Last cars to use those rears were the early 1966 Gilmore Flexi Fliers. By mid year Woody switched to the 8.75. Just to add to the trivia, Tony Nancy got the first of his 8.75 cars. The last of the Olds cars was sold by B&L Auto in NYC and became the Brewmaster T/Fer and was driven by Jimmy Messenger. It had a M/T magnesium center section and shortened stock axles.
When they would do a feature on a rail in Hot Rod Magazine back in the 60s they almost always mentioned the Olds rear. I had a subscription from about 64 on and I remember when they broke into the 7 second times but I can't remember who did it first. Cheers 🍻
The Kaiser Brothers a local engine shop, used an Olds rear end behind a 392 Hemi they set up to run on nitro. They still take it up to Bandimere on occasion as well as local car shows.
Yes. I never knew weather it was ok to try and cover up the ring gear to reduce welding splatter and do it in the diff or strip it down and weld it on the bench then clean and rebuild. It always seemed risky to just whip the rear cover off and start welding if you wanted your diff to last even though I have seen it done a few times.
On a short wheelbase drag car or a high power street rod, if an axle breaks on a posi/spool/ect., all the power goes immediately to the "good" axle and the car can hard turn almost in its own length. An open rear will lose all forward thrust. If the car has a properly designed four link, the right rear can have some pre-load applied, and both tires will plant as they should. This is a safety concern that no-one thinks about. Good topic Tony!
Open diffs are more robust in my opinion, especially in trucks. A little known secret with an open diff: If you are stuck and one wheel is spinning, just slowly apply the e brake and the load will shift to the non spinning wheel. This has worked for me many times.👍
Modern traction control systems use the computer to apply the brake to the slipping wheel --just like the guy below talks about using the dual foot brake on a tractor. With the speed the computer does it, you never notice. You just go.
@@danjones1897 There's a reason nobody uses traction control in drag racing or off-roading. Every traction control system I've ever seen had an extremely delayed reaction time. By the time they cut power and apply brake an experienced driver would have already recovered without lifting as much or even braking at all. I've also seen traction control systems freak out and cut the throttle and apply the brake on a modded totally hooked up car with full traction because it couldn't tell the difference between losing traction and gaining power. All it saw was too much wheel speed too soon. They can also ruin your desired launch or your efforts to get unstuck by cutting power when you want or need max wheel speed.
I had a 71 road runner 440, 4 spd. With open rear differential. I put a traction bar on the passenger side spring and adjusted the snubber so the car was putting weight on it when the car was sitting still. Worked really well at getting both tires to grip
@@alanrader3016 That's really nice of you. I feel sad for the widow though this scenario isn't uncommon. Maybe make an offer. I've always had a soft spot for the pistol grip! I bet the husband bought it new, enjoyed it, stored it, and passed on.
Thanks for that content. I’ve never heard that explained the way you did. Might be my favorite sit down you’ve done. I saw a guy with an auto parts store “helper” spring on the right side only once at a track a million years ago. Thought he was crazy but now I think I understand what he was doing. Thanks for the Video.
I’ve had welded rear ends (8.8 fords) in pickups that’s gave ALOT of a use to and they survived, I think it would be a great video to make for your viewers. I’ll be tuning in from frostbackistan 👌
Yes Uncle Tony I did get something out of that. Thank you for making me think in terms of torques effect on wanting to load one side while unloading the other. Adding one leaf spring to the passengers rear corner is a great Idea and easy to do. Using a pinion snubber is also a great idea. You can tell the Chrysler engineers had a good understanding of the suspension dynamics on this. 😊
In tractor pulling we actually needle the spider gears and side gears to reduce friction so the side with less traction can spin more. It is the only way to get a high powered machine to go straight on an uneven dirt surface because traction varies so much. If you lock the wheels together you can be pretty confident it’s going to shoot of in any direction but straight!!
Damn good stuff, you remind me of the old time racer that taught me to build engines in the early 80s. The only welded spiders I ever saw growing up went south in my buddy's blown 67 Camaro and almost killed him. I honestly thought it was a no-no to weld them based on everything I ever heard. Then, I started running mini-spools in my rock crawlers back in 1998-07ish. They were not very forgiving and it donned on me that spools were basically the same as a welded diff. Personal preference now is to run open and deal with the wheel lift. But, I don't drag race anymore... I will run welded spiders in a burnout mini-truck I'm planning on building. Makes for better smoke having two wheels dong it.
Thanks for the info Tony. My dad has a 1970 340 Dart Swinger and has an open rear differential. Lots of great info to be had here regarding the racing history and performance of these parts!
Hey man, this is stuff that I never knew. I never have heard anyone discuss this kind of information, and I never would have even considered this as a possibility. This is amazing to hear, thanks so much for broadening my base of awareness.
