TT truck,what were rearend ratios?

[anteek]

What ratio were TT truck rearends?

[jackdaron]

5:1 and 7 1/2 :1 I believe.

[southfork]

Wow, with such low gearing in the rear end, I'm wondering how the TT trucks were made to scoot down the country roads so briskly (as the one did in the "Paper Moon" movie --- once the engine wasn't sputtering)?

Is there an easy way to look at a TT rear end housing and decipher whether it has the 5:1 gears or the 7:1 gears?

[Kelly mt]

You might have to pull the plugs, jack up the rear and hand crank the motor trans in high and count the tire rotations. That will give you the ratio. PK

[southfork]

Yes, I guess that would work in some instances. But when someone is looking at TT rear ends that have been out of the truck for 50 or more years, and maybe are not all there, it would be nice if there were an easier way. Just saying.

[Farmallcub49]

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I have pulled the plug half way up the pumpkin, cleaned the tooth if necessary, put a dab of white paint or grease stick and started counting as someone rotated the rear end. If the rear end has been gutted out of a chassis to make a trailer out of it, usually the worm has been removed, so you are only getting half of what you need.

[Erik Barrett]

You can remove the four bolt cover on the back end of the housing, remove the big nut, thrust bearing, and the rear roller bearing. Then you can peek in with a pen light and count the teeth on the worm gear. Four teeth is low speed, about 7.5:1. Six teeth is high speed, about 5.25:1. A TT with high speed gears and an overdrive auxiliary trans will easily make 40 MPH or better with a properly tuned engine. I have been well over 50 in my dump truck.
Erik

[anteek]

I'm contemplating using the martin-perry frame extension and TT rear on the back of an A chassis for a static display. It would only see parade use. I just can't junk the M-P conversion. It would be like something built with leftovers in early '28. The TT C cab is saveable,I have a good T hood and radiator with shell. Need front '28-'29 fenders. I have a '29 engine with a accessory T waterpump already installed. Henry used leftovers so why can't I?

[Willie in Houston]

I thought a 1929 (A) engine came from the factory with an "A" water pump

[anteek]

Willie,they did. I changed to go to a flat belt as part of antiqueing the look while the engine was in a modified.

[southfork]

Originally Posted by Erik Barrett

You can remove the four bolt cover on the back end of the housing, remove the big nut, thrust bearing, and the rear roller bearing. Then you can peek in with a pen light and count the teeth on the worm gear. Four teeth is low speed, about 7.5:1. Six teeth is high speed, about 5.25:1. A TT with high speed gears and an overdrive auxiliary trans will easily make 40 MPH or better with a properly tuned engine. I have been well over 50 in my dump truck.
Erik

This is good info, Erik. Thanks!

[southfork]

oh, Yeah, what if the rear end on the TT is a Ruxtell rear end??? Are those lower gearing or higher gearing?

[Erik Barrett]

The Ruckstell is an underdrive. It gives you an intermediate gear between Ford low and high. When it is in high gear the T operates the same as if the Ruckstell were not there.
Erik

[southfork]

Erik, have you posted any pictures of your TT truck on this or other sites? If so, let me know where, please. If not, it would be great if you did.