Author Topic: Tri-five Chevy rearend (Read 14809 times)

Eyeball · « **on:** September 05, 2006 8:38 pm »

I need some info on the rear in Kathy's 55-56 chev. I took it down the interstate and the tach showed around 3000 doing about 55-60 mph. So I figure it has 4:11 or something close. I need to get a better highway gear in it.... what are my optins as far as stock ones goes. What years interchange? I would prefer to just pull the center section out and not have to put gears in. It is dripping so it will have to be serviced anyway and I may as well fix the gears at that point.

sundance · « **Reply #1 on:** September 05, 2006 9:25 pm »

well i believe that '58 went to coil springs and didn't '54 have a closed drive line? that leaves the tri-5s
unless something like nova,s10 or whatever has leaf springs,but i don't think they have drop out centers
i have a tri 5 rear end , and have used 4.11 which is usually from a 6 cyl overdrive vehicle,and 3.08 and now 3.55
with the 700r4

Eyeball · « **Reply #2 on:** September 05, 2006 9:27 pm »

You don't have the 3:08's still do ya?

This was a 6cyl car when it was born.

sundance · « **Reply #3 on:** September 05, 2006 9:33 pm »

god, i don't know what i did with them,nobody wanted that ratio then, but one bad thig about that axle is axle brgs are a weak link and are quite spendy.the 6 cyl is probably why they are 4.11--maybe i should trade you for my 3.55 than i might be able to gain one tenth of a second in the 8th and beat a certain a coupe

overspray · « **Reply #4 on:** September 05, 2006 9:49 pm »

Overdrive cars in 1955-6 came with 4.11 gears-3 speed standard for 55-6 were 3.70- auto 55-6 was 3.55 (these were 15 inch wheel cars 14 inch were 57 and later). Later on 4.56--3.36--3.08 were available. All full size Chevy cars from 55-64 the pumpkin will interchange. 1962 and 63 Nova has the same pumpkin also. Rear end ratio code (usually 2 letters AN BN etc) is stamped on the passenger side front of the pumpkin case. Sometimes they are dirty and rusty so you can't read them easily. Codes should be on a Chevy site or I have a book. The date code and casting number on are on the drivers side front of the pumpkin and are raised (cast) letters/numbers. A big "P" cast on the drivers side indicated a posi case, although I have come across "P" cases with no posi left inside. Positraction was available around March or April of 1957. 4 speed with 14 inch wheels my choice would be 3.70 or 3.55 for a little more highway gear. 3.36 gets a little tall for a stick. For an auto (non overdrive) 3.36 or 3.08. I have a 57 Chevy rear with 15 in tires and 3.55 gears in the model A with overdrive, mainly because stock flathead V8's run at much lower RPMs than a SBC.

overspray

Tom · « **Reply #5 on:** September 05, 2006 10:01 pm »

Quote from: "overspray"

overspray

I was hoping he would see this thread, he has all this shit in his head. Don't need to look nothing up!!!

Eyeball · « **Reply #6 on:** September 05, 2006 10:08 pm »

So you don't think the 3:08 would be a good choice with a 4 speed manual tranny?

Kat · « **Reply #7 on:** September 05, 2006 10:34 pm »

Holy Crap, Overspray...you ROCK!

overspray · « **Reply #8 on:** September 05, 2006 11:03 pm »

Keith and I put a 3.36 in that 63 wagon we had with a SBC and a saginaw 4 speed. That was a highway cruiser, just a teeney weeney bit tall geared for a 4 speed, especially around town. 3.55 is good all around. 3.70 is a little more fun but 75mph on the interstate ups the RPMs into the--gas suck oops the power valve opens---mode. A lot of high speed cruisin with a low 1st gear saginaw or m20 muncie 3.36 is OK. Remember changing from 14 in to 15 in tires will up the ratio and down the RPMs also. I do have the recipe to put a saginaw 4 speed to an overdrive using a 66 to 69 chev 3 speed overdrive trans. With some slight mods you can add the overdrive onto the saginaw 4 speed (old 60's trick). Only the 66 up overdrives will work for this swap. Yes, I'm saving a couple for this.

overspray

Eyeball · « **Reply #9 on:** September 05, 2006 11:22 pm »

We are runing 750/14's on it wich is a 27" tall tire.

tracywiedrich · « **Reply #10 on:** September 06, 2006 2:37 am »

Eyeball, also if you still have a stock 55 rearend, you can only go to a 3:55, otherwise the ring gets to big and hits the rear housing. Although I've seen em bulged out to make em fit. In 56 they went to a little groove in the housing to accomadate this. I threw 3:36's in my moredoor and I like em with my stick, but as Reed said they are a little steep. I personally think a 3:55 is hard to beat. Should also mention too that I went to 14 inch wheels to help my take off a little. 3:36 came out in 57 when they switched to 14 inch wheels. Also there is a pretty good thread on the Hamb about this, where I learned that 57's have a different wheel bearing than the other years and therefore is more expensive...hope that helps confuse ya even more...haha Weed

Eyeball · « **Reply #11 on:** September 06, 2006 4:04 am »

ok so I need a set of 3:55's i guess. should I look for a center section or just a gear set?

tracywiedrich · « **Reply #12 on:** September 06, 2006 12:34 pm »

I usually opt for the center section change but have done the gear change also. I did learn however when you change gears they changed the side load spacers somewhere around 58 I think, if I remember right the early centersections require 4 spacers and the newer ones only have two. That is one reason I like to stay away from changing gears, like Reed said you just gottta find a center chunk outta a powerglide equipped 55-56 car. I'd have to look, I might have one if ya cant find one locally...Weed
By the way, I think the centersection I put in the dragonwagon 56 that Serious now owns has either a 3:70 or 3:55 center....

Serious · « **Reply #13 on:** September 06, 2006 4:25 pm »

Dragonwagon went downt he road yesterday morning. its new owner lives about 2 miles from 31rodder

CJHacker · « **Reply #14 on:** September 06, 2006 6:22 pm »

What? Really? Who is it?