Drill transaxle oil port with trans in-car

[Sodo]

In a discussion on the phone with member PCforno, a plan was hatched to drill an oil cooler/filter port that is higher than the "oiling plates" and thus ensures oil delivery to the most critical location. The idea was bandied about,,,, that it may be feasible for John Q. Public to drill & tap --- with the trans mounted in the van. PC declined to drill because his trans (GoWesty) has a 48k mile warranty but others with big engines / big torque might consider this PROPOSAL.

Another thread with info: "
Temperature Control (electric) - Manual Transaxle gearoil cooler" includes links to other Samba threads.

Of course you need to do this with the transaxle pressurized to blow the magnesium chips out. Drilling with a rotabroach creates all the chips OUTSIDE the trans, and the 'plug' remains inside the holecutter, so no problem drilling with the proper tool. Search Blair rotabroach and typo Blair rotobroach to see both kits. Many magnesium chips are created while tapping threads, luckily the air blows them out. You can see and feel them hitting your hand as you turn the tap. You need to unscrew, and spray the tap clean, about every full turn. The miniscule magnesium chips that might remain in the trans are not much to worry about, and your filter will catch them before too long. Steel in your trans oil is worrisome, but not magnesium. You are making progress to filter all new steel (from over-engining the trans) OUT, a few minutes of magnesium is a small price to pay for the coming years of steel-free oil.

Vertical height is in-line with the "hole". Drill 24mm rearward of the case junction.

8AN fitting duct-taped on location. (Right place, wrong method ) Note that this trans has a hose with cooled gear oil being pumped into the filler bung below. Drilling the oil hole above the filler bung allows you to check oil level much easier.

The oil blast hits 4th gear, also blasts into the 1/8" gap between 4th gear and the gear carrier housing. The goal is to cool and lubricate the mainshaft ball bearing. When 4th gear is being used there is a force on the gear faces. It is a rolling line contact. The equal and opposite force is on the ball bearings. This is more like a point contact, and the forces are much higher. The steel deflects a little, like a bowling ball setting on carpet. This deflection is what creates heat in an over-loaded transmission. On an overdriven powertrain component, your only hope is that cool oil will take the heat away. An oil jet is just the ticket!

In addition to cooled, directed oil, if you FILTER the oil at 10 microns you remove many of the metal fines generated by over-engining a transaxle. Possibly soon after they're generated, and before they've done other damage. Thus your metal fines don't beget more metal fines. Every time the cooler runs, it's purifying the gear oil. Its a beautiful thing.

Here is a pic suggesting that if the FRONT MOUNT of the trans is unbolted, and "let down" about 6 inches, there may be room for a drill motor to get in there and drill the hole. AFAIK,,,, nobody has tested if this is possible.

Location of the hole above the filler bung.

Photo of the fitting and the tools necessary. The fitting is 8AN x 1/4NPT
6AN x 1/4NPT is also feasible. FYI: Army-Navy standard 8=8/16"=1/2" hose. And the "6" designates 6/16"=3/8" hose.

Measuring the 'plug' created by the Blair holecutter. The case thickness here is appx 0.177" = 4.5mm

No problem with space to the tap to go deep. I think. I don't have a trans open, only have the gear carrier shown. It would be good info, for this proposal, if this can be confirmed.

Well here's the proposal. Nobody's done it AFAIK. If anybody sees a reason this WON'T work, please respond. Or reasons it will work too, and of course if there's a better way. All in the name of Vanagon Science. [/url]
_________________


'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

[flomulgator]

Oh that is clever. Any idea if the oil stream will hit both 4th gear and the mainshaft bearing area to the side?
_________________
She's built like a steakhouse, but she handles like a bistro!

[Sodo]

The water hose has been adjusted to 2 gallons/minute because the Weddle "gear" oil pump flows 2gpm.
The video helps to visualize the effect of 2gpm.


