Tiger03447

How much drag should a balance shaft have with the B.S. belt off? My yet unfired engine has a very stiff drag on it when I tried to turn it today with a ratchet wrench. . The engine has been assembled using assembly lube several years ago, but now is installed in the car. The crank rotates OK along with the camshaft. The upper balance shaft is also stiff to turn, but not as much as the lower shaft. When I rebuilt the engine, I put in all new bearings and seals on the balance shafts when I rebuilt it. But as it is right now, I don't think that the starter will have enough power to turn it over. They turned over nicely when I rebuilt the engine, if I remember correctly. I proposed to inject oil into the engine under pressure through the oil pressure sender hole (I have an adapter for this) to try to lube things up better and float the crank off it's bearings. . Any suggestions will be helpful. Thanks.

wildcat077

The balance shafts shouldn't have any drag ... if the covers are installed in the right position
There's a number stamped on the covers and they need to go back in the same position on the engine.
I've rebuilt two engines lately and i had no drag on the balance shafts with new bearings !

Maybe remove the covers and reassemble everything with fresh assembly lube ?

Cheers
Phil

harveyf

As I recall, mine did not have an significant drag. And you say yours didn't either when the rebuild was fresh. So I like the idea of injecting the oil to see if you can free things up. Of course you could also just remove the drive belt (as in it must already be removed or how are you checking them for drag?) and fire the engine up. You'll get the oil flow, hot to boot, and you can see if that resolves the problem. Then reinstall the belt.

Tiger03447

You are right, Harveyf, the belt is removed and we turned the balance shafts with a pin spanner. If I go ahead and inject the oil, what do I have to lose? There has to be oil in the engine anyway. And when I inject the oil, it will go throughout the oiling system and possibly loosen things up quite a bit. If necessary, I will just have to drain the fresh oil. I put the covers back on the engine properly, and torqued it all down as per the WSM. I was very careful to get the correct ones where they should go on the block. I really don't want to pull the lower cover, as I will have to remove at least one of the exhaust manifolds to get it back out. We are close to fining the engine for the first time. Every solution breeds new problems. Thanks guys for the inputs...I'll keep you posted.

JustinL

They should turn with fingers. Are you absolutely sure you put the right covers back on? Both shafts are tough to turn? If you need a wrench to turn them, I'd strongly suggest investigating before trying to run the engine with the balance shaft belt on. I had to take a couple shots at my covers before finally getting them to turn nicely.

StoogeMoe

You could try loosening the bearing caps and see if that frees up the shaft. It doesn't take much to bind them. But you probably don't want to hear that. I'm sure you have the covers on.

tempest411

I've read that it's not uncommon to get the wrong rear balance shaft bearings. Is that a possibility? When I did mine, with new bearings front and rear, and assembly lube, the shafts would turn just on the counterweights.

Tiger03447

Yep...sounds about what I thought too. does anyone have any numbers for the oil clearance between the nose housing bearing and balance shaft? Today, we put pressurized oil (40lbs) into the oil sender port. We also put about 3 quarts into the sump. The crank turns over much easier now, but the balance shafts are fairly easy? to turn with a wrench (8"ratchet") but they seem to bind in some places and not so much in others. I tried to lift the lip of the front seal on the upper shaft and tried to "inject" some oil under it with a squirt can. (old fashioned, I know). It didn't seem to help much except to make a minor mess. Now it appears that to pull the noses off the balance shafts, I'm going to have to remove almost all the front of the engine, to get the rear cover off..before going any further. If I try to start the engine, I don't want or need any metal shavings floating around...to lunch my new main and rod bearings. Trying to avoid a complete engine pull to rectify this problem. Thanks for the input..any more suggestions..I am open to them, so please comment. BTW, all the BS bearings and seals were new when they were installed. I think I bought these from Pelican, but I could be wrong. What are the correct/incorrect bearing numbers? I went to the PET to get the correct parts in the 82-85 PET, so they should be correct numbers.

T&T Racing

I am interested in how you injected the oil into the pressure sending connection.

Now thoughts on the balance shafts. If the front bearing was replaced, was it pressed in all the way?
The rear halves are inserted into a pin to prevent spinning of the bearing half. Where they pressed in until seated or was the half shell not pressed in the bearing retainer surface?

harveyf

Are both balance shafts equally stiff. If yes, it would appear to be a parts problem.

