Detailed Step by Step Rebuild of 1972 5 Speed - Alfa Romeo Bulletin Board & Forums
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post #1 of 73 (permalink) Old 03-16-2016, 11:55 AM Thread Starter
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Detailed Step by Step Rebuild of 1972 5 Speed

All -

I'm upgrading the 1300 in my 1972 GT Junior to a 2L, and while I'm at it, I will be rebuilding the transmission. I thought it would be helpful to the rest of the crew to post pictures and details on the process. Once completed, I think it would make a good sticky...

I have rebuilt engines and transmissions in the past, but this is my first Alfa 5 speed. The plan is to do this in my garage with readily available tools.

I believe this to be the original and un-rebuilt transmission from my car. It was working fine, minus the periodic 2d gear grind. I plan a stock rebuild but with lightened gears.

The Alfa 5 speed was introduced in 1959. It remained basically the same until 1967, when the hydraulic clutch replaced the mechanical clutch. Note - the 1967-1968 GTV 1600's and Giulia Supers still used the mechanical clutch. The hydraulic clutch bellhousings are easily spotted; they have a provision for mounting the clutch slave cylinder.

From 1967-1972 the gearboxes are the same, and can be identified by the front bearing on the input shaft -- it's secured by a circlip/snap ring, and the rear drive yoke is secured by a 32 mm bolt with is locked by a flanged lock washer. THIS IS THE TRANSMISSION I AM REBUILDING NOW.

Beginning at some point during model year 1972, the transmission was changed slightly -- the front bearing and rear flange were secured with 32 mm nuts that have a built in flange; pictured in a later post. The flange is peened into a small groove in the shaft to keep it from moving.

I bought the car several months ago. Here's what it looked like before I completely disassembled it.



What I will not cover - transmission removal, clutch fork and throwout bearing removal. That's already done. I have also drained the trans oil and given the exterior a good cleaning.

The victim, seen here hanging off the backside of the 1300...


Another "before" picture...


References (to be completed)
Alfa Manual...check with AlfaBB member PapaJam

Alfa BB Threads
Gear Lightening - http://www.alfabb.com/bb/forums/gt-1...ightening.html
First Gear Crunch - http://www.alfabb.com/bb/forums/gear...-gear-fix.html

Dogteeth removal

Sources for Parts (to be completed)
Richard Jemison
Centerline - https://www.centerlinealfa.com/gearbox - seals, bearings, bushings, dogtooth gear, transmission mount, sliders, synchro rings, etc.
Alfaholics - http://www.alfaholics.com/browse-par...erential-part/ and http://www.alfaholics.com/race-perfo.../transmission/ - seals, bearings, bushings, transmission mount, sliders, synchro rings, 5th/reverse selector lever, close ratio gear sets, etc.
Alfa Parts Exchange (APE) - used parts


Tools Needed (to be completed)
Socket or box end wrenches: 1 1/4" or 32 mm socket (12 point) or box end wrench with deep offset; 19 mm, 13 mm
Flat-tip screwdriver
Ratchet and extension
Snap ring pliers
Non-marring hammer (dead blow with plastic face, hammer with rawhide face, etc) - strongly recommended
Impact driver (not required)
Impact screwdriver (not required) - http://www.amazon.com/TEKTON-2910-2-...ct+screwdriver
3 Jaw Puller...
Brushes, solvent, pics, etc (for cleaning the exterior)
Hydraulic press (not required)
Anti-Seize - Permatex - strongly recommended
Kroil or 50/50 (auto trans fluid/acetone mix) strongly recommended for loosening bolts
Seal Removal Tool - makes easy work out of removing the...wait for it...seals! http://www.amazon.com/Lisle-56750-Se...+remover+lisle

Also strongly recommend a fairly large and well-lit place to work. Here's my workbench...(pic to follow)
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72 GTV; 66 Fairlane GT convt, 428, 4 sp; 68 GTO Convt, owner built 455 and TH400; 71 Javelin road race project, owner built 401, T10

Last edited by bulletpruf; 06-17-2016 at 10:44 PM.
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post #2 of 73 (permalink) Old 03-16-2016, 11:55 AM Thread Starter
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Before I started the rebuild, I spent quite a bit of time cleaning the exterior of the transmission. There's no real trick to it, just a few different types of brushes (plastic, steel, and brass bristles), picks, paper towels, brake cleaner, and Simple Green.


I used to buy brake cleaner from the local auto parts store by the case. It's far from cheap, but I love how it cleans and evaporates without leaving a greasy residue. Anyway, I got tired of paying $4/spray can, so I bought the pressurized sprayer from Amazon and I fill it up with the Brake Cleaner that I buy by the gallon. Much more cost effective.



The finished product.









72 GTV; 66 Fairlane GT convt, 428, 4 sp; 68 GTO Convt, owner built 455 and TH400; 71 Javelin road race project, owner built 401, T10

Last edited by bulletpruf; 03-17-2016 at 01:42 PM.
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post #3 of 73 (permalink) Old 03-16-2016, 11:56 AM Thread Starter
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Time to start the disassembly!

