Clutch shaft, bearing guide tube and top gear disaster

Try Bill at GT Car parts, ([email protected]). I got parts from them. They are really nice. Super fast shipping and they will give you real down to earth prices that won't make you spit out explatives.

They are great!!

Joseph M.

 

I would be more inclined to get three good matched / used gears rather than replace just 1. However, let's see what others feel about this.

 

THINGS TO WATCH OUT FOR:
(Just got thru send it in response to your eMAIL, then saw that you'd started a thread)...

Ferrari changed from 'shaved' (machined) gears to 'ground' gears, supposedly in early '83. (SB 30-3 dated 4/20/83). However, the ground gears were to be retrofitted as mating sets into earlier trannys when/if the supply of shaved gears ran out.

You can only mate ground gears with ground gears, or shaved gears w/shaved gears, ie: can't mix types. So you need to figure out which type of gear you have & make sure the used gear is the same type. This isn't as bad as it sounds as they changed gear p/ns. They also started scribing a 'G' near the tranny s/n when they started shipping with the newer ground gears. But probably not when just changing a pair of gears in an older tranny.

The SB says "It is possible to replace an individual gear by fitting an identical (ie same type) gear(This is justified only by the cost saving of the repair, but is not reccommended since it may bring excessive noise)." IMHO, this is a bit of CYA in case things turn out noisey. I personally know of a couple of cases where just 1 transfer gear was replaced with a used one with satisfactory results. Of course, The most conservative approach will always be to get a used set of the 3 transfer gears from the same transfer case.

The gears should have p/ns on them so you can tell which gear type you have. The shaved transfer gear p/ns are:

Shaved gear p/ns:
Driving gear(from clutch): 105542 w/clutch shaft # 109400
Interim Gear: 105543
Driven Gear(tranny main shaft): 105544

Ground gear p/ns:
Driving gear(from clutch): 119721 w/clutch shaft # 109400
superceded by 125531 w/shaft 125532/ring nut 125534 (think this was the stronger shaft used in the 328).
Interim Gear: 119722
Driven Gear(tranny main shaft): 119723

You also want to make sure that the used clutch shaft is the right one for the gear & the new ring nut are the right ones for the clutch shaft. I don't think the guide tube changed, but Ideally the gear, shaft, & guide tube would come from the same tranny. That way the gear & shaft splines will have worn in against each other & will have the best possible fit.

It's likely that there is going to be some unavoidable gear noise as the replacement gear will have a slightly different wear pattern than the old gears. I haven't done it, but I know that it's possible to 'lap' gears against each other with a very fine abrasive(NOT valve lapping compound - it's way too course) to reduce gear noise. But lapping takes several days & some special setting up, followed by a lot of cleanup. I suspect the bearings would get the compound in them & have to be replaced. So, I don't think you want to get into lapping given your time schedule. Also, your the replacement may not be particularly noisey. Best to try it & then if it's too noisey I'll help you with the lapping procedure.

Just saw your post saying your gears are marked "0144". I don't know, possibly it identifies them as a set. SWAG: What's your tranny & engine S/Ns? Would one of them be '0144'?

 

Chris,

One of my core motors had suffered this same failure .. . the bearing guide tube should positively load the bearing race on the shoulder in the bellhousing . .. this one had about .005" clearance meaning the outer race could actually float back and forth in the bellhousing. Also, make sure the outer race is not loose in the belllhousing . . . it might of beat up the bore of the bellhousing if it was that loose . .. there's some risky fixes if it is . .. right thing to do is bore it out and sleeve it though . .. but there's always green loctite if you like living dangerously.

I made a shim for the end float problem and have 300+ hrs on the setup with the original bearings and gears out of my car in this different bell housing.

Sean

 

Didn't Nick Forza have a custom made gear set?

 

Yes, they are straight cut for easy changing at/for the track as i recall. Reading this thread i wanna either laugh or cry looking at those prices.. and thinking of the many hours it will take to fix it on a 308.

 

like these . .. a bit noisey for the street though.
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Chris,

Were there indications things were this bad before you got in there? Chips on the drain plugs? I've been monitoring mine since rebuild . . . I wipe them down with a clean paper towel and take a photo every 20-40 hrs so I have a relative indication of what "normal" build up is so hopefully I can prevent a catastrophic failure.

