Anyone else?

[grandpanystrom61]

I just love how clean everything looks. Bummer that you have to open it up, but at least you get to look over everything involved and see if anything else is showing signs of stress. A chance to build it up stronger, that is some horsepower you have cranking it all.

 

[LarryA]

hopefully case and shafts are good? Good luck! Always a bummer when something fails.

 

[DeathBySnuSnu]

It did not do a major blow out.

Trans still functioned just not correctly.

Everything should still be good except for whatever is the failing part.....hub....thrust bearing...ect.

This was not a rev it up and dump the clutch thing like drag racing is.

More a gentle accel the drum in 1 and 2.

Get into 3rd and get it stable and at an rpm you think you can start at without bogging. Basically as slow as you can go in 3rd without chugging and pinging. Get stable aaaand....start recording......and nail it. No jerk, dump, snatch.....just as hard as it will dead pull.

Computer calculates the rate of acceleration of the heavy rollor.

I spun it 132mph in third gear.

 

[vwbug72501]

Time to think about tire speed ratings? Don't want a tire exploding even on the dyno. :xzqxz:

 

[DeathBySnuSnu]

All 3 are 130mph rated tires.

 

[DeathBySnuSnu]

I have the gear stack out and on the table.

Not yet tore down. Just by a visual inspection it looks like 3-4 hub and/or slider is not round.

The big thing is both brass syncros are broken into several pieces.

 

[Jack Klarich]

Ouch, broken synchros, that is going to hurt

 

[LarryA]

could it be a shaft bending under load , or a worn hub/gear tooth profile allowing the partial disengagement in

3rd gear? doesn,t sound like it popped out of gear, but some sleeve or bearing allowing 3rd gears/hubs to rattle around?

 

[DeathBySnuSnu]

It looks like the hub twisted.

It is not as hard as a gear.

The gears and shafts will take it.

The syncro hubs are what connects the gears to the shaft.

 

[LarryA]

hopefully there are stronger hubs available.....I had thought that a loose pocket bushing/bearing or loose countershaft front bearings, or worse yet spreading case bores could let the 3rd gears get loose....a bad hub is actually maybe the best news you could get!...at least that would explain the broken syncronizer I suppose with a direct 4th gear tranny 3rd is the weakest gear, but the gear that catches most of the grief....just the way it goes...good luck...hope you can make it stronger!

 

[DeathBySnuSnu]

4th gear is not 1 to 1.

Mine is .82 to 1

Most normal is .89 to 1

Third and fourth are both aftermarket gears.

First and second are stock vw gears.

The output/pinion shaft is aftermarket splined shaft to do away with the keys.

It looks like I put a replacement "heavy duty" aftermarket hub and slider assembly on 3-4.

After talking to a race trans builder I have been told that that heavy duty unit is half junk. Said the slider is excellent but the hubs were soft. A stock hub would be better.

I think I am gonna put it back together with a German hub, the hd slider, and new syncro rings.

Now to dig in my junk pile for an original keyed 3-4 hub. Then buy some new brass parts.

 

[LarryA]

Just familiar with old school transmissions. Good to hear there was minimal damage. I suppose stock hubs have some heat treatment, whereas aftermarket, who knows what material and heat treatment?

Are they a cast steel item, then internally and external broached?

Anyway you've found the weakest link in the chain.

Good luck on your way back together.

 

[LarryA]

looked at the vw transmission diagrams this am. I am assuming the reason that the vw 4th or top gear is gear driven instead of coupled, must be that the power flow must take a 180 deg turn whereas in our conventional transmissions power flow is straight thru. Hope I am on the right track....lol I try to do my heavy thinking in the morning!

 

[DeathBySnuSnu]

That is basically it.

Good thing is that it can be changed to different ratios.

 

[DeathBySnuSnu]

Muncha Buncha

 

[vwbug72501]

Ouch!!!:AGGHH::Crap::busted::AGGHH:

 

[DeathBySnuSnu]

3-4 hub is not round anymore. These broke rings are just collateral damage.

I tore down another core.....and not happy with the rings in it either.

But the hub was real nice.

I thought I was going to scrounge up some parts and put it right back together. Just ain't working out that way. Looks like I will be ordering parts.

 

[grandpanystrom61]

Bummer

Not good at all, but at least you found what went wrong and have the ability to fix it.

Never opened up a tranny yet, you were my first, wow, what a whole new world. I am not a motor head, just that person that learned what was needed to fix what was needed. I just keep finding new info on new subjects I never thought of.

so you have to wait, yet so that you fix it.

 

[DeathBySnuSnu]

Yeah....I am just gonna replace this weak link and see if it holds up.

This trans is far far from stock. It has some hp parts in it already. It just was not built or heavily worked on this time around.

I built it with the original build of the trike. And then did not like the gear ratios and took it back apart and changed a lot of parts. Not because of broken but to up gear it more.

I changed 3 and 4. I also put a new hub assembly in for them. Now years later I find out that the hub in that assembly is weaker than stock.

 

[LarryA]

years ago....like 45+ a guy at work, who ran vw's said you needed special fixtures to work on and assemble these transmissions, for that reason he just swapped with good used trannys. Any truth to the fixture business?