tools by myself. could you please also put a picture in here with the pattern on the pinion before you start with the "big job"? may be you don´t have to do this all. sorry please vincenzo, but my english is not so good that I understand all the particular words and the translator gives no right answer. what please is: ring gear heel and top of tooth toe coast pattern I think I know what those mean but want to make sure. 2dinos: right, not terrible off, but not ok Image Unavailable, Please Login
As I am using the terms... Ring gear or crown gear - the gear that contacts the pinion Heel - the portion of the crown gear which is on the large diameter (outside) side of the crown Toe - the portion of the crown gear which is on the small diameter (inside) side of the crown Top of tooth - literally at the top, rather than the root (bottom) of the gear face Coast pattern - the contact pattern on the side of the crown gear's tooth which contacts the pinion when the car is coasting rather than under power. Rgds, Vincenzo
qwaz... The enclosure appears to back up your intent to move the pinion. In my post#80, I interpreted their use of 'shim' to mean a diff shim rather than a pinion shim - after more research it seems an incorrect interpretation. Hope this helps... ...apologies for any confusion Rgds, Vincenzo Image Unavailable, Please Login
Hey guys, thanks for all the input. I am going to put it all back together one more time with a few more changes. I was looking at all my pics and there was one where the drive side appeared a lot more centered than the others. So I am going to shoot for that again. If I remember right, this was with way too much backlash. That would make sense though. Moving the crown gear away from the pinion will cause the same pattern change (moves drive closer to heel and coast closer to toe) as moving the pinion away from the crown gear except it will increase backlash. So this is probably all moot but I have nothing else to lose. Image Unavailable, Please Login
good idea scott could you please put in here a picture of the pinion with yellow color to see how the pattern looks there thx very much vincenzo for the explaining and also thx for the nice pictures with the pattern. that will help scott a lot - and also others
No need for pics Romano. It didn't work. I get the same pattern no matter how hard I try to change it. The only way to make it line up heel to toe is to move the crown away from the ring gear. That moves the pattern too far to the face and too much backlash. The only solution I can see (or anyone who knows) is to move the pinion towards the front of the car. It will move the pattern to the center and allow me to keep backlash within spec. I just got the CAD file from Robert Hayden to cut the right side cover shims. Robert still believes that something must have stretched during the diff explosion. After thinking about where I'm at, I have a theory: I was doing about 80MPH when the diff went. If you think about the rotational direction and gear pattern of the crown and pinion during forward movement, I think that the sudden "stopping" of the diff would have put significant stress on the pinion and actually pulled it towards the back of the car. I'm lucky the C&P didn't shatter as I have seen others here do. Maybe I should just take a 5lb sledge and just whack the pinion towards the front....just kidding. Image Unavailable, Please Login Image Unavailable, Please Login
if there is soemthing stretched it is important then to change this. but it is nearly impossible that the pinionshaft stretched ??? and also the power of blocking the diff would push the pinion to the front, not to the rear. very strange the whole thing. I still believe that Ferrari had not fitted correctly or when you dismantle all now you will see some very bad thing - broken gearbox case inside? I don´t hope and I don´t wish this to you
Romano, It isn't the pinion I was referring to. I am speculating here but if something did change it would have had to be a bearing, or a shim. Putting that much pressure on those can change it a small amount. That's all we're looking at here is about .003". I have to disagree with you on the direction it would have moved. If you consider the gear mesh and direction of rotation, if the diff suddenly stopped, the pinion would have tried to "crawl" up the crown gear pulling it towards the rear of the car. Of course, just a theory. I may be completely full of poo poo. I'm in the gearbox now and I don't expect to find anything wrong. The car drove and shifted no problem even after the diff puked. I haven't actually pulled the lay and main shafts out yet but everything else is removed and all looks perfect. Image Unavailable, Please Login
Would anyone be willing to give me some pointers on disassembly? I've read the WSM and reviewed the exploded diagram but the WSM just says to take it apart. It only gives reassembly steps.
you may loosen the 2 nuts on the shafts in the front. best to loose them is to put in 2 gears so that the shafts may not turn. and remember: the pinion shaft has right thread, the other shaft left thread remove the little screw ( 3 mm allen screw ) on top for the shaft for the reverse and take this shaft out. the gear may fall down, but that is not a problem. the pinion shaft is very hard to get out because the center bearing is pressed on the shaft. I always take a 2 kg hammer and a piece of aluminum. sometimes it just works, sometimes it takes long time. so when you do this 1st time you may think that there is something wrong, but this is normal. it takes sometimes much power to get this shaft out. when you remove the transmitting disk for the puls generator there is a small ball. be carefull not to lose it. I see that all the switching forks are out. so now only those 2 nuts and the screw to remove. good luck and don´t give up
Great chart. I'm feeling nervous just reading this. My anxiety would be to have to pull it all apart to sort should there be a prob. Question 1: Is it possible or realistic to get the high percentage of tooth contact which I guess is what is strived for here or could be considerd ideal?? Question 2: Is there any way to test before buttoning it all back up?? Can it be spun with a drill to listen for whine or detect other prob's? Mountains of respect for you taking such great care to assemble correctly.
mel you are great ! ! ! but I wonder: on your shaft there is a gear for the speed, on mine a "piece of metal" for inductiv sensor. could it be that your picture is from a BB 512? that would make sence because there the sensor is outside and driven by those gears.
Good morning friends, all I ever post is of my 512TR ... If you had a close look, you must see that in the top foto, the ball will not fit pefectly... mistake of the carver of my new pinion achse... The pinion had to be taken out again, sent back to the maker to be 0.8 mm deeper ... my gb builder takes no faults, it should all be perfect (very happy with that) It cost me more waiting time ...
that is strange now mel this helical gear for the speed is only on the 356 BB ( 106339 and 107015 ) and the 512 BB ( 109477 ), since the BB512i up to the 512M it is all the same ( 116352 ). please have a look in the parts catalog so this gear on your gearbox is not original as I see it???
Here's the one from mine. Romano, I'm curious. I know that hall effect technology wasn't used in most production vehicles until the late 80's. So was it previously a gear driven cable? If Mel's is a 512TR how is that possible and why would anyone do that? I looked at the lay shaft pic for every car from 512bb to 512m and Romano is right. Solve the mystery Mel... Image Unavailable, Please Login
