TheSamba.com :: View topic - Building a strong gearbox with 95% OEM parts

Sat Jul 18, 2020 1:55 pm

Interesting information. Speaking of parts swapping I have a question about a swingaxle transaxle I have. I didn't check the 1st or 2nd gear ratios but did check 3rd and 4th and the final drive ratios. Third is 1.32 and forth is 0.93, with a 4.375 final drive. What parts did someone have to combine to use a 40 horse 3rd and late type 4th and 4.375 R&P?

Sun Jul 19, 2020 6:48 am

EVfun wrote: Interesting information. Speaking of parts swapping I have a question about a swingaxle transaxle I have. I didn't check the 1st or 2nd gear ratios but did check 3rd and 4th and the final drive ratios. Third is 1.32 and forth is 0.93, with a 4.375 final drive. What parts did someone have to combine to use a 40 horse 3rd and late type 4th and 4.375 R&P?

I’m not sure what an AM transaxle like the one ngobet is working on over in Switzerland, but ones I’ve found in the US from the Canadian market had a 4.37 r&p with 3.78/2.06/1.26/.93 gearing. A 1.32 could have simply been substituted from that OEM configuration. Or you could have taken a late Split Bus splined 4.37, a 1.32 3rd, and combined it with the later gear stack. You would need to turn down the 002 hub some, and open up the inside of the early 1.32 gear. I’ve also seen the 002 hub turned down completely to clear a non-modified 113 year. ngobet posted a pick of the work on the gear, maybe they can post a pic of the hub? I always thought the sliders associated with each gear drive tooth needed to be used with the early/late gears, but the late 002/091 slider will work with both.

Sat Jul 02, 2022 5:17 am

Found this post as I’m in the process of doing similar.

I’m starting with an AT code IRS gearbox that I’m converting to SA.

I already have a Rhino HD case, super diff, steel HD side plate with the reinforcement half rings for the axle tubes, 15T side gears, HD clutch fork….

I picked up coarse tooth 3rd & 4th gears but they are keyed when I needed splined :cry:

A couple of questions if I may?

How strong are the fine tooth gears? Do I really need the coarse tooth gears and if so what gearbox am I looking for to source please?

What other upgrades for strength & reliability am I needing?

I have the 3.875 R&P from the AT gearbox so what 4th gear ratio would be best/better than the stock (fine tooth) 0.93?

Cheers all :D

Sat Jul 02, 2022 5:31 am

Ohio Tom wrote: a few things to add:

1. there is another option to put 113 gears on a late model main shaft.
You can cut the hub down and bore the gear out to provide clearance needed.
I have a stack of cut down hubs just for that purpose.

This I’m interested in should I decide to change 3rd & 4th gears…

Not sure why you think super diff's don't load all the spider gears?
Most quality superdiffs do just fine and make it much stronger.
I do add oil holes to keep them lubed up for one wheel burnouts..

Do you have any pictures of how/where you add the extra oil holes?

Sat Jul 02, 2022 6:13 am

benozoval56 wrote: Found this post as I’m in the process of doing similar.

Just be forewarned, with 95% OEM and 10% aftermarket, you might wind up with extra parts. :wink:

Sat Jul 02, 2022 6:54 am

benozoval56 wrote: Found this post as I’m in the process of doing similar.

I’m starting with an AT code IRS gearbox that I’m converting to SA.

I already have a Rhino HD case, super diff, steel HD side plate with the reinforcement half rings for the axle tubes, 15T side gears, HD clutch fork….

I picked up coarse tooth 3rd & 4th gears but they are keyed when I needed splined :cry:

A couple of questions if I may?

How strong are the fine tooth gears? Do I really need the coarse tooth gears and if so what gearbox am I looking for to source please?

What other upgrades for strength & reliability am I needing?

I have the 3.875 R&P from the AT gearbox so what 4th gear ratio would be best/better than the stock (fine tooth) 0.93?

Cheers all :D

The durability of the fine tooth gears is debatable. While some run them with turbos, others break them. Abuse is what breaks them. They are fragile in a sense that, as soon as a tooth chips, the surrounding teeth can deteriorate quickly. Ultimately the coarse tooth gears are stronger.

You can turn the splined hub, and bore the keyed gears to use the splined shaft. You also need a thicker stop washer for the gear hub.

https://weddleindustries.com/sites/weddleindustries.com/files/downloads/8A-CONE-SW105-INST.pdf

Here’s a pic from Jpaull’s post where Mcmscott is turning down the hub.

I’ve also talked with a few builders that simply turned down the spined hub to fully clear the bore of the keyed gears without modifying the gears.

You can also get the splined mainshaft where the splines have been ground down, and a keyway cut to use the factory earlier keyed hub. You would also need to get an earlier gear carrier that would use an earlier 113 mainshaft bearing.

