What the heck did I do?

General chat about the car goes in here.
Post Reply
zachmac
Posts: 1278
Joined: Sun Aug 24, 2008 9:20 am
Your car is a: 1978 Spider [1979 2 ltr engine]
Location: Aiken, SC

What the heck did I do?

Post by zachmac »

I am VERY depressed. I was hopimg I might hear my newely rebuilt motor run for the first time this weekend but I don't think so now. All I had left were coolant system and ignition. Got the coolant system installed, filled and bled and was getting ready to start timing the new distributorless ignition module so I needed to rotate the engine to line up the timing mark to 10 degree BTDC. But now when I rotate the assembly (not in gear) I get a metal to metal rubbing sound and it is very hard to turn. Coming from bellhousing area. When I was hooking up the guibo and driveshaft I had it in neutral so I could spin the output shaft and that was fine with no noise. Before I bolted the engine to the tranny I did lots of rotations once the timing belt was on, again with everything fine. That sort of narrows it down to somewhere between the crank and the tranny input shaft.

Now as I tired to turn the motor the whole assembly reaches a point where it is totally bound and won't turn. I can counter rotate however. BTW, the aux shaft fuel pump lobe is gone so can't be a bind there and it wouldn't cause the rubbing noise. Ditto cam timing, still on the mark and roated fine before tranny bolted up. Update, carefully counter rotated and found intake cam had slipped so that was the binding so I removed timing belt and will retime. BUT nosie in bellhousing still there. I was using that cam sprocket bolt as my rotation point as my normal crank socket won't fit with the radiator installed. Guess rotating the engine using the cam sprocket is a very bad idea?

I used a centering tool when I bolted on the clutch and pressure plate. Any ideas where to start before I just pull the tranny? I pulled the inspection plate, no change. The only NEW factor was I did spin the engine a littel today with the starter (gear reduction unit). Could it be the cause? Stuck, bolted up to tight? Help!
Jeff Klein, Aiken, SC
1980 FI Spider, Veridian with Tan (sold about a year ago), in the market for another project
1989 Spider, sold
2008 Mercedes SL65
2008 S600 Mercedes V12
zachmac
Posts: 1278
Joined: Sun Aug 24, 2008 9:20 am
Your car is a: 1978 Spider [1979 2 ltr engine]
Location: Aiken, SC

Re: What the heck did I do?

Post by zachmac »

So having slept on it here is my plan:
1) re-time cams / install timing belt
2) go get some tool to fit and turn crankshaft by hand with radiator installed (I'd rather avoid draining the system again as the timing belt is already in place, just not on the pulleys / tensioner)
3) start the tranny removal process with hand rotation of engine along the way to see if and when noise stops

I am pretty sure at this point something is simply rubbing against the big flat sheet metal closure plate that sandwiches between the block and bell housing. That is certainly where the noise is coming from and there is a gap on the exhaust side between it and the housing so it is clearly not as flush / flat as it should be. Maybe it got bent enough to just be bowed and is rubbing the rotating assembly? Of course that will require complete tranny removal to fix!!!! :(
Jeff Klein, Aiken, SC
1980 FI Spider, Veridian with Tan (sold about a year ago), in the market for another project
1989 Spider, sold
2008 Mercedes SL65
2008 S600 Mercedes V12
DieselSpider
Posts: 2130
Joined: Wed Dec 24, 2014 10:21 pm
Your car is a: 1978 124 Spider with Isuzu Turbo Diesel

Re: What the heck did I do?

Post by DieselSpider »

How big a gap are we talking about? Dollar bill thick or larger fractions of an inch. The transmission does need to be bolted flat to the engine all around the bell housing however also check that the clutch fork is still engaged properly with the throwout bearing and with its pivot.
zachmac
Posts: 1278
Joined: Sun Aug 24, 2008 9:20 am
Your car is a: 1978 Spider [1979 2 ltr engine]
Location: Aiken, SC

Re: What the heck did I do?

