|Topic Review (Newest First)|
|03-11-2016 02:10 PM|
|Gordon Raymond||If you can turn the input shaft with a 3/4 inch drill, even slowly, no gear oil, you can. Preferred is a huge lathe, or best, installed in a car. My lathe is not big enough, and I have used the biggest electric drill I could find, held by a helper, while i fiddled with issues.|
|03-11-2016 11:02 AM|
|swallow||Actually one last question from a 105 owner who as yet to drive the thing (bought it in pieces..) - can I get a reasonable idea/feel of gear selection quality with the gearbox on a bench, with shift lever attached, of course?|
|03-11-2016 10:32 AM|
|swallow||Thanks again Gordon - nicely explained! Feel more confident putting it all back together now..|
|03-11-2016 10:27 AM|
The welded tip is often to get the reverse lock out to work correctly. This is a wear issue, the fix being to weld a bit then file it back until the r-lock-out works reliably, every time.
The breather gets lots of mist lubrication, but the bow washers contact area will wear against the aluminum over time, even from normal vibration. Installing very thin hardened washers against the aluminum breather will reduce wear, how much I can't guess. Put in a thin washer, and try it. If the assembly binds, readjust with more or less shims. Note that some rebuilders may have hand laped the breather inside end to fit flat washers. One shim on one side and 5 on the other has to do either with sloppy assembly, or trying to get it to function as it should.
Try three on each side if you want, and see if it works correctly, or switch the breathers side-to side and see what that does. This is a final set up, that is done to get smooth pattern gear changes without force or jiggling the shift lever around. The parts book shows even spacing, but the parts book transmission is the "ideal" situation. Move the shims areound. See what happens. Then adjust for easy function.
|03-11-2016 10:09 AM|
Thanks Gordon, I've not driven this gearbox as I bought it, having sat "out" of a car for many years. The condition of all of the dog gears suggests it was rebuilt, then stood unused. I won't be changing the selectors, although on examination, the selector fork for 5th/reverse appears to have had some metal added/welded to the tip and then ground back - not sure if this is something often done during a rebuild?
My other concern over the lack of any flat washers would be eventual wear to the alloy breather castings, if just using the wavy washers.
One other thing, the shims underneath the breathers, one side has just one, the other side has 5 - again, is this normal?
Just a bit worried as I don't know who rebuilt the gearbox - were they skilled/knowledgeable OR hamfisted/clueless....
Thanks again, Tom
|03-11-2016 09:53 AM|
This has to do with linkage "feel" or precise gear selection. Generally, if it worked well before disassembly, it may or may not work as well IF selector forks are replaced. Fortunately, once back in the car and functional, this can be changed. Sometimes the breathers in some applications are right even with the opening in the transmission tunnel, and a jack is required to R & R. Other times it's necessary to remove the rear mount bolt to jack it up, or lower it for clearance. In some applications, there is plenty of room. Put it together the way it was, and try it driving (No boots). Adjust one way or the other until it works smoothly.
From my experience.
|03-11-2016 09:32 AM|
Originally Posted by Vintre View Post
Mine had two wavy washers and no flat washers. Can anyone suggest what I need and at what spec/measurements to rectify this? I think a previous owner had had this gearbox rebuilt at some point as (apart from the above missing/duplicate washers) the rest is in excellent condition.
Thanks in advance, Tom
|06-15-2015 06:48 AM|
|05-16-2015 05:22 PM|
Translation: It's a sturdy box except for the sycros.
Don't know about glasses for pissing, though. I can't find them in the Alfa tool catalog, either...
|05-16-2015 04:38 PM|
|jcslocum||It's s Trudy box except for the syncros. Inspect with a glass for pissing or galling and if good, reuse.|
|05-15-2015 08:35 AM|
I'm getting in on the action too, opening up a tranny from a car I bought as a roller so I have no knowledge of how she shifted.. After I pick up a deep 32mm impact socket to get that yoke off, I should have her split open in short order. Seems like this thread is the place to be so I might post some follow-ups.
Any comments on the synchro/dog ring products centerline now has on the market? https://www.centerlinealfa.com/gearbox/2849
Does one typically replace the mainshaft/layshaft bearings as a matter of course or examine and determine needs as you go?
|03-23-2015 06:22 PM|
|1750GT||Subscribed....and thanks RJ......for sharing your wealth of experience with the Alfa community once again.|
|03-22-2015 08:53 AM|
|Jim G||One other thing on syncro rings. I've seen syncro rings that are worn on the inside were the smaller quadrant rubs on the syncro ring. If its also worn here flipping it probably won't do you much good.|
|03-22-2015 07:35 AM|
As Mike said, done correctly with some parts swapped things will be fine.
However I disagree on a couple of things you brought up, and Mikes comment on using 1st gears old syncro assembly on 5th gear.
The 1st gear syncro is one directional only, It does not function in both directions.... best to either discard it or if the teeth are not rounded (which causes barbs on top of the teeth and beneath them, which causes hard release and engagement) then it can be disasembled and the internals (between the assembly and the friction ring ) can be swapped for those out of the 2nd gear syncro assembly, (as it most certainly needs to be replaced by a donor complete assembly) as both the teeth and friction band are generally trashed. Between 1s/2nd the slider should be swapped for a good one. I suggest the 3/4 slider using the 5th slider between the more used 3/4 gears.. The rest of the syncros should be checked for wear on the teeth and the friction band. and replaced if even questionable.
As Karen has warned, you won`t have good results from turning the friction bands over, as the edge under the teeth most likely is grooved/worn. This is why tpically you need a 2nd trans to harvest the 4th and 5th syncros from, as those are generally ok.
The other issue is shift forks. 3rd/4th fork is generally worn more due to use.
Sealing is critical, I use Permatex Ultra Grey a high torque sealant. You need sealant around all the holes or you will have leaks from the bolts. I even seal around bolt heads and washers to insure the thing is tight.
When it is finished only use Redline 75-90 NS as the lube!
|03-22-2015 04:43 AM|
|gigem75||Folks have been doing that for a long time. It does work. If it was mine I'd get a new syncro for 2nd. Take the one on 5th and move it to 1st. Flip the 1st and move it to 5th. Flip the 3rd and 4th in place. I would consider a new sleeve for 1st-2nd. Some may prefer a different order. The one big cavet is that it hasn't already been done. I've switched dogs before but it requires a good press and a good way to hokd tge gears.|
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