Speedo reducer what's it for

[cdn454LS6]

Anybody know what this reducer is for ?
666F V8
.9444W

Thanks for your help
Ken

[McCune]

Low Rear Gear cars.

[XXXGoldL34M20]

My Guess later model Truck after 1970 with 4.10 gear ratio.
Checked eBay completed items and one sold for $64 but had no info at all for what it was for.

[BCreekDave]

There are charts from GM that show when a particular combination of trans and wheel-tire size got a particular part number reducer. The part number is not one of the numbers you listed. you have to do a bit of google searching to cross reference the GM part number to the reduction number, in your case the .9444.

Here's an example for a 1970 Camaro,Chevelle, Nova 4 speed cars:

http://www.gmpartswiki.com/getpage?pageid=12662

If you plan on actually using it, you would be advised to open it up and clean out and re-pack the grease. It dries out over time.

[cdn454LS6]

I found one guy selling a reducer
and claiming it's for LS6 410 rear
666F V8
.8241C
maybe mine is for 456 rear ?

[NorCam]

A friend here in Calgary gave me one that I used in the green 4:10 gear car I recently finished. They work well if you know what gear conversion they were intended for.

[L78steve]

If you repack it with grease use a light grease. Otherwise the load can snap the tab on the drive gear clip inside the tail housing.

[hiperf406]

Are these also used on the automatic cars, mine came with 4:10 gears but someone put in 3:73 gears. If I return to the factory gears I will have to get a reducer.Thanks

[Igosplut]

I have a box full of those, there was two different kinds. Mostly for trucks.

[WILMASBOYL78]

Originally Posted by hiperf406

Are these also used on the automatic cars, mine came with 4:10 gears but someone put in 3:73 gears. If I return to the factory gears I will have to get a reducer.Thanks

Yes auto cars got these as well.