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Tabcon
12-08-2009, 10:07 PM
After watching the British pound soar and the price of an LSD for my rear end do the same, I decided to wait on one and go ahead with the rebuild of my differential. I did install the 4.1:1 crown and pinion though.

As this is my first attempt at rebuilding a rear end, it would be helpful if you guys could look at the following pics and let me know if the mesh looks alright. It's a little bass ackwards as the white craft paint I used seemed to spread to the bottom of the teeth and the actual contact area is almost paint free.

I hope it's okay because I really do not want to take it apart AGAIN!

LOL

https://i779.photobucket.com/albums/yy77/Tabcon1/Crown-2.jpg

https://i779.photobucket.com/albums/yy77/Tabcon1/Crown-5.jpg

https://i779.photobucket.com/albums/yy77/Tabcon1/Crown-1.jpg

TR3driver
12-08-2009, 11:12 PM
Nope, doesn't look right to me. You should be able to see the contact in the center of the tooth, not at the edges. Looks to me like you need to move the ring gear closer to the pinion.
https://i258.photobucket.com/albums/hh260/TR3driver/Stag%20diff/DSCF0065.jpg

Tabcon
12-08-2009, 11:50 PM
I've got 2 .010" shims under the main pinion bearing already. You think I need to go another .010"?

I'm going to try a different marker material. The liquid hobby paint I used was a little runny. I'll try some white lithium grease tomorrow as no one around these parts even knows what bluing is.

TR3driver
12-09-2009, 01:54 AM
I was thinking more of removing a shim from the pinion side of the carrier, and moving it to the gear side.

MMC has a warehouse in Atlanta. https://www.mcmaster.com/#contact/=4uovpa
If you order tonight & pay for 2-day shipping, you should have it Friday. Or, there is a Grainger office in downtown NO:
Google maps (https://maps.google.com/maps?hl=en&source=hp&ie=UTF8&q=new+orleans+industr ial+supply&fb=1&gl=us&hq=industrial+supply&hnear=n ew+orleans&ei=MEkfS--fDpW4owTwuvzTBA&ved=0CBAQpQY&view=map&cid=98263373 29181023035&ll=29.957017,-90.087032&spn=0.109017,0.183849&z=13&iwloc=A)

Brosky
12-09-2009, 11:15 AM
I agree with Randall. Try to center the internal gear cage as well as centering the wear on the ring and pinion gear faces. Both are equally important.

Tabcon
12-09-2009, 12:08 PM
I tried torquing down the pinion nut a little more today and the pattern changed a good deal. I've been shooting in the dark as I do not have an inch pound torque wrench to measure the pre-load. I found one at Autozone for about $25 so I'm going to pick one up today.

Do you guys know a basic foot pound setting for the pinion nut? I've heard anywhere from 100 to 175 ft. pounds. 175 sounds way high, so I'm guessing the number should fall closer to 100.

Anyway, after torquing the nut a little more, the pattern changed to indicate contact on the outside edge of the teeth which I interpreted to mean the pinion and crown need to be closer together, as Randall first stated. After I get the inch pound wrench, I'm going to place another .005 shim under the pinion main and see where that gets me.

BTW, don't you think that $1,200.00 is a ridiculous price for a Quaife LSD?
When I first considered one, they could be had for around $800, which ain't too bad, but I can think of better ways to spend 1,200 bucks...like some bling-bling pimpin wheels...maybe the kind that keep spinning long after you've stopped!

Oh Randall, thanks for the info on the shims. I've actually been making my own though. I hate to wait on deliveries. The local Ace Hardware store has little packs of brass shim stock. The only problem being, the thickest shim is only .005", so I had to use 4 of them to get to .020".

swift6
12-09-2009, 12:21 PM
BTW, don't you think that $1,200.00 is a ridiculous price for a Quaife LSD?
When I first considered one, they could be had for around $800, which ain't too bad, but I can think of better ways to spend 1,200 bucks...like some bling-bling pimpin wheels...maybe the kind that keep spinning long after you've stopped!

Depends upon how important putting power down through both rear wheels is to you. The blin-bling wheels won't do that.

