Low gears for Powerglide

[Beck]

I'm researching LOW planetary sets for a Powerglide.
ATI makes some all the way down to 2.18 ratio.
I need a set with the shorty shaft. Those that ATI makes are only available in the standard 28" length.
Does anyone know a vendor with something low like that?
ATI doesn't sound real impressed with their strength either. They are listed for low HP light cars only.
Another issue with the ATI set is the price. There $1200 plus the ride.

[Beck]

Crosley??  Your the man.  Any ideas?

[chimp koose]

look on racing junk . you may be able to find some used stuff

[GPster]

Years ago I heard that the powerglide transmission use in the early Chevy II behind the little four cylinder engines had a differant gearing in low to help the engines. They also used these engines and transmissions in the little Jeep like Postal Vehicles. I've always wondered if some parts like these might be found in lower production types of vehicle to keep their specialty parts designing at a lower number. Corvairs and early 4 cylinder Tempests had 2 speed automatic  transmissions and they probably could have used some low end help. GPster

[Crosley.In.AZ]

Crosley??  Your the man.  Any ideas?

Depends on the application:

Gear ratios for the glide have gone the other direction for most part.  Engines making more power, converter tech has changed..  So a gear ratio of lower numbers is often needed.  There is a 1.58 - 1 gear for the glide now.  Common race gear ratios are also 1.69 and 1.80 ratios.  Both are custom machined gears which is expensive

The higher horse power level brought the development of the 2 speed turbo 400. 2nd gear and 3rd are used in the 400.  2nd gear in a thm400 is 1.48-1.  Custom ratios for the thm400 opens up a whole new game in drag racing 1/8th and 1/4 mile.

As suggested watching for a used gear set will be more budget friendly.

[Beck]

Years ago I heard that the powerglide transmission use in the early Chevy II behind the little four cylinder engines had a differant gearing in low to help the engines. They also used these engines and transmissions in the little Jeep like Postal Vehicles. I've always wondered if some parts like these might be found in lower production types of vehicle to keep their specialty parts designing at a lower number. Corvairs and early 4 cylinder Tempests had 2 speed automatic  transmissions and they probably could have used some low end help. GPster

GM built the Powerglide with 2 different ratios. The 4s and 6s got the 1.82 ratio. The V8 got the 1.76 ratio. The 1.76 was a little stronger. I was not aware that the Postal Jeep used them. I'm guessing they were powered by GM 4 cylinders. The Corvair, and I expect Tempest, had a version of the Powerglide in it. I don't know what gearing they used.

I've been using the 8.8 Ford rear axle. The lowest gear ratio available for them is a 5.71. That gear coupled with the common Powerglide ratios doesn't get me low enough for my intended use. I may have to switch to the 9" Ford. I can get those gears down to 7.00. I like the 8.8 because it it lighter and available at the recycle yard.

[Crosley.In.AZ]

Speaking of Postal vehicles...  they used a GM 4 cylinder engine and a torque flight transmission for a few years.

The TF was a 904 transmission with a chevy bell housing. These cases can be difficult to locate and expensive if a person has an idea how rare they are now.

The TF 904 can be retro fitted with a gear train from a 998 TF trans which is simply an updated 904 with lockup converter. The gear ratio in the 998 is 2.74 first gear  compared to the OE 904 first gear ratio of 2.45 - 2.50 gear.

The 904 TF is longer in over all length than a power glide.

The 2.10 ratio in power glides was a common used gear back in the day. They were built in short versions for dragster use.  Most of these were OEM 1.76 carriers with cut down and resplined output shaft

[Beck]

The 2.10 ratio in power glides was a common used gear back in the day. They were built in short versions for dragster use.  Most of these were OEM 1.76 carriers with cut down and resplined output shaft

Was 2.10 a mistype? I hadn't heard of that ratio as factory, just 1.82 and 1.76.
Mine is a short version that was cut down as you said, with the 1.76 planetary.
The shory modification takes the tail shaft off and puts a bearing plate on instead. This shortens it about 10". It also looses the rear mount.

[kb426]

Beck, the 2:10 is correct. That was aftermarket for econorails back in the 80's. It was real popular.

[Beck]

Beck, the 2:10 is correct. That was aftermarket for econorails back in the 80's. It was real popular.

I wish I could find one of those. That would work for me.

[Crosley.In.AZ]

Was 2.10 a mistype? I hadn't heard of that ratio as factory, just 1.82 and 1.76

Sorry I was not clear.  The 2.10 gear set was aftermarket creation as mentioned .  

The OEM gear set ratio on the glide as you know is 1.82 and 1.76 ...  there were high strength 1.76 helical cut gears offered by some companies.

A used gear set with ring gear may be out there sitting on someone's shelf.

[Beck]

Was 2.10 a mistype? I hadn't heard of that ratio as factory, just 1.82 and 1.76

Sorry I was not clear.  The 2.10 gear set was aftermarket creation as mentioned .  

A used gear set with ring gear may be out there sitting on someone's shelf.

Thanks Crosley, I realized they were aftermarket.  I posted I would like a set hoping, as you said, someone had one sitting on the shelf.

[chimp koose]

If you look on racingjunk under transmissions /racing transmissions there is a company selling aP/G 1.98 ratio new gear set for $700ish. Dont know about the quality , just saw the ad

[Beck]

If you look on racingjunk under transmissions /racing transmissions there is a company selling aP/G 1.98 ratio new gear set for $700ish. Dont know about the quality , just saw the ad

Thanks. I contacted them. The information they gave me is the 1.98 gearing is the lowest you can go in the 1.76 housing. The gearing I was looking for is set up in the weaker 1.82 case so they won't sell them.
I guess I need to rethink this.

[chimp koose]

I guess you need a case from a v8 car. They had the 1.76 gears