Re: '77 Chevelle Malibu Classic - Disco Malibu

by driveit Sat Dec 07, 2013 8:17 am

Glad to hear that you have made some progress. Wish I could help on that, but I am not sure what to advise. My speedometer if off too.

by 77mali Sat Dec 07, 2013 9:56 am

Looking good!

Check w/ a good trans shop or some of the online companies for your trans gear. If you have a 3.08, then there s/b something that should compensate for the big tires. There's a calculator on this page here:
http://www.tciauto.com/tc/speedometer-gear-calculator/

by pila Sat Dec 07, 2013 3:16 pm

The speedo gears; the drive gear (on the trans output shaft), and the driven gear, for the cable, are color coded, for the number of teeth, to identify them. Tire diameter enters into the calculations too of course, as well as gear ratio....
NPD has the driven gears...TH350 etc, for 6 bucks each..

by DiscoMalibu Sat Dec 07, 2013 5:02 pm

The problem is that i'm running a 4spd. I know speedo gears are available for the automatics but I've never seen them for four speeds.

by 77mali Sat Dec 07, 2013 5:07 pm

DiscoMalibu wrote:The problem is that i'm running a 4spd. I know speedo gears are available for the automatics but I've never seen them for four speeds.

Duh, that's right isn't it....my bad.

There must be a way to compensate though- maybe the little gears in the speedo/odometer?

by DiscoMalibu Sat Dec 07, 2013 7:12 pm

Yeah, this is where i'm at a loss. Also with the large tires it's messing up my final drive ratio. I'm doing over 100mph in the top of 3rd gear. It seems really geared out and reverse is really long too. Curious about what ratio I could use to bring it back normal while keeping the big 'ol meats on the back.

by JB2wheeler Sun Dec 08, 2013 4:35 pm

Use this calculater to find percentage of size diff in your tires and then use that percentage to change either speedo gear or rear end ratio. JB http://www.miata.net/garage/tirecalc.html

by pila Sun Dec 08, 2013 10:12 pm

Speedo cable hooks up the same on a 3 or 4-speed as it does on a TH auto, and they both have drive & driven gears, so it's just a matter of getting the correct combo to have accurate speed indication.
I believe the TCI site has the info you need....
http://www.tciauto.com/

It even tells which drive gears are in various transmissions.. look under "tech resources"...

by DiscoMalibu Sun May 18, 2014 2:29 am

'77 Chevelle Malibu Classic - Disco Malibu - Page 3 DSCF0155_zpsa4848d1a

'77 Chevelle Malibu Classic - Disco Malibu - Page 3 DSCF0216_zps7529350e

How to kill a Saginaw transmission. It's easy! I grenaded this thing at the end of the winter. I figured I'd rebuild it after the trans shop told me $500 plus I'd have to find my own gears. Found the cluster gear but never found first gear. I couldn't locate the parts or another Saginaw for it so I searched for another.

Found a Muncie M-20 four speed at the swap meet. Needs an input shaft bearing due to someone taking it apart and losing three ball bearings. The internals are all in good shape. Here's the dilemma... the Muncie shifter is different and back farther. That means I need another shifter and I'll have to pull the carpet and relocate the shift hump. The saga continues!

by driveit Mon Oct 13, 2014 1:44 pm

Any updates on this one?

by DiscoMalibu Tue Oct 21, 2014 3:17 pm

Updates? I've been driving the crap out of this thing haha. I installed the M-20 four speed after cleaning it up and replacing the front bearing. The downside is it jumps out of second unless i'm on the throttle. I was planning on pulling it apart this winter and replacing the likely worn shift keys.

The downside is that first gear is really long. I have difficulty taking off with it. I pulled the 285/70/15 monsters off of the rear which is depressing but made it easier to drive. It's a 3.08 rear, I think i'd have run a 3.42 or something to accommodate the massive tires.

Plus after sitting for four months, now it runs like crap and just doesn't have the power it did before. On top of that it developed a tick yesterday from the top end. Perhaps a lifter isn't loading with oil or it bent a pushrod on me. It's one thing after another. I'm hoping to get this thing running better soon and drive it the rest of the fall. We'll see what happens...

by thatfnthing Wed Oct 22, 2014 9:09 am

Good luck. In upstate NY, 'the rest of the fall' is going to be about 15 minutes. Smile

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