i can see only a few bearing numbers... i will check it out. Starting to put it back together now... I installed the pinion shaft and made a special tool to check the bearing pre-load. It came in at .550Kg ... it should be 1.1-1.3Kg so will have to order some shims and check again. Calling out to the stooges for some help here... The current shim is 2mm. Should i get a 1.95, 1.9 or 1.8 to try? They are $60-$70 each! Image Unavailable, Please Login Image Unavailable, Please Login
Does your shim look anything like this: http://www.ebasicpower.com/pc/BOR1013-037-004/ALL3G/Shim.html This: http://www.ebasicpower.com/pc/BOR1308-037-016/ALL3G/Shim.html or this: http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=260307167680&crlp=1_263602_263622&ff4=263602_263622&viewitem=&guid=3a96b65f1240a0aad412a6c2ff8a6a9d&rvr_id=&ua=WXI8&itemid=260307167680
I think the only real way to know is to try them in steps. Maybe someone has some old ones laying around you can borrow and test out before you buy them. The reason I say this is because of my experience with adjusting the valve shims. Even though the shim had a figure of lets say 4.25 printed on it, when you put a micrometer to it the actual measurement differed. I ended up going to different independent shops, as well as different dealers before I FINALLY got the correct shims that mic's up to the specs I needed. So........ My thinking is, why would it be different with the shimming for the preload??? Hate to say it but, I don't think it is. The gearbox is made by ZF, who makes industrial heavy equipment. So maybe if you have access to a shop that deals with fixing bulldozers, landmovers, graders, etcetera, etcetera, you can take your current shim with you and see what they have that could MAYBE be used????
Daniel, What size wheel are you using? When I did this I used the same wheel system you are using at the lockring not the pinion. I welded two old ringnuts to a piece of rollcage tubing. Then I could place shims and use the outer ringnut to torque. I then threaded the wheel into the inside of the ringnut and that was my rig. It was ugly lookin. Preloading bearings IMO you don't have to be super precise if you have experience. I for example do not and have never used a staeger tensiometer to do timing belt tension. I can't tell you how many cars I have done but never had a failure either. The goal of bearing preload is just to take up the axial play so that the pinion rides with no runout against the layshaft. Ferrari like everyone else has a spec. The spec needed is whatever it takes to maintain zero runout and not generate heat in the bearing. So once I made that stooge wheel tool and it sat around my garage for years. Then one day I ran out of tubing for my rollcage. I need just a shortpiece to gusset some NASCAR bars. So I canibalized my tool for the tubing. Ever since I have just done preload by hand just like timing belts. I'm not telling you to do it this unreliable way. I'm just saying you can do it that way. There is no spec for the wheel size so you have to guess and use common sense anyway. You can't make an assumption on the wheel size then try and hit an absolute number based on that assumed wheel size. Also realize a bearing will loose preload with wear since there is nothing to maintain preload in this system. So how important is that preload? Well I just do it by feel and I will take the time to use shims until I get what I want. But I don't loose any sleep over it. The harder job for which I have no tool is the test rig for the pinion gear height which changes when you swap the new "main" pinion bearing. Since i don't have that test rig I did it the hard way which is to install the pinion to torque and prusian blue the pinion against an installed layshaft and shimming by gear patterning. Now that is a pain. But this is the heart of the gearbox and if you want it to run a long time that's what you have to do.
Thanks for the reply. I am using a wheel size of 8". I am reusing the pinion bearing so i guess the loose reading is due to the the bearing wear. In that case i will order a 1.95mm shim and hope for a 0.6-0.8Kg reading... but wont loose any sleep over it. I am not changing the main pinion bearing so i should be ok... but will check gear meshing with the mainshaft to be shure.