How many miles did you drive with the oil leak? Did the oil leak start all of a sudden or was it very small for a long time?

Thanks,

Sean

 

Chris,

Do you think that the transfer case ran out of fluid? I have always thought that this could not happen since the oil would be able to flow back from the transaxle to the transfer case as long as the oil level was ok in the transaxle. Any thoughts appreciated.
Thanks.

 

how about magnet condition . .. did you look at them before this point? especially the one in the drop gear housing . .. what do they look like now?


Sean

 

I'd also check for proper clearnace/load on the bearing race I'm referring to via the tube/seal retainer in my other post . .. it's critical that the tube/retainer piece is pushed up against the race IMO and I saw it NOT that way on the messed up housing which was not as damaged as yours sounds. I can see how this area of the casting can flex and permanently distort a few thou especially if the nut has backed off and it's getting hammered back and forth.

 

Why not take the opportunity to write a "Clutch replacement manual" with pictures?
It would help others (like me) a LOT while preventing some expensive mistakes, and I've never seen one before.

 

Hello,

We have these kits available, identical to the Michelotto Gr.4 cars.
Advantage is you can also change ratios. We have kits spanning from 190Km/h top speed at 8000 RPM using the normal 308 gearbox to 240Km/h in the same conditions.
To change ratios you only need to change 1 center gear and the lower gear.
The kit includes the cover, clutch shaft and on set of cascade gears of your choice.
Let me know if you are interested.
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Chris,
I'm sure you're ahead of me on this: Check the fit of the outer race OD in the bell housing. It should be very snug, almost a press fit (ideally you'd have to heat up the bell housing to 150F or so before it'd move). However, given your description of the failure, my suspicion is the bearing was sliding around a lot & most likely has worn the hole oversize.

If it's worn enough so that the outer race slips in & out quite freely(ie: hole is 5 thou or more oversize), then make an emergency trip to your machinist friend to have the hole bored out & a sleeve inserted. The sleeve is going to have a lip for the tube to preload the bearing against.

Be sure to take the bearing & tube with you so you can verify that the tube will preload the bearing.

The sleeve will have to be supported somehow to transfer the preload to the case. Either a lip for the sleeve to press against, or else the sleeve will have to be pinned somehow.

If you can't get to your machinist friend, you might talk to a local transmission rebuilder, they have to deal with this problem a lot. I know they often insert sleeves, & I believe I've seen tranny's where they built the bearing mounting hole up with welding & re-bored the hole.

If the bearing is only very slightly loose ie: barely slides into/out of the hole (say the hole is 2 or 3 thou oversize), then Loctite 640 Sleeve retainer (aka: Green Loctite) is an option:
https://tds.us.henkel.com//NA/UT/HNAUTTDS.nsf/web/062262D5231164B0882571870000D85C/$File/640-EN.pdf
To use it, thoroughly degrease & clean the hole & outer race. Insert the bearing, use the sleeve to ensure it's seated against the lip. Remove the sleeve & drop the green loctite around both sides of the bearing where it fits into the bell housing. Green loctite flows very freely & will wick into the gap. Working as quickly as possible, reinstall the sleeve to ensure the bearing is firmly against the lip while the loctite is curing.

BTW, if you use green loctite, you're going to have to heat up the bell housing to remove the bearing. Their spec sheet says 400F, but I've heard that pouring boiling water over it 2-3 times will also do the job.

Not so, fluid moves from the transfer case into the tranny thru the main shaft opening that's several inches above the tranny sump. Thus the fluid transfer is effectively 1-way: from the transfer case into the tranny.

 

I am .. . how much? . . I like the helical cut vs. straight.

 

The kit with 1 ratio is 4500 euro for anyone interested.
Additional advantage it is compliant with the FIA homologation papers for the 308 hence you can compete with on worries.

Cheers.

 

Ahh yes, but all those noises are helps a race car driver to know when everything is working correctly

 

I know that TRutlands has at least 3 sets of gears because I sold him 2 sets last year. They are expensive as a set--about 1800 if I recall.

I purchased 4 sets on ebay 2 years ago at 200 each just to use as trading collateral.

 

and I have 2 spare bellhousings too that someday will be worth a lot

grrr--my garage is looking like a parts depot----