Need a light weight transmission

[Beck]

I am looking for a light weight transmission. This is for use behind a 4 cyl motor in a little pulling tractor. I am hoping to make up to 400 hp. I am struggling to make it into a weight class. It has to fit a Chevy bellhousing. The transmission only needs 1st and reverse gears. If the transmission has a granny gear I will need to use 2nd. I can adjust the rear axle ratio to get my final gearing where it needs to be so the 1st gear ratio isn't very critical, but a Powerglide 1.76 or 1.82 gearing is getting marginally high.

The following figures are from online (so they have to be true).  GM automatic weights:  Powerglide 110, TH350 130. I believe the 200R4 is about the same weight as the TH350. I don't know what the 700R4 weighs. The TH400, 4L60E and 4L80E are too heavy. These weights were wet, but no converter. These would require a loose converter (4500 area). The weight of the flex plate and converter needs to be added to the transmission weight.

I have not found the weights of any of the manual transmissions. The weight of the bellhousing, flywheel, and clutch parts need to be added to the total package weight.

If it is practical the transmission could be stripped of all the other gears to save some weight.

What is the lightest package I could use?

I understand that the Powerglide will rob about 4% of the power. A TH350 will take about 12%. I don't know what losses there are in a manual transmission. I expect less.

I looked at the Powerglides designed for dirt track that don't use a converter. They cannot be launched under full power, so they won't work. I also looked at the Burt, Brinn, and Falcon dirt track manual boxes. They don't use an external clutch, but have a small internal clutch for low gear. Full power cannot be used in their low gears, so those are also ruled out.

[Crosley.In.AZ]

you can remove a few parts from the glide to reduce rotational mass  weight more since only reverse and 1st is used

[unklian]

What is the weight limit on the sled ?

[Beck]

What is the weight limit on the sled ?

The tractor is allowed to weigh 1400 lb with the driver on it. I'm at 250 lb right now, but that is a New Year's resolution... I need to go on a diet!

[enjenjo]

Ford toploader three speed. first gear 2.42 reverse 2.33 it is about bullet proof and weighs about 90 lbs id number is RAT-V

[Beck]

Ford toploader three speed. first gear 2.42 reverse 2.33 it is about bullet proof and weighs about 90 lbs id number is RAT-V

None of the unused gearing can be removed in a manual transmission like this can it? Doesn't it need the rest of the gears to space everything on the shafts?

How would I get it mounted to a GM bellhousing?

What were these used in?

Any idea what a bellhousing, flywheel and complete clutch assembly weigh? Comparing manuals to automatics is almost like apples to oranges.

[unklian]

Ford toploader three speed. first gear 2.42 reverse 2.33 it is about bullet proof and weighs about 90 lbs id number is RAT-V

Doesn't it need the rest of the gears to space everything on the shafts?

Worst case, Aluminum spacers could be made.

[Digger]

Ford toploader three speed. first gear 2.42 reverse 2.33 it is about bullet proof and weighs about 90 lbs id number is RAT-V

None of the unused gearing can be removed in a manual transmission like this can it? Doesn't it need the rest of the gears to space everything on the shafts?

How would I get it mounted to a GM bellhousing?

What were these used in?

Any idea what a bellhousing, flywheel and complete clutch assembly weigh? Comparing manuals to automatics is almost like apples to oranges.

I'm pretty sure that Wilcap has the adapters for that.

[enjenjo]

Ford toploader three speed. first gear 2.42 reverse 2.33 it is about bullet proof and weighs about 90 lbs id number is RAT-V

None of the unused gearing can be removed in a manual transmission like this can it? Doesn't it need the rest of the gears to space everything on the shafts?

How would I get it mounted to a GM bellhousing?

What were these used in?

Any idea what a bellhousing, flywheel and complete clutch assembly weigh? Comparing manuals to automatics is almost like apples to oranges.

The RAT-V is a Ford built transmission that was eventually sold to Tremec, where it was modified and built as the T150. I would recommend the RAT-V over the T150 because it has a stronger case, bronze vs plasic bushings in reverse, and needle bearings in the cluster vs plastic bushings.Also the RAT-V is a side shift with a tin cover, and the T150 has a cast iron cover with a top shift and it weighs more.

The RAT-V was used in short wheelbase F100 and F250 trucks and Econoline vans, and V8 Broncos. It used a larger input shaft for big blocks, or in the case of the Broncos, heavy duty use. In this application it is about 18" long, vs the passenger car models which were about 23" long.

