Automatic transmission installation Warning Oil pump driveshaft

[Wasted youth]

To link to this thread

[orwell84]

This is just a shot in the dark. I'm curious as I have the same engine and transmission. There is a ground wire on the transmission that needs to be grounded. I don't think this is your problem though. best of luck.

[Wasted youth]

Ground strap cleaned and properly connected. White wire to transmission base connected also.

Bus now up on jack stands. Shift linkage disconnected from transmission. Shift lever on transmission seems to have a huge amount of radial slop, like it won't engage anything. Pressing it all the way back against its spring is the only time I feel anything that might be an engagement. Rotating shift lever towards front of bus I feel no resistance or shift 'bumps' at all.

Started engine, idling. Crawled underneath; shift linkage still detached, I tried to manually shift it through a full range of motion. No reaction at all.

[Wasted youth]

I was reading the downloaded manual in our Technical Archives, and this has me wondering:

https://www.thesamba.com/vw/archives/manuals/techtran_vw_transmission_003_010/80.jpg

I am concerned that I am not building hydraulic pressure for some reason.

Given that the pump drive shaft will slide out by hand during assembly, and it needs to be inserted down into the tube before mating to the torque converter, is it possible that it might not still be engaged to the base of the pump?

Wouldn't that be obvious because the drive shaft would be too far out of the tube and also wouldn't you feel it bind when mating to the torque converter?

[Wasted youth]

I opened pressure test ports; 2 - Main Pressure and 3 - Primary Throttle Pressure per Bentley, Ch. 7 Fig 3-1 on page 7-8

You're supposed to attach gauges to each port and follow the procedure specified to analyze pressures, but I do not have any of the correct fittings nor do I have the correct gauges, so I pulled the plug off the Main Pressure first, had my son start the engine and I hoped fluid would spray out, but found zero fluid coming out. It's supposed to be 45.5 PSIG at 1,000 engine RPM. I then put the plug back in that, then did the same for Primary Throttle pressure port. Nothing there, either.

Both ports did drip some fluid out when I pulled the plugs, but absolutely no pressure was seen.

I am not building hydraulic pressure for some reason.

Besides a missing or damaged Pump Drive Shaft, what else could cause the lack of pressure build up? ATF Sump level is full on the dipstick.

[Wasted youth]

EDITED FOR CONTENT...

Let's assume I somehow screwed up mating the engine to the transmission, and the pump drive shaft is not engaging the pump.

Aside from dropping the power train and separating it to verify this, is there another way to tell if the pump is rotating?

Could there be something in the Throttle Body or Vacuum Governor Unit (Modulator) be stuck and not allowing the pump to draw a suction?

My understanding of basic, initial fluid flow is that it goes from the pan/sump to the filter, to the pick-tube and drawn into the pump, and then discharged to the Throttle Body Manual Valve, and then distributed through the Throttle Body depending on what Shift Lever and operation is required.

It is also my understanding that the pump is positive displacement, so even if there was air in the suction side of the pump, it would eventually be purged if there was sufficient fluid.

Should I consider dropping the pan and trying to see if any of the pistons are stuck? My gut tells me this is an unlikely venture, as the fluid is fresh, clean and properly filled. I suppose a piston could get stuck if it were sitting around for months in bad fluid, but I moved the bus under its own power in December. Also, I am not knowledgeable about theory, so is it possible that one of the pistons could be causing a failure of fluid pressure build up?

[Alex6373]

Make sure the gear selector is aligned right and not positioned just off the position to drive I had my 003 completely rebuilt and I had to adjust the cable at the trans a bit to get the Transmission to find the drive positions.
Mine was off just a bit and would not move also!

[Wasted youth]

I tested all four pressure taps and I got nothing out of any of them while at idle and manually cycling the shift lever. I left all four plugs out, then I briefly increased engine RPM then looked underneath for a spray or puddle of ATF, but nothing found so shut it down. Want to avoid heating things up if there is no ATF moving in there.

I have left the linkage removed from the cab shift tower and the bus is still up on jack stands.

Dropped the pan and checked for shrapnel and debris, but it was clean.

Made a new pan gasket, refilled the fluid with fresh Dexron.

No improvement - no action.

[rugblaster]

This is a total shot in the dark, I haven't worked on these in several decades. I did go to the factory school for the repair of these units.

As you already know, there is a oil pump driveshaft that goes from the torque converter to the oil pump in the trans. I suspect something has compromised the driveshaft. I did have one that snapped in two just past the splines on one end.

