Ring and pinion video inspection

[Parkker]

[Parkker]

[61Scout]

Okay, I know a lot of folks are going to roll their eyes at me right now, and let me say upfront that it seems a rebuild is in your near future. That said, you may want to run an additive like this in the meantime:

http://www.archoilcart.com/frictionmodifier.aspx

This won't save your gearbox if you've already got metal floating around, btw. But it might just extend the life a bit. YMMV.

I'll also say, and again I know some of you will roll your eyes, but at times some gearbox or diff noise isn't always an instant death. I have a Dana 44 with some whine on decel. I've checked the pattern on it and it's not perfect, but okay. No noise at all under acceleration. Anyway, this axle has been noisy now for over 50K (since I've owned it) and is still going strong.

Okay, now all the experts around here can throw me on the spit and rotisserie my butt. I'm not going to engage in a debate over this, just sharing my life experience. It's your rig and your money, so do as you please. Have a nice day!

-Kevin
_________________
1986 Westfalia Weekender Wolfsburg, RJE 2.3
1985 Tin Top, Subie 2.2 + 5MT
Floppy Mirrors no more: http://www.thesamba.com/vw/forum/viewtopic.php?t=653018&highlight=
Remove the front spindle nut with ease: https://www.thesamba.com/vw/forum/viewtopic.php?t=679567&highlight=
Remove the rear wheel bearing housing without messing with the big 46mm nut: https://www.thesamba.com/vw/forum/viewtopic.php?t=679507&highlight=

-Nec Spe, Nec Metu

[Parkker]

Thanks for the tip 61.
I have a feeling from what I have learned here and all the indicators that it's probably a main shaft bearing.
I likely won't be driving it much. Not feeling to confident about venturing far from home with it now.
Over 15k into it and have never gotten to enjoy it yet.
Not sure what I will do at this point.

[Sodo]

I wonder if you can insert a lever into the oil filler hole and 'feel' for slop in the mainshaft ball bearing.
_________________


'90 Westy EJ25, 2Peloquins, 3knobs, pressure-oiled GT mainshaft, filtered, cooled gearbox
'87 Tintop w 47k 53k, '12 SmallCar EJ25, cooled filtered gearbox
....KTMs, GasGas, SPOT mtb

[Parkker]

[Sodo]

Your "low" temps are interesting. What engine do you have? Did you squirt it with the IR at the same time you measured 145* with the other unit?

[Parkker]

[Sodo]

63k, thats kind of a jewel!

One problem you may have is the 3rd-4th slider cracking. This does not generally create dust in the oil, but parts can break out, and damage other stuff. if your plug is still out you might try to devise a way to sweep the floor looking for "parts".
The 3-4 slider problem was "solved" in appx mid-1989 so it's certain your trans has this weak spot.

Other problem can be the 4th gear itself cracking, in which case it can push hard on the "end-play", rubbing very hard on the mainshaft bearing, overheating it, ruining stuff (such as the mainshaft ball bearing). Perhaps making some noise. In the lower gears the relative motion of 4th against the mainshaft ball race is fastest, diminishing eith each gear until in 4th the gear is spinning same speed as the bearing thus no rubbing (motion).

I don't know if the 4th-gear cracking was ever solved (by VW), and I don't know how widespread the 4th gear problem was. One trans builder (small, one-man shop) said he sees a broken 4th gear at least every year.
_________________


'90 Westy EJ25, 2Peloquins, 3knobs, pressure-oiled GT mainshaft, filtered, cooled gearbox
'87 Tintop w 47k 53k, '12 SmallCar EJ25, cooled filtered gearbox
....KTMs, GasGas, SPOT mtb

[gears]

I'd like to correct a couple misconceptions before they become "common knowledge":

I often see the term "cracked slider" used, when in fact the slider never cracks. The "slider" is actually the operating sleeve. The operating sleeve slides over its matching clutch gear, aka the "hub". It's the hub that cracks. So, "cracked slider hub" would be the correct slang description.

While the hub design changed in at least 3 ways around '89, it wasn't until VW began Nitriding the newly designed hub that it became more reliable. The non-nitrided hubs probably lasted about as long as the previous square slot design .. an average of around 120K miles. Nitriding alone may have been the key. We'll never know.

While one shop may see a cracked 4th gear each year, this doesn't mean our 4th gears are weak. It's the overheating of 4th gear that causes the EB weld area of the gear to fail.

It isn't the friction of 4th gear thrust surface against the mainshaft ball bearing that's causing the overheating of 4th gear, nor is this friction the direct cause of wear seen on the ball bearing race.

As discussed numerous times before, when our heavy vans are driven long distances without cool-down (especially uphill with upgraded engines) 4th gear heats to such a high temperature that the two thrust surfaces begin to fuse together. The act of disengaging 4th gear then pulls material away from the grossly overheated mainshaft ball bearing. Once this process begins, it's a steady downhill decline for this thrust surface.

I doubt any of the above pertains to the OP's noises.
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[Sodo]

Thks for clarifications.

In lower gears the mainshaft (and the inner mainshaft bearing race) spins faster than the 3rd/4th gears, and OP said there's "noise in lower gears". Anyway that's the reason I suggested 3rd/4th problems as possible sources of noise that goes away under other conditions.

