Starter rubbing flywheel?

[datto510]

I installed a dogleg in my 521 with a L20b. When I lett off of the gas at highway speeds it makes a terrible grinding noise, I thought it was the throw out bearing. I pulled the motor last night and found this:

 

 

 

 

 

I'm not sure if you can tell by the pics, but there is some obvious wear on the teeth of both the flywheel and starter. Anybody heard of this before? Why does it do this only at higher speeds and how can I fix it? Spacers on the starter?

 

Thanks!

[datzenmike]

Seen worse flywheel/starters, but I don't think it's that, as the flywheel and starter aren't near each other when driving. I would suspect the counter gear bearing.

 

Does the problem go away in 4th gear???

[datto510]

Seen worse flywheel/starters, but I don't think it's that, as the flywheel and starter aren't near each other when driving. I would suspect the counter gear bearing.

 

Does the problem go away in 4th gear???

 

 

No, it does it in any gear as long as I am up to speed. It dosen't matter if the cluth is engaged or not engaged. I know where you are coming from, I couldn't figure why the starter would be near the flywheel when driving. There is a lot of metal dust there too.:mad:

 

Pardon me, but WTF is a counter gear bearing? :D Is it replace/repairable?

[slodat]

I'm with Mike. Your starter and ring gear could look a lot worse.

 

There is a DQ article that covers the rebuild of a dogleg. The company that sells the rebuild kit is in Portland. That might be the answer..

[datto510]

I'm with Mike. Your starter and ring gear could look a lot worse.

 

There is a DQ article that covers the rebuild of a dogleg. The company that sells the rebuild kit is in Portland. That might be the answer..

 

Thanks Steve, I'll look into that. Did you ever sell your dogleg?

 

I haven't taken the tranny off of the engine yet, maybe that will reveal more.

[slodat]

Yea, it sold. Pull it apart and let us know what you find.

[datzenmike]

See if the starter gear is loose and able to slide back and hit the flywheel... I doubt it will.

 

On all 5 and 4 spds power is transmitted down on to the counter shaft then back up onto the main shaft through any gear selected EXCEPT 4th gear which isn't a gear really but is a straight through connection in the tranny. All other gears produce a sideways force between the main and counter shafts trying to force them apart. This force is handled by the front main and counter bearings. Generally the counter bearing is smaller and will fail first. This is why it's not advisable to tow, carry heavy loads or climb steep hills in 5th over drive gear as it exerts a strong and sustained force on the counter shaft bearing. 4th gear should be used.

 

http://i138.photobucket.com/albums/q251/datzenmike/Tranny/620CAFS5W71B85turbo200sx019Large.jpg[/img]"]

 

ABOVE

Power is transmitted in to the top left gear. For now power does not continue further through the transmission and out the end unless 4th gear is selected. Instead power flows down to the lower counter drive gear. These gears are driven and the counter gear shaft is always driven. The next three gears over on the counter shaft are 3rd 2nd and 1st and are in constant mesh with the gears above them on the main shaft. The main shaft is splined to the upper 3rd 2nd and 1st gears and are locked or unlocked by the two shift forks and synchros. None of the gears you see here are the ones you hear grinding when you mis-shift. 5th gear is on the other side of the adapter plate but operates under the same principal.

 

If you look up at the upper left input gear you'll see just to the right of it is the 4th/3rd synchro. When 4th is selected the synchro moves left and locks this input gear to the main shaft and power can now flow right and straight through the tranny and out. Although the counter gear is still driven it drives nothing and has no load on it.

 

 

BELOW

Here on the LEFT is an FS5W71B tranny with the front case off showing the larger spacing between the main and counter shafts, allowing larger stronger gears and bearings to support them. On the right is the FS5W63A dogleg. As you can see it has smaller gear centers and a much smaller, weaker counter gear bearing.

 

http://i138.photobucket.com/albums/q251/datzenmike/Tranny/trans280anddoglegonright.jpg[/img]"]

 

All gears except 4th transmit power onto and back off the counter shaft. Under load it'd natural for these gears to push sideways away from each other loading the front bearing.

 

BELOW

Here are the two front covers for the main and counter bearings. (I flipped the picture to keep the counter at the bottom) The wider gear center line and larger bearing is evident on the FS5W71B tranny on the right. Compare it to the much smaller dogleg on the left.

 

http://i138.photobucket.com/albums/q251/datzenmike/Tranny/trans1280anddoglegfrontcovers.jpg[/img]"]

Edited February 15, 2009 by datzenmike

[datto510]

The starter gear dosent move.

 

So, after reading a few times.... While in 4th gear there is no load on the counter/main bearings. Since my truck is grinding, even in 4th gear, can I eliminate that as the problem?