TR3driver
12-09-2009, 12:35 PM
Do you guys know a basic foot pound setting for the pinion nut? I've heard anywhere from 100 to 175 ft. pounds. 175 sounds way high, so I'm guessing the number should fall closer to 100.100 should do fine. My TR4 manual gives 80-100, the Stag manual ups that to 90-110.

The Quaife certainly isn't cheap; but my main objection is that, as I understand it, it will not work if one wheel has no traction at all. So it's not much help with one wheel in the air.

I've thought about trying to make my own, but the thought of machining custom gears from billet, then having them heat treated, and blowing up a few sets before getting it right all makes $1000 look like a bargain.

Tabcon
12-09-2009, 12:59 PM
Yea, I heard the same thing about the wheel lift and the only fix for that, other than welding your spider gears, is a Salisbury type, which is even more expensive. The Salisbury type also can run very hot, requires regular maintenance and can be somewhat harsh if you plan on using your car on the road, which I do. I've heard some great things about the Quaife and the wheel lifting really doesn't bother me since my car in not going to be an outright race car, but more of a fast road/track day type car.

I've done a little checking on the Phantom Grip device that you bolt in between your spider gears and the verdict is mixed. Some say it really bites, while others say it's only okay. I checked their website out and it reeks of gimmicky to me.

I'll drive my car for a while, one day, and see how it goes. I can always pop in an LSD later since all the bearings, seals, ring and pinion are brand new. I've been watching the British pound lately and if it goes back down to the 1.50 exchange rate, I'll most like get one.

TR3driver
12-09-2009, 02:23 PM
I've done a little checking on the Phantom Grip device that you bolt in between your spider gears and the verdict is mixed. Some say it really bites, while others say it's only okay. I checked their website out and it reeks of gimmicky to me. The theory seems sound to me; basically it just adds friction to the differential action somewhat like a Salisbury does. The amount of friction is adjustable to some extent (springs & shims), and ISTR it also varies slightly depending on the difference in speed between the two wheels. But it's definitely an approximation; with one wheel in the air that friction defines exactly how much torque can be transmitted to the wheel on the ground. And just like the Salisbury, the friction surfaces wear.

Don't know if they are still available, but I hear the "Detroit Locker" is the best compromise for the race track. As I understand it, it basically operates as an open diff until some critical difference in wheel speeds is reached, then becomes fully locked. Makes kind of a dramatic change in the car's handling when it happens (not to mention a big bang), but it's very predictable so you learn to anticipate it.

Not sold for TRs (AFAIK), but a viscous coupling (ala Audi, Subaru, etc.) would be interesting, too.

Or, come to think of it, probably both the best and simplest solution would be a full-blown electronic traction control system. Hide some star wheels on the backside of the wheel hubs, hang some servo motors on the e-brake levers ... the rest is only a small matter of programming <<GRAEMLIN_URL>>/grin.gif

startech47
12-09-2009, 05:55 PM
Scott had a TR-3 with a Detroit Locker. It would suddenly change lanes while going down the interstate highway at 60 MPH. It was rather interesting.

mallard
12-09-2009, 07:54 PM
There must be a ton of people here in AZ that have the Detroit Lockers in their cars because I see it all the time on the freeway.

Tabcon
12-20-2009, 11:28 AM
I took everything apart once again and added a bit more shim height to the pinion and everything meshed perfectly. Randall hit the nail on the head.

I was having difficulty with getting a really good imprint I could make out on the gears, so I went shopping. I read where you could make your own machinists blue formula out of prussion blue paint and alcohol, so I tried that. That really sucked and made a huge mess. I then tried one of those really big Sharpie's. It worked perfectly, I think even better than the real machinists blue and absolutely no mess.

Anyway, the rear end is like butter now and all back where it should be.
Thanks for the help!

hondo402000
12-21-2009, 09:53 AM
you should also check the tooth contact pattern on the other( breaking )side of the tooth, I believe thats the term, I think but be certain, the contact pattern should be in the exact place on both sides, and then there is backlash you need to check too

Keep up the good work, I never tackeled a rear end job, painting is enough

Hondo