I know that shaft is relatively fragile, even brittle. You will have to take it apart to find out. I can't think of any other way. I have pulled the automatic part from the final drive with the engine still in the bus, but I don't remember the specifics other than tilting it down in the front.
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[Wasted youth]

[Multi69s]

Before you pull it, add more trans fluid. The way these dipsticks are inserted and wipe the edges when they go in and out makes checking the fluid difficult at best. Throw another quart in, at worst it comes out the top breather.

If you pull it inspect the pump shaft at both ends, and using a flashlight examine the splines in the torque converter and the transmission pump. I have seen these spline get destroyed by improper engine installation.
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[Wasted youth]

Thanks for the insight. I'll try to add a bit more fluid, but I'm pretty confident at this point I somehow scewed up the reinstallation. I asked a coworker of mine who rebuilds transmissions as a sideline to read this thread, and he responded along the same lines as you and rugblaster

By the way, Mutli69s, it was your 003 rebuild thread that inspired me to rebuild mine! You paved the way for me on that, and it ran fine! (Until I done mess' with it! )

The possibility that I let the driveshaft become un-indexed during the mating up may be compounded by it jamming and damaging either end as I tightened everything up.

Only way to tell is by removing and separating the engine/transmission and take a look.

Yay!

That won't be this week, but I will post results... no matter how embarrassing.

[Wasted youth]

This morning, I pulled this all out again...

So I could try to find out why my refreshed engine that I married up to my rebuilt transmission still did not get me down the road...

I have discovered that I have ruined my oil pump. The Oil Pump Driveshaft was not seated properly and ruined the impeller when I put it all together. This happened because I failed to install the Torque Converter onto the Turbine and Oil Pump drive shafts once I verified they were both properly seated.

What I actually did was leave the Torque Converter installed on the Flex Plate on the engine, then carefully aligned the TC onto the aforementioned driveshafts and married up the engine and transmission. I did it that way based on my memory... which served me poorly and was grossly incorrect.

You should not do it that way.

Always install the TC as mentioned above, marry the engine up and then rotate the mass while lining up and installing the three Flex Plate bolts that hold the TC to the Flex Plate. If you don't, there is great risk in having the Torque Converter not marry up the Oil Pump Driveshaft on both ends of the splined shaft... one end to the TC and one end to the Oil Pump.. and the damage could occur. It can seem like you have them indexed, and you probably do at the beginning of the move. But the natural movements and shaking of the two units coming together likely jarred the driveshaft out of its seat in the Oil Pump. Kiss it all good-bye once you bolt everything in place. Of course, you won't know how fucked you are until after everything is completely installed and you try to drive the bus.

I did find some information in the Bentley about TC install, and also on how to remove it from the Flex Plate, but nothing so far that warns of the danger that doing it the way I did could allow the Pump Driveshaft from dropping out of its impeller in the Oil Pump without me knowing it. The damage occurs when this is all buttoned up, and the shaft now press back against the impeller with nowhere to go except shattering the impeller.

I found this thread, where this poor guy suffered what seems to be the same problem:

https://www.thesamba.com/vw/forum/viewtopic.php?p=4023187#4023187

I removed the Turbine Shaft and the Oil Pump Driveshaft and took a mini maglight and looked down in there. I can see the broken impeller, and cannot ever find the seat for the driveshaft.

The Oil Pump Drive shaft splines looked great and indexed nicely into my rebuilt Torque Converter...

But it didn't matter, because the Oil Pump impeller was all broken up so there was nothing the driveshaft could turn... which is why I could not develop fluid pressure! It is not supposed to look like this: The Oil Pump Driveshaft is too far down into the Turbine shaft indicating serious damage to the oil pump.

[Wildthings]

I like to stand the tranny on end to install the TC. Even then it can be hard to get the splines to align. You then need to wire the TC in place so that it can not come off the splines if bumped or otherwise mishandled during install.

[Tcash]

That sucks.

[Wasted youth]

[Xevin]

Ah shitski Wasted youth. That's a bummer. But you will solve the puzzle. Bus on. PM on its way.
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Keep on Busin'

[Wasted youth]

Thanks, Xevin... will be looking.

Also, I will be digging around for information, but does anyone know off the top of their head if the oil pumps were interchangeable through the 010 series (later models, up into the water-cooled Vanagon era) transmissions?

Wonder if I can replace the damaged impeller off this 003 with one off an 010?

[Abscate]

This mistake will never be made again on the Samba.

Thanks for the write up and share. Painful, but this is how we all get smarter.
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[Wasted youth]