I just finished installing strang 3.73's in my car, but there is a very loud whine when the car is decelerating with or without the brakes. I did not have a dial indicator to measure backlash, so I used the gear paint method and got the wear pattern fairly dead on. The only thing was that there is a very small amount of play in the pinion becasue I was afraid to tighten the nut any further and ruin the crush collar and have to redo everything.

Do you guys think the problem is the pinion play? I am going back downstairs and about 10 minutes to tighten the nut up so I will update then also, but any suggestions would be awesome.

Thanks
-Scott

 

There shouldn't be any pinion play. You also should not be using a crush sleeve. You should be using the solid spacer by Ratech.

 

The pattern has nothing to do with backlash, you have to check backlash, 0.002" for genuine GM AAM gears, dont let people tell you Motive makes for GM, As far as I know, American Axle still has the contract and they cut their own gears, I have yet to see proof that Motives, supply to GM, Motives are a good gear and they get 0.010" Richmonds get 0.006" I never did strange gears bit they shgould have a pinion depth scriped on the pinion and a backlash dimension in the box they came in, if not call strange, they will tell you.

as for the solid pinion spacer theroy, IMO another waist of money, I see no benifit to using a solid pinion spacer, the inner and outter pinion bearing seat in two tapered cavities with races press fit in them, not every rear is machined exactly the same. The crush collar is designed to let both bearings bottom out on the collar as you apply torque to the nut, as the crush collar starts to crush the bearings will seat and the further down you tighten the nut, you are just creating preload on the bearings as they rest in the races, at this point the crush coller has compressed EXACTLY where the bearings seat. The crush allows for the imperfections in machinging of the rear, thats the point of it. A solid pinion spacer is machined at one nominal dimension, if the preload is set on the bearings and the soild pinion spacer is as much as a few thousandths of an inch too short it will not keep proper preload, if its too long the spacer will keep the bearings from properly seating, there are shims that come with the solid pinion spacer for just this reason, how would you know how to shim it with out being able to see in the rear itself, I have asked this question before and no one has an answer for me. If the solid pinion spacer happens to be exactly the right size down to the 0.001" of an inch you will be fine, i wont take that gamble with my street car or my race car, crush collars have been used and all types of gear boxes for over 100 years to set preload, use it it is fine.


It takes a bit to get the crush collar to start crushing, but once it starts its pretty easy, you can apoply a little oil to the bearings and take an inch pound torque wrench and put ot on the nut, set the torque wrench to aprox 20 in/lbs for new bearings, or 12 in/lbs for used bearings, spin the yoke around if the wrench does not click, you dont have enough preload, tighten the nut 1/4 thread more, do it agian, and again until the torque wrench clicks, thats how you know if you have proper pre load.

good luck

 

Thanks for the replies guys.

I tightened up the pinion nut only til it had no play as to not tighten it too far. This made the whining a bit quieter, so I think I will give it a little bit more tightening and see if it helps any more.

-Scott

 

id take the time and remove the carrier and set the proper preload, its kinda important for durability,

check out the Stickys too, good info there...

 

You are correct, it does take some time to get the solid spacer right. It comes with shims and instructions. You tighten the pinion nut to a specific torque value when you install the solid spacer. If the drag is too many in/lbs, you take a shim out. If the drag is too few in/lbs, you add a shim. The shims also come in two thicknesses, so there are several combinations possible for you to set the proper preload on the bearings. I put one in with my gears and I'm satisfied it's an improvement over the crush sleeve.

You have to ask the question: How much torque does it take to colapse the crush sleeve when you are installing it, and might you be applying a greater force against the crush sleeve when you launch a little hard or accellerate hard? The solid spacer eliminates the possibility of the crush sleeve collapsing and screwing the pooch. Of course, that's just one of the many things that can go wrong with our 10 bolt rears. We're all aware of that. I don't know about using a torque wrench that breaks away. The ones I've seen just aren't very accurate on the short scale you need for the pinion bearings. I think the best way to check for preload is with a dial wrench whether you are using the crush sleeve or the solid spacer. A good dial wrench has a sweep that shows what the highest load was as you turned the pinion with it. IMHO, if you don't have a dial wrench for the pinion bearing preload, take it to someone who does.

Then again, I guess this really ain't rocket science, and a ten bolt probably isn't worth arguing about.

 

thats good info, cause only time i saw a solid pinion spacer it came with shims but no directions...

 

That is actually backward. If there is too much drag that means the pinion is too tight and you need to ADD shim too loosen it up. If it is too loose then you remove shim to shorten the distance between the inner and outer bearings to tighten it up when the pinion nut is torqued.

 

Well, maybe I've gotten confused now. In any event, it is adjustible and the retach spacer does come with instructions and shims. I tried looking through my stuff to see if I could find the instructions and I can't put my fingers on them right now. If I find it I'll try to get it on here.

 

Now I'm confused . Somebody make a diagram to post so idiots like me can get the picture. I have a solid spacer and shims, just a little nervous about trying it for the first time.

 

That's correct. I must have had a brain fart. The spacer goes between the bearings, so too tight would mean not enough shims, and not enough drag would mean too many shims. I remember that it was kind of a PITA having to remove the pinion each time to try to get the shims right for the correct load.

 

see, yet another reason i use the collar....