Doug85.5944na

Hi all,

We're her at Doug's trying to put his N/A engine back together but the balance shafts are binding when we torque them down. They're fine before torquing them.

Any ideas?

Thanks,
Tomrc

Charlie

The best I recall when rebuilding mine, I had the rear bearing shells reversed, the bottom should have been on the top and top on the bottom and this was causing a binding problem (using the old bearings). Are you using new bearings are the old ones?

Doug85.5944na

Well, it's only binding in the front housing. And it changes as the tourqe of the bolt is tightened.

brad-cam

Any chance the shaft is bent ? I had the exact same problem when I had a block shipped to me and one of the shafts was damaged in shipping... Probably a long shot if your balance shaft was just running in that motor...

Doug85.5944na

Yeah, I guess that could be happening.

Here's how it goes - we tourqe the housing per factory manual, the shaft spins like it should. We bolt the front housing on, and it continues to spin freely. We put the pulley on and tourqe it to the specified 42 ft/lbs and then it binds so bad that you can hardly turn it with a wrench.......

It's got me stumped, is there a chance that the shafts could be reversed - are they different or are both the actual shafts the same?

mark944turbo

Make sure that the dowel pin that aligns the balance shaft housing on the block is still there. I forgot to put those back in once and had this problem. But i dont see how torqueing the pulley would have any effect. For me it binded when I torqued down the front piece or the housing.

45 foot pouds sounds high by the way, but that might just be me.

Doug85.5944na

The dowel is indeed there and working, it only gets tight when the bolt that retains the drive sprocket is tightened. 42 sounds high to me, but that is what the factory manual says.....

Dilberto

I have another shaft if you need one. Includes: cover, bearings, seals, roller. PM if need be...

Zach

Doug85.5944na

Here's another question - are the top and bottom balance shafts the exact same? Also, are late and early shafts the same even though one of them doesn't have the rubber peices on the couterweights?

Dilberto

Considerable difference between the early and later ones. I only have a pair of the 85.5-up ones. Turbo included.

Zach

RedlineMan

Hey;

You have the sprocket, the thick domed washer, the bolt, the tin orientation flange (with the key and "window"), then the Woodruff key, and the seal sleeve on the end of the shaft. Something is pulling the shaft outward when torque is applied is my guess. I don't really know what, but since it only happens when the bolt is torqued, that is all that makes sense. There is not enough free room on the end of the shaft.

Thought # Two - I do not know whether the shafts are interchangeable between all early cars, and/or all late cars. However, all of the cover and bearing cap components are SPECIFIC TO THAT SHAFT ONLY. Each cover and bearing bridge is line bored to that block and position (upper or lower) ONLY. These components CANNOT be mixed between engines without being re-line bored. You may get lucky and find one that fits if you have enough pieces to try, but it is a crap shoot.

If you've mixed and matched, then you have just found your problem! Take it apart and inspect the bearing. If you've turned the shaft, it will have left a track on the bearing which will tell you where it is binding. If indeed it is a bearing binding.