My First Transmission Rebuild (Photo Heavy)

[19-VW-74]

Here are a couple of photos of 4th gear on the pinion side. This trans has a splined 4th gear. The gear shows no perceivable damage.

_________________
-Austin
My 1974 Standard Beetle Build:
http://www.thesamba.com/vw/forum/viewtopic.php?t=492617

[nsracing]

YOu do some fine work - Austin! IMpressive!

Before i had my toolpost grinder, I machined a special mandrel on the lathe to fit inside the 1/2 hub. I surfaced the galled areas w/ valve grinding compound w/ that mandrel. The finish was not too bad.

But the hub is soft so you can machine those surfaces on the lathe if you like.

When I did my first trans - it was just an overhaul. I cleaned the case and split all the parts. Washed/dried and put them back together. I did minimal job on the galled areas just making sure they were better than before. I put it back together and used that trans a long time.

I took measurements before I pull all the Ring/Pinion apart -in case I got ahead of myself -so i can put it back where I got it first time.

I wanted to ask how you got all the detents and balls/springs back in the carrier. Did you utter some fine words?

[Clatter]

Wow! You got SO lucky with that core!

I’ve taken apart about a dozen of these boxes now,
And none of them looked as nice as yours.
Congrats.

And, nice work/write-up, too.

If only all of them were so easy..!
_________________
Bus Motor Build

What’s That Noise?!?

[19-VW-74]

[19-VW-74]

[19-VW-74]

Here are some photos of the 3/4 clutch hub and slider, along with the detent keys which are shaped differently from 1/2.

3/4 detent keys:

3/4 slider has grooves that allow you to index the slider on the hub in a number of positions, unlike 1/2 slider and hub.

Here you also see the flanks cut into the teeth on the 4th gear side. These engage the dogs on the 4th gear idler. These flanks are only cut on the load side of the teeth facing 4th gear.

Here you see the groove on the 3/4 slider. The groove on the right side faces 4th gear.

The teeth on the clutch hub are in nearly perfect condition all around. Very nice.

_________________
-Austin
My 1974 Standard Beetle Build:
http://www.thesamba.com/vw/forum/viewtopic.php?t=492617

[19-VW-74]

4th gear thrust washer. In good shape, the wear on the main shaft bearing side is very light. Looks worse in photos. I checked 4th gear idler clearance and it was 0.007".

Pressing off the 3rd gear stop washer:

Pressing the new washer on:

And assembled with the new washer:

_________________
-Austin
My 1974 Standard Beetle Build:
http://www.thesamba.com/vw/forum/viewtopic.php?t=492617

[19-VW-74]

Third gear idler and bearings in great shape.

Diehl 3/4 syncro on left, OG on right. According to the Bentley, these new syncros are designed to be off balance to prevent nuisance noise.

OG syncro gap on 3rd gear:

Diehl syncro gap on 3rd gear:

_________________
-Austin
My 1974 Standard Beetle Build:
http://www.thesamba.com/vw/forum/viewtopic.php?t=492617

[19-VW-74]

4th gear idler and bearings also in nearly perfect condition. Thrusts surfaces both look very nice, dogs on the syncro cone also look near new.

OG 4th gear syncro (well out of spec):

Diehl 4th gear syncro:

_________________
-Austin
My 1974 Standard Beetle Build:
http://www.thesamba.com/vw/forum/viewtopic.php?t=492617

[19-VW-74]

When I cleaned up the original reverse gear and selector linkage, I found that, not only was the reverse gear pretty worn out, the cradle was also pretty worn. There were brass shavings all over the inside of the trans.

I also discovered that the shift lever for reverse had a pin that was coming loose. You can see a gap, I could jiggle it with my finger. This would have failed at the most inopportune time, I'm sure.

In a box of used transmission parts that I picked up along with my new transmission jig, I procured a nearly complete late IRS (73+) reverse selector assembly. The only thing I couldn't use was the reverse gear.

The reverse gear for the 73+ IRS trans has 15T and uses a different 1/2 slider with 40 teeth for engaging reverse. My early IRS trans uses a 17T reverse gear with a 44T 1/2 slider.

Luckily, Weddle makes an adapter reverse gear with 17T that fits the late linkage and the early 1/2 slider.

I'll compare the two setups below.

Weddle gear on left, OG early gear on right:

And this is how the linkage looks in the transmission.

You can see that the early linkage has a solid block that mounts to the selector shaft and the late linkage has a stamped piece. They are not interchangeable.

I like the late style, because the brass cradle on the early style sags under its own weight in the trans and constantly rubs and erodes away against the reverse gear teeth.
_________________
-Austin
My 1974 Standard Beetle Build:
http://www.thesamba.com/vw/forum/viewtopic.php?t=492617

[19-VW-74]

These are photos of the 1/2 shift fork. The brass one is the OG fork from this transmission and the steel one is from a swing-axle transmission. They are both 4mm wide and interchangeable.

Though the brass shift fork was in fine reusable shape, I've read all over that the brass forks break even under normal use. So I found a used steel 1/2 slider from somebody in a VW Facebook group for $50. I had it in under a week. It's cool that there are people out there willing to help under short notice like that.

The steel 4mm 1/2 shift fork comes from a 62?-67 Beetle swing-axle trans, I believe.

The brass 4mm 1/2 shift fork comes from the 68-72 Beetle trans.

I believe that late 73+ IRS came first with 5mm brass 1/2 shift fork, then went to steel 5mm fork later. Weddle makes a new replacement for the 5mm fork, but not for the 4mm, at this time.

Below are pictures of the 4mm steel 3/4 shift fork. As far as I'm aware, all 3/4 shift forks are steel in Beetle transmissions. From 73+ they are widened to 5mm.

_________________
-Austin
My 1974 Standard Beetle Build:
http://www.thesamba.com/vw/forum/viewtopic.php?t=492617

[19-VW-74]

These are the shift selector rods from the transmission. All are in good shape.

Left is reverse, middle is 1/2 rod, right is 3/4 rod.

The 2 notches at the top of reverse, and 3 notches at the top of the others are for the shift detent balls. These are spring loaded ball bearings that are pressed against the shaft to hold it in or out of gear.

The single notch on each shaft just below those are for these spherical ended dowel pins that prevent you from selecting more than one gear at a time.

The threaded hole on reverse shaft bolts to the reverse lever linkage.

The slotted portions on both 1/2 and 3/4 rod allow you to adjust the position of the shift forks when you assemble the trans.

_________________
-Austin
My 1974 Standard Beetle Build:
http://www.thesamba.com/vw/forum/viewtopic.php?t=492617

[19-VW-74]

This is the small pinion shaft bearing. It goes towards the front of the transmission and the inner race butts up against 4th gear on the pinion shaft.

The inner race is able to move fore and aft in the needle bearing, as the pinion depth is adjusted by changing shims. The outer race is held into the gear housing with a single bolt with 11mm head.

This transmission is probably the only time I have used my 11mm socket.

_________________
-Austin
My 1974 Standard Beetle Build:
http://www.thesamba.com/vw/forum/viewtopic.php?t=492617

[mcmscott]

[nsracing]

I love those fresh reverse gears!

Pretty soon, we may have to mix-n-match parts as the supplies run out. I hope we are not there yet.

[19-VW-74]