Grinding down into 2nd tranny teardown

[Gimmedatharpboy]

Hi all,

I have been having issues when only shifting down into 2nd on my '72 Beetle. Gearbox number is 113 301 103. I have ruled out a bad shifter setup having completely replaced all the bushings to no avail. I therefore reasoned that the 2nd year synchro was bad and took apart the tranny after finding lots of metal shavings on the end of the drain plug.

Most notable wear seems to be on the reverse gear and 1-2 slider where the ends are rounded off and shiny. I am now wondering if this still is a synchro issue and 2nd gear doesn't seem to have much wear on it at all.

Any thoughts?
Thanks,
Dariusz.

Shift fork is brass.

1-2 Slider:

1-2 Slider teeth:

Reverse gear:

1st and 2nd gear Synchros:

2nd Gear:

[VW_Jimbo]

I'll start you off. Bent shift fork? But I am no expert.
_________________
Jimbo

There is never enough time to do it right the first time, but all the time necessary the second time!

[Gimmedatharpboy]

Hi again Jimbo! Here's the brass shift fork:

It does appear to be quite straight:

Kind regards,
Dariusz.

[allamaabroad]

Are the syncros warped? set them on their respective gear and see if it wobbles. How do the teeth on the inside of the selector hub look?

On second gear, you need to find the primary dog teeth and check for wear/chips taken out of the primaries. Primaries are slightly wider dog teeth that are usually in 3 groups of 3 equally spread across the gear.

My bet is worn/warped syncros

Set the second gear syncro on second gear and post a picture of it.
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[anthracitedub]

Lay the synchro on the 2nd gear hub and measure the gap. I don’t have the specs on hand but if the gap is narrow it’s worn... if your in it that far, you’re gonna replace them anyway, but it will let you know if it was the contributor to the 2nd gear crunch.

[Gimmedatharpboy]

Thanks for all your help thus far.

The inner teeth of the slider:

The primary dogs on the 2nd gear seem to be sharp with no visible chips or dings:

The 2nd gear synchro doesn't touch the gear yet and sits at about 0.8mm:

However, there does seem to be quite a bit of wobble in it:


Link


Kind regards,
Dariusz.

[anthracitedub]

My service manual lists .6mm as the wear limit on the synchro, you’re close... could be the problem. I’m no expert and I struggled rebuilding mine. I’m sure others with more experience will chime in.... transmission threads are much more fun for many of us to help with 😁

[allamaabroad]

Dang...thats a good looking 2nd gear. That syncro definitely worries me, as I'm sure it worries you and other people. That syncro for sure needs to be replaced. Not sure how far you are into this, or what your budget is, but if it were me this is what I would do:
New syncros all around

Clean everything super well and inspect all gears and sliders for worn dog teeth, check all bearings for wear and smooth operation, make sure the shift rails are tight in their bores with acceptable play.

You may be able to take a small file to the reverse gear and the teeth on the 1/2 slider to clean up the teeth, make them sharp again, but don't remove too much material. If they don't clean up very well, maybe consider new reverse gear and 1/2 slider. Just remember, reverse doesn't get used all that much.

Remove ring gear bolts and torque with red loctite - cheap insurance.

Possibly look into getting a steel 1/2 shift fork. Brass ones are known to fail. Just a simple upgrade to make sure you won't need to get in there again. (If you decide to do this, make sure the fork is compatible with your slider. There are different slot sizes and different fork thicknesses)


Then reassemble with new gaskets, seals, etc.

Check all your endplays and what not, and take your time with the jig. The last thing you want to do is have to get into this tranny again.

Good luck!
_________________
Dennis - 1973 Super Beetle ('16-'21)
Debbie- 1970 Baywindow Bus ('21 - Present)
Tin top camper/adventure bus

2180 TW: CNC Panchitos, Beehives Done Right, Web 163, Ultralight Lifters, 1.3 Rockers, CSP Python, Custom Speeduino EFI Conversion with 40mm Throttle Bodies

Distributors are lame

I have a really hard time leaving things alone...

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[Casting Timmy]

Put the 1st gear synchro on first and turn it with light pressure, you should feel a little dragging effect. Then do this on second gear, my guess is that it will slide easier. The synchro cone surface on the gear looks to be polished and almost starting to blue.

I'd take a scotch brite pad to the cone surface and haze it up and remove the bluing/ worn effect you can see in the photo. Also pull the synchro on either side of the key areas and see if it is broke, it will open up if it's broken.

If you've driven the car for a while, I'd ask if you down shift early into 2nd gear like coming off the highway. Or if the down shifting grinding happens when you wouldn't release the clutch.

[modok]

Why don't you put a shift rod in the fork and use a square to see if it's bent?

Syncro sure looks bad to me, since it doesn't fit right, but, I'm no expert.

[rugblaster]

The rocking 2nd gear syncro is a problem. If I recall (it's been several years since we struck oil and I don't have to work) the 1st gear and 2nd gear have different part numbers for the syncro rings and the 3rd and 4th gears use the same part number for the syncros. Somebody that still has to work on these can verify that. The part numbers cast into the rings, I think. They should almost "clamp" onto the cone. Not rock for sure.

The brass 1-2 fork is weak. I have in a pinch taken a late model steel one and machined down the pads to fit in a 1-2 slider groove.
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[allamaabroad]

[Gimmedatharpboy]

Thanks for everyone's input so far, this has been a massive help. Here is what the cone on the 2nd gear looks like, it's quite shiny:

Here are the reverse fork and cradle:

Kind regards,
Dariusz.

[mcmscott]

The part numbers for that trans are 113 311 269a for first
113 311 269 b for second
and 113 311 295 d for 3-4
It is commen practice to use the same second synchro for first and second.
_________________
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67 T-1
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[Gimmedatharpboy]

Brilliant thanks mcmscott!

Here are the numbers on my first and second synchros:

I am trying to decide what type of 1-2 shift fork I have. It seems to have the 3 distinct pads of the later style but doesn't have the thickness (4.85mm when new):

Maximum thickness measured of mine is about 3.9mm (0.1535 in.).

Kind regards,
Dariusz.

[gears]

2nd gear synchro ring sometimes cracks .. something you won't even see until you try tugging it apart.
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[Gimmedatharpboy]

Cheers gears, will definitely be replacing the synchros having come this far. I have managed to find the right shift fork. It's 113-311-551 for the 61-72 year beetles.

Kind regards,
Dariusz.

[mcmscott]

[allamaabroad]

Reverse fork looks pretty decent. Definitely scuff up all the syncro cones with scotch bright if you can. Syncros like having a little something to grab onto
_________________
Dennis - 1973 Super Beetle ('16-'21)
Debbie- 1970 Baywindow Bus ('21 - Present)
Tin top camper/adventure bus

2180 TW: CNC Panchitos, Beehives Done Right, Web 163, Ultralight Lifters, 1.3 Rockers, CSP Python, Custom Speeduino EFI Conversion with 40mm Throttle Bodies

Distributors are lame

I have a really hard time leaving things alone...

Innovative and affordable engine management systems and EFI conversions for your Vintage VW
Visit https://debbiesaircooled.com/

[Gimmedatharpboy]

Thanks allamaabroad, will definitely be doing that.