I know this has probably been asked over and over, but I didn't find any threads talking to much about 55-64 Chevy rear axles as far as durability. I am getting ready to put a motor and trans in my sedan delivery, and was thinking about looking for a better diff as well. I don't plan on thrashing this thing, and it's just a mild sbc with a cam and some 461 camel hump heads... but I've been know to do a few burnouts and such! At the very least I was going to get one of these kits http://www.classicchevy.com/chevy-rear-differential-bearing-and-rebuild-kit-1955-1957.html and go through the rear end before I put it back in. If everyone screams at me to replace it with a 10 bolt or something maybe I'll bite the bullet and update it now instead of being broke down on the side of the road this summer.
The axles are weak. But they hold up fine for street driving. it is not a burn out that breaks an axle it is traction that breaks an axle.
I can only speak for myself. My '56 Nomad with original 3.70 rear axle behind a mild 350 and M-20 Muncie has taken me 300,000 miles in the last 22 years. It gets rubber in all four gears and has done its share of burnouts.
If they are set up right they will handle 350-400 hp , especially if it is not a 4 speed with banzai launches. I still have one in a car i have owned for 40 years.
they hold up fine for street use and for racing behind an automatic---but you will break a few with a stick or a trans-brake---very traditional
Sub-standard rear axles even for 235 six cylinder vehicles...notorious for bad wheel bearings. With so many bolt-in upgrades available, it's silly NOT to install a newer/better rear axle in Tri-5's these days. Too many folks happily pour money into bigger engines and speed equipment, yet balk at the notion of spending a few hundred dollars to insure that the power reaches the ground in a reliable and useable fashion by upgrading the rear axle (and driveshaft). Cheap insurance in the long run.
That gives me a bit more piece of mind. I figured that they are plenty strong for my stockish low hp sbc but I wanted some opinions. I am thinking about trying to speedweek this year... Don't need to be stuck 1000 miles from home because of a burnout!
A lot of the Tri 5 cars racing in the 60's used them, a lot of the Super Stock 58-64's used them, sure a lot broke but they were being hammered on. If I was out looking to put a rear in I would not buy one with all the options available but right now my 56 Sedan delivery has a 454 with a turbo 400 and the stock rear.Just don't bang the crap out of it and enjoy,and once things start going like axle bearings look for another rear rather than fix it, there are a lot of rears the right width out there.
An old racer quoted once: " put any real power in front of them, and they will scatter like leaf's in the breeze" and he's right-I did one. After that upgrade. Maybe a Nova/Camaro is in your area.
Don't focus on just the axle, anything can break when you get too wild doing burnouts and high revs. The axle isn't the only part of the car being abused during burnouts. I once cracked the 3rd member on my 55 Nomad after showing off. I didn't even know until the next morning when I woke up and saw oil all over my driveway. My heart sunk, I thought it was from the motor. Thank God it was just the 3rd member so I just installed a extra one that I had. But it could have been the motor, or driveshaft, or etc....etc....get the picture?
Work fine if you don't beat them-have 2 cars with them-have driven many many miles over the past 36 years with them. One car ran at the drags alot with an automatic and was wife's daily driver--never broke-still going strong. Won't stand up to abuse with a 4 spd and good traction for long though.
Back in High School a friend with a '57 4sp broke quite a few axles before finally swapping the rear.
I think my plan might be to go through the stock axle and replace all the bearings etc... and try and not beat on it to bad. I'm over the race car phase I just want to cruuuuiisee
Hayden or Strickler coming off the line in a 409 full size car says abuse. Did they run those same rear ends?
A popular upgrade 'back in the day' was the Oldsmobile axles. Plenty strong and available with decent ratios. Still makes sense for a true 'traditional' build.
They are good rearends but, as someone said if they start leaking or axle bearings go out start looking for a replacement.
Broke a lot of spider gears and a few axles back in the day-283,4-speed - fuel injection - beer- in a 56' vette. Did I mention beer?
I actually broke a rear end housing in my 57....was stupid [lotsa beer involved] and did a burn-out across a speed bump. Housing broke right next to the spring pad. Car had a 327/4 speed. Never broke any gears in many years of 55-64 chevy abuse tho.
I have a stock posi in my 56 I DID replace all the studs but its done ok with my 327/4spd Sent from my DROID device using the TJJ mobile app
I had a '34 Plymouth with a narrowed '57 Chebby rear axle and a 383 stroker small block/T-10 combo. Granted I didn't thrash the hell out of it on a regular basis, but it took what I dished out and had been in the car since the late 70's. It was still in it and doing its' job when I sold the car 3 years ago...
Agreed we ran a 56 rear for a few weeks of heavy burn outs w/ a 485HP 383 and it heald up fine, but we knew not to try to hook it up! porknbeaner I love that quote!!!! "its not a burn out that breaks an axle....its traction that breaks an axle!'
IF you have the 55 third member, you have the weaker of the tri-fives (55-56 are the "weaker ones). IF it's an open rear end, definitely get a Positraction, and the NEW Eaton unit is far superior than the Dana Arma-Steel units. Go to BruneauPerformance.Ca (a Canadian site), and look at what he has for the 55-64 Chevrolet/Canadian Pontiac rear ends. Get the cap supports and aftermarket axles to go with the Eaton, and it'll be pretty strong. OR, an 8.5 10 bolt from a Nova/Camaro/Firebird, or even a MOPAR 8 3/4. Traction bars to prevent wheel hop; trust me, loading and unloading the rear end is almost as bad as putting slicks on a stock rear end. The final thing for the stock rear, reweld the spring perches as they are only SPOT WELDED in 3 places on each side of the perch. If the spot welds break, the entire rear end will rotate, and in a wagon/sedan delivery, it will take out the fuel tank. Butch/56sedandelivery.
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