For an 8" ford rear, they were 31 spline, a 9" mini spool worked great and were only $35. I ran modified 4cyl dirt for 10 yrs, first rear was a 7 1/2/" with welded spider gears.
We have an 88 4X4 Blazer that is wheeled a lot. It has an electrically activated locker in the rear axle. To be able to select open or locked is a big plus. The front axle has a lunch box locker. The only thing wrong with that is the steering gets harder, especially the tighter you turn. An E-locker in the front also would be perfect. Not in the budget though since we have three other trucks that eat money.
HOWdy U-T-G, ... Fascinating OPEN Rear-End FACTS ! ... I was a USPS / Letter-Carrier for a while in my early life & we drove 2WD JEEP DJ-5 vehicles all equipped with Limited-Slip Differentials ( in the REAR ENDS ) ... and they were fine Fine Fine Spring, Summer, & FALL ... but in the Winter with SNOW & ICE on a "CROWNED" Street or HIGHWAY ... the "LOCKER REAR ENDS = sucked pond water !!! stopping at each & every mailbox = these DJ-5 JEEPS would slide to the CURB ass-end 1st ... Thanks COOP the WiSeNhEiMeR from Richmond, INDIANA ...
That really brings back memories. I did a Lincoln locker for a friend back when we were 20. That was 1990. I told him not to call when he turned a corner too fast. He did about 3 months later. Thanks Tony
After watching this I put a chain on the right rear tire (I have a set) of my Chevy 1 ton to plow snow. That thing was unstoppable!!! Thinking I might put the other one on the left front…
i've never used them but lunchbox lockers i guess are an intermediate between mini spools and regular limited slip cost-wise. interesting take on open diffs i never knew.
I have a lunchbox in one of my cars. It was roughly the same price as an LSD, but it's an actual locker. The real cost savings you're harvesting with a lunchbox is in the complete lack of setup required to install one. Just roll the spider gears out and roll the lunchbox in. No bearings, shims, crush sleeves, etc. It works well enough. Lots of clicks and clacks like the big-boy lockers without the big boy price and durability. Nothing I will ever own is likely to make enough power to break a factory carrier, so... should be fine. 🤞
@@brandonford8092 Powertrax Lock-Right (what I have) is an example. The locker assembly goes inside a factory open carrier and replaces the side gears with 2 pairs of drive dogs. The drive dogs apply load from the carrier to the axles via the vertical cross pin until there's enough of a speed difference from either wheel for one pair of dogs to jump past each other. They function like a regular locker, but for a fraction of the price of a locker. They're about the same price as entry level LSD units, but superior in function if you _really_ want 2 wheels driven as much as possible. I've heard the "lunchbox" nickname comes from either the idea that the locker is packed inside of the carrier, like a lunchbox, or that the lockers are so small they can fit inside a lunchbox. No clue if either is accurate, but that's the slang term for that style of locker.
Lunchbox lockers, like all lockers, are a whole other level from clutch based stuff like positrac, but much more streetable than stuff like spools (and a lot of times, the clutch based stuff.)
@@immikeurnot Is that what's in an '83 Camaro Z-28? I's open until it locks, then it stays locked sometimes until you can make a slight turn, then it's open again. You can't run a mini-spare ! Shredded the crap out of a tire once, needing to get home.
For years when I would bring up the extra leaf on the right side people would look at me like I was nuts. Thanks for mentioning this. Another trick is to cut out four rectangular plates from 3/8" sheet metal, blow some holes in them, and bolt them on the front sections of leaves on each side, clamping the leaves together so they did not bow apart under acceleration. I never noticed this making the ride rougher, just that it kept the car straighter coming out of the hole. Also, I used an adjustable pinion snubber instead of traction bars to keep the axle from twisting. It was easy enough to crawl under and raise the snubber for the track, drop it back down for the street.
I remember the first set of spiders I welded up. Back in 1969, several of the home towners were doing much the same things as the Mission Impossible 318 and welding the rear spiders. These were street-able(?) and you could tell when one came to street race at the local cruise-ins. The rears would 'chirp' around a corner (hopefully you didn't break and axle!). One fellow had a 1964 Ford Fairlane 'Thunderbolt' clone with 260 V8 badges but had trailered the real Thunderbolt that was identical, even to the 260 badges! It sure made for many a story. Keep bringing these tidbits!!!!
The barracuda1970 model blew the side gears💥💥💥 after i transplanted all the running gear outa of a 70 Cuda 383/727....after wards i put the 83/4 355 gears in 🤣👍
I had a 440 66 charger with 355 open 8 3/4 and with the weight transfer to the back corner was great . I had a 391 gear but with my 4 speed 1st gear was useless
Most times we welded diffs for speedway the spider gears would let go so all tip's would be appreciated thanks for sharing, all the best to yous and your loved ones
Contrary to welding spider gears, I'd love to see more stuff about using open rears and what they can do. A tech video on tightening up the slop to get a better bite and the kind of suspension work to get an even bite would be great. I know suspension can be less exciting than engine tech though.
