Rear End Pain

[Noel K.]

No, this isn't a middle age hemorroid problem for me personally. But (no pun intended ) after having my 65 small block less than road friendly with it's 4:11 rear end, I've decided this winter's project should be to put in a more user friendly road gear - probably a 3.55 - which I know has been discussed before.

However, thinking that I want to purchase a complete new or rebuilt third member, not just change out the ring/pinion I would like to request suggestions to start my search for the new rear end. I checked the Driveline and found an advertisement for a company in Florida that will rebuild my existing rear end - but I believe, at least in the beginning of my research, that I'd like to purchase a complete new unit. I don't believe the existing rear end is "matching numbers" and purchase of the entire unit is not numbers critical - especially since this is a non-judged item.

Thoughts - suggestions ?

Thanks in advance.

Noel Kendall

[Larry S.]

Re: Rear End Pain

Try Bairs in Linesville PA.
1 800 421 9644.
They are top-notch in the gear area.

[Larry S.]

Re: Rear End Pain

Try Bairs in Linesville PA.
1 800 421 9644.
They are top-notch in the gear area.

[Joe L.]

Re: Rear End Pain

Noel------

No such thing as a complete NEW differential carrier unit anymore. They've been discontinued for years. Most of the components to build one up from all new pieces are long-gone, too. The best you can do is to buy a rebuilt unit and pay the core charge. By the time it's all said and done, you'll be talking about a grand and more if you want a new aftermarket ring and pinion gears installed in the unit.

[Joe L.]

Re: Rear End Pain

Noel------

No such thing as a complete NEW differential carrier unit anymore. They've been discontinued for years. Most of the components to build one up from all new pieces are long-gone, too. The best you can do is to buy a rebuilt unit and pay the core charge. By the time it's all said and done, you'll be talking about a grand and more if you want a new aftermarket ring and pinion gears installed in the unit.

[Erich C.]

Re: Rear End Pain

Another option would be to install a 5 speed Overdrive trans. Do a search for 5 speeds, there are several companies offering kits using the Tremec trans. O.D. ratios available are .64/.68/.82 . These kits are supposed to be bolt-ins with no mods. to the car. Probably more $$$ than just doing the rear but you would keep the accel. of the 4.10 and still be able to cruise comfortably on the highway.

[Erich C.]

Re: Rear End Pain

Another option would be to install a 5 speed Overdrive trans. Do a search for 5 speeds, there are several companies offering kits using the Tremec trans. O.D. ratios available are .64/.68/.82 . These kits are supposed to be bolt-ins with no mods. to the car. Probably more $$$ than just doing the rear but you would keep the accel. of the 4.10 and still be able to cruise comfortably on the highway.

[Mike M.]

Re: Rear End Pain

Noel, I'm just wondering why you want to change your gear ratio. I have 4:10 and I like them. I don't do much highway driving, but it wouldn't stop me. Mike

[Mike M.]

Re: Rear End Pain

Noel, I'm just wondering why you want to change your gear ratio. I have 4:10 and I like them. I don't do much highway driving, but it wouldn't stop me. Mike

[Mike M.]

Re: Rear End Pain

agree with mike. i routinely drive our 57 vette with 4.56:1 couple hundred miles one way. little hard on fuel but as long as the engine is healthy, 4000 to 5000 RPM won't hurt a sbc within specs. hate leaving the line with anything under 4.11 to 1.mike

[Mike M.]

Re: Rear End Pain

agree with mike. i routinely drive our 57 vette with 4.56:1 couple hundred miles one way. little hard on fuel but as long as the engine is healthy, 4000 to 5000 RPM won't hurt a sbc within specs. hate leaving the line with anything under 4.11 to 1.mike

[john daly]

Re: Rear End Pain

If you have an M20 trans I would suggest you consider a 3:36 ratio. I have that in my 67 sb and it seems like a perfect all around combo....no drag racing though.

john

[john daly]

Re: Rear End Pain

If you have an M20 trans I would suggest you consider a 3:36 ratio. I have that in my 67 sb and it seems like a perfect all around combo....no drag racing though.

john

[Noel K.]

Re: Rear End Pain

Currently with the 4:11 I'm running about 3600 rpm at 65 mph so the 6500 tach redline for the 365HP is not excessive. I do get some shifter vibration as the tach goes higher. The car tracs and drives straight ( has had a frame off about 4 years ago) and I've wondered if there is a balance problem in the drive shaft. I've had the front end aligned and tire balanced. I had to have the engine rebuilt last year and the flywheel was balanced at the time.

The vibration is annoying and not evident at lower rpm - that's one reason. Secondly I would like to get a little better gas mileage for the trips I do take, although I'm not sure I want to put $1,000 into the project. No more miles than I drive the car a year, it will take a long time for an increase in gas mileage to add up to the rear end exchange cost.

Any thoughts on the driveline/shifter vibration - causes and/or cures ?

Again, thanks in advance.

Best to all this holiday season

Noel Kendall

[Noel K.]

Re: Rear End Pain

Currently with the 4:11 I'm running about 3600 rpm at 65 mph so the 6500 tach redline for the 365HP is not excessive. I do get some shifter vibration as the tach goes higher. The car tracs and drives straight ( has had a frame off about 4 years ago) and I've wondered if there is a balance problem in the drive shaft. I've had the front end aligned and tire balanced. I had to have the engine rebuilt last year and the flywheel was balanced at the time.

The vibration is annoying and not evident at lower rpm - that's one reason. Secondly I would like to get a little better gas mileage for the trips I do take, although I'm not sure I want to put $1,000 into the project. No more miles than I drive the car a year, it will take a long time for an increase in gas mileage to add up to the rear end exchange cost.

Any thoughts on the driveline/shifter vibration - causes and/or cures ?

Again, thanks in advance.

Best to all this holiday season

Noel Kendall