Lower Balance Shaft Won't Turn When Tightened

[Deemar]

The car is a 1983 Porsche 944 with 22,XXX miles and has been sitting for 13 years.

I have been all over the internet with this and up and down Facebook groups, nobody can figure it out. I see many other people with the same issue on other forums and each time they figure it out, they don't post how.

I took apart the front of my 1983 944, replaced the water pump, all the pulleys, the timing belt and then it came time to reassemble the housings for the upper and lower balance shafts. The upper one went together no problem, I torqued it down to 33 foot pounds and I can spin it with one hand.

The lower one I had issues with, I put a burr on the shaft trying to hammer the woodruff key out and had to use a pry bar to get the pulley off but eventually got it off. When I put it back together, I did the following:

• Greased up a new O-ring and put it on the backside of the lower balance shaft assembly.
  Put the assembly onto the balance shaft.
  Bolted the assembly on with moderate arm torque.
  Oiled and slid on a new thin mylar gasket.
  Oiled and slid on a new race.
  Oiled and slid on a new 48mm seal and tapped it in.
  Tapped in a new woodruff key.
  Slid on the old pulley with the O on the bottom, key at the top.
  Put on that cover plate thing, a new gold washer and the old bolt.

At this point without tightening it, I can spin the pulley no problem, it's really easy. Once I give the bolt a 1/4 turn so it's just snug, I cannot move that pulley with my hand, it's impossible. It'll turn quite easily with a pin wrench but not with my hand.

I took it apart multiple times, made sure everything is sliding properly, the shaft is spinning freely inside the race, the shaft pushes in and out freely. The only thing I haven't done is take the big plate cover off the balance shaft itself to look inside and I'd like to avoid that if possible. I don't have a torque wrench that goes down low enough to put it back on.

Someone mentioned I should try putting 3 of the thin mylar gaskets on instead of one but I don't have 3 so I'll have to order some if I want to try that. I'm not sure if that would help. Someone else mentioned loosening an L-bracket that's behind the lower balance shaft assembly but I think that's for power steering and I don't have power steering so I don't have that bracket. My assembly bolts directly to the block.

The last thing I discovered last night is if I assemble everything without the thick gold washer on the pulley, everything works fine and I can spin by hand with it tightened down. The second I put that washer on there and tighten it down, it's no bueno. I'm not sure how that's even possible, maybe without the washer it can't push tightly enough against the pulley, who knows.

I did hammer down on the woodruff key to pop it out so maybe I could have bent the shaft but I doubt that, I wasn't slamming it. And it doesn't feel bent.

I'm almost at the point now where I want to finish the timing belt, drive it to a shop and have them do the balance shaft assembly because I have no more ideas. Please help!

[michaelmount123]

The balance shaft needs to be properly positioned fore and aft. Out of position it doesn't want to spin. What positions the shaft? Once the drive gear is assembled The fore and aft position is established and the shaft should spin freely. Don't add additional mylar seals, don't do anything not in the FSM. Note that sometimes the bearing(s) are not seated properly due to the pin not precisesly located in the bearing. Ensure this is okay.
MM

[Tom]

The car is a 1983 Porsche 944 with 22,XXX miles and has been sitting for 13 years.

I have been all over the internet with this and up and down Facebook groups, nobody can figure it out. I see many other people with the same issue on other forums and each time they figure it out, they don't post how.

I took apart the front of my 1983 944, replaced the water pump, all the pulleys, the timing belt and then it came time to reassemble the housings for the upper and lower balance shafts. The upper one went together no problem, I torqued it down to 33 foot pounds and I can spin it with one hand.

The lower one I had issues with, I put a burr on the shaft trying to hammer the woodruff key out and had to use a pry bar to get the pulley off but eventually got it off. When I put it back together, I did the following:

• Greased up a new O-ring and put it on the backside of the lower balance shaft assembly.
  Put the assembly onto the balance shaft.
  Bolted the assembly on with moderate arm torque.
  Oiled and slid on a new thin mylar gasket.
  Oiled and slid on a new race.
  Oiled and slid on a new 48mm seal and tapped it in.
  Tapped in a new woodruff key.
  Slid on the old pulley with the O on the bottom, key at the top.
  Put on that cover plate thing, a new gold washer and the old bolt.

At this point without tightening it, I can spin the pulley no problem, it's really easy. Once I give the bolt a 1/4 turn so it's just snug, I cannot move that pulley with my hand, it's impossible. It'll turn quite easily with a pin wrench but not with my hand.

