Transmission grumbling

[VW_Jimbo]

Hey all,

I am in need of some more help. Damn it, all I want to do is drive the damn car!

So, got the oil starvation issue solved, engine back in the car. Was going to set some basics and decided to drive around the block to warm everything up. It was running so good that I gave it a little more throttle than I should have, at the time. Well, long to short, the tranny locked itself out of 1st and 2nd gears. Drove back home in 3rd, never tries 4th. Then half way back, 1 & 2 came back - uh oh, this is not going to be good!

Went for a little bit of a cruise to see what was going on. Well, at more than 1/2 throttle accelerating through the gears, everything is good. Slowing down and downshifting is when it happens, but only after a hard acceleration. It keeps locking me out of 1st and 2nd. Never experienced anything like it, ecspecially, since it comes back! That to me is just freaky.

Then,.........I get back to the house, put it in reverse and the noise!!! Like the differential bearings are shot. Get it in the garage and it hops a few times backing up into the garage. We have no slope, so something is locking up and then releasing.

Decide to remove the tranny during the week and find out what it is.

I have only disassembled a few VW trannies in my years. Replaced differential bearings and set the preload, but that was in a shop with actual tranny tools for VW trannies!

Now, I am in the garage and want to tackel it. Lets see what is possible. Worst case is buying a rebuilt tranny!
_________________
Jimbo

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

[modok]

It's probably end-play. Pull and push on the input shaft and feel it go in and out 1/4 inch.......it's not supposed to do that!!!

Take the nosecone off the trans I think you will see the top bearing has eaten into the nosecone. mill/sand it flat and put it back on. Fixed enough to last until the next rebuild.

Can cause a loud gear noise on deceleration. I bought a rebuilt trans that howled on decel....took off the nosecone, worn into the nosecone as usual, could not believe they somehow didn't notice this. Maybe it was the new guy.
That trans has been ok since, thank god.

What year/kind of transmission is it?
The earlier ones are easier. i like the SSC late model ones but I have my buddy do the assembly as he has the tools and 30 years experience. if he quits i will have to learn, and buy the tools. Not really looking forward to that, gear oil stinks. I guess I'd use scented gear oil. Mystic brand is nice.

[mcmscott]

Worst case is you buy a rebuilt tranny that you know nothing about and pay a stupid core charge, probably the cost of the trans it self
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[VW_Jimbo]

Ok. I am back. Sorry for posting limited info. I did not realize I was going to the Angel game last night. Had to get the stink of gear oil off me!

Here we go, down the rabbit hole!

No in and out play on the input shaft, but about a 1/4 of an inch of side to side play. You tell me, seemed excessive but not off to badly.

This is what transpired yesterday.
Got it on the stand and started draining the oil.

Found drivers side inner flange seal unseated and a decent amount of tranny oil in the grease.

Got that on the stand, rotated it over to the drivers side and pulled the axel flange and diff cover off. Pulled the diff. Bearings look great. Spider gears you good, no abnormal wear marks, diff gear looks good. Pinion gear looks good. I thought for sure the diff had blown a bearing and was wobbling around inside. That was what the noise was like! Reverse gears where in really good shape. Let dig deeper.

Pulled the nose cone. All looking good.

Bearing look good. I do not feel anything on the shafts. Did some marks on the gear selector shafts and took a bunch of measurements.

Then pulled the nuts from the gear carrier housing and removed the pinoin nut.

Put the gear housing up on the bench and loosened the selector forks.

Marked the selector forks and rods. Took measurements, as always!

Removed reverse gear from its fork. All looking normal. Took the circlips off the shafts.

Then over to the press, being really careful of the teeth interaction, them dropping out and of anything abnormal. Both shafts pressed out easily. Still nothing!

3/4 shaft came out last so I disassembled this one first. This was the shaft I was not having any issues with, so I was expecting nothing to show up.

3rd gears synchronizer hub had a loose mass of metal stuck in each of the recesses.

No wear on the gear that I can see. What do you guys think?

And the inside of the hub has some roughness to it.

What are these two marks on each of the teeth and how pointy are those synchronizer teeth suppose to be. They all have a point to the face of the tooth and the top of each tooth is also beveled. Normal? Back side is flat.

Onto 1 & 2

See anything I missed?
_________________
Jimbo

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

[modok]

It looks like on the 3rd and 4th gears, the hubs were welded to the gears by the last guy who built it, but the welds are just terrible, and came loose.
Maybe....the weld falling out JAMMED them.... like they had no end play?

[67rustavenger]

Admittedly, I know nothing about the inside of a VW trans.
But in the image below, those look like welds on the 3rd gear hub.

But what do I know?

I hope you get it fixed with little $$$ involved.
_________________
I have learned over the years.
Cheap parts are gonna disappoint you.
Buy Once, Cry Once!

There's never enough time to do it right the first time. But there's always enough time to do it thrice.
GFY's Xevin and VW_Jimbo!

[VW_Jimbo]

In addition to the above. Man, I took a ton of photos!

Here is the inside of the nose cone. I do not see any bearing hit or rubbing. Am I just not seeing it?

And the inside of the gear housing, looking at the shaft carrier bearings.

The differential.

Teeth look nice.

Bearings look good.

Reverse shaft and gears look good.

Did I miss anything?

Spider gears in the diff look nice. They seem tight with light resistence. I cannot see any issues with that. Should I disassemble the diff or am I good with just inspecting it from the current prespective?
_________________
Jimbo

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

[VW_Jimbo]

[modok]

I think the two notches on the reverse gears identify them as being for late 70's transmissions.
Earlier ones looked kinda the same, but have no notches. There must be some important differences, but I don't really remember what it is.

Some people TIG the gears, others like to MIG them, and, whichever works is fine IMO.

And, there is supposed to be two or three reliefs to let oil flow through there, but it looks like they put the weld IN the oil relief, which wasn't real smart either.

[VW_Jimbo]

[VW_Jimbo]

[VW_Jimbo]

[gears]

It seems pretty clear that this sloppy weld:

Was rubbing here on the hub:

Clean up the parts, weld both gears correctly (or replace), install new bearings, and zip it up. I have confidence you can repair it yourself, thereby saving yourself a bunch of money.
_________________
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[modok]

you got this far, fairly quick. Problem seems clear enough.
I'd guess it does not have a lot of miles on it since the last build, since the nosecone and reverse gears look perfect.

If you were down the street I'd re-weld the gears for you, touch up the thrust surfaces, and maybe we swap to a later model diff and side cover which are stronger...........
maybe it would hold up just fine?

[Dougy Dee]

Is there any notchiness when spinning that pinion bearing?

Recently I've had several SKF bearings split the inner race. I noticed a slight hiccup when spinning it that wasn't visible until removed.

Also take a deeper look at the Mainshaft bearing. Get a good light and check both races and balls all the way around. That crap the weld dug up has to go somewhere...

[jpaull]

From the looks of the spatter around the weld, looks like they used flux core wire, pretty nasty to do that.

[modok]

I was guessing stick weld

flux core, or dual shield, would actually work great, if it was done right, which it sure as hack wasn't

[oprn]

I am not tranny expert but have been into a few over the years. Yes someone did a bit of a redneck job of welding the gears but I like others do not see the real problem there.

Could it just possibly be a broken tranny mount or a shift tube come lose in the tunnel?

Just wondering...

[modok]

The problem he was describing is VERY similar to what happens when the end play gets jammed, from the 3rd or 4th gears spinning.........which is why you weld them so they don't spin.
it's just, kind of ironic, that the weld caused the problem it was supposed to prevent.

[oprn]

Ah! So the gear is moving back and forth on the hub then?