Post by zachmac »

Okay so good news bad news. The noise is coming form the starter, AR gear reduction unit that was on car before tear down and worked with issues. As soon as you snug up the three bolts (not overly tight) the noise return. That's great news as I don't think I need to pull the tranny but I do need to diagnose /fix this.

So what's different? The main difference between now and when is worked before is a different flywheel. I had purchased a used lightened unit (stock unit with metal removed) from a forum member and put it on the car when I re-assembled.

First Q: are the flywheel for the 1800 and 2 liter the same? It came off an 1800 and I have a 2 ltr. (please say yes). It bolted up fine and without the starter in place everything rotates easily and without any noise.

Second Q: has anyone experienced a similar problem with a gear reduction unit? Maybe it has to be shimmed? But is didn't before and as far as I know it spans most all years of production as far a fitment?
Jeff Klein, Aiken, SC
1980 FI Spider, Veridian with Tan (sold about a year ago), in the market for another project
1989 Spider, sold
2008 Mercedes SL65
2008 S600 Mercedes V12
zachmac
Posts: 1278
Joined: Sun Aug 24, 2008 9:20 am
Your car is a: 1978 Spider [1979 2 ltr engine]
Location: Aiken, SC

Re: What the heck did I do?

Post by zachmac »

DieselSpider wrote:How big a gap are we talking about? Dollar bill thick or larger fractions of an inch. The transmission does need to be bolted flat to the engine all around the bell housing however also check that the clutch fork is still engaged properly with the throwout bearing and with its pivot.
The bell housing itself is flush all around. When I said gap I meant between the bell housing and the flat sheet metal plate that covers the flywheel where the bell housing sticks out past the block on the exhaust side. The sheet metal cover plate is just a little bent so there is a small air gap there.
Jeff Klein, Aiken, SC
1980 FI Spider, Veridian with Tan (sold about a year ago), in the market for another project
1989 Spider, sold
2008 Mercedes SL65
2008 S600 Mercedes V12
BEEK
Posts: 1833
Joined: Wed Mar 24, 2010 10:45 pm
Your car is a: 1975 Spider
Location: clermont fl

Re: What the heck did I do?

Post by BEEK »

did you put back both locating dowels between the block and the transmission on the lower bolts?
not having those can cause misalignment and starter issues
Automotive Service Technology Instructor (34 year Fiat mechanic)
75 spider
, 6 Lancia Scorpions, 2018 Abarth Spider, 500X wifes, 500L 3 82 Zagatos. 82 spider 34k original miles, 83 pininfarina, 8 fiat spider parts cars
son has 78 spider
BEEK
Posts: 1833
Joined: Wed Mar 24, 2010 10:45 pm
Your car is a: 1975 Spider
Location: clermont fl

Re: What the heck did I do?

Post by BEEK »

delete please
Automotive Service Technology Instructor (34 year Fiat mechanic)
75 spider
, 6 Lancia Scorpions, 2018 Abarth Spider, 500X wifes, 500L 3 82 Zagatos. 82 spider 34k original miles, 83 pininfarina, 8 fiat spider parts cars
son has 78 spider
zachmac
Posts: 1278
Joined: Sun Aug 24, 2008 9:20 am
Your car is a: 1978 Spider [1979 2 ltr engine]
Location: Aiken, SC

Re: What the heck did I do?

Post by zachmac »

BEEK wrote:did you put back both locating dowels between the block and the transmission on the lower bolts?
not having those can cause misalignment and starter issues
Yup, it's all back together now with no issues. It was indeed the fact that the "lightened" flywheel mating surface had been machined.
Jeff Klein, Aiken, SC
1980 FI Spider, Veridian with Tan (sold about a year ago), in the market for another project
1989 Spider, sold
2008 Mercedes SL65
2008 S600 Mercedes V12
Post Reply