Link


I made a new nozzle this morning that "I THINK" will clear an Aluminum splash plate. But it doesn't blast the lower 4th gear partner, like the non-plate nozzles do.

This video shows the two methods. The nozzle is aiming a little better at the (fabled 3mm) .5 mm gap between 4th gear and the bearing, thus I think it's more likely to JET cool oil to the bearing. It's also possible to attach a nozzle to the upper fitting, to jet oil a little "forward" into that gap. But lots of John Qs can do this upper fitting method without welding. Or perhaps JBWeld a bent copper nozzle into their fitting.

It's my theory that the only way the bearing balls can get rid of their heat is by movement of oil and that flow to the balls is paramount for this project. It's comforting to see the firehose of oil that 2gpm is. Another thing to consider is a smaller pump of 1gpm might be easier to place on the van and is still huge flow.

Other thing to remember is the CCW rotation of 4th gear may carry oil upward, where it drains by gravity into the bearing. CW rotation of 4th gear will fling the oil downward. A nozzle from the driver side would fling the oil upward where it could drip down on other parts.

As a wild guess, with the nozzle aimed at the gap, 25% of the oil might go into the gap to the bearing, 75% might go to 4th gear. With the "straight shot John Q. fitting method", maybe 10% to the bearing, and 90% to 4th gear. A less-anal person might say "ferchrissake that's a firehose of oil and 10% of a firehose is PLENTY wet!"

====== EDIT July2 =====

Finally got ahold of a 4th gear to mock up the modification. There is no "3mm gap" between 4th gear and "the wall" The gap is about 1/2 mm. So the bearing won't get as much oil as was hoped. If you backed off your external transaxle case bolts 1/2 mm,,, oil would flow onto your garage floor. So it's not worthless., but not as 'cool' as envisioned.
_________________


'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

[pedrokrusher]

This is a great idea!

Can you drill a hole on the other side instead, where there is no shifter rod?
More space...
_________________
Pedro
1989 vanagon Karmann Gipsy #652, TDI AFN
1991 vanagon westfalia conversion TDI ALH Silverfox
ex-1989 vanagon syncro passenger Syncrofox (Sold)
http://www.thesamba.com/vw/forum/viewtopic.php?t=598791&highlight=
http://www.thesamba.com/vw/forum/viewtopic.php?t=493964&highlight=speed+aap+trans
http://www.thesamba.com/vw/forum/viewtopic.php?t=496589&highlight=carrier+bars
http://www.thesamba.com/vw/forum/viewtopic.php?t=506025

[Sodo]

Driver side is clear on the outside, but there's lots of monkeybusiness on the inside.

Continuing in the direction, where John Q. does this mod (with no welder or electroplating....)

If the hole is drilled rearward some (39mm from the case gasket surface)....

Then a curved nozzle can be used to aim the oil jet at the (fabled 3mm) 1/2 mm gap between 4th gear and the bearing.

This time I made the nozzle out of 3/8" copper tubing (in true John Q fashion). I had to drill out the end of the fitting with a normal 3/8" drillbit about 3/8" deep. Copper tube surface will be roughened and JB-Welded into the fitting.
_________________


'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

[dobryan]

You are having way too much fun with this.
_________________
Dave O
'87 Westy w/ 2002 Subaru EJ25 and Peloquin TBD

"To travel hopefully is a better thing than to arrive." Robert Louis Stevenson

MD>Canada>AK>WA>OR>CA>AZ>UT>WY>SD
https://www.thesamba.com/vw/forum/viewtopic.php?t=620646

Building a bus for travel in Europe (euroBus)
https://www.thesamba.com/vw/forum/viewtopic.php?t=695371

The Western Syncro build
https://www.thesamba.com/vw/forum/viewtopic.php?t=746794

[Pcforno]

hey sodo-looking good, but id be a little worried the length of the last port would hit fourth gear. how about a hole a little higher and tighter to the wall, like pictured below? it could possibly hit the 'gap' without a nozzle if theres enough clearance.