I took it apart multiple times, made sure everything is sliding properly, the shaft is spinning freely inside the race, the shaft pushes in and out freely. The only thing I haven't done is take the big plate cover off the balance shaft itself to look inside and I'd like to avoid that if possible. I don't have a torque wrench that goes down low enough to put it back on.

Someone mentioned I should try putting 3 of the thin mylar gaskets on instead of one but I don't have 3 so I'll have to order some if I want to try that. I'm not sure if that would help. Someone else mentioned loosening an L-bracket that's behind the lower balance shaft assembly but I think that's for power steering and I don't have power steering so I don't have that bracket. My assembly bolts directly to the block.

The last thing I discovered last night is if I assemble everything without the thick gold washer on the pulley, everything works fine and I can spin by hand with it tightened down. The second I put that washer on there and tighten it down, it's no bueno. I'm not sure how that's even possible, maybe without the washer it can't push tightly enough against the pulley, who knows.

I did hammer down on the woodruff key to pop it out so maybe I could have bent the shaft but I doubt that, I wasn't slamming it. And it doesn't feel bent.

I'm almost at the point now where I want to finish the timing belt, drive it to a shop and have them do the balance shaft assembly because I have no more ideas. Please help!

Maybe post a picture of your assembly so we can see what you are up to. Pictures worth a thousand words and all. What bolt are you tightening that makes the shaft tighten up??

I highly doubt you bent the balance shaft, but if you remove the front carrier and spin the shaft, you should be able to see any run-out (bend). You might check the bearing in the nose piece too, just to make sure you didn't knock it out of position (which seems unlikely).

[Deemar]

This is the balance shaft pulley and the gold washer I mentioned. You can see the pulley here without the washer and I can spin this fine. Add the washer and it locks up.

IMG20241108220154.jpg (2.77 MiB) Viewed 578 times

[Deemar]

The balance shaft needs to be properly positioned fore and aft. Out of position it doesn't want to spin. What positions the shaft? Once the drive gear is assembled The fore and aft position is established and the shaft should spin freely. Don't add additional mylar seals, don't do anything not in the FSM. Note that sometimes the bearing(s) are not seated properly due to the pin not precisesly located in the bearing. Ensure this is okay.
MM

Sorry, I don't quite understand. What do you mean by, "Once the drive is assembled?" Do you mean the camshaft? Does that somehow link a gear to the balance shaft? From your explanation, it sounds like something is not connected somewhere but I need to know more to understand what you mean.

[blueline]

Here are a couple of links regarding posting videos on Carpokes.

viewtopic.php?t=1733&start=910#p37696

viewtopic.php?t=1733&start=910#p37698

[Deemar]

I thought maybe the whole balance shaft assembly wasn't compacting down enough to put the balance shaft more in the middle of its housing and I noticed the O-ring on the back of the assembly had gotten pinched. I was hoping that was stopping it from sitting all the way in so I tried removing the O-ring completely and reassembling just to check it but nothing changed. It still didn't work. I still don't know what the issue is.

[Tom]

Here is a diagram of the lower balance shaft assembly. I would take yours apart and make sure every piece is in place as shown. Maybe document it with pics here in case we see something you don't. I would also loosen the front carrier to finger tight, then torque the pully bolt and see if it still binds. If not, the carrier just needs to be installed carefully, as I mentioned above, to avoid the binding.

lower bs parts 1.jpg (512.8 KiB) Viewed 533 times

[Deemar]

Here is a diagram of the lower balance shaft assembly. I would take yours apart and make sure every piece is in place as shown. Maybe document it with pics here in case we see something you don't. I would also loosen the front carrier to finger tight, then torque the pully bolt and see if it still binds. If not, the carrier just needs to be installed carefully, as I mentioned above, to avoid the binding.


lower bs parts 1.jpg

Thanks, I'll remove the carrier and see if that's it, it's possible the previous owner didn't properly assemble it. I don't have a torque wrench to properly put it back on but it's not working at the moment anyway. I'll borrow one before I reassemble everything eventually.

Where is the carrier? Is that the 4 bolts at the front of the long plate on top of the shaft? I see 4 bolts right behind the assembly, I think they're 10mm or 12mm. I'll try that today, I'm just about out of options at this point. If I can't figure this out, I'm taking it to a mechanic to figure out and that'll probably cost close to the entire value of the car. I'm willing to try anything you can suggest.

[Tom]

By carrier, I meant the part shown as 19/25 in the diagram above. If you don't have power steering yours will look different, but it's the part the oil seal sits in. Take lots of pics when you take it apart. If you haven't taken it apart to see what's back there, that's a must!!