As far as I can tell the mainshaft from a 4x4 Bronco, or a T150 mainshaft from a 4x4 Jeep will bolt right in and give an overall length of about 13" but would need a custom tailhousing with a support bearing in it.

LUK makes a clutch assembly that will work with a Chevy flywheel,and some of the Ford flywheels. Weighing a Ram 10" clutch and 5.0 flywheel I have here the whole thing weighs about 22 lbs. You could use an aluminum flywheel to reduce that weight.

To remove weight from the trans, you can eliminate second gear on the mainshaft, along with the 2-3 syncro assembly and replace them with a spacer to hold the remaining parts in position. On the cluster shaft you can grind the second gear off, leaving just the drive gear,and the 1st-rev gear.

For the bell housing, Lakewood makes a dual pattern bell housing scattershield that will fit both a Chevy and small block Ford block bolt pattern, and both a Muncie and Ford toploader trans.

[wayne petty]

from an interchange section i have..

RAT-V
Ford 3 spd. (med. duty)
Ford F100 Pickup '68-70 114" W.B.,
4x2, 8-390

RAT-V1
Ford 3 spd. (med. duty)
Ford F100 Pickup '68-70 114" W.B.,
4x2, 8-390

RAT-V2
Ford 3 spd. (med. duty)
Ford F100 Pickup '71 114" W.B., 4x2,
8-390

RAT-V3
Ford 3 spd. (med. duty)
Ford F100 Pickup '71 114" W.B., 4x2,
8-390


i see there are more variations in RAT models.. perhaps somebody will assist in sorting them out.
RAT-W
Ford 3 spd. (med. duty)
Ford F100 Pickup '68-70 131" W.B.,
4x2, 8-390

RAT-W1
Ford 3 spd. (med. duty)
Ford F100 Pickup '68-70 131" W.B.,
4x2, 8-390

RAT-W2
Ford 3 spd. (med. duty)
Ford F100 Pickup '71 131" W.B., 4x2,
8-390

RAT-W3
Ford 3 spd. (med. duty)
Ford F100 Pickup '71 131" W.B., 4x2,
8-390

RAT-X
Ford 3 spd. (med. duty)
Ford F250 Pickup '68-70 131" W.B.,
4x2, 8-390

RAT-X1
Ford 3 spd. (med. duty)
Ford F250 Pickup '68-70 131" W.B.,
4x2, 8-390

RAT-X2
Ford 3 spd. (med. duty)
Ford F250 Pickup '71 131" W.B., 4x2,
8-390

RAT-X3
Ford 3 spd. (med. duty)
Ford F250 Pickup '71 131" W.B., 4x2,
8-390

RAT-Y
Ford 3 spd. (med. duty)
Ford Van '68-70 E100 thru E300,
105.5" W.B., 8-302

RAT-Y1
Ford 3 spd. (med. duty)
Ford Van '68-70 E100 thru E300,
105.5" W.B., 8-302

RAT-Y2
Ford 3 spd. (med. duty)
Ford Van '71 E100 thru E300, 105.5"
W.B., 8-302

RAT-Z1
Ford 3 spd. (med. duty)
Ford Van '70-71 E100 thru E300,
123.5" W.B., 8-302

RAT-Z2
Ford 3 spd. (med. duty)
Ford Van '70-71 E100 thru E300,
123.5" W.B., 8-302

RAT-Z
Ford 3 spd. (med. duty)
Ford Van '68-69 E100 thru E300,
123.5" W.B., 8-302

[Beck]

The Rat-V are cast iron cases, not aluminum, correct?

[enjenjo]

The Rat-V are cast iron cases, not aluminum, correct?

Yes. As far as I can find there were no aluminum cases for these.

[chimp koose]

ford c4 is about the same weight as the powerglide with a lower 1st gear.they have been made to adapt to almost anything , a friend of mine has one on his rotary engine drag car.

[jaybee]

a friend of mine has one on his rotary engine drag car.

If that won't make you put in ear plugs nothing will. I watched RX8 road racers live a couple of times. They were great, nimble little race cars but also the only thing on the track capable of making a more obnoxious noise than the jet dryers.

[unklian]

Yes, very loud, with little torque.

Wind them up high enough, and they can make decent power.