Turbo 400 speedometer gear help - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**68350** · 07-25-2015, 08:11 PM

Put in brand new B&M turbo 400 and now speedometer won't work. Can take cable off and spin speedometer freely which makes me believe that the cable isn't going far enough into gear housing. But I was checking to see if anyone else has ran into a similar problem and figured out a solution. I thought about running a Stewart Warner speedometer correction block and seeing if it worked. Anyway let me know if anyone has any suggestions. Thanks

hugger6933 · 07-25-2015, 08:29 PM

Sounds to me like your missing a speedo gear. It may be the drive gear inside the trans sometimes your not gonna get one with a trans cause there are so many drive and driven gear to cover thousands of applications.You may have to pull the speedometer "bullet" [the part where the speedo cable screws on to and check and see if there is a driven gear that the cable fits into, or pull out the " bullet" and see if you can tell if the drive gear is in there.

midniteblues · 07-26-2015, 08:36 AM

you would think if there was no gear in there the trans would leak badly.

Redline novdog · 07-26-2015, 04:16 PM

It might leak if the driven gear( on the 'bullet' end) If it is the drive gear missing, you will have to take the cable adapter(bullet) out. There should be an oring on it so lube up the o-ring before putting it back in.

07-25-2015, 08:11 PM	#1
68350 Senior Member Join Date: Jan 2002 Location: Williston, ND Posts: 2,999	Turbo 400 speedometer gear help Put in brand new B&M turbo 400 and now speedometer won't work. Can take cable off and spin speedometer freely which makes me believe that the cable isn't going far enough into gear housing. But I was checking to see if anyone else has ran into a similar problem and figured out a solution. I thought about running a Stewart Warner speedometer correction block and seeing if it worked. Anyway let me know if anyone has any suggestions. Thanks __________________ 68 Chevy CST/10, 50th Anniversary, 327/th400, 373 posi, buckets 68 GMC Shortbox Stepside, 402/th400, Tilt, Tach, Bucket Seats, 3.08 Positraction 69 Chevy Camaro SS, 383, 4 speed, positraction 70 Chevy El Camino SS396, Triple Black, 454/th400, Tach 70 Chevy Shortbox Stepside 4x4, 350/th350, Tilt, Tach, Cab Lights, Bumper Guards, Tow Hooks 70 Chevy 3/4 Longbox, 350/auto, 70k, SURVIVOR 71 Chevy Blazer, CST, 350/auto 71 GMC Sierra K2500, 454, 4 speed, 4.10 posi, 37s 71 Custom/30, Open Road, 350/th400, tilt 72 Chevy Shortbox Fleetside, 496 Stroker/th400, Tilt, Tach, Bucket Seats, 3.42 Posi 72 GMC Sierra Grande 2500. 427/th400, tilt, a/c, tool and stowage, buckets/console, 3.54 posi

07-25-2015, 08:29 PM	#2
hugger6933 Registered User Join Date: Oct 2008 Location: Marianna Arkansas Posts: 7,257	Re: Turbo 400 speedometer gear help Sounds to me like your missing a speedo gear. It may be the drive gear inside the trans sometimes your not gonna get one with a trans cause there are so many drive and driven gear to cover thousands of applications.You may have to pull the speedometer "bullet" [the part where the speedo cable screws on to and check and see if there is a driven gear that the cable fits into, or pull out the " bullet" and see if you can tell if the drive gear is in there.

07-26-2015, 08:36 AM	#3
midniteblues Registered User Join Date: Jul 2011 Location: strausstown pa Posts: 3,394	Re: Turbo 400 speedometer gear help you would think if there was no gear in there the trans would leak badly. __________________ 81 camaro 355 4/spd 342 posi my first love. 67 swb step 454/4spd ott 373 posi 4/7 drop. 2000 s10 zr2 little blue truck that never gets stuck. '74 heald super bronc vt8. tecumseh powered moon rover.

07-26-2015, 04:16 PM	#4
Redline novdog Registered User Join Date: Jan 2012 Location: Washington,Il Posts: 632	Re: Turbo 400 speedometer gear help It might leak if the driven gear( on the 'bullet' end) If it is the drive gear missing, you will have to take the cable adapter(bullet) out. There should be an oring on it so lube up the o-ring before putting it back in. __________________ It builds on my intelligence when I make a mistake, Boy am I building on it! '67 C-10,'70 Nova SS



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