 

Let me elaborate a little more on the problem. It only grinds when my foot is slightly on the gas pedal. If it is completley off it wont grind. It won't grind under a mild load either. Kind of makes it tough to go down a hill on the freeway, I have to accelearate all the way down to keep from grinding! Also hitting a bump seems to magnify the problem. Its not the carrier bearing, I can hear it coming from the transmission/clutch.

[slodat]

Did you separate them yet? Is your t/o bearing installed correctly? Did you install a new pilot bushing? Is it possibly your driveshaft somehow? Maybe a small amount of front to back movement causing it?

[datto510]

Did you separate them yet? Is your t/o bearing installed correctly? Did you install a new pilot bushing? Is it possibly your driveshaft somehow? Maybe a small amount of front to back movement causing it?

 

Just pulled them apart. The throwout bearing show wear, as does the point of contact on the pressure plate. There is a groove about 1/32in the pressure plate teeth. Is this normal?

 

The pilot bushing is new and I cut about half an inch off of splined back section of the driveshaft. I know some fore and aft movement is normal, but I am pretty sure thats not the problem. Ideas?

 

Back to my original pics, this isint tdirt or grime..... its shavings!

 

[slodat]

Check your flywheel mounting bolts. Are they torqued?

[datzenmike]

Let me elaborate a little more on the problem. It only grinds when my foot is slightly on the gas pedal. If it is completley off it wont grind. It won't grind under a mild load either. Kind of makes it tough to go down a hill on the freeway, I have to accelearate all the way down to keep from grinding!

 

Also hitting a bump seems to magnify the problem. Its not the carrier bearing, I can hear it coming from the transmission/clutch.

 

This last one sounds like an exhaust pipe rubbing the tranny or something. Always noisier when the suspension flexes. Also the motor twists from side to side under load or when let off and the truck is pushing the motor.

Edited February 15, 2009 by datzenmike

[datsunaholic]

I'm of the opinion that the problem is inside the transmission as well. Somethings about to go out in a big way; I wouldn't be surprised to find metal in the gearbox.

 

I've had a flywheel hit the starter before. The flywheel will make a groove in the starter case long before the starter drive teeth hit the ring gear. The exception is if the bendix isn't letting the drive gear retract, but that'll make noise ALL the time, not on decell.

 

In my case it was actually a very serious mechanical issue INSIDE the engine that made the flywheel run the starter (and the steel backing plate) becuase the thrust washer was installed on the wrong journal. Ate it to pieces and made the crank move axially.

[datzenmike]

Drain the tranny. If silver filings then could be it. I drained one once and there was a ball bearing stuck to the drain bung magnet. Counter shaft bearing grenaded and counter shaft snapped off at adapter plate:

 

http://i138.photobucket.com/albums/q251/datzenmike/Tranny/transNAPSZ5spdbroken.jpg[/img]"]

[datto510]

Damn it. I do have another 5-speed. I was gonna use it for my goon.

 

[Cuts metal like mad]

engine is fully rebuilt, thrust washers installed per fsm, all clearencrs checked properly as well... But who knows.

[Cuts metal like mad]

engine is fully rebuilt, thrust washers installed per fsm, all clearencrs checked properly as well... But who knows.

 

I forgot to say, the wear on the clutch diaphram does not look normal to me...

[datto510]

I forgot to say, the wear on the clutch diaphram does not look normal to me...

 

 

Thats what I thought! Screw it, gonna put a 4-speed in it.

[datzenmike]

 

Left one is Z series tranny right is an L series. You mean the right one, right?

[datto510]

 

Left one is Z series tranny right is an L series.

 

It says 82 200SX on it. It has a taller 5th gear than a dogleg, no?

[datsunaholic]

Overdirve is a tad bit taller, yes, but being a NAPS-Z transmission it'd sit funny and put stress on the motor and transmission mounts because they'd be fighting the opposite mounting angles. Plus the length difference.

[datto510]

ARRGH!! I wanna kick myself in the face!:mad: I checked everything, clutch, pilot bushing, flywheel, ect. I put it all back together and got it back in the truck. The only thing I could figure, other than a trashed tranny, was the starter. I added washers to move it away from the flywheel. Still f***ing grinding!!

 

Time for a new tranny.......

[datto510]

Here is a stupid question. Is the throwout bearing collar the same for the 521's 4 speed and the dogleg 5 speed? I have found some conflicting info.

[datzenmike]

Throw out bearing collar is matched to the clutch. Use the one that was on it with the new tranny.

[Cuts metal like mad]

I think its gotta be that collar... thew throwout bearing should absolutely NOT be wearing a groove in the clutch diaphram