[tschroeder0]

sodo, this is really great research! It seems like the only thing need to find out is if you can get a drill in there to drill out the case, if I didnt have some more travel planned I would do it. Hopefully someone will be able to figure that part out soon. Thanks for doing this.
Todd

[Sodo]

You're welcome Todd. Just having some garage fun (As Dobryan suggested) and hoping to post something useful for theSamba. A year ago I didn't really "know" a single person with a Vanagon. And haven't yet met one willing to slide under (wild-eyed) with a drill in-hand, but that would be my kind of party. Except I did meet Boroko, he might be a candidate. Alika's notafraidofit (but went a different direction). PCforno's gathering info (and Rotabroach bits). I'm certain that gear carrier metal will fly soon. There could be differences between the magnesium and aluminum gear carrier housings.

What I **NEED** now, is a neighbor with a gear cluster that I can borrow. Ya'know like "a cup of sugar"?

I think that 3-4 slider/hub is forward of the nozzle, much bigger, and obscuring the smaller 4th gear. Need clearance for the nozzle to spin out a 'cone' while threading in. Also the 'bend' of the nozzle can be slight, just enough to blast oil at the 3mm gap. The hole location, then length & bend of the nozzle is what we need. It has to "clear" all the parts as it spins in, and end up aimed at the (fabled 3mm) 1/2mm gap.

Here's the envelope diagram. If I had a genuine gear cluster I could draw much better. The sole intent of this diagram is to show why I (currently) think the bend in the nozzle is important. 4th gear will get oil, but spinning at 3500RPM will throw it off. Blasting into that (fabled 3mm) 1/2mm gap to flow cooled, filtered oil past the over-worked mainshaft ball bearing is another very important goal.

_________________


'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

[Pcforno]

Thanks Sodo. It would be great if somebody could either confirm or post a picture of the gear carrier with he gears installed to see how much space for a nozzle exists before hitting the 3/4 slider or 4th

[Zeitgeist 13]

Where's the consensus location for an oil temp sender?
_________________
Casey--

'89 Bluestar ALH w/12mm Waldo pump, PP764 and GT2052
'01 Weekender --> full camper
y u rune klassik?

[Sodo]

These two locations are tested to be good. There are lots of other acceptable locations these are only the two I have tried. I think the flat surface near the serial number was chosen for the large Weddle thermoswitch, mostly because its the only "flat" surface and the hole is so big. Also it's clear behind about 1+inch for the large 3/4-16 tap.

There is also the "failed front transaxle drain" location but I think being near the pinion is key because the pinion is a significant contributor of heat. A location where heated oil is flowing past enroute to the oil pickup - is a good location too. A sensor in your oil-cooler lines is not so good, because you will be required to run the pump to see the temp.

You fellas tapping 1/8 pipe threads: Note there is a 1/8-27 NPT (USA) and a 1/8-28 BSP (British Std Pipe, metric). 27 threads per inch and 28 threads per inch, and the tapers are different too. Be sure you know specifically what thread your sensor has. They are both called "1/8 pipe" but they are NOT compatible. See this pic for clarification: (NPT and BSP taps).


Here's another pic of the oil blast angle. Note that the gear carrier case I have, the bearing land is broken out.

Would be great if someone can post a pic with the mainshaft and 3rd, 4th cluster inserted into the mainshaft ball bearing. And gear carrier case NOT broken.
_________________


'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]

While heat is being generated by the 4th gear pair, it's really the top (mainshaft) idler gear that overheats. The lower pinion gear doesn't overheat as badly because it's able to shed its heat directly via the press fit on the splined shaft.

On the other hand, the upper idler gear is looking for any way to shed heat. While 4th is engaged and heat is being generated, heat transfers to the mainshaft ball bearing inner race, virtually trying to fuse the gears thrust surface to the race. This usually leads to early ball bearing failure .. not an uncommon problem.

