Rear Gears are expensive

[81 Corvette]

My advice is to take care of yours. :cry


My rear gear swap/ujoint replacement turned into gear, ujoint, side yoke, carrier, spindle support (shop busted trying to remove shock mount), strut rod replacement.

Today is day 15 and tommorrow there is a 50/50 chance it will be done. With my luck, it will rain, and that will prevent me from trying out my new 3.54 gears.

 

[mr mctavish]

waiting and watching

 

[Glensgages]

81 Corvette:

Sorry to hear of your continuing hassles.

I guess I was lucky, as my car had 'only' 19,000+ miles on it at the time, and my guy completed the swap in less than 5 hours.

But, once you get the car back with those deeper gears, you'll think it is another car entirely.

 

[81 Corvette]

i'm sure it will be 100% better, its just taking forever. first the yokes and strut rods had to be ordered, then a week later they bust the rear spindle support and of course that has to be ordered.

Such is life with a 24 year old car.

i feel better after ranting a bit.

 

[Glensgages]

.....i feel better after ranting a bit.

You'll "feel better" once you put your foot down, and that car explodes (comparatively-speaking) off the line from a standing-start!!!


The 5 MPH that I picked-up (86-to-91) was the equivalent of 26 more RWHP (154 vs. 182).

Are you having your speedo re-calibrated as well? :confused

 

[81 Corvette]

not touching the speedo...i'm running out of spending money. If I'm corret is saying, it doesn't look to difficult to get to the speedo gear, I'll change that myself. It'll mess up the miles on the odemeter, but not really a big deal. I drove a motorcycle for a year with no speedo so it doesn't really bother me.

 

[Glensgages]

81 Corvette:

Changing the driven speedo-gear is no-biggie, but when I went from 2.87s to 3.73s, we had to ALSO change the drive-gear, IN the transmission, too.

GM also has speedo-re-calibration units, that mount between the cable and your current speedo-gear, OUTSIDE the transmission, but in my instance, the unit, about 2" long, put such a bind on the speedo-cable, that it froze-up, and the square-head of the cable 'bored' the square-hole in the speedo-gear 'round', and the speedo didn't work.

This 'binding' caused me to change the drive AND driven gears instead:
hope this helps.....

 

[titan81]

It will be worth losing those horrible 2.8 gears.
When I had my camaro, the 700R4 got 3.73 gears or 3.79?
and with a shift kit, transgo, it would chirp shifting itself into 4th/od

 

[81 Corvette]

81 Corvette:

Changing the driven speedo-gear is no-biggie, but when I went from 2.87s to 3.73s, we had to ALSO change the drive-gear, IN the transmission, too.

GM also has speedo-re-calibration units, that mount between the cable and your current speedo-gear, OUTSIDE the transmission, but in my instance, the unit, about 2" long, put such a bind on the speedo-cable, that it froze-up, and the square-head of the cable 'bored' the square-hole in the speedo-gear 'round', and the speedo didn't work.

This 'binding' caused me to change the drive AND driven gears instead:
hope this helps.....

I'm sure the hell not opening up the transmission for a stupid gear. I'm gonna try and track down a driven gear that will not require a change. Where did you find your gear at? I found one place on teh net, but lost the link.

 

[Glensgages]

81 Corvette:

I had a link to a web-page (since gone) that listed drive-gear/driven-gear combos to use when making drastic gear swaps, but since some Vettes in the mid-'70s actually came with 3.55s, you might find those drive-gears will work with your THM350C.

Since the 700R4s only came with 2.72/2.87 rear gearing, I needed to get inside the tail-housing to swap-out the drive-gear too, which didn't take all that long to do.

My buddy, who did the gear-swap, has been performing Chevy & Corvette drive-train maintainence for 25+ years, and had an assortment of speedo-gears in a tin can, so I had no trouble finding the correct gears.....

 

[LanceB]

gears

My mechanic swears the gears on my 81 are 3.55. I know that wasn't stock and it sure doesn't perform like 3.55. I thought about putting 3.73 in there until he told me it was already 3.55. To my knowledge, (owned car 5-6 years) there has never been new gears put in. I suppose there is no way to tell unless I start taking it apart.

 

[81 Corvette]

My mechanic swears the gears on my 81 are 3.55. I know that wasn't stock and it sure doesn't perform like 3.55. I thought about putting 3.73 in there until he told me it was already 3.55. To my knowledge, (owned car 5-6 years) there has never been new gears put in. I suppose there is no way to tell unless I start taking it apart.

jack up the car and spin the tires...as you spin the tires, count the tire revolutions it takes to turn the drive shaft. that will tell you what gear you have.

 

[81 Corvette]

Its DONE!!!!!!!!

Shop just called. I'll be picking up at 5:30est. Of course its raining out so I will have to be careful until the roads are dry