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914World.com _ 914World Garage _ Dizzy lifts up when turning by hand
Posted by: jeffdon Aug 15 2014, 04:45 PM
Got my engine on the stand with heads on. When turning the engine over by hand, I am getting a little binding that I think is coming from the dizzy. It also wants to lift out of the hole by about a 1/4 inch. The hold down is tight. What could this be? I am turning the motor clock wise as I face the fan.
Posted by: Cap'n Krusty Aug 15 2014, 06:33 PM
Could be the drive gear on the crank got banged up during the process, or that the washer is missing, or the distributor's not clamped down.
With a good flashlight you can see the drive gear from above.
The Cap'n
Posted by: worn Aug 15 2014, 08:00 PM
Could be the drive gear on the crank got banged up during the process, or that the washer is missing, or the distributor's not clamped down.
With a good flashlight you can see the drive gear from above.
The Cap'n
Did you add the thrust washer, and did it stay in place? I had trouble because I machined one to the wrong size. It got hung up in the crank. Just a little off.
Posted by: jeffdon Aug 15 2014, 10:07 PM
Could be the drive gear on the crank got banged up during the process, or that the washer is missing, or the distributor's not clamped down.
With a good flashlight you can see the drive gear from above.
The Cap'n
I might have done a bit of boogering up of the drive gear. Washer is in there, I flipped the motor upside down an pulled out the gear, and verified the washer is there. Paranoid about droping it into the case.
Posted by: bdstone914 Aug 15 2014, 10:51 PM
Could be the drive gear on the crank got banged up during the process, or that the washer is missing, or the distributor's not clamped down.
With a good flashlight you can see the drive gear from above.
The Cap'n
I might have done a bit of boogering up of the drive gear. Washer is in there, I flipped the motor upside down an pulled out the gear, and verified the washer is there. Paranoid about droping it into the case.
When reinstalling the washer and spring first insert a thin rod and slide the washer and spring down the rod. Keeps them from dropping into the case. Figured that out after dropping a spring into the case.
Posted by: Mark Henry Aug 16 2014, 11:01 AM
Could be the drive gear on the crank got banged up during the process, or that the washer is missing, or the distributor's not clamped down.
With a good flashlight you can see the drive gear from above.
The Cap'n
I might have done a bit of boogering up of the drive gear. Washer is in there, I flipped the motor upside down an pulled out the gear, and verified the washer is there. Paranoid about droping it into the case.
So at this time did you roll over the engine to see if you were still "getting a little binding"?
Posted by: Cap'n Krusty Aug 16 2014, 11:34 AM
On a T4, unlike a T1 or a 356, you can simply use a dab of grease to stick the washer to the shaft. No need to install it first. I agree with the advice on the spring.
The Cap'n
Posted by: jeffdon Aug 16 2014, 04:25 PM
Thought I had it solved, everything was behaving normally during the valve adjust. Put my fan housing on, and I noticed once again that the dizzy had pushed up a little and was not engaged with the drive gear.
WTF? Is it possible my old dizzy has too much up and down slop in it?
Posted by: jeffdon Aug 16 2014, 09:40 PM
Thought I had it solved, everything was behaving normally during the valve adjust. Put my fan housing on, and I noticed once again that the dizzy had pushed up a little and was not engaged with the drive gear.
WTF? Is it possible my old dizzy has too much up and down slop in it?
Shameless bump.
Posted by: Java2570 Aug 17 2014, 07:48 AM
I've had it happen in my old dizzy, one of the inner bushings on the shaft of the dizzy either broke or wore out. I had about 1/4" of up/down movement in the shaft and I had to source another dizzy. I believe Bosch used to sell rebuild kits for all the internal bushing, washers, etc. I'm not sure if they still do or not.....but it looks like a fairly involved process to repair. I opted to purchase a used dizzy through Bruce Stone to replace my broken one.
Posted by: jeffdon Aug 17 2014, 11:50 AM
I've had it happen in my old dizzy, one of the inner bushings on the shaft of the dizzy either broke or wore out. I had about 1/4" of up/down movement in the shaft and I had to source another dizzy. I believe Bosch used to sell rebuild kits for all the internal bushing, washers, etc. I'm not sure if they still do or not.....but it looks like a fairly involved process to repair. I opted to purchase a used dizzy through Bruce Stone to replace my broken one.
Anyone know what acceptable endplay for a distributor would be? I am getting about 2mm play, but also able to tilt the drive tang about 3mm back and forth. This look within tolerance or is it toast?
Posted by: Java2570 Aug 17 2014, 12:44 PM
Maybe the Cap'n will comment on this but I think there are supposed to be some fiber washers in the space you are seeing. It's possible that they've broken and disintegrated over time. Not sure what the spec is for play there, sorry....hopefully, someone who knows will share!
Posted by: Java2570 Aug 17 2014, 12:53 PM
Ok, I took a photo of my broken dizzy and a spare one that is ok.....you can see my broken one has about the same play as yours. The one that is ok, you can move the drive tang a bit but not very much at all. My broken one does have at least one fiber washer above the drive tang but it has a broken bushing inside; that keeps the shaft from moving too much. 
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