Differential Talk with our Uncle Tony... Shut up for a Minute and listen.. Even you know it all's ... Have a great weekend folks or whatever version of "that" is to you . Keep on wrenching folk's @∅
Tony, I would like to see how you shim behind the spiders to tighen them up a little. I just as soon keep an open rear, I don't race and it is some much easier on tire wear but it would be nice to get that little bit when needed. I always thought an electric locker would be nice but the few I've seen didn't fit what I have and are too costly. Thanks, good vid, DC.
A pipe going from the transmission casing to the differential casing is the cure chevrolet uses on some corvettes. It is a good way to have your suspension act symmetrical during normal driving and still launch good on the drag strip.
Our 68 charger was built to drag and the guy had put 8 springs on right side and 5 on left. He never broke any rear window that way. It was long ago and the 3.91 gears were not weld but à lot of folks did it. They has the yellow drag antispin bars on the rear end that looked funny. I was 12. Lol Another important message and I learned again from how to proper weld spider gears. Didnt know about heating prior to weld. Actualy, dint even realy know how to weld it. Thanks again to all the community.
My favorite "hack" posi on old gm cars with rear coil suspension was always putting a football in the right rear coil spring. Change the air pressure to change preload, and it only costs $5 and little playing around with pressure to get them to bite like they had a posi in them.
I was going to comment the same! Worked on a bunch of g-body's and a-body's with a football or dedicated fit airbag. When we started to install anti-roll bars more often they went away.
Id love to see a video on welding spider gears!!! Im about to rebuild my front axle in my 77 power wagon (total trail rig).... perfect timing...all your mopar videos kick ass tony!!
I welded up a Dana 60 rear in my mud truck and used it for a few races. I was backing it up one night to load on the trailer for an early start the next day and I feel and hear this clunk. I go ahead and load then I see oil running out on the trailer. Well a chunk of spider broke out and wedged under the ring gear and popped a hole in the case. I decided the Lincoln locker wasn't gonna cut it so I found a spool and patched the pumpkin. Sure hated to miss that race though.
I was stuck in the snow with my van last week. Good thing I had tire chains, cable chains actually. What I noticed as always, the right rear is the one that looses traction, all the time, as long as I'm on the same slippery mess with both wheels. One of the cable chains came off, but I didn't want to stop because I thought I would get stuck and have to put it on again, so I kept it going. Cable chain was on the right rear. I made it. Don't know why it's always the right rear. ('91 Dodge van, 8 1/4) Well, maybe it is torque reaction, because even in those situations there is a little bit of torque, even if you only apply the accelerator minimally. Maybe that's all there is to it.
I almost ordered a Torsen diff for my 8¾ once, but a friend suddenly let me have his Sure-Grip when he bought a Dana 60. I still want to try a Torsen someday.
Very interesting topic. So for a typical a suspended rear end drivetrain, the axle housing is allowed to twist, and the torque reaction of the driveshaft will try to spin the rear end in the opposite direction and unload one wheel (passenger side). The rear springs counteract the reaction torque torque. Is that also what caused rear steer? So on a top fuel dragster, the engine/ slipper clutch/ bellhousing was bolted to the differential housing so it was like a rigid member? Makes sense it wouldn't try to lift the one tire from driveline torque. But it still seems like when the engine jumped up to speed from idle at the green light the inertia of the crank would still momentarily plant one tire from the torque reaction. Once the car was under power and the revs level out a bit both tires would get equal pressure. Didn't Don Garlits try to run a transverse mounted rear engine dragster in his later years to counteract that? Doesn't seem like that would matter much for anything except for a dragster (and maybe not even for them). Maybe I'm overthinking it.
If you have a coil spring car you can put a foot ball in the right rear spring and inflate it as a tuning mechanism instead of an air shock... That's another old timers trick.. 😉
I Don't weld them in the carrier just weld 2 or 3 theeth on oppisite sides of each side gear and grind the edges smooth. Install them same way they came apart. Welding a carrier with C clips the other way you will never be able to take it apart again.
Forgot to mention weld 1 and 2 teeth on opposite sides of spider pinions also so they all mesh and can be installed that way. similar to a mini locker and if you ever want to change back to open diff you can remove them and put spider gears back in
I liked the old front engine rails the rear engine dragster was cool but those dudes that ran the old rails looking around that massive blown motor setting between those tires with a helmet and gas mask on now those fuckers was crazy lol but that's about as badass as it gets. I love your videos uncle tony man I have and still learn alot from watching them.
Great content, I always had a open diff, on the street. I had friends with lockers or posi but usually you would end up headed for the ditch. In those days 70’s, tires weren’t the best. So I figured out if you wanted to play on the street it was line lock , a B&M with a stall converter and a open 9”