My new favorite 3rd/4th gear combo in a personal car is an aftermarket 1.35 with a stock .89. You could get real close with an early stock 1.32, and .89. Just be careful in that you need an engine large enough to pull the 3.88/.89 combo, and this can slow the fan speed down if you highway cruise with large diameter tires.

benozoval56 wrote: Do you have any pictures of how/where you add the extra oil holes?

This thread has some info about enlarging the oil holes in a super diff.

https://www.thesamba.com/vw/forum/viewtopic.php?t=...mp;start=0

This is what I ended up with on my last personal build.

KEGZ wrote: Just be forewarned, with 95% OEM and 10% aftermarket, you might wind up with extra parts. :wink:

The stuff I’m using comes from as many as 3 Type 1 transaxles, and up to 2 Type 2 transaxles, so you end up with quite a bit of extra parts....

Sat Jul 02, 2022 7:48 pm

KEGZ wrote: benozoval56 wrote: Found this post as I’m in the process of doing similar.

Just be forewarned, with 95% OEM and 10% aftermarket, you might wind up with extra parts. :wink:

:lol:

Sat Jul 02, 2022 8:20 pm

This is a great thread.

Next is for the details of doing all this,
And it'll get long and off-track for sure! :D

Like,
What drill bits are hard enough to drill holes in the hubs?

Some 3-4 hubs just drill like butter.
Others are so hard that homeowner drill bits don't stand a chance of even starting.
None of these even had a prayer.

Sat Jul 02, 2022 8:49 pm

Clatter wrote: This is a great thread.

Next is for the details of doing all this,
And it'll get long and off-track for sure! :D

Like,
What drill bits are hard enough to drill holes in the hubs?

Some 3-4 hubs just drill like butter.
Others are so hard that homeowner drill bits don't stand a chance of even starting.
None of these even had a prayer.

I’ve had luck with the Cobalt bits. I usually drill a small hole, then open it up slightly with a single flute carbide countersink.

Sun Jul 03, 2022 12:53 am

[email protected] wrote:

The durability of the fine tooth gears is debatable. While some run them with turbos, others break them. Abuse is what breaks them. They are fragile in a sense that, as soon as a tooth chips, the surrounding teeth can deteriorate quickly. Ultimately the coarse tooth gears are stronger.

You can turn the splined hub, and bore the keyed gears to use the splined shaft. You also need a thicker stop washer for the gear hub.

I’ve also talked with a few builders that simply turned down the spined hub to fully clear the bore of the keyed gears without modifying the gears.

You can also get the splined mainshaft where the splines have been ground down, and a keyway cut to use the factory earlier keyed hub. You would also need to get an earlier gear carrier that would use an earlier 113 mainshaft bearing.

My new favorite 3rd/4th gear combo in a personal car is an aftermarket 1.35 with a stock .89. You could get real close with an early stock 1.32, and .89. Just be careful in that you need an engine large enough to pull the 3.88/.89 combo, and this can slow the fan speed down if you highway cruise with large diameter tires.

I've machined down the hub to suit 002 gears but for early 113 mainshaft from an AC code gearbox but will likely need to do same for the carrier on the AT "Super beetle" mainshaft as its thicker.

It gives me 1.26/0.82 3rd/4th ratios with coarse teeth so should suffice (actually forgot I had these 002 gears) :roll:

also building a solid 2276cc so should have enough HP to drive through these gear ratios well enough :D

[email protected] wrote:
benozoval56 wrote: Do you have any pictures of how/where you add the extra oil holes?

This thread has some info about enlarging the oil holes in a super diff.

This is great information and that thread alone is very informative!! :D

Hand packing the 1st gear bearing is a clever/smart solution for sure, makes perfect sense..

I've also got the Berg "Poor Mans Posi" to add to this so should be a good/strong set up once complete.

8)

Sun Jul 03, 2022 12:58 am

Ohio Tom wrote: a few things to add:

1. there is another option to put 113 gears on a late model main shaft.
You can cut the hub down and bore the gear out to provide clearance needed.
I have a stack of cut down hubs just for that purpose.

I'm hoping/planning on doing this or using 002 gears but I need to change the pinion bearing/carrier from late (screw style) to early (4 bolt style) to suit the Rhino case :?:

Sun Jul 03, 2022 1:15 am

Clatter wrote: This is a great thread.

Next is for the details of doing all this,
And it'll get long and off-track for sure! :D

Like,
What drill bits are hard enough to drill holes in the hubs?

Is there more info on this mod please? :?:

Sun Jul 03, 2022 2:48 am

I haven't had much luck drilling them with HSS but had good success with a carbide drill in a drill press. What was odd to me is the carbide drill had to be run at high speed :shock:

Sun Jul 03, 2022 9:10 am

benozoval56 wrote: It gives me 1.26/0.82 3rd/4th ratios with coarse teeth so should suffice (actually forgot I had these 002 gears) :roll:

also building a solid 2276cc so should have enough HP to drive through these gear ratios well enough :D

A 2276 should have enough power to use the taller gear. Keep in mind the rpm drop from 3rd-4th will be there irregardless of hp. More hp will help accelerate the vehicle though. Also keep in mind your cruising rpm. If you’re wanting to run a tire around 26 inches, your cooling fan may not be spinning fast enough to overcome the heat produced.

benozoval56 wrote: Hand packing the 1st gear bearing is a clever/smart solution for sure, makes perfect sense..