SUPER overheated gears look for further ways to shed heat, and will often leave needle-shaped divots on the 4th gear bearing race. The needles begin transferring too much heat, virtually fusing themselves in place.

The actual physical damage occurs when the overheated "engaged" gear is disengaged.

Anyhow .. your latest iteration, getting oil directly to the backside of the gear via the tube will probably cool it best. This is the most critical overheated area, IMO.
_________________
aka Pablo, Geary
9.36 @ 146 in '86 Hot & Sticky
'90 Syncro Westy SVX
'87 Syncro GL 2.5
https://guardtransaxle.com

[Sodo]

[ejimmi]

[gears]

[Sodo]

OK I see that, looks more like a fretting (with heat) than spinning abrasion.

Trying to comprehend this......In 3rd, with 3rd gear spinning 4th gear faster against the bearing race,,,,,, then abrades this fretted material off the thrust faces (into the oil)?. This is a difficult situation. Wouldn't 4th gear have to be a dull red-hot to do that? Whats happening to the gear faces at this temperature if simple heat+pressure is fretting the material? The gear faces have to be much hotter. Isn't the gear oil 'burned black' after one high-speed highway incident?

MORE OIL, and COOLED is about the best you can do from the outside. It seems that blasting oil at the bearing from the front side (the low-gear case) would be a more certain solution. But now we're talking about TWO ports; one to cool 4th gear, and another port in the next fwd case section to blast the mainshaft bearing. This would be good for you hi-torque fellas.

Now I wish I borrowed a low-gear case too. (ejimmi has one that can be perforated for John Q.)

========= HOWEVER i did borrow a cup o'gears (.77) from neighbor ejimmi =========

Photo is a Weddle .77 pair; The OEM VW (.85) 4th gear is about 3mm smaller (on radius) than the .77 so there is a 3mm ledge for an angled jet to impinge against.

A little setback here; the 1/8" gap (between 4th and the bearing land) that the Weddle guy told me about (that I renamed 3mm so I didn't have to type the slash on my phone) was a fable. The actual gap to pack oil into (to cool the mainshaft bearing) is only 1/2mm. Dang. Certainly some will go in. If you can imagine a 1/2mm gap between your transaxle cases, you would NOT consider your garage floor to be un-lubricated but not "cooled". Except if it's really hot then it will cool. Adding oil to the starved, problem-heat area that gears mentioned, is still a worthwhile goal. Just not as good as hoped.

I also did a small video so it's easier to see the relationships between the nozzles. The bent nozzle has lost its superiority over the "JohnQ straight shot at 24mm". Probably still better, but not by much. Phone movie was sent from the boonies so its real short, you may have to pause it.


Link

_________________


'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

[thasty07]

Just a pondering thought, but what about pointing that nozzle more towards the case with the expectation that cooled oil will cool the case and lower the ambient temp? as well as slide down the case into the 1/2mm opening?

Im following all of this closely as we are about to get ours set up for cooling.

[Sodo]

I agree that cooling the case will in turn cool the bearing and retain some of the bearing's press-fit tension. But if anything wrong with that,,,,it could be localized & un-even cooling. Can't tellya if that's good or bad but doubt the differential is enough concern.

The portion of the oil jet (most of the jet) that hits the gear will be turned into a spray and disperse around the entire case.
_________________


'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

[MR GAS]

Sodo, in your second post you corrected yourself about the CW rotation. I install the return port on the DR side spraying the Gear / Bearing interface. To do exactly what you had said initially .
Use the gears natural rotation to take the oil onto and over the gear. Over the top to allow more of the oil to drain off of the teeth into the MS Bearing ? Naturally . Not trying to spray into the Gear/ Bearing interface wanting to force the oil down?
You also aren't going to have to plumb lines right by the shifter. which seems more tricky.
_________________
Transaxles Rebuilt, Repaired and Re Geared 25 years. www.MRGASRebuilds.com