Setting new gears in the rear

[84BuickGNYorkPA]

Hi,

Can someone tell me if this looks ok, it's a new motive street set, the pinion depth looks good to me, but the contact looks kinda of high on the gear, but the backlash is .009 (.006 - .009 motive spec) so not sure if there is anything else I can do with it. If anyone wants to follow my jorney to this point here is a link
Thanks,rear end oil change... and busted gears - TurboBuicks.com

Chuck

 

[johnnyttype]

well after consulting with my gear buddy and his papers on this stuff, it appears that you need a larger pinion shim for more pinion depth. the coast side it too high on the tooth. the drive side pictures look like you did not have enough pressure on the ring gear to get a good footprint.

backlash moves the contact point inside to outside or heel to toe, pinion depth will affect height on the tooth. thinkin about gears gets me all confused just tryin to picture everything hth

 

[84BuickGNYorkPA]

ok thanks, I have the old bearings(modified) on the pinion gear so they are easy to take in and out of the rear. I appricaite the extra effort that you took to respond to this thread. I will add more shim to the pinion gear, readjust the back lash, get a new footprint and report back.

Chuck

 

[Lee Thompson]

Imo

I would go .006 extra thick shim on the pinion gear. Read somewhere once that it took atleast .003 to show a difference. BTW as johnnyt said adding shim thickness will move the pattern closer in to the root of the tooth. As far as from toe to heel, use a bar and wedge it between the ring gear and housing to simulate a LOAD on the gear. As load increases the pattern will move from heel outward to the toe. Hope I'm remembering my wording right. Increasing backlash will move pattern outward toward the end of ring gear tooth (toe). Best of luck.

 

[boostingbuick]

More pinion shim as said and I have set my backlash from .004 to .006.

 

[84BuickGNYorkPA]

Wow, thanks for all the advice, I went another .005 on the pinion shim which took me from .037 to .042 and it looked right on the money, according to the pattern. So then I installed the new bearings on the pinion, set the backlash to .007 and did the check..... well lets just say that something didn't repeat to well. The wear pattern is now 2/3 of the way toward the heel, with no pattern on the coast side. I will have to look at my instructions again tomorrow for the solution, but I think that I will have to take .003 out of the pinion to move it away from the ring gear. I don't care if this takes me 10 tries, I will get it right.
It was hard to tell how tight to make the nut for the pinion gear, as that tightens up I guess that also pulls the bearing into position?? I guess that I will now need a new crush sleeve napa should have that... anymore advice?
Thanks,

Chuck

 

[cruzn57]

advice?

just don't drive it til you have the correct pattern,

the more you work at it the more experience you'll have , and the easier it'll be next time,
practice makes perfect.

 

[johnnyttype]

Wow, thanks for all the advice, I went another .005 on the pinion shim which took me from .037 to .042 and it looked right on the money, according to the pattern. So then I installed the new bearings on the pinion, set the backlash to .007 and did the check..... well lets just say that something didn't repeat to well. The wear pattern is now 2/3 of the way toward the heel, with no pattern on the coast side. I will have to look at my instructions again tomorrow for the solution, but I think that I will have to take .003 out of the pinion to move it away from the ring gear. I don't care if this takes me 10 tries, I will get it right.
It was hard to tell how tight to make the nut for the pinion gear, as that tightens up I guess that also pulls the bearing into position?? I guess that I will now need a new crush sleeve napa should have that... anymore advice?
Thanks,

Chuck

im wondering since you checked the pattern before putting the new bearings on, in affect what happened was the old worn bearings acted as if there was not enough pinion shim from being worn and now with the new bearings it was just enough to push it outside of what you were looking for?! Maybe

be careful when tightening the pinion nut. on new bearings i think if you put a in lbs. torque wrench with one of those needles rather than a clicker wrench, you will want to crush the sleeve until you have 20-25 in lbs. of drag. old bearings is more around 15 in lbs. if reusing a crush sleeve what i have done is referenced the nut to where it was on the pinion before removing it and then when reinstalling take it to the mark and then approx. 1/8 of a turn more and then staked the nut.