I've also got the Berg "Poor Mans Posi" to add to this so should be a good/strong set up once complete.

8)

While Ray Vallero has forgotten more about VW stuff than most know, the overwhelming majority of builders I’ve spoken with only use the hand packed bearings in a race application. The added friction of the rollers running beside each other is not something you want for a prolonged drive in a street car. Some of the early 60’s transaxles used a metal caged bearing with 28 rollers compared to the more common 24. Weddle also has new metal caged bearings with 26 rollers. The OEM style metal caged ones are more than adequate in most instances.

Also, be careful with the poor man’s posi. Applying preload to the spider gears is also a race only application, and will destroy everything in short order in a street car. You can use the shims to tighten the tolerances, but imo you need .005-.006 backlash for lubrication for street use.

Mon Jul 04, 2022 12:10 pm

You could consider using a ‘61 -‘67 Type II 1.22:1 third gear instead of the 1.26:1 to lessen the spread between 3rd and 4th.

VW went from the 1.32/0.89 combo they used in the 1960 buses to the 1.22/0.82 combo in 1961. Might be a lot more useful when you need a slightly taller 3rd gear in certain instances at higher speeds when 4th gear can’t be used.

Mon Jul 04, 2022 1:32 pm

b-man wrote: You could consider using a ‘61 -‘67 Type II 1.22:1 third gear instead of the 1.26:1 to lessen the spread between 3rd and 4th.

VW went from the 1.32/0.89 combo they used in the 1960 buses to the 1.22/0.82 combo in 1961. Might be a lot more useful when you need a slightly taller 3rd gear in certain instances at higher speeds when 4th gear can’t be used.

I try to do this any time I use a .89 4th, they are getting hard to find tho

Mon Jul 11, 2022 3:39 am

Clatter wrote: This is a great thread.

Next is for the details of doing all this,
And it'll get long and off-track for sure! :D

Like,
What drill bits are hard enough to drill holes in the hubs?

Some 3-4 hubs just drill like butter.
Others are so hard that homeowner drill bits don't stand a chance of even starting.
None of these even had a prayer.

what size holes am I drilling here please?

Mon Jul 11, 2022 12:08 pm

[email protected] wrote:

You can turn the splined hub, and bore the keyed gears to use the splined shaft. You also need a thicker stop washer for the gear hub.

https://weddleindustries.com/sites/weddleindustries.com/files/downloads/8A-CONE-SW105-INST.pdf

Here’s a pic from Jpaull’s post where Mcmscott is turning down the hub.

.

Checking the Weddle site right now,
They seem to be out of the regular early 3-4 cones:
https://weddleindustries.com/products/8A-CONE/8A-CONE

They do have this cone with the later-style teeth.
Seems an adaptor cone?? :-k
https://weddleindustries.com/products/8A-CONE-LATE/8A-CONE-LATE

If you trim down the hub/gear,
could you use this different cone instead of the early cone and thick washer?
This when running a late 4th and late slider..

Mon Jul 11, 2022 12:14 pm

benozoval56 wrote: Clatter wrote: This is a great thread.

Next is for the details of doing all this,
And it'll get long and off-track for sure! :D

Like,
What drill bits are hard enough to drill holes in the hubs?

Some 3-4 hubs just drill like butter.
Others are so hard that homeowner drill bits don't stand a chance of even starting.
None of these even had a prayer.

what size holes am I drilling here please?

ngobet wrote:
Drill 3mm holes in the hub. .

Just have to read the thead.. :wink:

Mon Jul 11, 2022 3:04 pm

Clatter wrote: Checking the Weddle site right now,
They seem to be out of the regular early 3-4 cones:
https://weddleindustries.com/products/8A-CONE/8A-CONE

They do have this cone with the later-style teeth.
Seems an adaptor cone?? :-k
https://weddleindustries.com/products/8A-CONE-LATE/8A-CONE-LATE

If you trim down the hub/gear,
could you use this different cone instead of the early cone and thick washer?
This when running a late 4th and late slider..

The early cones have been out of stock for quite some time, and unless Weddle decides to start making them, they are pretty much nla.

I have yet to need to use the later hubs that don’t use the washer. That’s something I would run by Scott. It’s my understanding they are a direct replacement for the early hub with the washer, so I would imagine you still will have excess endplay to take up if using a late splined slider hub. You may need to trial assemble the shaft to find out how much endplay you have. You still need to weld the late style washerless cone for the 113 gears. You could get some shim stock and cut out a small spacer washer to set your endplay to press the hub up against before welding.