: Crank pulley on 94 SLS



Rob Benham
09-21-04, 03:35 AM
Hi, I have a 94 SLS which has about 92k and runs well. I have had the usual suspension messages, which I ignore. The main problem is, although the engine is smooth and uses no oil, I notice that the crank pulley to the Serpentine belt (which is cast and looks okay in itself, ) wobbles laterally 3mm or so...ie. It looks as though it has been hit from the side. Is this pulley, fastened right onto the crank, so that it might be the end of the crank that is bent?

I don't know how to check if this engine has been ‘imported' into this car.

I have done about 6k in this car and love it...but I carry a spare belt at all times. Rob

growe3
09-21-04, 09:13 AM
The harmonic balancer should always run true. Any wobble is a sign to replace it. If it were able to come apart, replacing the serpentine belt would likely be the least of your problems.

I can't believe that the end of the crank is bent. It is possible that the balancer is separating; this would be a rare occurrence.

More likely you may be looking at a casting flaw or turning mark that is giving the illusion of wobbling.

In either case you need to verify if the harmonic balancer is actually damaged, and if so get it fixed before it can come apart.

The harmonic has a special tightening method that must be followed, or oil pump failure will result.

-George

Rob Benham
09-22-04, 01:22 AM
Thanks George,

I'm sure it is distorted - assuming the end of the crank is not bent. I hadn't considered the possibility of it having been like this since it was made, rather that the engine may have come from a car that was damaged. Now that I know that there is more to this pulley than meets the eye (not a solid casting) I will gather more info and change it. Rob

peteski
09-22-04, 02:37 AM
I think I recall our local expert (Bbob) say that the pulley is a casting which gets the mounting hole and groovees for the belt machined on it. Then it is balanced. But the face of the pulley is not machineed and it can appear to be wobbly.

So, look at the belt itself instead of looking at the face of the pulley. If the belt doesn't wobble (just the pulley face) then I think there is nothing wrong with it.

Peteski

Eldyfig
09-22-04, 11:59 AM
Peteski hits it right on the spot. I believe it was Bbob that did post that. That is the way the balancer was cast. My eldorado has been like that since I got it 2 years ago. I thought the same thing as you. I do not worry about it anymore.

Rob Benham
09-23-04, 04:27 AM
Fingers crossed, I'll look first thing in the morning...thanks again. Rob

Rob Benham
10-04-04, 04:25 AM
Thanks George and others,

Finally got to look at the pulley today, and sure enough, the centre is true and the part outside the rubber is way off. I may have to get someone else to fix it as my tools are in the UK but i will look at the feasibility of doing it with a pair of pliers and a lawnmower plug wrench.

Seriously though, is there a quick description of the danger to the oil pump if i can tackle it.? RB

caddyshack24
10-04-04, 05:01 AM
i know nothing.
I belive you can loose oil pressure if it fails. belive it would burn the pump up.
if for some reason you have it fixed, would be a great time to check the belt tensioner & pulleys.

BeelzeBob
10-04-04, 03:49 PM
Thanks George and others,

Finally got to look at the pulley today, and sure enough, the centre is true and the part outside the rubber is way off. I may have to get someone else to fix it as my tools are in the UK but i will look at the feasibility of doing it with a pair of pliers and a lawnmower plug wrench.

Seriously though, is there a quick description of the danger to the oil pump if i can tackle it.? RB


Still not sure you are evaluating the correct thing. What you want to look at is the belt grooves that are machined into the outer ring of the damper. Those should run straight. If they are running straight (which is kind of hard to see as you have to look inside the belt track to see the grooves cleanly) then the damper is likely OK. If the machined grooves are wobbling then the damper outer ring has started to slip on the elastomeric layer that joins it to the hub (and gives the damping characteristics desired). The damper should be replaced immediately if the belt grooves are wobbling. Otherwise, any other features on the outer ring really don't matter.....

The center bolt on the damper is the "problem". It takes about 300 ft.lb. to torque it adequately on a 94...that engine still had the big bolt in the damper. Not possible with a lawn mower plug wrench...LOL. You might be able to lock the crank at the flexplate with the pliers, however, to hold the crank in position.

The oil pump drive sleeve is simply a slip fit onto the crank snout. The only thing that drives it is the compression of the damper onto the drive sleave due to the torque on the damper bolt...so...if the bolt is not torqued correctly then the oil pump will not turn and there will be no oil pressure and a bent damper will be the least of your worries. Also, NEVER attempt to pull the damper on with the production bolt. The damper is a tight press fit to the crank snout and requires a stout puller to remove it and a damper installation tool to pull it on BEFORE installing the damper bolt. The damper bolt is to hold the damper on ..... NOT install it. If you use it to install it the first few threads of the bolt are often distorted and then the bolt jams and seizes as you thread it in due to the extreme load on it when first starting to install the damper and the short thread ingagement. The crank is scrapped as a result as it is almost impossible to get the welded/galled bolt with the distorted threads back out again. It snaps off in the hole when you apply force...and it won't tighten far enough to pull the damper home. Always use a puller first to install the damper.

Rob Benham
10-05-04, 04:11 AM
Thanks again,

yep, the grooves wobble quite clearly while the inner casting is true. Thanks to this forum i got a bright light and saw the rubber insert for the first time.

it does sound as though the stash of tools that my wife and i spread around our hold baggage will still not surfice - off to a Caddy agent i guess. Frustrating, a lifetime of learning while hobbying on Jags BMW and Supras all going to waste.

Down in ‘the Valley' in Texas, the Caddy agent refuses to service cars over 5 years old. Kind of prima-donnerish i feel. They will sell me a new one quick enough...I wonder what Cadillac think about that - if they know.

growe3
10-05-04, 08:53 AM
The good news is that you caught it before it let go.

It should take only about one hour to replace it. It is a very straight foreward job. It is also critical that it be tightened properly so the oil pump will work.

-George