Guys, I have severe pitting on the layshaft to differential gear mating surfaces. This has increased over the last 2 years, and particularly worsened as I had the outer bearings changed by a specialist. Could it be that if the gears aren't aligned perfectly (eg. lateral spacing on the shafts due to thrust bearing wear or wrong shims used after replacement) they will be wearing asymetrically and thus generate more heat on a much smaller surface? I may have a solution here. I live pretty clsoe to silverstone in the UK and found a metal workshop who can replicate cut lay/mainshafts from any vehicle. He quoted me GBP1000 per shaft +/- 10%, then a fraction for any additional one thereafter. The bulk onf the cost is measuring and setting up machinery, the rest is wear and materials. I was going to order a set of 2 each for myself, but I realized if we did a buld buy of 10+ we can reduce the cost for everyone. Daniel, would you care to stock a couple of sets? if so I will take mine to him and get a formal quote done. He also does any type of gears etc, including custom cuts. The gears will need lapping then hardening, so it is a bit more complex of a process... Marco
Why not take your 2mm shim and a flat surface plate and sand it thin on wet/dry emery. Then sand until you get the preload you want. Then measure the sanded shim and order a new one accordingly because it is hard to guarantee a perfectly flat sand. Problem solved.
Try and contact Bruce... he set me up with a mainshaft/1st gear set from his parts gearbox. I think he has a LAYSHAFT/DIFF gear set. I think the pitting happens due to gear overload and/or improper oil film thickness... but thats just from reading. i have no first had experience with this problem other than it happened to me. Bruce (plugzit) set me up so i dont need any shafts now. But nice to see there are options out there. Note... the layshaft has a mating gear with the diff so i think you would have to have the diff ring gear and layshaft made by your guy as a set.
Marco, Pitting is an issue in about 20% of the boxes I have taken apart. I do not know the cause but I am careful about gear mating. One of our guys here in the states also had gears made. Making gears and shafts is easily doable. But If 10 could be made it would be so much cheaper. You got a great idea doing a group buy if you could work out the logistics. Steve's grendaded gearbox had perfect shafts by the way. I don't remember seeing a single pit. That would have been the place to see wornout shafts. Seeing such contrast as Steeve's box , I'm almost inclinded to thing the pits can that way from the factory on some boxes or some shafts missed the heat treatment cycle or something.
Well now, that's encouraging! Hey Marco, i'm glad Bruce had the stuff you needed, i'm sure he saved you a LOT of hassle and money! Thanks to Bruce, we'll both be rollin' again soon!!
Not that easy. I made a strong puller and I had to modify it twice because it was not strong enough. It was my first time to pull this F348 shaft, what a surprise. Finally it cames out. Now time to check the gear splines. Debbie Image Unavailable, Please Login Image Unavailable, Please Login
Get the heck outta Dodge! We have a female on here that does her own work to a 348 and she makes her own tools?!?!???
I haven't done that job on a 348 but the 355 is the same design. On the 355 the degree of difficulty can be quite different from one car to the other. The puller is a nice design.
Hi guys, Jaja... very fun Ernie You should read a book from Georgine Clarsen, 'Eat my Dust' Today I took my F348 shaft apart. The nut was lose and playing a bit between the corners of the 'safety hole' where it's punch but not completely free. The some of the inner gear splines are worn out and the same on the shaft. Now what? rebuild or new?... I have to think about it. Then the other option is turn the gear 180 degrees respect the shaft initial position were the splines are fine, put a bunch of loctite, tight the nut and run for some more miles... First, I'm going to check the 'budged' for new/used parts. I also did some quick internet seach and it looks that early gears have diffent ratio and they are very hard to find. PS. Thanks to my friend to let me use his ring nut socket. I don't have this long one in my collection yet. Debbie Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
I say it's up to you. Me, I would get both parts cryogenically treated, then send the shaft and the gear to WPC for their treatment, turn the gear 180° and reuse it. Be sure to tape up the threads for the ring nut, and let WPC know you don't want the threads treated. Why? Because they are silly expensive to buy new.
I had the same gear/shaft rebuilt on my 348 and it lasted about 1000 miles. Yours doesn't look quite as bad, so might be salvageable.
Weld it together. Been done many times and works great if done well. The splines are not going to do it on their own.
I'm afraid to weld the shaft, It could be very dangerous if temp goes up/down and remove the heat treatment.... the hard Loctite is my best option. I mean, if fails the worse thing i could happen is the same situation. but I'm still waiting the price of a used gear. We will see. I'm also getting a new bearing Debbie. Thanks to all for you answers!
Hi, I have been driving my car for two weeks to work. The Loctite on the shaft is doing well. Also, I did the clutch with a new press and resurface the friction plate, new bearing for the shaft, rebuild the throw out bearing and regrease the flywheel. Debbie
Did you use threadlocker or sleeve retainer? I agree that welding is the best solution here but I'm interested to see how it holds up for you.