i hope all this is correct, it has been awhile since messing with rears. hth

 

[Jeff Rand]

I am sure this will get some reaction on this post, but years ago I was having a problem with getting the crush sleeve to crush. Tom at Tom's differential said if I use a new locking nut and red Locktite that I can run without the crush sleeve. Just tighten the nut to give you the correct preload and go. (By the way no one mentioned the preload on the carrier bearings) For the last 8 years that is how I have been setting up my differentials. I was real nervous at first but I trust Tom. At the time when I originally did this I was using the car on the street and for racing; now it is just a race car. Since it is a race car with an Eton posi, I set the backlash between .001"-.002" per Tom's recommendation.
Jeff

 

[84BuickGNYorkPA]

I am sure this will get some reaction on this post, but years ago I was having a problem with getting the crush sleeve to crush. Tom at Tom's differential said if I use a new locking nut and red Locktite that I can run without the crush sleeve. Just tighten the nut to give you the correct preload and go. (By the way no one mentioned the preload on the carrier bearings) For the last 8 years that is how I have been setting up my differentials. I was real nervous at first but I trust Tom. At the time when I originally did this I was using the car on the street and for racing; now it is just a race car. Since it is a race car with an Eton posi, I set the backlash between .001"-.002" per Tom's recommendation.
Jeff

the preload on the carrier bearings... well the shim in my car had to be slightly persuaded to go in, but it always comes out with a slight pry on the pry bar.
I was told to heat the foward pinion bearing in the oven up to 350 deg. then install it, I had a rough time getting that all the way on the shaft. Because I'm doing the job with out a lift... Tomorrow I will start over...
And as someone mentioned, I'm feeling a lot more comfortable working on the rear. Being a PA certified journeymen machinist, I will not run the car untill I have it on the money. I have all the time in the world to get it right...it is somewhat frustrating though...

Chuck

 

[gnxtc2]

This is how my gears were set up

Foward

Reverse

Billy T.
gnxtc2@aol.com

 

[charlie]

I know alot of people dont have one but a pinion depth checker from T&D machine products makes things much easier , purchased one a few years ago and every rear i have done has required only one assembly phone number if interested for T&D 775-884-2292

 

[84BuickGNYorkPA]

Ok, finally figured out what my problem was, (I think anyway) my 1/2" impact wrench did not have enough power to even get the bearings tight, never mind the 20" or 30" pounds of rotation torque value or bearing load. So I borrowed the one from work(it's newer and better quality) took off all the couplers on the air gun running the hose straight to the gun. It took it about another half a turn and now the bearing is tight but still does not have the bearing load at 20" lbs. So after thinking about it, I checked my distance from the center line of the ring gear to the face of the pinion gear.(To do this I brought home my depth mic set, filed the burrs off the face of the rear housing to get rid of raised metal, depth mic'd to the OD of the carrier race, then depth mic'd to the pinion gear face, subtracted these two values from each other then subtracted half the diameter of the carrier bearing.) And it was exactly the size vibratooled on the ring gear from the factory 2.592
So then I set the carrier back up in the car and adjusted the shim untill I got .006 backlash with the carrier bolts torqued down. Painted it up and here is what it looks like... I then reassembled everything and drove the car last night, everthing is nice and quiet, but I have to take it in to work (they have 1" impact wrench, which is over kill) and redo the job right.... I'm pretty sure that I do need that bearing preload to be right....
Any comments?

Chuck

 

[S10xGN]

This is how my gears were set up



Billy T.
gnxtc2@aol.com

Dang, that's as full a contact patch as I've ever seen! What brand gearset?

