evanw66

I'm at a bit of a loss as to why this happened and would really appreciate any insight into the situation.

I pulled the engine out a few months ago and totally rebuilt it. Block, crank machined, new pistons, bearings, valve job, comp cams camshaft, etc, etc, etc.

I started it this afternoon for the first time. Started right up and ran great. I held the RPM at 2000 for the cam break in. The motor ran for about 15 seconds and then abruptly stopped. I investigated and found that the rotor in the distributor was not turning when the engine was cranking. I removed the valve cover and found to my horror that all the teeth had sheared off the distributor drive gear! This is the one that is at the front of the camshaft.

The teeth on the distributor gear look OK, motor still cranks OK.

Has anyone seen this before? I re-used the old drive gear, but it looked in fine shape when I installed it.

Help?

growinseed

never heard of this one myself, but all the pieces should be in the oil pan. I'd find a 'new' drive gear, pull the oil pan and get all the shards out. Hopefully nothing got pulled into any of the passageways. Does the distributor spin freely. Did you put the drive gear on with the correct orientation?
Sorry for your misfortune
Nathan

evanw66

I can't currently get the distributor to spin freely, as it's wedged against what's left of the drive gear. I think I'm going to have to pull the gear off the end of the cam before I can remove the distributor, because right now it won't budge; I already removed the hold-down bolt.
I *think* I put the gear on the right way. I don't think it could go on backwards because then the teeth wouldn't mesh with the gear on the distributor, right?

growinseed

I pretty sure the gear only fits one way as well, the bolt goes into a machined space. Just ideas bubbling in my head as to why this happened.
Just looked at my FSM for a 85 22R. All I see is the dis.drive gear and spacer plate with a drive pin for the fuel pump drive cam. If this pin wasn't pushed to the fuel pump cam side it could have interfered with the dis drive gear and driven gear. Since you have to replace some stuff we may as well figure out the culprit behind this mishap
Cheers

evanw66

I don't remember seeing a spacer plate, but I won't be able to confirm that or know any more until Monday.
Do you have any pics or scans of the TSM that shows how everything's supposed to fit?
Thanks

growinseed

I've got a few scans but can figure out how to post them right now. I get them up asap

growinseed

Well here goes


HTH

toy283

Does the distributor itself turn? I've had two distributors sieze on me over the years. The first was on a 429 Ford which destroyed both the camshaft and distributor (the gear and distributor shaft are one piece). The second was on my '84 Camry. When the shaft siezed the pin on the drive gear sheared and the gear just popped off, saving the camshaft.

evanw66

Thank you very much for the scans, growinseed! I think those will help me out alot.
I'll take it apart this afternoon and see what I can find out.

evanw66

After much effort, I managed to remove the distributor. The "pilot" where the tip goes into a hole drilled in the head, had seized up in the bore. I guess that's my fault for installing it dry. Is there an oil passage that's supposed to lube this up, or are you just supposed to put some grease on it before installation.
The real problem, I think, is that the distributor is pretty seized up. I can get about 5 degrees of rotation in either direction before the bearing prevents movement.
Weird that the distributor would last 277,500 miles and then seize up seconds after I get the rebuilt engine started.
So, anyone know how the "pilot" on the bottom of the distributor shaft is supposed to stay lubricated?

evanw66

I got a used distributor from a friend and a new drive gear from the local Toyota dealership.
This time, I put some chassis grease on the "pilot" of the shaft, and slathered plenty of oil over the distributor shaft after it was installed in the head.
I got it running finally, set the timing, adjusted the valves hot, changed the oil.
I think it's gonna be OK

Yoda

The gear wasn't hitting that little bolt that is hidden (8mm from head to front chain cover) under the dist gear?

evanw66

Nope, it wasn't hitting the bolt.
I *think* it was a combination of the pilot being dry, the distributor shaft being dry from me cleaning it with brake clean; basically not getting adequete lubrication. On initial startup on a new engine, it takes a bit for oil to be pumped all the way to the top of the motor. Also having a distributor with 277K miles on it, the bearing was probably not in the best shape either.

evanw66

Well, this is fun.
31.5 miles into the break-in of the new motor, it throws a rod!
I'll pull it back out in the morning and try to find what went wrong.

evanw66

Got it torn down today.
#1 rod bearing had massive oil starvation. The rod and that part of the crank are both dark color due to super-heating resulting from the non-oiling.
I guess it's back to square one.