As you can see from the above pictures, the transmission still has the rubber donut/guibo attached to the drive flange at the back of the transmission.

To remove it, use a 19mm wrench or ratchet and socket to undo the three nuts that hold the guibo to the drive flange. Then you can slip off the guibo.



Next, you can remove the drive flange itself. Before you remove the nut that holds it on, pull the rubber grommet off the end of the output shaft. Seen here.

Then you'll need to tap the flattened keeper (really just a washer made of soft metal with a tang that holds it in place) down so you can get a socket on the bolt. You can see the keeper in this photo on the side of the nut. NOTE: this is for 1967-1972 cars; sometime during model year 1972 the bolt was held in place as pictured below.


Anyway, try to get the keeper tapped down without mangling it. I had to use a small chisel to get it started and finished with a larger chisel. The chisels are sharp, so I had to take care so I wouldn't cut or damage the keeper.


You may also have the nut held onto the drive flange like the picture below; this is what was used beginning at some point in 1972. It's the same as the transmission that I have that came with a 512 2L engine. in the transmission that I got from a 2L car of the same vintage (1972, give or take a year or two). Below picture is from AlfaBB member jcslocum's thread on trans rebuilding.


It's a 32 mm nut holding the drive flange on but a 1 1/4" will work, too. Plan to use a 12 point deep socket (not sure a 6 point will fit in there) and make sure it's on good. Tap the socket on with a small hammer if you need to; if it's not flush, you may end up stripping it. I used my Milwaukee electric impact for this.

You can see the drive flange and related hardware in the below photo. You can tap the other three bolts out of the drive flange, too. As you can see from this photo, all 6 of the drive flange bolts are the same. I also took some measurements of the hardware in case you have a big box of bolts and gears but you don't know what's what. Speaking of hardware, you may notice the green ring at the top of the nuts. This is plastic of some sort designed to keep bolts from backing out. They are commonly referred to as Nylock nuts.

72 GTV; 66 Fairlane GT convt, 428, 4 sp; 68 GTO Convt, owner built 455 and TH400; 71 Javelin road race project, owner built 401, T10

Last edited by bulletpruf; 06-17-2016 at 10:48 PM.
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post #4 of 73 (permalink) Old 03-16-2016, 12:11 PM Thread Starter
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After cleaning and inspection, related hardware goes into a ziplock bag that's labeled with contents. I usually add a bit of auto trans fluid so I don't have any issues with rust.


And then into a clear plastic storage box. Everything should easily fit in here when done.



The backup light switch and harness are next. The switch is inside the bell housing at the top (you can see the two screws in the picture below) and attached with two screws.



The screws were quite difficult to get loose, even after using some Kroil. I ended up using the impact screwdriver to get them off.



You'll notice that I label bolts with OAL (overall length) and thread size, just in case anything gets mixed up. I measure length with inexpensive digital calipers and thread size with a thread checker.


72 GTV; 66 Fairlane GT convt, 428, 4 sp; 68 GTO Convt, owner built 455 and TH400; 71 Javelin road race project, owner built 401, T10

Last edited by bulletpruf; 03-17-2016 at 10:27 PM.
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post #5 of 73 (permalink) Old 03-16-2016, 12:18 PM Thread Starter
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Time to remove the bell housing. You can see the 6 nuts that hold it on in this picture.


Remove the nuts with a 17 mm socket. Each has a flat washer. Thread is M10-1.0 Once the nuts are removed, you should be able to easily slide the bell housing off.


Once the bell housing is off you can use a screwdriver or seal remover to pop off the seal in the bell housing.


Bellhousing seal, dimensions, and part numbers.

72 GTV; 66 Fairlane GT convt, 428, 4 sp; 68 GTO Convt, owner built 455 and TH400; 71 Javelin road race project, owner built 401, T10

Last edited by bulletpruf; 03-23-2016 at 02:03 PM.
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post #6 of 73 (permalink) Old 03-16-2016, 12:18 PM Thread Starter
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Working on the tail housing.

Use a 10 mm wrench to remove the bolts that hold the speedometer gear in and then slide it out of the tail housing.


Speedometer gear assembly, bolts, washers.


Remove the metal cap that covers the shifter. It's pressed in; I sprayed it with some Kroil and then pried it out using a large screwdriver.


The ratchet gear and plate are under the cap, also a press fit. Same here - spray with Kroil or 50/50 (acetone/ATF) and then pry the plate out. The ratchet gear is attached to the plate, and comes out with the plate.


And a picture of the cap and the ratchet gear and plate.


Now you can see the actual shifter base. Recommend you take good notes here -- the shifter is centered in the housing with washers on either side inside the housing and with shims between the vent covers and tail housing. If you take a picture and good notes you shouldn't have any trouble getting it back together just the same as it was.


Below picture shows the thin metal shims as well as the washers and dimensions. Note - the number of shims and placement/thickness of washers will vary from car to car.