 

[johnnyttype]

very nice, glad to hear things are working out! no need to use a 1" gun, there is a trick my mentor taught me a few years back. the washer that is behind the pinion nut is probably binding. what you should try is put anti-seeze on both sides of the washer and then give it a go. i did this on an SSR rear end and it didnt even put up a fight with the anti-seeze. before that we broke a breaker bar with a pipe on it and used an expensive snap-on 1/2" gun on shop air and could not get it to go down!hth

john

 

[84BuickGNYorkPA]

very nice, glad to hear things are working out! no need to use a 1" gun, there is a trick my mentor taught me a few years back. the washer that is behind the pinion nut is probably binding. what you should try is put anti-seeze on both sides of the washer and then give it a go. i did this on an SSR rear end and it didnt even put up a fight with the anti-seeze. before that we broke a breaker bar with a pipe on it and used an expensive snap-on 1/2" gun on shop air and could not get it to go down!hth

john

John,

Are you kidding me?? Wait till I tell the guys at work... I must of had about 6 of them brainstorming with me on my problem throughout the day. Now I guess I have to go buy two more quarts of napa rear oil, and get busy!
Thanks for the tip....

Chuck

 

[johnnyttype]

John,

Are you kidding me?? Wait till I tell the guys at work... I must of had about 6 of them brainstorming with me on my problem throughout the day. Now I guess I have to go buy two more quarts of napa rear oil, and get busy!
Thanks for the tip....

Chuck

haha, sounds like what me and the other guys around the SSR were doing, but it was only about 4 of us! I was in shock when all it needed was some anti-seeze on the washer. Its been a couple years but that should do the trick, if not, then you can subject it to the 1" gun on shop air

 

[turbofabricator]

One trick to get the crush sleeve to start to move is to re-use the old one. Just take the old crush sleeve and slide it over a pipe of appropriate size and tap it with a hammer (the "bulging" part). Just measure the length of the sleeve before you start and lengthen it by about .020" and it will then crush real easy. I built my first gear set up on my 1st GN (about 17 years ago) It had a broken ring gear tooth caused by a flaw from the factory (a piece of un-melted steel they had thrown into the mix, and it just snapped on a 12.5 second car) A buddy that builds lots of rear-ends told me the trick AFTER I had to use a 18" breaker bar and a floor jack to get it to start to crush. IT would wind the suspension up and lift the car off the jack-stands before it even started to crush. (I placed the breaker bar at 90* and put a floor jack under the bar handle and jacked it up. I also borrowed a pinion holding bar from my local dealership, that I layed against the floor.) A 500 ft/lb impact does the trick easily, but I didn't have an air compressor back then. There are lots of Ford 9" race cars running with-out a crush sleeve, also. Many debate this, but it makes sense to me to leave it out. What does it really do? It just puts a little pre-load between the bearings. So, can it be eliminated? Probably, but I am too chicken to do it. After doing a few of these things over the years, I sure can appreciate a Ford 9" design. Ford does have a MUCH, MUCH better design. (even though it costs a few horsepower) They can easily be build in a vise on a bench.

 

[gnxtc2]

Dang, that's as full a contact patch as I've ever seen! What brand gearset?

Richmond Gear 3.73 Street gears

Billy T.
gnxtc2@aol.com

 

[Dr.drivability]

I am sure this will get some reaction on this post, but years ago I was having a problem with getting the crush sleeve to crush. Tom at Tom's differential said if I use a new locking nut and red Locktite that I can run without the crush sleeve. Just tighten the nut to give you the correct preload and go. (By the way no one mentioned the preload on the carrier bearings) For the last 8 years that is how I have been setting up my differentials. I was real nervous at first but I trust Tom. At the time when I originally did this I was using the car on the street and for racing; now it is just a race car. Since it is a race car with an Eton posi, I set the backlash between .001"-.002" per Tom's recommendation.
Jeff

Don't be a hillbilly. Your GN deserves a proper setup not, some halfa$$ job. you're on the right track!!