Hey guys, I have a big rear problem.... :moonu: Err, no not THAT rear. ou: our '74 Apollo's "booty" is giving me and pop some prob's. :spank: Our mechanic gave us 3 choices when selecting to do a Posi rear. He asked what dad preferred to go with. 1)...was a 3:83 I think, 2)...a 4:11 or 3)...a 4:56. Not knowing diddly squat ( o No: ) Dad asked what the difference was between the 4:11 and the 4:56. The mechanic mainly recommended the 4:56 for more launching power, but let me just say right now we told him that the car would be basically for cruising and taking to shows and whatnot when done...or the occassional peel out at the traffic light :3gears: . He did say that the 4:56 would burn a whole lot more gas, but dad figured if that was all, who cared because of the engine work we had done anyway it sucked down gas big time anyway because it's a high performance engine. SOOO...Dad acting on the mechanic's recommendations on the 4:56. we had it done. $1500 down the crapper and nothing but trouble in return! ou: NOW it's too much rear! Other mechanics are recommending a 4:10 or less. Our mechanic doesn't agree and suggests we go with a 700R4 Tranny and bigger tires. Dad has a feeling he's going to have to take the loss and attempt to cut it back ourselves. What do you guys recommend?? What total complete kit would we go with? The whole rear was done from drum to drum. Another shop want's around $800 for cutting it back, but because of our financial situation, we want to try and do it ourselves. Any recommendations would be greatly appreciated guys. Thanks! --John--
4.56 is way too tall for a street car. They'd work fine in a race car with 30" tall rear tires and a 8000 RPM built motor, but not if you're driving the car often. I'd get those gears out, give us some more specifics on your combo and we can help find what you need. I usually run no higher than a 3.73 in an auto car on 26" tall tires, and go through the lights around 6k RPM.
rear problems 800 to fix a rebuilt rear already... ???? Some one is taking you guys to the cleaners... I wish you were over here in the ohio area I could help you out. Are you guys at all mechanically inclineded...The truth. Who built the motor? I can try to help you if you want to try doing it. It really is not all that. Please email me mitschke454@earthlink.net I will give you a number to call and will talk. Ok? Will get you on the road before spring. Jim GM JIM DIFFERENTIALS ANYHTING GM
Hey guy's sorry for the belated response. Got tied up momentarily....anyway as far as more info on our combo, that's tricky because for some strange reason my father has repeatedly requested such info from the shop that has done all the engine/rear/etc. for us, but all the owner gives is one of these "Yeah, okay no prob. I'll write everything down for ya'." And we get diddly. Is this normal for shop's to do? Or is this shop trying to pull a fast one here? Tell you what though, the engine DOES sound very powerful and mean, I have to give them that much. Has very quick throttle response. All I know is is that the engine is the origional 350, but had everything totally redone. It's now 450 Horse. That's all the shop told us...not much help, huh? Now you know how we feel. LOL. Origionally, the car was going to be 390 horse. We noticed from the getgo that the rear main engine seal was leaking (rope seal). Our mechanic told us that this was normal, and that after 500 breaking-in miles, it should swell and seal. He said that it would take time because the shaft that the rope seal was wrapped around was gnarled and needed to tighten around the shaft, which would have taken, approx. 500 miles. Well.....it's been over 2 years now, and we're STILL leaking, only now it's gotten progressively worse! :rant: Each time it would be sent to the shop to get other things done to the car, Dad would tell the mechanic of the leaking, and for him to fix it, but the mechanic kept on coming up with other issues. He said, dad would need to locate a thin brass rod used, with the rope seal to add more pressure to it around the shaft. And for this to be done, the engine would have to be taken totally out of the car to do the seal replacement. o No: What do you guy's think? Are me and pop getting messed over or what? Does what the mechanic said sound truthful? Or is this place just trying to milk us out of more $$$? The engine, rear, exhaust, torque converter came to a little shy of $10,000. My father is sick to his stomach, and my mother wants to kill him. :spank: This saturday dad is taking it to another high performance shop to evaluate our mechanic's work. If the engine is sound, my father will pay this new shop to fix the rear main seal for about $275 and bear the expense. BUT, if it turns out that there is big problems with the work this guy and his shop did, we will need to know what steps to take, if this guy doesn't want to correct them? Any info on what legal steps could we take if this is not resolved would also be greatly appreciated. Getting back to the rear...we were thinking of going with a 3:73 ratio. When doing this, can this be done without dropping the rear axle from the car? And are there any specific guages (E.g. Feeler, etc.) that will be needed?? Moreover can we keep the Posi differential that was used? I mean it IS brand new and all, or because a 4:56 went in, will it have to be replaced as well? Thank's again guy's for the help!! :TU: -John-
John He used the wrong seal. He should have used a rubber seal like those sold by www.TAperf.com. The rope seals are so known to leak that no one uses them except those who do not realize the newer seals are available. They are old technology. Make sure you get the correct seals this time. I would not use a 3.73 if you want to go any where much at highway speed.
Wow Ok as far as the engine goes ...I am a Chevy guy...ooops. But that is the mechanics problem. Rope is old school. and if it starts leaking it will not just seal itself...lol. probably put the rope in dry and burned it. Any seal needs to be lubed on the area where it will ride against its ride surface( crank.) Now the rear - I am assumming this is an 8.5 rear. you can use any gear ratio with the 3 series carrier all the way down to 2.73. What ever gear you choose will work with that posi. All depends on what you want the car to do and what you are going to do with it. 3.42 and 3.55 are nice all around gears . 3.73 is more agressive for the street strip guy. 4.10 is - drive to that track and race every weekend kind of gear. anything above that with out a overdrive trans is to me all out race. Or around the town crusie. Just my opinion on the gears... That is how I tell my customers about gears. They still must be tailored to how the individual person can handle the rpms. Some people CAN deal with all of the fun that goes with steep gears. good luck! Like I said give me a call 1 330 659 7117 Jim
this is an 8 1/2" ring gear rear end, yes? if so, a new ring and pinion set should cost you <$200 iirc. after that it's just labor. and it's not exactly rocket science to get the stupid thing out either. $600 in labor to swap ring and pinion sounds outrageous to me ... especially when this bozo recommended the 4.56 in the first place. no profiessional in his right mind would put a 4.56 in a 3 speed car meant for the street. i'd say, tell him that you're not going to let him do any more work on the car until he provides you with an itemized list of what he's done to it already, broken out with part#, vendor, price and labor for install. if he refuses to do that then the best that can be said for him is that he's incredibly disorganized. and it's not usually a good idea to let slobs work on your pride and joy. worst case, he's found himself a couple of suckers and he's milking you for everything he can get.
4.10! You have to be out of you're mind! Now I'm no expert on 350's but on a 455 anybody that is doing any street driving at all wouldn't go over 3.73 I think you'll find a lot of people saying that 3.23-3.42 is the way to do it. I'm pretty sure there are some people around the board running 2.56 posi gears, granted on a 455 but I know the 350 is no slouch either.