Remove the tail housing next. There are 7 nuts holding it on. Once removed, you'll probably need to use a soft faced hammer to tap the tail housing off.

72 GTV; 66 Fairlane GT convt, 428, 4 sp; 68 GTO Convt, owner built 455 and TH400; 71 Javelin road race project, owner built 401, T10

Last edited by bulletpruf; 03-23-2016 at 10:07 PM.
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post #7 of 73 (permalink) Old 03-22-2016, 01:19 PM Thread Starter
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Tail housing is pretty much stripped now. Just need to remove the transmission mount, which seems to be stuck pretty good, and scrape off the gasket for the speedo housing.






72 GTV; 66 Fairlane GT convt, 428, 4 sp; 68 GTO Convt, owner built 455 and TH400; 71 Javelin road race project, owner built 401, T10

Last edited by bulletpruf; 03-24-2016 at 02:12 PM.
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post #8 of 73 (permalink) Old 03-22-2016, 01:20 PM Thread Starter
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Next you have to remove the plate and sheaths holding the rod positioning balls in place. Use a 10 mm socket.



Once you remove the bolts, the spring pressure should press the plate and sheaths up.



Pull the sheaths and springs out, then turn the transmission over so the 7.85 mm rod positioning balls fall out.



Once that's done, it's time to remove the 5th gear/reverse gear selector rod. Starting point.



Just one bolt to remove, seen here. You can see the tab on the outside edge of the bolt. Use a flat tip screwdriver to bend the tab down.



Once you have bent the tab like this, remove the bolt with a 12 mm socket.


Then you can slide the rod out, and remove the shift fork.

72 GTV; 66 Fairlane GT convt, 428, 4 sp; 68 GTO Convt, owner built 455 and TH400; 71 Javelin road race project, owner built 401, T10

Last edited by bulletpruf; 03-27-2016 at 02:52 AM.
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post #9 of 73 (permalink) Old 03-23-2016, 07:53 AM Thread Starter
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Next step is to open 'er up. Using a 13mm socket, remove the nuts holding the case halves together. You may need to use your soft-faced hammer to tap a bit here and there to the case halves apart.

Click on the picture for details on the hardware. You have some long bolts, short bolts, thick washers, and wave washers. You'll see that it looks like I'm missing one wave washer. Bottom line is that all the nuts take a wave washer. And the long bolts also have two thick washers - one under the bolt head and one under the nut with the wave washer. And there are two studs in the case that take the two remaining thick washers (at least that's where I think they go; I have to double-check my pictures).



Now we're making progress...next, you can lift out the layshaft, followed by the main shaft.


Next you can remove the gear selector rods and shift forks for the 1/2 and 3/4 gears.



Same process as the 5th/reverse rod/shift forks. Bend the tab down with a screwdriver (already done in this picture) then remove with a 12 mm socket.



Once the bolts are removed, slide the rods out and remove the shift forks.


Now you can set the case halves aside.




Your box of parts should be filling up by now.

72 GTV; 66 Fairlane GT convt, 428, 4 sp; 68 GTO Convt, owner built 455 and TH400; 71 Javelin road race project, owner built 401, T10

Last edited by bulletpruf; 03-27-2016 at 03:09 AM.
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post #10 of 73 (permalink) Old 03-23-2016, 08:24 AM
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Not always just washers, but also body shims (between the vent cap pieces and the rear case).
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post #11 of 73 (permalink) Old 03-24-2016, 06:01 AM Thread Starter
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Quote:
Originally Posted by carl750 View Post
Not always just washers, but also body shims (between the vent cap pieces and the rear case).
Carl -

Yep. I added a picture and details in post #6. I had two shims on one side and three shims on the other. They are all quite thin; I should measure just in case there are different thicknesses available.

thanks

Scott

72 GTV; 66 Fairlane GT convt, 428, 4 sp; 68 GTO Convt, owner built 455 and TH400; 71 Javelin road race project, owner built 401, T10
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post #12 of 73 (permalink) Old 03-24-2016, 07:02 AM
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Use a "finishing" nail to open up the peened part of the locking nut before you use the image wrench to take the nut off. Once off carefully reshape the bend part of nut for reuse.
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post #13 of 73 (permalink) Old 03-24-2016, 08:05 AM
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This is a keeper!
The last one I "had to do" was a 52 Chev, 3spd. What a difference!

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post #14 of 73 (permalink) Old 03-24-2016, 08:17 AM
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I'm in for this thread!

Good luck,

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post #15 of 73 (permalink) Old 03-24-2016, 11:44 AM Thread Starter
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Quote:
Originally Posted by carl750 View Post
Use a "finishing" nail to open up the peened part of the locking nut before you use the image wrench to take the nut off. Once off carefully reshape the bend part of nut for reuse.
Thanks, Carl. Good tip.

Scott

72 GTV; 66 Fairlane GT convt, 428, 4 sp; 68 GTO Convt, owner built 455 and TH400; 71 Javelin road race project, owner built 401, T10
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