I agree with comments about loosening the caps as a test. I vaguely recall assembling some in the past that were stiff, well actually I would say could not be turned. I can't quite remember the details so no help.

Regarding assembly lube issues, if it was years old I might suspect it but let's face it, I've been using the same bottle off my shelf for a number of years and it's not like it sets up in the bottle. So I don't think that is has a high probability of being the cause.

Can't you at least reach the end of the upper balance shaft, to loosen the cap bolts, without having to remove too much stuff? I'm sure you know this but having to use a rachet is not a good sign.

Tiger03447

Dear Guys: Thanks for the input and the questions. I took an old sender unit, cut off the shell and reduced it to just the threaded fitting at the bottom. I drilled and tapped it to take a 1/4NPT fitting. My buddy had a converted 134A tank with a filler port, an air injection port from the compressor,w gauge, and a converted outlet port with an airline. Both of the inlet and outlet had a ball valve to help regulate the pressure and oil..The threaded fitting was screwed into the sender port on the engine, and the airline connected. I put 3 quarts of oil into the tank, and dumped 2 more into the sump. I opened the valves and watched the pressure gauge. I think that was enough to lift the crank, fill the filter, and pressurize the system on a non-running engine. The crank now turns nicely, and has somewhat lessened the drag on the balance shafts. I will today, start tearing down the front of the engine, removing the front exhaust manifold, removing the rear TB cover and start the upper balance shaft and lower shaft removal..I'll pull the noses first and mike the clearances and check for oil distribution. Upper first, then lower. The intake manifold, and fuel rail will all have to be removed as well as all the ignition stuff. All of this will negate about two month's worth of work. Sign me: unhappy camper. On the more positive side, The primary exhaust pipe is not totally installed and neither is the starter. I could connect up and install the starter to turn the engine over under battery power, but I don't think there would be enough oil pressure to do any good. I think I got more pressure out of the pressure unit than could be provided by the starter. I am very reluctant to drop the engine to a bench since that would require even more work to unhook the electrics as well as all the vacuum stuff as well as the front suspension Trying not to compound the problem. Hope all this info will help someone in the future.

Tiger03447

Dear Harveyf: There is one bolt behind the rear cover at the lower portion of the upper nose.(Isn't this the way it always is? Just one bolt...LOL!) I think I'll put a 3/4 inch hole through the back cover so I can put a socket on it. That way I could move the nose forward ..some. But the rear TB cover will still have to be removed to get the nose totally out and off the engine. Not to mention the bottom BS nose. At least the radiator and fans are still not yet installed. Two steps forward, thirteen back..thanks for your comments...At this point I think I'll take a break from the car until next week starting tomorrow as a dishwasher installation crew will be at the house. Any additional thoughts are always welcome. Thanks again.

Tiger03447

OK...On with the continuing saga of the balance shafts. today, I was able to tear down the front portion of the engine, removing the cam timing belt and associated idlers, and cogs..I also backed off the nuts on the front manifold, so I can perhaps sneak the lower balance shaft cover off of the block..I was able to remove the three bolts that secure the front housing on the upper shaft and gently tap it off about a1/2 inch. When I tried to turn the shaft with a wrench, it was still tight, so I think it was the bearings at the rear of the shaft. I can't unscrew the crankshaft bolt, even with a hefty impact..Is that a left handed-bolt? I presumed that it was right handed...It takes 155 lbs torque, and I thought it was rt handed when we put it into the crank. I hafta remove this pulley assembly before I can remove the rear cover. Any help from more knowledgeable folks out there would be helpful. Thanks.

931guru

The crank bolt is a normal bolt. You will need a flywheel lock to remove the bolt, torqued to 155 lb ft, if done properly.

Charlie

Years ago I bought an 86 944 that had lost oil pressure.. The upper rear balance shaft bearing was toast. I bought a replacement bearing and when I would torque the balance shaft cover to spec the rear bearing was too tight. My solution was to fit the bearing. I removed the bearing and took very fine emory to remove a very small amount of material from the bearing. I would then use some fine scotch bright to smooth the surface. After that I would reinstall and torque the bolts to spec and turn the shaft. After doing this a few times the shaft would turn easily. Just be patient and take your time, small steps. I never had any problems with it..

Probably the reason I had to do this was that I had to replace the balance shaft cover because of damage to the original. Best I recall on the 86 the rear bearing fit into the cover and 87 and later the bearing did not? If you have an 86 or earlier make sure you didn't get the covers switched.