Inline

Well well, quess the most asked question from guys doing first time their rear.
So, am i at your mind good to go and start to install rear back to car, or try to improve a bit. And if, to where?
Spend whole day setting my gears, and this is best i could achieve.
JMO, well worth to pay for someone who does these more often than maybe ( and hopefully) once on their life. I did it just because i have time, and interest to do it myself.

Its a BOP 8.5, truetrac and used OEM gearset, which looks about perfect & as new.

For backlash i ended up to 0.0071". At the range, when 0.006" - 0.010" are the given values. For this im myself really satisfied.

And this is where i ended up with pattern, best i could achieve:

Drive-side is maybe a bit too close? Maybe.







On the other hand, coast-side is spot on. And the standard gear leaflet states that when installing used gear-sets, main focus should be on coast-side, of course without forgetting drive-side.



Soo.. Would you run this setup ( 0.0071" backlash, and given patterns) or maybe try to set the pinion a bit farther away? Or..?

Thanks. Just want to hear opinions, dont want to install the whole setup under the car just to notice there was something wrong which could have been noticed earlier.

Inline

Well, ill take silence as its cant be far off. Did go fiddle with it at morning for a bit.
Now i have backlash set, carrier bearing preload set by a feel, and everything quadra-checked.

Started to install everything back under the car, i think ill hear it if it wasnt good. Just waiting for axles anymore. Next to blow my trans apart after christmas.

And heres the final pictures at last checking to be sure everything was still right.

Ozzie

The first photos were a bit too dark to tell. On these I tend to agree that it seems to be "close". If I would do anything it would be to move the ring away from the pinion just a bit, (and adjust pinion to correct backlash), but if the backlash is right, perhaps it is good where it is.

Inline

Thanks for opinion.

At this moment its going under with these. If it happens to whine, then ill change the shim under pinion then, i settled to .036 at my tests.
Btw. One single thing making you run nuts, is the need of using converter whole the time. Metric tools, and US units, grr...

Inline

Im just assuming there, but ive thought that the sentence about focusing to coast as long as drive is acceptable, on used gears, is to take the slight possible worn from drive in account, by assuming gears were set perfect from factory. That way by getting coast perfect, it should be at same position as from factory , and wont start to worn and possibly ruin the already driven-in and slightly worn gears from drive. Since coast faces a lot less wear in normal automotive use.

Just a thought if it makes any sense. With smaller shim-stack coast started to run, imo, too near to top of the teeth. So thats the best i achieved, and by factory service manual, which is far more vague from contact pattern, it should do. Both drive and coast have space to flank and face. Will see when driven.

Ozzie

USA is gradually converting to the metric system, which is better, but for those of us that do the old car hobby, we must still endure the old SAE system and tools. Sometime there is frustration.

Ozzie

You are correct that the photos in the '76 manual are weak on the tooth patterns. I have seen much better in other manuals. And it is important to get this correct. It is the best way to check for setting the gears properly.

Inline

I used other leaflet with 3 pages of patterns, fear away!
Everything was set up properly on pictures, backlash, pinion preload, and no preload on carrier bearings, just a "snug" fit.
Backlash settled to 0.0075".


E: F****t. Ill torn it apart once more and play a bit with pinion depth. Just cant give up until i get it perfect.

RROLDSX

The original pic looked good to me, I' m no expert but I did stay at a Holiday Inn.

oddball

Monaz and Brian (507olds) to a ton of rear end work. I'd reach out to them directly.

Inline

I know. Everything you see here is bought from Monzaz
Aint it odd that its cheaper to buy from a guy across the bond and pay all the shippings customs etc, than from local speedshop?

Bwahaha cheated my fiancee with me to do one setup.
Decreased pinion shim. .035 & 0.0078" BL.

Now both sides are imo nicely between the flank and face. Drive looks to be nearly perfectly sentered between flank and face, coast a bit on the face-side but still "on boundaries" i think. Only irritating thing for me is the "picture" of drive-side, its not a soft mark, rather sharp instead. But it almost runs through toe to heel, so aint that an pretty good contact.. Wondering if this is just the case with used gears?

Got better pictures of patterns when read somewhere that adding a tad of gear-oil helps to show them better.





E: Still back to the garage. Want to get that drive pattern to blur.

65Delta

Drive side looks a lot better now than in the first picture. As your b/l is in spec I'd say run it.

monzaz

So what was the first pictures pinion depth shim?

The .035 does look a lot better... Open up the backlash to .009 - .010 and see where the pattern goes. Remember these are USED gears and we do not know the complete life of where it road.
try a .038 and see what it does. You have to be sure.

Inline

Lets close the deal so it wont be left sit on air. I hate it.

I had to throw my hands in the air, i just couldnt tell acceptable drive from used set. Its just not like in all books and leaflets, so experience needed to walk in. Worked it out with Monzaz, special thanks to him once more for everything, parts and help

Last, final, "funny", twist comes now. When doing numerous different settings ( i tested over 20 different setups easily from my head with different backlashes and pinion shims) i somewhere along damaged my original pinion nut, so i had to use my new as a setup-nut. And of course i proceeded to order new one from our most known US-parts dealer to wait for final assembly. I asked for way different part number, but somehow i received Dorman Help!-product.

This is JUST MY OPINION, but i wont trust ~2000$ worth of rear-end parts behind that nut. First, it has some really sketchy socket size, 32,5mm?? Whut??
Second, it has only nearly half of the threads than OEM nut, for example, has. From what i remember from school, the nut thickness should be atleast the diameter of the bolt. This one has roughly half of it. Threads look also strangely harsh? And no use to return it, since postages were over half of the cost. That piece of **** did cost an 24-pack of beer!!!!!!
Once again, just my opinion, but that nut wont come to my car, when everything else is done properly & is new ( except R&P). Maybe as Help! part it would do until receiving proper one...

SOO i did what i should had at for starters, i dug out OEM part number, and contacted Finnish Chevrolet dealer. We even have one locally where i live. Well, contacted them, and found out that they had 1 of them at Finland. But the guy at our local dealer was an total *******, really hard to deal with, and at last suggested (!) me to contact myself the dealer who had it at ware ( obviously so he wouldnt need to order it).
So i did, was done with that *******, and when they questioned why i wasnt ordering it from our local dealer, i told them why. Now its on the way. Oh yeah, and it ended up to be cheaper than that Dorman..

Oh well, dont know should i laugh or cry from this episode. But thanks for participating. Cant wait to drive 3.42's after 2.41'

Fun71

That will certainly put a big grin on your face.
I did similar with my 70 Supreme - changed the entire axle from 2.56 to 3.55. Wow, what a difference!

76olds

[QUOTE=Inline;975786] Cant wait to drive 3.42's after 2.41'

I did the same, purchased all my 3:42 gears/posi and parts from Monzaz although all new parts, yours will be just the same . My 76 had 2:41 as well prior to the change.
The first time you drive it you will know its a totally different animal, but try to go heasy until you break them in haha.
Ohhh and BTW Your wife will know that smile as soon as you get on er'!!

Eric