In that pic linked above the friction wear between the 4th gear and bearing race occurred because the 4th gear became "wider" after cracking. This was from a van with an SVX (6-cyl 228HP motor) so certainly 4th gear could have been a sorry unit!
_________________


'90 Westy EJ25, 2Peloquins, 3knobs, pressure-oiled GT mainshaft, filtered, cooled gearbox
'87 Tintop w 47k 53k, '12 SmallCar EJ25, cooled filtered gearbox
....KTMs, GasGas, SPOT mtb

[jberger]

[gears]

[Waldi]

The cracking 4-th gear has nothing to do with heat.
What about are we speaking ? 200C ? Sure not more under conditions with no bad bearings etc.

I have seen in 12 years 2 cracked 4-th gears in about 100 gearboxes.
Both ran on JX.
In the Austrian forum is a threat about another cracked 4-th on a JX.

Friktion welding, like the gears are put together , seems not always be under control. So i think its just some low % production foults.
They braek within hard load cycle. For example while emergency breaking in 4th without pushing the cluch.

A subi engine can never destroy a good 4-th gear or a new style hub.
Who has a gear ratio, than allows to drive in 4-th with 5800 revs ?

The old hubs breaks because of the design on every engine.
Like the first planes hat square windows and cracks from them, now all windows are round.

The needle bearing - i saw only 1 totaly melted bearing. On some bearing ends i see sometimes grinding tracks on the plastic, but as long the surface on the gear and mainshaft is ok, there was/is no problem with this.
I use also metal cages, just because ppl want it.

Here is the 2nd broken 0,85 4-th wich i found last week in a syncro box.
Hard to tell what happend first. (the needle bearing was ok)
But i think, 1st the hub breaks, than the 4th gear, than the bearing.

[gears]

You're probably correct, Waldi. But the average temperatures of our 4th gears here in the U.S. are WAY higher than any in Germany. What's the longest freeway distance driven @ 70+mph in Germany? Lots of guys in overpowered and heavy Vanagons have driven at high speeds from dawn to dusk. I've personally driven 26.5 hours straight, stopping only for fuel & coffee (not enough time for proper cool-down).

I'd venture that some of our 4th gears are heated to 400+*F .. to the point that the mainshaft's bearing surface itself takes on a mottled texture (without other parts self-destructing). That's some serious heat, when a long shaft can't distribute/shed heat from end to the other.
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[Waldi]

Why should a 4-th gear get hotter after 1000 miles than after 20 ?
I am not really asking, i know this is not the case.
If i drive 20km uphill in 4th it becomes hotter than driving 5000miles flat.
Or if i pull my 2,5t trailer over the Alps it will become hotter than driving at 70 all year long.

We have here also engine conversions.
And we have also stupid ppl driving full speed for hours over the highway.

I am happy that this kind of drivers are not my clients.

The temps you get on the gears while driving cannot change the metal resistance. And i dont think it bekomes near to 200 C. Otherwise the oild would carbonize in short time. Usually i dont see carbonized oil inside the box like on the pistons.

[gears]

I'm basing that statement on GT3 race car experience, in which race duration makes ALL the difference in gear longevity. Cars running 45 minute races can expect gears to last 100+ hours. Cars running 2+ hour races must replace their gears after 30 hours. The difference is heat build-up in longer duration races.

The evidence of heat build-up is pretty clear in Vanagon transaxles that are driven for longer distances with upgraded engines.

Maintaining the same speed as everyone else is the safest way to drive. Not everyone on U.S. roads appreciates the cuteness of a slow VW van. Our efforts at cooling our gear lube are centered around this reality.
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[ZsZ]

To Waldi and to Gears: Maybe oils are different on the two markets.
_________________
Zoltan
1.9 MTdi 2wd Multivan (ex Caravelle)
Van since 2006, engine since 2008

[Sodo]

I've driven on the Autobahn for long periods. It was a 4 hour drive from Freiberg to Kassel and we held it at 115-120mph the whole time. Peugoet Turbodiesel station wagon, pedal to the metal. This was about halfway across Germany. I am certain that a 4th gear can be put to the test in Germany.

I saw lots of T3 Dokas pulling trailers in germany, full of tools, workers, materials like a load of gravel for example.

This transaxle problem in the US has me puzzled. It should be worse in Germany, they drive pedal to the metal always. I think there are some crap rebuilds being done here in the US. And LOTS of them. Perhaps different quality replacement parts too.
_________________


'90 Westy EJ25, 2Peloquins, 3knobs, pressure-oiled GT mainshaft, filtered, cooled gearbox
'87 Tintop w 47k 53k, '12 SmallCar EJ25, cooled filtered gearbox
....KTMs, GasGas, SPOT mtb

[gears]

Probably some truth to that. I've heard a well-known trans builder here reject the notion that a reconditioned pinion bearing bore was essential. I'd say it's REALLY essential with upgraded power.

Part of the "problem" is the cost of replacement OEM parts in the U.S. compared to Germany. Some builders became conditioned to whiney customers who wanted cheap rebuilds (although what clearly happened to you defies explanation. You should have been given the option during a time of non-availability).
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com